diff --git a/.gitignore b/.gitignore
index 1918894..ffd3ba6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -22,8 +22,9 @@ overviewer_core/c_overviewer.pyd
 overviewer_core/c_overviewer_d.pyd
 overviewer_core/c_overviewer.dylib
 
-# generated version file
+# generated files
 overviewer_core/overviewer_version.py
+overviewer_core/src/primitives.h
 
 # Mac OS X noise
 .DS_Store
diff --git a/overviewer.py b/overviewer.py
index 60fc7f1..7f02289 100755
--- a/overviewer.py
+++ b/overviewer.py
@@ -18,25 +18,13 @@
 import platform
 import sys
 
+# quick version check
 if not (sys.version_info[0] == 2 and sys.version_info[1] >= 6):
     print "Sorry, the Overviewer requires at least Python 2.6 to run"
     if sys.version_info[0] >= 3:
         print "and will not run on Python 3.0 or later"
     sys.exit(1)
 
-isBareConsole = False
-
-if platform.system() == 'Windows':
-    try:
-        import ctypes
-        GetConsoleProcessList = ctypes.windll.kernel32.GetConsoleProcessList
-        num = GetConsoleProcessList(ctypes.byref(ctypes.c_int(0)), ctypes.c_int(1))
-        if (num == 1):
-            isBareConsole = True
-
-    except Exception:
-        pass
-
 import os
 import os.path
 import re
@@ -44,110 +32,13 @@ import subprocess
 import multiprocessing
 import time
 import logging
-from overviewer_core import util
-
-def doExit(msg=None, code=1, wait=None, consoleMsg=True):
-    '''Exits Overviewer.  If `wait` is None, the default
-     will be true is 'isBareConsole' is true'''
-    global isBareConsole
-    if msg:
-        print msg
-
-    if wait == None:
-        if isBareConsole:
-            if consoleMsg:
-                print "\n"
-                print "The Overviewer is a console program.  Please open a Windows command prompt"
-                print "first and run Overviewer from there.   Further documentation is available at"
-                print "http://docs.overviewer.org/\n"
-            print "Press [Enter] to close this window."
-            raw_input()
-    else:
-        if wait:
-            if consoleMsg:
-                print "\n"
-                print "The Overviewer is a console program.  Please open a Windows command prompt"
-                print "first and run Overviewer from there.   Further documentation is available at"
-                print "http://docs.overviewer.org/\n"
-            print "Press [Enter] to close this window."
-            raw_input()
-
-    sys.exit(code) 
-
-
-this_dir = util.get_program_path()
-
-# make sure the c_overviewer extension is available
-try:
-    from overviewer_core import c_overviewer
-except ImportError:
-    ## if this is a frozen windows package, the following error messages about
-    ## building the c_overviewer extension are not appropriate
-    if hasattr(sys, "frozen"):
-        print "Something has gone wrong importing the c_overviewer extension.  Please"
-        print "make sure the 2008 and 2010 redistributable packages from Microsoft"
-        print "are installed."
-        doExit()
-
-
-    ## try to find the build extension
-    ext = os.path.join(this_dir, "overviewer_core", "c_overviewer.%s" % ("pyd" if platform.system() == "Windows" else "so"))
-    if os.path.exists(ext):
-        print "Something has gone wrong importing the c_overviewer extension.  Please"
-        print "make sure it is up-to-date (clean and rebuild)"
-        doExit()
-
-    import traceback
-    traceback.print_exc()
-
-    print ""
-    print "You need to compile the c_overviewer module to run Minecraft Overviewer."
-    print "Run `python setup.py build`, or see the README for details."
-    doExit()
-
-from overviewer_core import textures
-
-if hasattr(sys, "frozen"):
-    pass # we don't bother with a compat test since it should always be in sync
-elif "extension_version" in dir(c_overviewer):
-    # check to make sure the binary matches the headers
-    if os.path.exists(os.path.join(this_dir, "overviewer_core", "src", "overviewer.h")):
-        with open(os.path.join(this_dir, "overviewer_core", "src", "overviewer.h")) as f:
-            lines = f.readlines()
-            lines = filter(lambda x: x.startswith("#define OVERVIEWER_EXTENSION_VERSION"), lines)
-            if lines:
-                l = lines[0]
-                if int(l.split()[2].strip()) != c_overviewer.extension_version():
-                    print "Please rebuild your c_overviewer module.  It is out of date!"
-                    doExit(code=1, consoleMsg=True)
-else:
-    print "Please rebuild your c_overviewer module.  It is out of date!"
-    doExit()
-
 from optparse import OptionParser
+
+from overviewer_core import util
+from overviewer_core import textures
 from overviewer_core import optimizeimages, world
-from overviewer_core import googlemap
 from overviewer_core import configParser, tileset, assetmanager, dispatcher
 
-# definitions of built-in custom modes
-# usually because what used to be a mode became an option
-# for example, night mode
-builtin_custom_rendermodes = {}
-#     'night' : {
-#         'parent' : 'lighting',
-#         'label' : 'Night',
-#         'description' : 'like "lighting", except at night',
-#         'options' : {'night' : True}
-#     },
-
-#     'smooth-night' : {
-#         'parent' : 'smooth-lighting',
-#         'label' : 'Smooth Night',
-#         'description' : 'like "lighting", except smooth and at night',
-#         'options' : {'night' : True}
-#     },
-# }
-
 helptext = """
 %prog [OPTIONS] <World # / Name / Path to World> <tiles dest dir>"""
 
@@ -195,7 +86,6 @@ def configure_logger(loglevel=logging.INFO, verbose=False):
         logger.setLevel(loglevel)
 
 def main():
-
     # bootstrap the logger with defaults
     configure_logger()
 
@@ -204,7 +94,7 @@ def main():
     except NotImplementedError:
         cpus = 1
     
-    avail_rendermodes = c_overviewer.get_render_modes()
+    #avail_rendermodes = c_overviewer.get_render_modes()
     avail_north_dirs = ['lower-left', 'upper-left', 'upper-right', 'lower-right', 'auto']
    
     # revert to a vanilla OptionParser for right now 
@@ -216,7 +106,6 @@ def main():
     #parser.add_option("--forcerender", dest="forcerender", help="Force re-rendering the entire map (or the given regionlist). Useful for re-rendering without deleting it.", action="store_true")
     #parser.add_option("--stochastic-render", dest="stochastic_render", help="Rerender a non-updated tile randomly, with the given probability (between 0 and 1). Useful for incrementally updating a map with a new mode.", type="float", advanced=True, default=0.0, metavar="PROBABILITY")
     #parser.add_option("--rendermodes", dest="rendermode", help="Specifies the render types, separated by ',', ':', or '/'. Use --list-rendermodes to list them all.", type="choice", required=True, default=avail_rendermodes[0], listify=True)
-    parser.add_option("--list-rendermodes", dest="list_rendermodes", action="store_true", help="List available render modes and exit.")
     #parser.add_option("--rendermode-options", dest="rendermode_options", default={}, advanced=True, help="Used to specify options for different rendermodes.  Only useful in a settings.py file")
     #parser.add_option("--custom-rendermodes", dest="custom_rendermodes", default={}, advanced=True, help="Used to define custom rendermodes.  Only useful in a settings.py file")
     #parser.add_option("--imgformat", dest="imgformat", help="The image output format to use. Currently supported: png(default), jpg.", advanced=True )
@@ -253,59 +142,54 @@ def main():
                 print "Build machine: %s %s" % (overviewer_version.BUILD_PLATFORM, overviewer_version.BUILD_OS)
         except ImportError:
             print "(build info not found)"
-            pass
-        doExit(code=0, consoleMsg=False)
-
-    # setup c_overviewer rendermode customs / options
-    for mode in builtin_custom_rendermodes:
-        c_overviewer.add_custom_render_mode(mode, builtin_custom_rendermodes[mode])
-    # TODO allow custom rendermodes to be specified in a settings.py file
-    #for mode in options.custom_rendermodes:
-    #    c_overviewer.add_custom_render_mode(mode, options.custom_rendermodes[mode])
-    #for mode in options.rendermode_options:
-    #    c_overviewer.set_render_mode_options(mode, options.rendermode_options[mode])
-    
-    
-    
-    if options.list_rendermodes:
-        list_rendermodes()
-        doExit(code=0, consoleMsg=False)
+        return 0
 
     if options.check_terrain:
         import hashlib
-        from overviewer_core.textures import _find_file
-        if options.textures_path:
-            textures._find_file_local_path = options.textures_path
+        from overviewer_core.textures import Textures
+        # TODO custom textures path?
+        tex = Textures()
 
         try:
-            f = _find_file("terrain.png", verbose=True)
+            f = tex.find_file("terrain.png", verbose=True)
         except IOError:
             logging.error("Could not find the file terrain.png")
-            doExit(code=1, consoleMsg=False)
+            return 1
 
         h = hashlib.sha1()
         h.update(f.read())
         logging.info("Hash of terrain.png file is: `%s`", h.hexdigest())
-        doExit(code=0, consoleMsg=False)
+        return 0
+
+    if options.display_config:
+        # just display the config file and exit
+        parser.display_config()
+        return 0
     
     # TODO remove advanced help?  needs discussion
-    #if options.advanced_help:
-    #    parser.advanced_help()
-    #    doExit(code=0, consoleMsg=False)
-
     # TODO right now, we will not let users specify worlds to render on the command line.  
     # TODO in the future, we need to also let worlds be specified on the command line
 
+    # if no arguments are provided, print out a helpful message
+    if len(args) == 0:
+        # first provide an appropriate error for bare-console users
+        # that don't provide any options
+        if util.is_bare_console():
+            print "\n"
+            print "The Overviewer is a console program.  Please open a Windows command prompt"
+            print "first and run Overviewer from there.   Further documentation is available at"
+            print "http://docs.overviewer.org/\n"
+        else:
+            # more helpful message for users who know what they're doing
+            logging.error("You need to give me your world number or directory")
+            parser.print_help()
+            list_worlds()
+        return 1
+    
     # for multiworld, we must specify the *outputdir* on the command line
-    if len(args) == 1:
+    elif len(args) == 1:
         logging.debug("Using %r as the output_directory", args[0])
         destdir = os.path.expanduser(args[0])
-
-    elif len(args) < 1:
-        logging.error("You need to give me your world number or directory")
-        parser.print_help()
-        list_worlds()
-        doExit(code=1, consoleMsg=True)
     elif len(args) == 2: # TODO support this usecase
         worlddir = os.path.expanduser(args[0])
         destdir = os.path.expanduser(args[1])
@@ -319,14 +203,7 @@ def main():
                     if os.path.exists(" ".join(args[start:end])):
                         logging.warning("It looks like you meant to specify \"%s\" as your world dir or your output\n\
 dir but you forgot to put quotes around the directory, since it contains spaces." % " ".join(args[start:end]))
-                        doExit(code=1, consoleMsg=False)
-
-    
-    if options.display_config:
-        # just display the config file and exit
-        parser.display_config()
-        doExit(code=0, consoleMsg=False)
-
+                        return 1
 
     # TODO regionlists are per-world
     #if options.regionlist:
@@ -363,11 +240,11 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
     #    except IOError as e:
     #        logging.error("Unable to open file %s to use for changelist." % options.changelist)
     #        logging.error("I/O Error: %s" % e.strerror)
-    #        doExit(code=1, consoleMsg=False)
+    #        return 1
 
     #if options.changelist_format != "auto" and not options.changelist:
     #    logging.error("changelist_format specified without changelist.")
-    #    doExit(code=1, consoleMsg=False)
+    #    return 1
     #if options.changelist_format == "auto":
     #    options.changelist_format = "relative"
 
@@ -382,7 +259,7 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
         tex.generate()
     except IOError, e:
         logging.error(str(e))
-        doExit(code=1, consoleMsg=False)
+        return 1
 
     # look at our settings.py file
     mw_parser = configParser.MultiWorldParser("settings.py")
@@ -429,127 +306,7 @@ dir but you forgot to put quotes around the directory, since it contains spaces.
     dispatch.close()
 
     assetMrg.finalize(tilesets)
-
-    sys.exit("early abort")
- 
-    # First do world-level preprocessing. This scans the world hierarchy, reads
-    # in the region files and caches chunk modified times, and determines the
-    # chunk bounds (max and min in both dimensions)
-    w = world.World(worlddir)
-    rset = w.get_regionsets()[0] # use the default
-    if north_direction == 'auto':
-        # TODO get this from the asset manager # north_direction = w.persistentData['north_direction']
-        options.north_direction = north_direction
-
-    # TODO deal with changed north direction
-    
-    # A couple other things we need to figure out about the world:
-    w.get_regionsets()[0].determine_bounds()
-    # w.find_true_spawn()
-
-    logging.info("Rendering the following tilesets: %s", ",".join(options.rendermode))
-
-    bgcolor = (int(options.bg_color[1:3],16),
-               int(options.bg_color[3:5],16),
-               int(options.bg_color[5:7],16),
-               0)
-
-    # Create the quadtrees. There is one quadtree per rendermode requested, and
-    # therefore, per output directory hierarchy of tiles. Each quadtree
-    # individually computes its depth and size. The constructor computes the
-    # depth of the tree, while the go() method re-arranges tiles if the current
-    # depth differs from the computed depth.
-    q = []
-    qtree_args = {'depth' : options.zoom,
-                  'imgformat' : imgformat,
-                  'imgquality' : options.imgquality,
-                  'optimizeimg' : optimizeimg,
-                  'bgcolor' : bgcolor,
-                  'forcerender' : options.forcerender,
-                  'rerender_prob' : options.stochastic_render
-                  }
-    for rendermode in options.rendermode:
-        if rendermode == 'normal':
-            qtree = quadtree.QuadtreeGen(rset, destdir, rendermode=rendermode, tiledir='tiles', **qtree_args)
-        else:
-            qtree = quadtree.QuadtreeGen(rset, destdir, rendermode=rendermode, **qtree_args)
-        q.append(qtree)
-    
-    # Make sure the quadtrees are the correct depth
-    for qtree in q:
-        qtree.check_depth()
-
-    # create the distributed render
-    r = rendernode.RenderNode(q, options)
-    # for the pool_initializer
-    r.builtin_custom_rendermodes = builtin_custom_rendermodes
-    
-    # write out the map and web assets
-    m = googlemap.MapGen(q, configInfo=options)
-    m.go(options.procs)
-    
-    # render the tiles!
-    r.go(options.procs)
-
-    # finish up the map
-    m.finalize()
-
-    if options.changelist:
-        changed=[]
-        for tile in r.rendered_tiles:
-            if options.changelist_format=="absolute":
-                tile=os.path.abspath(tile)
-            changed.append(tile)
-            for zl in range(q[0].p - 1):
-                tile=os.path.dirname(tile)
-                changed.append("%s.%s" % (tile, imgformat))
-        #Quick and nasty way to remove duplicate entries
-        changed=list(set(changed))
-        changed.sort()
-        for path in changed:
-            changefile.write("%s\n" % path)
-        changefile.close()
-
-def list_rendermodes():
-    "Prints out a pretty list of supported rendermodes"
-    
-    def print_mode_tree(line_max, mode, prefix='', last=False):
-        "Prints out a mode tree for the given mode, with an indent."
-        
-        try:
-            info = c_overviewer.get_render_mode_info(mode)
-        except ValueError:
-            info = {}
-        
-        print prefix + '+-',  mode,
-        
-        if 'description' in info:
-            print " " * (line_max - len(prefix) - len(mode) - 2),
-            print info['description']
-        else:
-            print
-        
-        children = c_overviewer.get_render_mode_children(mode)
-        for child in children:
-            child_last = (child == children[-1])
-            if last:
-                child_prefix = '  '
-            else:
-                child_prefix = '| '
-            print_mode_tree(line_max, child, prefix=prefix + child_prefix, last=child_last)
-    
-    avail_rendermodes = c_overviewer.get_render_modes()
-    line_lengths = {}
-    parent_modes = []
-    for mode in avail_rendermodes:
-        inherit = c_overviewer.get_render_mode_inheritance(mode)
-        if not inherit[0] in parent_modes:
-            parent_modes.append(inherit[0])
-        line_lengths[mode] = 2 * len(inherit) + 1 + len(mode)
-    
-    line_length = max(line_lengths.values())
-    for mode in parent_modes:
-        print_mode_tree(line_length, mode, last=(mode == parent_modes[-1]))
+    return 0
 
 def list_worlds():
     "Prints out a brief summary of saves found in the default directory"
@@ -582,18 +339,14 @@ def list_worlds():
         size = "%.2fMB" % (info['SizeOnDisk'] / 1024. / 1024.)
         print formatString % (name, size, playstamp, timestamp)
 
-
 if __name__ == "__main__":
     multiprocessing.freeze_support()
     try:
-        main()
+        ret = main()
+        util.exit(ret)
     except Exception, e:
-        print e
-        if e.args[0] == "Exiting":
-            logging.info("Exiting...")
-            doExit(code=0, wait=False)
         logging.exception("""An error has occurred. This may be a bug. Please let us know!
 See http://docs.overviewer.org/en/latest/index.html#help
 
 This is the error that occurred:""")
-        doExit(code=1, consoleMsg=False)
+        util.exit(1)
diff --git a/overviewer_core/__init__.py b/overviewer_core/__init__.py
index c3d3680..ec4081e 100644
--- a/overviewer_core/__init__.py
+++ b/overviewer_core/__init__.py
@@ -1,7 +1,71 @@
-# c_overviewer must be imported first, because it imports other
-# modules; leaving this out can lead to bad dependency loops
+#
+# Code to check to make sure c_overviewer is built and working
+#
 
-try:
-    import c_overviewer
-except ImportError:
-    pass
+import os.path
+import platform
+import traceback
+import sys
+
+import util
+
+def check_c_overviewer():
+    """Check to make sure c_overviewer works and is up-to-date. Prints
+    out a helpful error and returns 1 if something's wrong, returns 0
+    otherwise.
+    """
+    root_dir = util.get_program_path()
+    # make sure the c_overviewer extension is available
+    try:
+        import c_overviewer
+    except ImportError:
+        ## if this is a frozen windows package, the following error messages about
+        ## building the c_overviewer extension are not appropriate
+        if hasattr(sys, "frozen") and platform.system() == 'Windows':
+            print "Something has gone wrong importing the c_overviewer extension.  Please"
+            print "make sure the 2008 and 2010 redistributable packages from Microsoft"
+            print "are installed."
+            return 1
+
+        ## try to find the build extension
+        ext = os.path.join(root_dir, "overviewer_core", "c_overviewer.%s" % ("pyd" if platform.system() == "Windows" else "so"))
+        if os.path.exists(ext):
+            traceback.print_exc()
+            print ""
+            print "Something has gone wrong importing the c_overviewer extension.  Please"
+            print "make sure it is up-to-date (clean and rebuild)"
+            return 1
+
+        print "You need to compile the c_overviewer module to run Minecraft Overviewer."
+        print "Run `python setup.py build`, or see the README for details."
+        return 1
+
+    #
+    # make sure it's up-to-date
+    #
+
+    if hasattr(sys, "frozen"):
+        pass # we don't bother with a compat test since it should always be in sync
+    elif "extension_version" in dir(c_overviewer):
+        # check to make sure the binary matches the headers
+        if os.path.exists(os.path.join(root_dir, "overviewer_core", "src", "overviewer.h")):
+            with open(os.path.join(root_dir, "overviewer_core", "src", "overviewer.h")) as f:
+                lines = f.readlines()
+                lines = filter(lambda x: x.startswith("#define OVERVIEWER_EXTENSION_VERSION"), lines)
+                if lines:
+                    l = lines[0]
+                    if int(l.split()[2].strip()) != c_overviewer.extension_version():
+                        print "Please rebuild your c_overviewer module.  It is out of date!"
+                        return 1
+    else:
+        print "Please rebuild your c_overviewer module.  It is out of date!"
+        return 1
+    
+    # all good!
+    return 0
+
+# only check the module if we're not setup.py
+if not sys.argv[0].endswith("setup.py"):
+    ret = check_c_overviewer()
+    if ret > 0:
+        util.exit(ret)
diff --git a/overviewer_core/rendermodes.py b/overviewer_core/rendermodes.py
index e3386a3..ffa2e43 100644
--- a/overviewer_core/rendermodes.py
+++ b/overviewer_core/rendermodes.py
@@ -16,59 +16,125 @@
 from PIL import Image
 import textures
 
-# Render 3 blending masks for lighting
-# first is top (+Z), second is left (-X), third is right (+Y)
-def generate_facemasks():
-    white = Image.new("L", (24,24), 255)
-    
-    top = Image.new("L", (24,24), 0)
-    left = Image.new("L", (24,24), 0)
-    whole = Image.new("L", (24,24), 0)
-    
-    toppart = textures.Textures.transform_image_top(white)
-    leftpart = textures.Textures.transform_image_side(white)
-    
-    # using the real PIL paste here (not alpha_over) because there is
-    # no alpha channel (and it's mode "L")
-    top.paste(toppart, (0,0))
-    left.paste(leftpart, (0,6))
-    right = left.transpose(Image.FLIP_LEFT_RIGHT)
-    
-    # Manually touch up 6 pixels that leave a gap, like in
-    # textures._build_block()
-    for x,y in [(13,23), (17,21), (21,19)]:
-        right.putpixel((x,y), 255)
-    for x,y in [(3,4), (7,2), (11,0)]:
-        top.putpixel((x,y), 255)
-    
-    # special fix for chunk boundary stipple
-    for x,y in [(13,11), (17,9), (21,7)]:
-        right.putpixel((x,y), 0)
-    
-    return (top, left, right)
-facemasks = generate_facemasks()
-black_color = Image.new("RGB", (24,24), (0,0,0))
-white_color = Image.new("RGB", (24,24), (255,255,255))
-
-# Render 128 different color images for color coded depth blending in cave mode
-def generate_depthcolors():
-    depth_colors = []
-    r = 255
-    g = 0
-    b = 0
-    for z in range(128):
-        depth_colors.append(r)
-        depth_colors.append(g)
-        depth_colors.append(b)
+class RenderPrimitive(object):
+    options = {}
+    name = None
+    def __init__(self, **kwargs):
+        if self.name is None:
+            raise RuntimeError("RenderPrimitive cannot be used directly")
         
-        if z < 32:
-            g += 7
-        elif z < 64:
-            r -= 7
-        elif z < 96:
-            b += 7
-        else:
-            g -= 7
+        self.option_values = {}
+        for key, val in kwargs.iteritems():
+            if not key in self.options:
+                raise ValueError("primitive `{0}' has no option `{1}'".format(self.name, key))
+            self.option_values[key] = val
+        
+        # set up defaults
+        for name, (description, default) in self.options.iteritems():
+            if not name in self.option_values:
+                self.option_values[name] = default
 
-    return depth_colors
-depth_colors = generate_depthcolors()
+class Base(RenderPrimitive):
+    name = "base"
+
+class Nether(RenderPrimitive):
+    name = "nether"
+
+class HeightFading(RenderPrimitive):
+    name = "height-fading"
+    
+    black_color = Image.new("RGB", (24,24), (0,0,0))
+    white_color = Image.new("RGB", (24,24), (255,255,255))
+
+class Depth(RenderPrimitive):
+    name = "depth"
+    options = {
+        "min": ("lowest level of blocks to render", 0),
+        "max": ("highest level of blocks to render", 127),
+    }
+
+class EdgeLines(RenderPrimitive):
+    name = "edge-lines"
+    options = {
+        "opacity": ("darkness of the edge lines, from 0.0 to 1.0", 0.15),
+    }
+
+class Cave(RenderPrimitive):
+    name = "cave"
+    options = {
+        "only_lit": ("only render lit caves", False),
+    }
+
+class DepthTinting(RenderPrimitive):
+    name = "depth-tinting"
+    
+    @property
+    def depth_colors(self):
+        depth_colors = getattr(self, "_depth_colors", [])
+        if depth_colors:
+            return depth_colors
+        r = 255
+        g = 0
+        b = 0
+        for z in range(128):
+            depth_colors.append(r)
+            depth_colors.append(g)
+            depth_colors.append(b)
+            
+            if z < 32:
+                g += 7
+            elif z < 64:
+                r -= 7
+            elif z < 96:
+                b += 7
+            else:
+                g -= 7
+
+        self._depth_colors = depth_colors
+        return depth_colors
+
+class Lighting(RenderPrimitive):
+    name = "lighting"
+    options = {
+        "strength": ("how dark to make the shadows, from 0.0 to 1.0", 1.0),
+        "night": ("whether to use nighttime skylight settings", False),
+        "color": ("whether to use colored light", False),
+    }
+
+    @property
+    def facemasks(self):
+        facemasks = getattr(self, "_facemasks", None)
+        if facemasks:
+            return facemasks
+        
+        white = Image.new("L", (24,24), 255)
+        
+        top = Image.new("L", (24,24), 0)
+        left = Image.new("L", (24,24), 0)
+        whole = Image.new("L", (24,24), 0)
+        
+        toppart = textures.Textures.transform_image_top(white)
+        leftpart = textures.Textures.transform_image_side(white)
+        
+        # using the real PIL paste here (not alpha_over) because there is
+        # no alpha channel (and it's mode "L")
+        top.paste(toppart, (0,0))
+        left.paste(leftpart, (0,6))
+        right = left.transpose(Image.FLIP_LEFT_RIGHT)
+        
+        # Manually touch up 6 pixels that leave a gap, like in
+        # textures._build_block()
+        for x,y in [(13,23), (17,21), (21,19)]:
+            right.putpixel((x,y), 255)
+        for x,y in [(3,4), (7,2), (11,0)]:
+            top.putpixel((x,y), 255)
+    
+        # special fix for chunk boundary stipple
+        for x,y in [(13,11), (17,9), (21,7)]:
+            right.putpixel((x,y), 0)
+        
+        self._facemasks = (top, left, right)
+        return self._facemasks
+
+class SmoothLighting(Lighting):
+    name = "smooth-lighting"
diff --git a/overviewer_core/src/iterate.c b/overviewer_core/src/iterate.c
index 22cfabd..f1e7bc2 100644
--- a/overviewer_core/src/iterate.c
+++ b/overviewer_core/src/iterate.c
@@ -18,7 +18,6 @@
 #include "overviewer.h"
 
 static PyObject *textures = NULL;
-static PyObject *support = NULL;
 
 unsigned int max_blockid = 0;
 unsigned int max_data = 0;
@@ -47,11 +46,6 @@ PyObject *init_chunk_render(void) {
         return NULL;
     }
     
-    support = PyImport_ImportModule("overviewer_core.rendermodes");
-    if (!support) {
-        return NULL;
-    }
-    
     tmp = PyObject_GetAttrString(textures, "max_blockid");
     if (!tmp)
         return NULL;
@@ -388,7 +382,7 @@ chunk_render(PyObject *self, PyObject *args) {
     RenderState state;
     PyObject *regionset;
     int chunkx, chunkz;
-    const char* rendermode_name = NULL;
+    PyObject *modeobj;
     PyObject *blockmap;
 
     int xoff, yoff;
@@ -406,14 +400,11 @@ chunk_render(PyObject *self, PyObject *args) {
 
     PyObject *t = NULL;
     
-    if (!PyArg_ParseTuple(args, "OiiOiisO",  &state.regionset, &state.chunkx, &state.chunkz, &state.img, &xoff, &yoff, &rendermode_name, &state.textures))
+    if (!PyArg_ParseTuple(args, "OiiOiiOO",  &state.regionset, &state.chunkx, &state.chunkz, &state.img, &xoff, &yoff, &modeobj, &state.textures))
         return NULL;
     
-    /* rendermode support */
-    state.support = support;
-    
     /* set up the render mode */
-    state.rendermode = rendermode = render_mode_create(rendermode_name, &state);
+    state.rendermode = rendermode = render_mode_create(modeobj, &state);
     if (rendermode == NULL) {
         return NULL; // note that render_mode_create will
                      // set PyErr.  No need to set it here
diff --git a/overviewer_core/src/main.c b/overviewer_core/src/main.c
index ca14065..11a12e2 100644
--- a/overviewer_core/src/main.c
+++ b/overviewer_core/src/main.c
@@ -17,10 +17,6 @@
 
 #include "overviewer.h"
 
-/* global variables from rendermodes.c -- both are dictionaries */
-extern PyObject *render_mode_options;
-extern PyObject *custom_render_modes;
-
 PyObject *get_extension_version(PyObject *self, PyObject *args) {
 
     return Py_BuildValue("i", OVERVIEWER_EXTENSION_VERSION);
@@ -33,20 +29,6 @@ static PyMethodDef COverviewerMethods[] = {
     {"render_loop", chunk_render, METH_VARARGS,
      "Renders stuffs"},
     
-    {"get_render_modes", get_render_modes, METH_VARARGS,
-     "returns available render modes"},
-    {"get_render_mode_info", get_render_mode_info, METH_VARARGS,
-     "returns info for a particular render mode"},
-    {"get_render_mode_inheritance", get_render_mode_inheritance, METH_VARARGS,
-     "returns inheritance chain for a particular render mode"},
-    {"get_render_mode_children", get_render_mode_children, METH_VARARGS,
-     "returns (direct) children for a particular render mode"},
-    
-    {"set_render_mode_options", set_render_mode_options, METH_VARARGS,
-     "sets the default options for a given render mode"},
-    {"add_custom_render_mode", add_custom_render_mode, METH_VARARGS,
-     "add a new rendermode derived from an existing mode"},
-    
     {"extension_version", get_extension_version, METH_VARARGS, 
         "Returns the extension version"},
     
@@ -69,17 +51,5 @@ initc_overviewer(void)
         return;
     }
     
-    /* create the render mode data structures, and attatch them to the module
-     * so that the Python garbage collector doesn't freak out
-     */
-    
-    render_mode_options = PyDict_New();
-    PyObject_SetAttrString(mod, "_render_mode_options", render_mode_options);
-    Py_DECREF(render_mode_options);
-    
-    custom_render_modes = PyDict_New();
-    PyObject_SetAttrString(mod, "_custom_render_modes", custom_render_modes);
-    Py_DECREF(custom_render_modes);
-    
     init_endian();
 }
diff --git a/overviewer_core/src/overviewer.h b/overviewer_core/src/overviewer.h
index 1155724..517bb5b 100644
--- a/overviewer_core/src/overviewer.h
+++ b/overviewer_core/src/overviewer.h
@@ -79,9 +79,6 @@ typedef struct {
     /* the Texture object */
     PyObject *textures;
     
-    /* the rendermode support module (rendermodes.py) */
-    PyObject *support;
-    
     /* the block position and type, and the block array */
     int x, y, z;
     unsigned char block;
diff --git a/overviewer_core/src/rendermode-normal.c b/overviewer_core/src/primitives/base.c
similarity index 56%
rename from overviewer_core/src/rendermode-normal.c
rename to overviewer_core/src/primitives/base.c
index 39bc679..4f13c47 100644
--- a/overviewer_core/src/rendermode-normal.c
+++ b/overviewer_core/src/primitives/base.c
@@ -15,39 +15,22 @@
  * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "overviewer.h"
+#include "../overviewer.h"
+
+typedef struct {
+    /* coordinates of the chunk, inside its region file */
+    int chunk_x, chunk_y;
+    /* biome data for the region */
+    PyObject *biome_data;
+    /* grasscolor and foliagecolor lookup tables */
+    PyObject *grasscolor, *foliagecolor, *watercolor;
+    /* biome-compatible grass/leaf textures */
+    PyObject *grass_texture;
+} PrimitiveBase;
 
 static int
-rendermode_normal_start(void *data, RenderState *state, PyObject *options) {
-    RenderModeNormal *self = (RenderModeNormal *)data;
-    
-    /* load up the given options, first */
-    
-    self->edge_opacity = 0.15;
-    if (!render_mode_parse_option(options, "edge_opacity", "f", &(self->edge_opacity)))
-        return 1;
-    
-    self->min_depth = 0;
-    if (!render_mode_parse_option(options, "min_depth", "I", &(self->min_depth)))
-        return 1;
-
-    self->max_depth = 127;
-    if (!render_mode_parse_option(options, "max_depth", "I", &(self->max_depth)))
-        return 1;
-
-    self->height_fading = 0;
-    /* XXX skip height fading */
-    /*if (!render_mode_parse_option(options, "height_fading", "i", &(self->height_fading)))
-      return 1;*/
-    
-    self->nether = 0;
-    if (!render_mode_parse_option(options, "nether", "i", &(self->nether)))
-        return 1;
-    
-    /*if (self->height_fading) {
-        self->black_color = PyObject_GetAttrString(state->chunk, "black_color");
-        self->white_color = PyObject_GetAttrString(state->chunk, "white_color");
-        }*/
+base_start(void *data, RenderState *state, PyObject *support) {
+    PrimitiveBase *self = (PrimitiveBase *)data;
     
     /* biome-compliant grass mask (includes sides!) */
     self->grass_texture = PyObject_GetAttrString(state->textures, "biome_grass_texture");
@@ -95,20 +78,18 @@ rendermode_normal_start(void *data, RenderState *state, PyObject *options) {
 }
 
 static void
-rendermode_normal_finish(void *data, RenderState *state) {
-    RenderModeNormal *self = (RenderModeNormal *)data;
+base_finish(void *data, RenderState *state) {
+    PrimitiveBase *self = (PrimitiveBase *)data;
     
     Py_XDECREF(self->biome_data);
     Py_XDECREF(self->foliagecolor);
     Py_XDECREF(self->grasscolor);
     Py_XDECREF(self->watercolor);
     Py_XDECREF(self->grass_texture);
-    Py_XDECREF(self->black_color);
-    Py_XDECREF(self->white_color);
 }
 
 static int
-rendermode_normal_occluded(void *data, RenderState *state, int x, int y, int z) {
+base_occluded(void *data, RenderState *state, int x, int y, int z) {
     if ( (x != 0) && (y != 15) && (z != 127) &&
          !render_mode_hidden(state->rendermode, x-1, y, z) &&
          !render_mode_hidden(state->rendermode, x, y, z+1) &&
@@ -123,39 +104,15 @@ rendermode_normal_occluded(void *data, RenderState *state, int x, int y, int z)
 }
 
 static int
-rendermode_normal_hidden(void *data, RenderState *state, int x, int y, int z) {
-    RenderModeNormal *self = (RenderModeNormal *)data;
+base_hidden(void *data, RenderState *state, int x, int y, int z) {
+    PrimitiveBase *self = (PrimitiveBase *)data;
     
-    if (z > self->max_depth || z < self->min_depth) {
-        return 1;
-    }
-    
-    if (self->nether)
-    {
-        
-        /* hide all blocks above all air blocks */
-        int below_air = 0;
-        
-        while (z < 128)
-        {
-            if (getArrayByte3D(state->blocks, x, y, z) == 0)
-            {
-                below_air = 1;
-                break;
-            }
-            z++;
-        }
-        
-        if (!below_air)
-            return 1;
-    }
-
     return 0;
 }
 
 static void
-rendermode_normal_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
-    RenderModeNormal *self = (RenderModeNormal *)data;
+base_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    PrimitiveBase *self = (PrimitiveBase *)data;
 
     /* draw the block! */
     alpha_over(state->img, src, mask, state->imgx, state->imgy, 0, 0);
@@ -299,85 +256,13 @@ rendermode_normal_draw(void *data, RenderState *state, PyObject *src, PyObject *
         if (facemask)
             tint_with_mask(state->img, r, g, b, 255, facemask, state->imgx, state->imgy, 0, 0);
     }
-    
-    if (self->height_fading) {
-        /* do some height fading */
-        PyObject *height_color = self->white_color;
-        /* negative alpha => darkness, positive => light */
-        float alpha = (1.0 / (1 + expf((70 - state->z) / 11.0))) * 0.6 - 0.55;
-        
-        if (alpha < 0.0) {
-            alpha *= -1;
-            height_color = self->black_color;
-        }
-        
-        alpha_over_full(state->img, height_color, mask_light, alpha, state->imgx, state->imgy, 0, 0);
-    }
-    
-
-    /* Draw some edge lines! */
-    // draw.line(((imgx+12,imgy+increment), (imgx+22,imgy+5+increment)), fill=(0,0,0), width=1)
-    if (state->block == 44 || state->block == 78 || !is_transparent(state->block)) {
-        Imaging img_i = imaging_python_to_c(state->img);
-        unsigned char ink[] = {0, 0, 0, 255 * self->edge_opacity};
-
-        int increment=0;
-        if (state->block == 44)  // half-step
-            increment=6;
-        else if ((state->block == 78) || (state->block == 93) || (state->block == 94)) // snow, redstone repeaters (on and off)
-            increment=9;
-
-        if ((state->x == 15) && (state->up_right_blocks != Py_None)) {
-            unsigned char side_block = getArrayByte3D(state->up_right_blocks, 0, state->y, state->z);
-            if (side_block != state->block && is_transparent(side_block)) {
-                ImagingDrawLine(img_i, state->imgx+12, state->imgy+1+increment, state->imgx+22+1, state->imgy+5+1+increment, &ink, 1);
-                ImagingDrawLine(img_i, state->imgx+12, state->imgy+increment, state->imgx+22+1, state->imgy+5+increment, &ink, 1);
-            }
-        } else if (state->x != 15) {
-            unsigned char side_block = getArrayByte3D(state->blocks, state->x+1, state->y, state->z);
-            if (side_block != state->block && is_transparent(side_block)) {
-                ImagingDrawLine(img_i, state->imgx+12, state->imgy+1+increment, state->imgx+22+1, state->imgy+5+1+increment, &ink, 1);
-                ImagingDrawLine(img_i, state->imgx+12, state->imgy+increment, state->imgx+22+1, state->imgy+5+increment, &ink, 1);
-            }
-        }
-        // if y != 0 and blocks[x,y-1,z] == 0
-
-        // chunk boundries are annoying
-        if ((state->y == 0) && (state->up_left_blocks != Py_None)) {
-            unsigned char side_block = getArrayByte3D(state->up_left_blocks, state->x, 15, state->z);
-            if (side_block != state->block && is_transparent(side_block)) {
-                ImagingDrawLine(img_i, state->imgx, state->imgy+6+1+increment, state->imgx+12+1, state->imgy+1+increment, &ink, 1);
-                ImagingDrawLine(img_i, state->imgx, state->imgy+6+increment, state->imgx+12+1, state->imgy+increment, &ink, 1);
-            }
-        } else if (state->y != 0) {
-            unsigned char side_block = getArrayByte3D(state->blocks, state->x, state->y-1, state->z);
-            if (side_block != state->block && is_transparent(side_block)) {
-                // draw.line(((imgx,imgy+6+increment), (imgx+12,imgy+increment)), fill=(0,0,0), width=1)
-                ImagingDrawLine(img_i, state->imgx, state->imgy+6+1+increment, state->imgx+12+1, state->imgy+1+increment, &ink, 1);
-                ImagingDrawLine(img_i, state->imgx, state->imgy+6+increment, state->imgx+12+1, state->imgy+increment, &ink, 1);
-            }
-        }
-    }
 }
 
-const RenderModeOption rendermode_normal_options[] = {
-    {"edge_opacity", "darkness of the edge lines, from 0.0 to 1.0 (default: 0.15)"},
-    {"min_depth", "lowest level of blocks to render (default: 0)"},
-    {"max_depth", "highest level of blocks to render (default: 127)"},
-    {"height_fading", "darken or lighten blocks based on height (default: False)"},
-    {"nether", "if True, remove the roof of the map. Useful on nether maps. (default: False)"},
-    {NULL, NULL}
-};
-
-RenderModeInterface rendermode_normal = {
-    "normal", "Normal",
-    "nothing special, just render the blocks",
-    rendermode_normal_options,
-    NULL,
-    sizeof(RenderModeNormal),
-    rendermode_normal_start,
-    rendermode_normal_finish,
-    rendermode_normal_occluded,
-    rendermode_normal_hidden,
-    rendermode_normal_draw,
+RenderPrimitiveInterface primitive_base = {
+    "base", sizeof(PrimitiveBase),
+    base_start,
+    base_finish,
+    base_occluded,
+    base_hidden,
+    base_draw,
 };
diff --git a/overviewer_core/src/rendermode-cave.c b/overviewer_core/src/primitives/cave.c
similarity index 64%
rename from overviewer_core/src/rendermode-cave.c
rename to overviewer_core/src/primitives/cave.c
index 9807ed2..f4d6605 100644
--- a/overviewer_core/src/rendermode-cave.c
+++ b/overviewer_core/src/primitives/cave.c
@@ -15,15 +15,32 @@
  * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "overviewer.h"
+#include "../overviewer.h"
 #include <math.h>
 
+typedef struct {
+    /* data used to know where the surface is */
+    PyObject *skylight;
+    PyObject *left_skylight;
+    PyObject *right_skylight;
+    PyObject *up_left_skylight;
+    PyObject *up_right_skylight;
+
+    /* data used to know where the lit caves are */
+    PyObject *blocklight;
+    PyObject *left_blocklight;
+    PyObject *right_blocklight;
+    PyObject *up_left_blocklight;
+    PyObject *up_right_blocklight;
+    
+    int only_lit;
+} RenderPrimitiveCave;
+
 static inline int
 touches_light(unsigned int x, unsigned int y, unsigned int z,
               PyObject *light, PyObject *left_light, PyObject *right_light,
               PyObject *up_left_light, PyObject *up_right_light) {
     
-    
     if (getArrayByte3D(light, x, y, z+1) != 0) {
         return 1;
     }
@@ -79,10 +96,11 @@ touches_light(unsigned int x, unsigned int y, unsigned int z,
     return 0;
 }
 
-static inline int
-rendermode_cave_adjacent_occluded(void *data, RenderState *state, int x, int y, int z) {
-    /* check for occlusion of edge blocks, using adjacent block data */
-    
+static int
+cave_occluded(void *data, RenderState *state, int x, int y, int z) { 
+    /* check for normal occlusion */
+    /* use ajacent chunks, if not you get blocks spreaded in chunk edges */
+
     if (z != 127) {
         if ( (x == 0) && (y != 15) ) {
             if (state->left_blocks != Py_None) {
@@ -133,26 +151,11 @@ rendermode_cave_adjacent_occluded(void *data, RenderState *state, int x, int y,
 }
 
 static int
-rendermode_cave_occluded(void *data, RenderState *state, int x, int y, int z) { 
-    /* first, check to see if it's "normally" occluded */
-    if (rendermode_lighting.occluded(data, state, x, y, z))
-        return 1;
-
-    /* check for normal occlusion */
-    /* use ajacent chunks, if not you get blocks spreaded in chunk edges */
-    return rendermode_cave_adjacent_occluded(data, state, x, y, z);
-}
-
-static int
-rendermode_cave_hidden(void *data, RenderState *state, int x, int y, int z) {
-    RenderModeCave* self;
+cave_hidden(void *data, RenderState *state, int x, int y, int z) {
+    RenderPrimitiveCave* self;
     int dz = 0;
-    self = (RenderModeCave *)data;
+    self = (RenderPrimitiveCave *)data;
     
-    /* first, check to see if it's "normally" hidden */
-    if (rendermode_lighting.hidden(data, state, x, y, z))
-        return 1;
-
     /* check if the block is touching skylight */
     if (z != 127) { 
         
@@ -190,51 +193,25 @@ rendermode_cave_hidden(void *data, RenderState *state, int x, int y, int z) {
     /* unfortunate side-effect of lit cave mode: we need to count occluded
      * blocks as hidden for the lighting to look right, since technically our
      * hiding depends on occlusion as well
-     *
-     * We leave out this check otherwise because it's fairly expensive.
      */
-    if (self->lighting) {
-        if ( (x != 0) && (y != 15) && (z != 127) &&
-             !is_transparent(getArrayByte3D(state->blocks, x-1, y, z)) &&
-             !is_transparent(getArrayByte3D(state->blocks, x, y, z+1)) &&
-             !is_transparent(getArrayByte3D(state->blocks, x, y+1, z))) {
-            return 1;
-        }
-        
-        return rendermode_cave_adjacent_occluded(data, state, x, y, z);
+    if ( (x != 0) && (y != 15) && (z != 127) &&
+         !is_transparent(getArrayByte3D(state->blocks, x-1, y, z)) &&
+         !is_transparent(getArrayByte3D(state->blocks, x, y, z+1)) &&
+         !is_transparent(getArrayByte3D(state->blocks, x, y+1, z))) {
+        return 1;
     }
     
-    return 0;
+    return cave_occluded(data, state, x, y, z);
 }
 
 static int
-rendermode_cave_start(void *data, RenderState *state, PyObject *options) {
-    RenderModeCave* self;
+cave_start(void *data, RenderState *state, PyObject *support) {
+    RenderPrimitiveCave* self;
     int ret;
-    self = (RenderModeCave *)data;
+    self = (RenderPrimitiveCave *)data;
 
-    /* first, chain up */
-    ret = rendermode_lighting.start(data, state, options);
-    if (ret != 0)
-        return ret;
-    
-    self->depth_tinting = 1;
-    if (!render_mode_parse_option(options, "depth_tinting", "i", &(self->depth_tinting)))
+    if (!render_mode_parse_option(support, "only_lit", "i", &(self->only_lit)))
         return 1;
-
-    self->only_lit = 0;
-    if (!render_mode_parse_option(options, "only_lit", "i", &(self->only_lit)))
-        return 1;
-    
-    self->lighting = 0;
-    if (!render_mode_parse_option(options, "lighting", "i", &(self->lighting)))
-        return 1;
-    
-    if (self->lighting)
-    {
-        /* we can't skip lighting the sides in cave mode, it looks too weird */
-        self->parent.skip_sides = 0;
-    }
     
     /* if there's skylight we are in the surface! */
     self->skylight = get_chunk_data(state, CURRENT, SKYLIGHT);
@@ -251,16 +228,13 @@ rendermode_cave_start(void *data, RenderState *state, PyObject *options) {
         self->up_right_blocklight = get_chunk_data(state, UP_RIGHT, BLOCKLIGHT);
     }
 
-    /* colors for tinting */
-    self->depth_colors = PyObject_GetAttrString(state->support, "depth_colors");
-
     return 0;
 }
 
 static void
-rendermode_cave_finish(void *data, RenderState *state) {
-    RenderModeCave* self;
-    self = (RenderModeCave *)data;
+cave_finish(void *data, RenderState *state) {
+    RenderPrimitiveCave* self;
+    self = (RenderPrimitiveCave *)data;
     
     Py_DECREF(self->skylight);
     Py_DECREF(self->left_skylight);
@@ -275,55 +249,13 @@ rendermode_cave_finish(void *data, RenderState *state) {
         Py_DECREF(self->up_left_blocklight);
         Py_DECREF(self->up_right_blocklight);
     }
-    
-    Py_DECREF(self->depth_colors);
-
-    rendermode_lighting.finish(data, state);
 }
 
-static void
-rendermode_cave_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
-    RenderModeCave* self;
-    int z, r, g, b;
-    self = (RenderModeCave *)data;
-
-    z = state->z;
-    r = 0, g = 0, b = 0;
-
-    /* draw the normal block */
-    if (self->lighting) {
-        rendermode_lighting.draw(data, state, src, mask, mask_light);
-    } else {
-        rendermode_normal.draw(data, state, src, mask, mask_light);
-    }
-
-    if (self->depth_tinting) {
-        /* get the colors and tint and tint */
-        r = PyInt_AsLong(PyList_GetItem(self->depth_colors, 0 + z*3));
-        g = PyInt_AsLong(PyList_GetItem(self->depth_colors, 1 + z*3));
-        b = PyInt_AsLong(PyList_GetItem(self->depth_colors, 2 + z*3));
-        
-        tint_with_mask(state->img, r, g, b, 255, mask, state->imgx, state->imgy, 0, 0);
-    }
-
-}
-
-const RenderModeOption rendermode_cave_options[] = {
-    {"depth_tinting", "tint caves based on how deep they are (default: True)"},
-    {"only_lit", "only render lit caves (default: False)"},
-    {"lighting", "render caves with lighting enabled (default: False)"},
-    {NULL, NULL}
-};
-
-RenderModeInterface rendermode_cave = {
-    "cave", "Cave",
-    "render only caves",
-    rendermode_cave_options,
-    &rendermode_lighting,
-    sizeof(RenderModeCave),
-    rendermode_cave_start,
-    rendermode_cave_finish,
-    rendermode_cave_occluded,
-    rendermode_cave_hidden,
-    rendermode_cave_draw,
+RenderPrimitiveInterface primitive_cave = {
+    "cave", sizeof(RenderPrimitiveCave),
+    cave_start,
+    cave_finish,
+    cave_occluded,
+    cave_hidden,
+    NULL,
 };
diff --git a/overviewer_core/src/primitives/depth-tinting.c b/overviewer_core/src/primitives/depth-tinting.c
new file mode 100644
index 0000000..80d5226
--- /dev/null
+++ b/overviewer_core/src/primitives/depth-tinting.c
@@ -0,0 +1,70 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+#include <math.h>
+
+typedef struct {
+    /* list of colors used for tinting */
+    PyObject *depth_colors;
+} RenderPrimitiveDepthTinting;
+
+static int
+depth_tinting_start(void *data, RenderState *state, PyObject *support) {
+    RenderPrimitiveDepthTinting* self;
+    self = (RenderPrimitiveDepthTinting *)data;
+
+    self->depth_colors = PyObject_GetAttrString(support, "depth_colors");
+    if (self->depth_colors == NULL)
+        return 1;
+
+    return 0;
+}
+
+static void
+depth_tinting_finish(void *data, RenderState *state) {
+    RenderPrimitiveDepthTinting* self;
+    self = (RenderPrimitiveDepthTinting *)data;
+
+    Py_DECREF(self->depth_colors);
+}
+
+static void
+depth_tinting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    RenderPrimitiveDepthTinting* self;
+    int z, r, g, b;
+    self = (RenderPrimitiveDepthTinting *)data;
+
+    z = state->z;
+    r = 0, g = 0, b = 0;
+
+    /* get the colors and tint and tint */
+    r = PyInt_AsLong(PyList_GetItem(self->depth_colors, 0 + z*3));
+    g = PyInt_AsLong(PyList_GetItem(self->depth_colors, 1 + z*3));
+    b = PyInt_AsLong(PyList_GetItem(self->depth_colors, 2 + z*3));
+    
+    tint_with_mask(state->img, r, g, b, 255, mask, state->imgx, state->imgy, 0, 0);
+}
+
+RenderPrimitiveInterface primitive_depth_tinting = {
+    "depth-tinting", sizeof(RenderPrimitiveDepthTinting),
+    depth_tinting_start,
+    depth_tinting_finish,
+    NULL,
+    NULL,
+    depth_tinting_draw,
+};
diff --git a/overviewer_core/src/primitives/depth.c b/overviewer_core/src/primitives/depth.c
new file mode 100644
index 0000000..87a14a6
--- /dev/null
+++ b/overviewer_core/src/primitives/depth.c
@@ -0,0 +1,53 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+
+typedef struct {
+    unsigned int min;
+    unsigned int max;
+} PrimitiveDepth;
+
+static int
+depth_start(void *data, RenderState *state, PyObject *support) {
+    PrimitiveDepth *self = (PrimitiveDepth *)data;
+    
+    if (!render_mode_parse_option(support, "min", "I", &(self->min)))
+        return 1;
+    if (!render_mode_parse_option(support, "max", "I", &(self->max)))
+        return 1;
+
+    return 0;
+}
+
+static int
+depth_hidden(void *data, RenderState *state, int x, int y, int z) {
+    PrimitiveDepth *self = (PrimitiveDepth *)data;
+    if (z > self->max || z < self->min) {
+        return 1;
+    }
+    return 0;
+}
+
+RenderPrimitiveInterface primitive_depth = {
+    "depth", sizeof(PrimitiveDepth),
+    depth_start,
+    NULL,
+    NULL,
+    depth_hidden,
+    NULL,
+};
diff --git a/overviewer_core/src/primitives/edge-lines.c b/overviewer_core/src/primitives/edge-lines.c
new file mode 100644
index 0000000..f1e4e42
--- /dev/null
+++ b/overviewer_core/src/primitives/edge-lines.c
@@ -0,0 +1,88 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+
+typedef struct {
+    float opacity;
+} PrimitiveEdgeLines;
+
+static int
+edge_lines_start(void *data, RenderState *state, PyObject *support) {
+    PrimitiveEdgeLines *self = (PrimitiveEdgeLines *)data;
+    if (!render_mode_parse_option(support, "opacity", "f", &(self->opacity)))
+        return 1;
+    return 0;
+}
+
+static void
+edge_lines_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    PrimitiveEdgeLines *self = (PrimitiveEdgeLines *)data;
+
+    /* Draw some edge lines! */
+    // draw.line(((imgx+12,imgy+increment), (imgx+22,imgy+5+increment)), fill=(0,0,0), width=1)
+    if (state->block == 44 || state->block == 78 || !is_transparent(state->block)) {
+        Imaging img_i = imaging_python_to_c(state->img);
+        unsigned char ink[] = {0, 0, 0, 255 * self->opacity};
+
+        int increment=0;
+        if (state->block == 44)  // half-step
+            increment=6;
+        else if ((state->block == 78) || (state->block == 93) || (state->block == 94)) // snow, redstone repeaters (on and off)
+            increment=9;
+
+        if ((state->x == 15) && (state->up_right_blocks != Py_None)) {
+            unsigned char side_block = getArrayByte3D(state->up_right_blocks, 0, state->y, state->z);
+            if (side_block != state->block && is_transparent(side_block)) {
+                ImagingDrawLine(img_i, state->imgx+12, state->imgy+1+increment, state->imgx+22+1, state->imgy+5+1+increment, &ink, 1);
+                ImagingDrawLine(img_i, state->imgx+12, state->imgy+increment, state->imgx+22+1, state->imgy+5+increment, &ink, 1);
+            }
+        } else if (state->x != 15) {
+            unsigned char side_block = getArrayByte3D(state->blocks, state->x+1, state->y, state->z);
+            if (side_block != state->block && is_transparent(side_block)) {
+                ImagingDrawLine(img_i, state->imgx+12, state->imgy+1+increment, state->imgx+22+1, state->imgy+5+1+increment, &ink, 1);
+                ImagingDrawLine(img_i, state->imgx+12, state->imgy+increment, state->imgx+22+1, state->imgy+5+increment, &ink, 1);
+            }
+        }
+        // if y != 0 and blocks[x,y-1,z] == 0
+
+        // chunk boundries are annoying
+        if ((state->y == 0) && (state->up_left_blocks != Py_None)) {
+            unsigned char side_block = getArrayByte3D(state->up_left_blocks, state->x, 15, state->z);
+            if (side_block != state->block && is_transparent(side_block)) {
+                ImagingDrawLine(img_i, state->imgx, state->imgy+6+1+increment, state->imgx+12+1, state->imgy+1+increment, &ink, 1);
+                ImagingDrawLine(img_i, state->imgx, state->imgy+6+increment, state->imgx+12+1, state->imgy+increment, &ink, 1);
+            }
+        } else if (state->y != 0) {
+            unsigned char side_block = getArrayByte3D(state->blocks, state->x, state->y-1, state->z);
+            if (side_block != state->block && is_transparent(side_block)) {
+                // draw.line(((imgx,imgy+6+increment), (imgx+12,imgy+increment)), fill=(0,0,0), width=1)
+                ImagingDrawLine(img_i, state->imgx, state->imgy+6+1+increment, state->imgx+12+1, state->imgy+1+increment, &ink, 1);
+                ImagingDrawLine(img_i, state->imgx, state->imgy+6+increment, state->imgx+12+1, state->imgy+increment, &ink, 1);
+            }
+        }
+    }
+}
+
+RenderPrimitiveInterface primitive_edge_lines = {
+    "edge-lines", sizeof(PrimitiveEdgeLines),
+    edge_lines_start,
+    NULL,
+    NULL,
+    NULL,
+    edge_lines_draw,
+};
diff --git a/overviewer_core/src/primitives/height-fading.c b/overviewer_core/src/primitives/height-fading.c
new file mode 100644
index 0000000..589111e
--- /dev/null
+++ b/overviewer_core/src/primitives/height-fading.c
@@ -0,0 +1,68 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+
+typedef struct {
+    PyObject *black_color;
+    PyObject *white_color;
+} PrimitiveHeightFading;
+
+static int
+height_fading_start(void *data, RenderState *state, PyObject *support) {
+    PrimitiveHeightFading *self = (PrimitiveHeightFading *)data;
+    
+    self->black_color = PyObject_GetAttrString(support, "black_color");
+    self->white_color = PyObject_GetAttrString(support, "white_color");
+    
+    return 0;
+}
+
+static void
+height_fading_finish(void *data, RenderState *state) {
+    PrimitiveHeightFading *self = (PrimitiveHeightFading *)data;
+
+    Py_DECREF(self->black_color);
+    Py_DECREF(self->white_color);
+}
+
+static void
+height_fading_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    PrimitiveHeightFading *self = (PrimitiveHeightFading *)data;
+
+    /* do some height fading */
+    PyObject *height_color = self->white_color;
+
+    /* negative alpha => darkness, positive => light */
+    float alpha = (1.0 / (1 + expf((70 - state->z) / 11.0))) * 0.6 - 0.55;
+    
+    if (alpha < 0.0) {
+        alpha *= -1;
+        height_color = self->black_color;
+    }
+    
+    alpha_over_full(state->img, height_color, mask_light, alpha, state->imgx, state->imgy, 0, 0);
+}
+
+RenderPrimitiveInterface primitive_height_fading = {
+    "height-fading", sizeof(PrimitiveHeightFading),
+    height_fading_start,
+    height_fading_finish,
+    NULL,
+    NULL,
+    height_fading_draw,
+};
diff --git a/overviewer_core/src/rendermode-lighting.c b/overviewer_core/src/primitives/lighting.c
similarity index 83%
rename from overviewer_core/src/rendermode-lighting.c
rename to overviewer_core/src/primitives/lighting.c
index a6eca00..1eea2be 100644
--- a/overviewer_core/src/rendermode-lighting.c
+++ b/overviewer_core/src/primitives/lighting.c
@@ -15,7 +15,8 @@
  * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "overviewer.h"
+#include "../overviewer.h"
+#include "lighting.h"
 #include <math.h>
 
 /* figures out the color from a given skylight and blocklight,
@@ -35,7 +36,7 @@ static void
 calculate_light_color_fancy(void *data,
                             unsigned char skylight, unsigned char blocklight,
                             unsigned char *r, unsigned char *g, unsigned char *b) {
-    RenderModeLighting *mode = (RenderModeLighting *)(data);
+    RenderPrimitiveLighting *mode = (RenderPrimitiveLighting *)(data);
     unsigned int index;
     PyObject *color;
     
@@ -70,7 +71,7 @@ static void
 calculate_light_color_fancy_night(void *data,
                                   unsigned char skylight, unsigned char blocklight,
                                   unsigned char *r, unsigned char *g, unsigned char *b) {
-    RenderModeLighting *mode = (RenderModeLighting *)(data);
+    RenderPrimitiveLighting *mode = (RenderPrimitiveLighting *)(data);
     unsigned int index;
     PyObject *color;
     
@@ -95,7 +96,7 @@ calculate_light_color_fancy_night(void *data,
  */
 
 inline unsigned char
-estimate_blocklevel(RenderModeLighting *self, RenderState *state,
+estimate_blocklevel(RenderPrimitiveLighting *self, RenderState *state,
                          int x, int y, int z, int *authoratative) {
 
     /* placeholders for later data arrays, coordinates */
@@ -185,7 +186,7 @@ estimate_blocklevel(RenderModeLighting *self, RenderState *state,
 }
 
 inline void
-get_lighting_color(RenderModeLighting *self, RenderState *state,
+get_lighting_color(RenderPrimitiveLighting *self, RenderState *state,
                    int x, int y, int z,
                    unsigned char *r, unsigned char *g, unsigned char *b) {
 
@@ -273,7 +274,10 @@ get_lighting_color(RenderModeLighting *self, RenderState *state,
     
     if (block == 10 || block == 11) {
         /* lava blocks should always be lit! */
-        return 0.0f;
+        *r = 255;
+        *g = 255;
+        *b = 255;
+        return;
     }
     
     self->calculate_light_color(self, MIN(skylevel, 15), MIN(blocklevel, 15), r, g, b);
@@ -281,7 +285,7 @@ get_lighting_color(RenderModeLighting *self, RenderState *state,
 
 /* does per-face occlusion checking for do_shading_with_mask */
 inline int
-rendermode_lighting_is_face_occluded(RenderState *state, int skip_sides, int x, int y, int z) {
+lighting_is_face_occluded(RenderState *state, int skip_sides, int x, int y, int z) {
     /* first, check for occlusion if the block is in the local chunk */
     if (x >= 0 && x < 16 && y >= 0 && y < 16 && z >= 0 && z < 128) {
         unsigned char block = getArrayByte3D(state->blocks, x, y, z);
@@ -315,52 +319,41 @@ rendermode_lighting_is_face_occluded(RenderState *state, int skip_sides, int x,
 /* shades the drawn block with the given facemask, based on the
    lighting results from (x, y, z) */
 static inline void
-do_shading_with_mask(RenderModeLighting *self, RenderState *state,
+do_shading_with_mask(RenderPrimitiveLighting *self, RenderState *state,
                      int x, int y, int z, PyObject *mask) {
     unsigned char r, g, b;
-    float comp_shade_strength;
+    float comp_strength;
     
     /* check occlusion */
-    if (rendermode_lighting_is_face_occluded(state, self->skip_sides, x, y, z))
+    if (lighting_is_face_occluded(state, self->skip_sides, x, y, z))
         return;
     
     get_lighting_color(self, state, x, y, z, &r, &g, &b);
-    comp_shade_strength = 1.0 - self->shade_strength;
+    comp_strength = 1.0 - self->strength;
     
-    r += (255 - r) * comp_shade_strength;
-    g += (255 - g) * comp_shade_strength;
-    b += (255 - b) * comp_shade_strength;
+    r += (255 - r) * comp_strength;
+    g += (255 - g) * comp_strength;
+    b += (255 - b) * comp_strength;
     
     tint_with_mask(state->img, r, g, b, 255, mask, state->imgx, state->imgy, 0, 0);
 }
 
 static int
-rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
-    RenderModeLighting* self;
-
-    /* first, chain up */
-    int ret = rendermode_normal.start(data, state, options);
-    if (ret != 0)
-        return ret;
+lighting_start(void *data, RenderState *state, PyObject *support) {
+    RenderPrimitiveLighting* self;
+    self = (RenderPrimitiveLighting *)data;
     
-    self = (RenderModeLighting *)data;
-    
-    /* skip sides by default */
-    self->skip_sides = 1;
+    /* don't skip sides by default */
+    self->skip_sides = 0;
 
-    self->shade_strength = 1.0;
-    if (!render_mode_parse_option(options, "shade_strength", "f", &(self->shade_strength)))
+    if (!render_mode_parse_option(support, "strength", "f", &(self->strength)))
         return 1;
-
-    self->night = 0;
-    if (!render_mode_parse_option(options, "night", "i", &(self->night)))
+    if (!render_mode_parse_option(support, "night", "i", &(self->night)))
         return 1;
-
-    self->color_light = 0;
-    if (!render_mode_parse_option(options, "color_light", "i", &(self->color_light)))
+    if (!render_mode_parse_option(support, "color", "i", &(self->color)))
         return 1;
     
-    self->facemasks_py = PyObject_GetAttrString(state->support, "facemasks");
+    self->facemasks_py = PyObject_GetAttrString(support, "facemasks");
     // borrowed references, don't need to be decref'd
     self->facemasks[0] = PyTuple_GetItem(self->facemasks_py, 0);
     self->facemasks[1] = PyTuple_GetItem(self->facemasks_py, 1);
@@ -383,12 +376,12 @@ rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
         self->calculate_light_color = calculate_light_color;
     }
     
-    if (self->color_light) {
-        self->lightcolor = PyObject_CallMethod(state->textures, "loadLightColor", "");
+    if (self->color) {
+        self->lightcolor = PyObject_CallMethod(state->textures, "load_light_color", "");
         if (self->lightcolor == Py_None) {
             Py_DECREF(self->lightcolor);
             self->lightcolor = NULL;
-            self->color_light = 0;
+            self->color = 0;
         } else {
             if (self->night) {
                 self->calculate_light_color = calculate_light_color_fancy_night;
@@ -404,8 +397,8 @@ rendermode_lighting_start(void *data, RenderState *state, PyObject *options) {
 }
 
 static void
-rendermode_lighting_finish(void *data, RenderState *state) {
-    RenderModeLighting *self = (RenderModeLighting *)data;
+lighting_finish(void *data, RenderState *state) {
+    RenderPrimitiveLighting *self = (RenderPrimitiveLighting *)data;
     
     Py_DECREF(self->facemasks_py);
     
@@ -419,32 +412,14 @@ rendermode_lighting_finish(void *data, RenderState *state) {
     Py_DECREF(self->up_left_blocklight);
     Py_DECREF(self->up_right_skylight);
     Py_DECREF(self->up_right_blocklight);
-    
-    /* now chain up */
-    rendermode_normal.finish(data, state);
-}
-
-static int
-rendermode_lighting_occluded(void *data, RenderState *state, int x, int y, int z) {
-    /* no special occlusion here */
-    return rendermode_normal.occluded(data, state, x, y, z);
-}
-
-static int
-rendermode_lighting_hidden(void *data, RenderState *state, int x, int y, int z) {
-    /* no special hiding here */
-    return rendermode_normal.hidden(data, state, x, y, z);
 }
 
 static void
-rendermode_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
-    RenderModeLighting* self;
+lighting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+    RenderPrimitiveLighting* self;
     int x, y, z;
 
-    /* first, chain up */
-    rendermode_normal.draw(data, state, src, mask, mask_light);
-    
-    self = (RenderModeLighting *)data;
+    self = (RenderPrimitiveLighting *)data;
     x = state->x, y = state->y, z = state->z;
     
     if ((state->block == 9) || (state->block == 79)) { /* special case for water and ice */
@@ -473,22 +448,11 @@ rendermode_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject
     }
 }
 
-const RenderModeOption rendermode_lighting_options[] = {
-    {"shade_strength", "how dark to make the shadows, from 0.0 to 1.0 (default: 1.0)"},
-    {"night", "whether to use nighttime skylight settings (default: False)"},
-    {"color_light", "whether to use colored light (default: False)"},
-    {NULL, NULL}
-};
-
-RenderModeInterface rendermode_lighting = {
-    "lighting", "Lighting",
-    "draw shadows from the lighting data",
-    rendermode_lighting_options,
-    &rendermode_normal,
-    sizeof(RenderModeLighting),
-    rendermode_lighting_start,
-    rendermode_lighting_finish,
-    rendermode_lighting_occluded,
-    rendermode_lighting_hidden,
-    rendermode_lighting_draw,
+RenderPrimitiveInterface primitive_lighting = {
+    "lighting", sizeof(RenderPrimitiveLighting),
+    lighting_start,
+    lighting_finish,
+    NULL,
+    NULL,
+    lighting_draw,
 };
diff --git a/overviewer_core/src/primitives/lighting.h b/overviewer_core/src/primitives/lighting.h
new file mode 100644
index 0000000..0742167
--- /dev/null
+++ b/overviewer_core/src/primitives/lighting.h
@@ -0,0 +1,53 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+
+typedef struct {
+    PyObject *facemasks_py;
+    PyObject *facemasks[3];
+    
+    /* extra data, loaded off the chunk class */
+    PyObject *skylight, *blocklight;
+    PyObject *left_skylight, *left_blocklight;
+    PyObject *right_skylight, *right_blocklight;
+    PyObject *up_left_skylight, *up_left_blocklight;
+    PyObject *up_right_skylight, *up_right_blocklight;
+    
+    /* light color image, loaded if color_light is True */
+    PyObject *lightcolor;
+    
+    /* can be overridden in derived rendermodes to control lighting
+       arguments are data, skylight, blocklight, return RGB */
+    void (*calculate_light_color)(void *, unsigned char, unsigned char, unsigned char *, unsigned char *, unsigned char *);
+    
+    /* can be set to 0 in derived modes to indicate that lighting the chunk
+     * sides is actually important. Right now, this is used in cave mode
+     */
+    int skip_sides;
+    
+    float strength;
+    int color;
+    int night;
+} RenderPrimitiveLighting;
+
+/* exposed so that smooth-lighting can use them */
+extern RenderPrimitiveInterface primitive_lighting;
+int lighting_is_face_occluded(RenderState *state, int skip_sides, int x, int y, int z);
+void get_lighting_color(RenderPrimitiveLighting *self, RenderState *state,
+                        int x, int y, int z,
+                        unsigned char *r, unsigned char *g, unsigned char *b);
diff --git a/overviewer_core/src/primitives/nether.c b/overviewer_core/src/primitives/nether.c
new file mode 100644
index 0000000..3844d1c
--- /dev/null
+++ b/overviewer_core/src/primitives/nether.c
@@ -0,0 +1,42 @@
+/* 
+ * This file is part of the Minecraft Overviewer.
+ *
+ * Minecraft Overviewer is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Minecraft Overviewer is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General
+ * Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../overviewer.h"
+
+static int
+nether_hidden(void *data, RenderState *state, int x, int y, int z) {
+    /* hide all blocks above all air blocks */
+    while (z < 128)
+    {
+        if (getArrayByte3D(state->blocks, x, y, z) == 0)
+        {
+            return 0;
+            break;
+        }
+        z++;
+    }
+    return 1;
+}
+
+RenderPrimitiveInterface primitive_nether = {
+    "nether", 0,
+    NULL,
+    NULL,
+    NULL,
+    nether_hidden,
+    NULL,
+};
diff --git a/overviewer_core/src/rendermode-smooth-lighting.c b/overviewer_core/src/primitives/smooth-lighting.c
similarity index 79%
rename from overviewer_core/src/rendermode-smooth-lighting.c
rename to overviewer_core/src/primitives/smooth-lighting.c
index 28767ea..6036a52 100644
--- a/overviewer_core/src/rendermode-smooth-lighting.c
+++ b/overviewer_core/src/primitives/smooth-lighting.c
@@ -15,9 +15,15 @@
  * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "overviewer.h"
+#include "../overviewer.h"
+#include "lighting.h"
 #include <math.h>
 
+typedef struct {
+    /* inherits from lighting */
+    RenderPrimitiveLighting parent;
+} RenderPrimitiveSmoothLighting;
+
 /* structure representing one corner of a face (see below) */
 struct SmoothLightingCorner {
     /* where this corner shows up on each block texture */
@@ -123,12 +129,12 @@ enum
 };
 
 static void
-do_shading_with_rule(RenderModeSmoothLighting *self, RenderState *state, struct SmoothLightingFace face) {
+do_shading_with_rule(RenderPrimitiveSmoothLighting *self, RenderState *state, struct SmoothLightingFace face) {
     int i;
-    RenderModeLighting *lighting = (RenderModeLighting *)self;
+    RenderPrimitiveLighting *lighting = (RenderPrimitiveLighting *)self;
     int x = state->imgx, y = state->imgy;
     struct SmoothLightingCorner *pts = face.corners;
-    float comp_shade_strength = 1.0 - lighting->shade_strength;
+    float comp_shade_strength = 1.0 - lighting->strength;
     unsigned char pts_r[4] = {0, 0, 0, 0};
     unsigned char pts_g[4] = {0, 0, 0, 0};
     unsigned char pts_b[4] = {0, 0, 0, 0};
@@ -137,7 +143,7 @@ do_shading_with_rule(RenderModeSmoothLighting *self, RenderState *state, struct
     int cz = state->z + face.dz;
     
     /* first, check for occlusion if the block is in the local chunk */
-    if (rendermode_lighting_is_face_occluded(state, 0, cx, cy, cz))
+    if (lighting_is_face_occluded(state, 0, cx, cy, cz))
         return;
     
     /* calculate the lighting colors for each point */
@@ -189,55 +195,38 @@ do_shading_with_rule(RenderModeSmoothLighting *self, RenderState *state, struct
 }
 
 static int
-rendermode_smooth_lighting_start(void *data, RenderState *state, PyObject *options) {
+smooth_lighting_start(void *data, RenderState *state, PyObject *support) {
     /* first, chain up */
-    int ret = rendermode_lighting.start(data, state, options);
+    int ret = primitive_lighting.start(data, state, support);
     if (ret != 0)
-        return ret;
-    
+        return ret;    
     return 0;
 }
 
 static void
-rendermode_smooth_lighting_finish(void *data, RenderState *state) {
+smooth_lighting_finish(void *data, RenderState *state) {
     /* nothing special to do */
-    rendermode_lighting.finish(data, state);
-}
-
-static int
-rendermode_smooth_lighting_occluded(void *data, RenderState *state, int x, int y, int z) {
-    /* no special occlusion here */
-    return rendermode_lighting.occluded(data, state, x, y, z);
-}
-
-static int
-rendermode_smooth_lighting_hidden(void *data, RenderState *state, int x, int y, int z) {
-    /* no special hiding here */
-    return rendermode_lighting.hidden(data, state, x, y, z);
+    primitive_lighting.finish(data, state);
 }
 
 static void
-rendermode_smooth_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
+smooth_lighting_draw(void *data, RenderState *state, PyObject *src, PyObject *mask, PyObject *mask_light) {
     int light_top = 1;
     int light_left = 1;
     int light_right = 1;
-    RenderModeSmoothLighting *self = (RenderModeSmoothLighting *)data;
+    RenderPrimitiveSmoothLighting *self = (RenderPrimitiveSmoothLighting *)data;
     
     /* special case for leaves, water 8, water 9
        -- these are also smooth-lit! */
     if (state->block != 18 && state->block != 8 && state->block != 9 && is_transparent(state->block))
     {
         /* transparent blocks are rendered as usual, with flat lighting */
-        rendermode_lighting.draw(data, state, src, mask, mask_light);
+        primitive_lighting.draw(data, state, src, mask, mask_light);
         return;
     }
     
     /* non-transparent blocks get the special smooth treatment */
     
-    /* nothing special to do, but we do want to avoid vanilla
-     * lighting mode draws */
-    rendermode_normal.draw(data, state, src, mask, mask_light);
-    
     /* special code for water */
     if (state->block == 9)
     {
@@ -257,15 +246,11 @@ rendermode_smooth_lighting_draw(void *data, RenderState *state, PyObject *src, P
         do_shading_with_rule(self, state, lighting_rules[FACE_RIGHT]);
 }
 
-RenderModeInterface rendermode_smooth_lighting = {
-    "smooth-lighting", "Smooth Lighting",
-    "like \"lighting\", except smooth",
+RenderPrimitiveInterface primitive_smooth_lighting = {
+    "smooth-lighting", sizeof(RenderPrimitiveSmoothLighting),
+    smooth_lighting_start,
+    smooth_lighting_finish,
     NULL,
-    &rendermode_lighting,
-    sizeof(RenderModeSmoothLighting),
-    rendermode_smooth_lighting_start,
-    rendermode_smooth_lighting_finish,
-    rendermode_smooth_lighting_occluded,
-    rendermode_smooth_lighting_hidden,
-    rendermode_smooth_lighting_draw,
+    NULL,
+    smooth_lighting_draw,
 };
diff --git a/overviewer_core/src/rendermodes.c b/overviewer_core/src/rendermodes.c
index 545aad2..6ff99de 100644
--- a/overviewer_core/src/rendermodes.c
+++ b/overviewer_core/src/rendermodes.c
@@ -19,175 +19,174 @@
 #include <string.h>
 #include <stdarg.h>
 
-/* list of all render modes, ending in NULL
-   all of these will be available to the user, so DON'T include modes
-   that are only useful as a base for other modes. */
-static RenderModeInterface *render_modes[] = {
-    &rendermode_normal,
-    &rendermode_lighting,
-    &rendermode_smooth_lighting,
-    &rendermode_cave,
-    
-    &rendermode_spawn,
-    &rendermode_mineral,
-    NULL
-};
-
-PyObject *render_mode_options = NULL;
-PyObject *custom_render_modes = NULL;
+/* this file defines render_primitives,
+   a list of all render primitives, ending in NULL
+   all of these will be available to the user, so DON'T include primitives
+   that are only useful as a base for other primitives.
+   
+   this file is auto-generated by setup.py */
+#include "primitives.h"
 
 /* rendermode encapsulation */
 
-/* helper to recursively find options for a given mode */
-static inline PyObject *
-render_mode_create_options(const char *mode) {
-    const char *parent = NULL;
-    PyObject *base_options, *ret, *parent_options;
-    unsigned int i, found_concrete;
+/* helper to create a single primitive */
+RenderPrimitive *render_primitive_create(PyObject *prim, RenderState *state) {
+    RenderPrimitive *ret = NULL;
+    RenderPrimitiveInterface *iface = NULL;
+    unsigned int i;
+    PyObject *pyname;
+    const char* name;
+
+    pyname = PyObject_GetAttrString(prim, "name");
+    if (!pyname)
+        return NULL;
+    name = PyString_AsString(pyname);
     
-    base_options = PyDict_GetItemString(render_mode_options, mode);
-    if (base_options) {
-        ret = PyDict_Copy(base_options);
-    } else {
-        ret = PyDict_New();
-    }
-    
-    /* figure out the parent mode name */
-    found_concrete = 0;
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (strcmp(render_modes[i]->name, mode) == 0) {
-            found_concrete = 1;
-            if (render_modes[i]->parent) {
-                parent = render_modes[i]->parent->name;
-            }
+    for (i = 0; render_primitives[i] != NULL; i++) {
+        if (strcmp(render_primitives[i]->name, name) == 0) {
+            iface = render_primitives[i];
             break;
         }
     }
+    Py_DECREF(pyname);
+
+    if (iface == NULL)
+        return (RenderPrimitive *)PyErr_Format(PyExc_RuntimeError, "invalid primitive name: %s", name);
     
-    /* check custom mode info if needed */
-    if (found_concrete == 0) {
-        PyObject *custom = PyDict_GetItemString(custom_render_modes, mode);
-        if (custom) {
-            custom = PyDict_GetItemString(custom, "parent");
-            if (custom) {
-                parent = PyString_AsString(custom);
-            }
+    ret = calloc(1, sizeof(RenderPrimitive));
+    if (ret == NULL) {
+        return (RenderPrimitive *)PyErr_Format(PyExc_RuntimeError, "Failed to alloc a render primitive");
+    }
+    
+    if (iface->data_size > 0) {
+        ret->primitive = calloc(1, iface->data_size);
+        if (ret->primitive == NULL) {
+            free(ret);
+            return (RenderPrimitive *)PyErr_Format(PyExc_RuntimeError, "Failed to alloc render primitive data");
         }
     }
     
-    /* merge parent options, if the parent was found */
-    if (parent) {
-        parent_options = render_mode_create_options(parent);
-        if (parent_options) {
-            if (PyDict_Merge(ret, parent_options, 0) == -1) {
-                Py_DECREF(ret);
-                Py_DECREF(parent_options);
-                return NULL;
-            }
-            Py_DECREF(parent_options);
+    ret->iface = iface;
+    
+    if (iface->start) {
+        if (iface->start(ret->primitive, state, prim)) {
+            free(ret->primitive);
+            free(ret);
+            return NULL;
         }
     }
     
     return ret;
 }
 
-/* helper to find the first concrete, C interface for a given mode */
-inline static RenderModeInterface *
-render_mode_find_interface(const char *mode) {
-    PyObject *custom;
-    const char *custom_parent;
+RenderMode *render_mode_create(PyObject *mode, RenderState *state) {
+    RenderMode *ret = NULL;
+    PyObject *mode_fast = NULL;
     unsigned int i;
     
-    /* if it is *itself* concrete, we're done */
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (strcmp(render_modes[i]->name, mode) == 0)
-            return render_modes[i];
-    }
-    
-    /* check for custom modes */
-    custom = PyDict_GetItemString(custom_render_modes, mode);
-    if (custom == NULL)
-        return PyErr_Format(PyExc_RuntimeError, "Failed to find rendermode interface (custom not found)");
-    custom = PyDict_GetItemString(custom, "parent");
-    if (custom == NULL)
-        return PyErr_Format(PyExc_RuntimeError, "Failed to find rendermode interface (parent not found)");
-    custom_parent = PyString_AsString(custom);
-    if (custom_parent == NULL)
-        return NULL; // PyString_AsString sets an exception
-    
-    return render_mode_find_interface(custom_parent);
-}
+    mode_fast = PySequence_Fast(mode, "Mode is not a sequence type");
+    if (!mode_fast)
+        return NULL;
 
-RenderMode *render_mode_create(const char *mode, RenderState *state) {
-    PyObject *options;
-    RenderMode *ret = NULL;
-    RenderModeInterface *iface = NULL;
-    
-    iface = render_mode_find_interface(mode);
-    if (iface == NULL)
-        return NULL;
-    
-    options = render_mode_create_options(mode);
-    if (options == NULL)
-        return NULL;
-    
     ret = calloc(1, sizeof(RenderMode));
-    if (ret == NULL) {
-        Py_DECREF(options);
-        return PyErr_Format(PyExc_RuntimeError, "Failed to alloc a rendermode");
-    }
-    
-    ret->mode = calloc(1, iface->data_size);
-    if (ret->mode == NULL) {
-        Py_DECREF(options);
-        free(ret);
-        return PyErr_Format(PyExc_RuntimeError, "Failed to alloc rendermode data");
-    }
-    
-    ret->iface = iface;
     ret->state = state;
-    
-    if (iface->start(ret->mode, state, options)) {
-        Py_DECREF(options);
-        free(ret->mode);
-        free(ret);
-        return NULL;
+    ret->num_primitives = PySequence_Length(mode);
+    ret->primitives = calloc(ret->num_primitives, sizeof(RenderPrimitive*));
+    for (i = 0; i < ret->num_primitives; i++) {
+        PyObject *pyprim = PySequence_Fast_GET_ITEM(mode_fast, i);
+        RenderPrimitive *prim = render_primitive_create(pyprim, state);
+        
+        if (!prim) {
+            render_mode_destroy(ret);
+            Py_DECREF(mode_fast);
+            return NULL;
+        }
+        
+        ret->primitives[i] = prim;
     }
     
-    Py_DECREF(options);
     return ret;
 }
 
 void render_mode_destroy(RenderMode *self) {
-    self->iface->finish(self->mode, self->state);
-    free(self->mode);
+    unsigned int i;
+    
+    for (i = 0; i < self->num_primitives; i++) {
+        RenderPrimitive *prim = self->primitives[i];
+        /* we may be destroying a half-constructed mode, so we need this
+           check */
+        if (prim) {
+            if (prim->iface->finish) {
+                prim->iface->finish(prim->primitive, self->state);
+            }
+            if (prim->primitive) {
+                free(prim->primitive);
+            }
+            free(prim);
+        }
+    }
+    free(self->primitives);
     free(self);
 }
 
 int render_mode_occluded(RenderMode *self, int x, int y, int z) {
-    return self->iface->occluded(self->mode, self->state, x, y, z);
+    unsigned int i;
+    int occluded = 0;
+    for (i = 0; i < self->num_primitives; i++) {
+        RenderPrimitive *prim = self->primitives[i];
+        if (prim->iface->occluded) {
+            occluded |= prim->iface->occluded(prim->primitive, self->state, x, y, z);
+        }
+        
+        if (occluded)
+            return occluded;
+    }
+    return occluded;
 }
 
 int render_mode_hidden(RenderMode *self, int x, int y, int z) {
-    return self->iface->hidden(self->mode, self->state, x, y, z);
+    unsigned int i;
+    int hidden = 0;
+    for (i = 0; i < self->num_primitives; i++) {
+        RenderPrimitive *prim = self->primitives[i];
+        if (prim->iface->hidden) {
+            hidden |= prim->iface->hidden(prim->primitive, self->state, x, y, z);
+        }
+        
+        if (hidden)
+            return hidden;
+    }
+    return hidden;
 }
 
 void render_mode_draw(RenderMode *self, PyObject *img, PyObject *mask, PyObject *mask_light) {
-    self->iface->draw(self->mode, self->state, img, mask, mask_light);
+    unsigned int i;
+    for (i = 0; i < self->num_primitives; i++) {
+        RenderPrimitive *prim = self->primitives[i];
+        if (prim->iface->draw) {
+            prim->iface->draw(prim->primitive, self->state, img, mask, mask_light);
+        }
+    }
 }
 
 /* options parse helper */
-int render_mode_parse_option(PyObject *dict, const char *name, const char *format, ...) {
+int render_mode_parse_option(PyObject *support, const char *name, const char *format, ...) {
     va_list ap;
-    PyObject *item;
+    PyObject *item, *dict;
     int ret;
     
-    if (dict == NULL || name == NULL)
-        return 1;
+    if (support == NULL || name == NULL)
+        return 0;
+    
+    dict = PyObject_GetAttrString(support, "option_values");
+    if (!dict)
+        return 0;
     
     item = PyDict_GetItemString(dict, name);
-    if (item == NULL)
-        return 1;
+    if (item == NULL) {
+        Py_DECREF(dict);
+        return 0;
+    };
     
     /* make sure the item we're parsing is a tuple
        for VaParse to work correctly */
@@ -202,6 +201,7 @@ int render_mode_parse_option(PyObject *dict, const char *name, const char *forma
     va_end(ap);
     
     Py_DECREF(item);
+    Py_DECREF(dict);
     
     if (!ret) {
         PyObject *errtype, *errvalue, *errtraceback;
@@ -219,330 +219,3 @@ int render_mode_parse_option(PyObject *dict, const char *name, const char *forma
     
     return ret;
 }
-
-/* bindings for python -- get all the rendermode names */
-PyObject *get_render_modes(PyObject *self, PyObject *args) {
-    PyObject *modes;
-    unsigned int i;
-    PyObject *key, *value;
-    Py_ssize_t pos = 0;
-
-    if (!PyArg_ParseTuple(args, ""))
-        return NULL;
-    
-    modes = PyList_New(0);
-    if (modes == NULL)
-        return NULL;
-    
-    for (i = 0; render_modes[i] != NULL; i++) {
-        PyObject *name = PyString_FromString(render_modes[i]->name);
-        PyList_Append(modes, name);
-        Py_DECREF(name);
-    }
-    
-    
-    while (PyDict_Next(custom_render_modes, &pos, &key, &value)) {
-        PyList_Append(modes, key);
-    }
-    
-    return modes;
-}
-
-/* helper, get the list of options for a render mode */
-static inline PyObject *
-get_render_mode_options(const char *rendermode)
-{
-    PyObject *options;
-    unsigned int i, j;
-    
-    options = PyList_New(0);
-    if (!options)
-        return NULL;
-    
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (strcmp(render_modes[i]->name, rendermode) == 0) {
-            if (render_modes[i]->options == NULL)
-                break;
-            
-            for (j = 0; render_modes[i]->options[j].name != NULL; j++) {
-                RenderModeOption opt = render_modes[i]->options[j];
-                PyObject *name = PyString_FromString(opt.name);
-                PyObject *description = PyString_FromString(opt.description);
-                PyObject *option = PyDict_New();
-                if (!name || !description || !option) {
-                    Py_XDECREF(name);
-                    Py_XDECREF(description);
-                    Py_XDECREF(option);
-                    Py_DECREF(options);
-                    return NULL;
-                }
-                
-                PyDict_SetItemString(option, "name", name);
-                PyDict_SetItemString(option, "description", description);
-                PyList_Append(options, option);
-                Py_DECREF(name);
-                Py_DECREF(description);
-                Py_DECREF(option);
-            }
-            break;
-        }
-    }
-    
-    return options;
-}
-
-/* more bindings -- return info for a given rendermode name */
-PyObject *get_render_mode_info(PyObject *self, PyObject *args) {
-    const char* rendermode;
-    PyObject *info;
-    unsigned int i;
-    PyObject *custom;
-
-    if (!PyArg_ParseTuple(args, "s", &rendermode))
-        return NULL;
-    
-    info = PyDict_New();
-    if (info == NULL)
-        return NULL;
-    
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (strcmp(render_modes[i]->name, rendermode) == 0) {
-            PyObject *tmp;
-            
-            tmp = PyString_FromString(render_modes[i]->name);
-            PyDict_SetItemString(info, "name", tmp);
-            Py_DECREF(tmp);
-            
-            tmp = PyString_FromString(render_modes[i]->label);
-            PyDict_SetItemString(info, "label", tmp);
-            Py_DECREF(tmp);
-            
-            tmp = PyString_FromString(render_modes[i]->description);
-            PyDict_SetItemString(info, "description", tmp);
-            Py_DECREF(tmp);
-            
-            tmp = get_render_mode_options(rendermode);
-            PyDict_SetItemString(info, "options", tmp);
-            Py_DECREF(tmp);
-            
-            if (render_modes[i]->parent != NULL) {
-                tmp = PyString_FromString(render_modes[i]->parent->name);
-                PyDict_SetItemString(info, "parent", tmp);
-                Py_DECREF(tmp);
-            }
-            
-            return info;
-        }
-    }
-    
-    custom = PyDict_GetItemString(custom_render_modes, rendermode);
-    if (custom) {
-        PyObject *tmp, *copy = PyDict_Copy(custom);
-        Py_DECREF(info);
-        
-        tmp = PyString_FromString(rendermode);
-        PyDict_SetItemString(copy, "name", tmp);
-        Py_DECREF(tmp);
-        
-        tmp = PyList_New(0);
-        PyDict_SetItemString(copy, "options", tmp);
-        Py_DECREF(tmp);
-        
-        return copy;
-    }
-    
-    Py_DECREF(info);
-    return PyErr_Format(PyExc_ValueError, "invalid rendermode: \"%s\"", rendermode);
-}
-
-/* bindings -- get list of inherited parents */
-PyObject *get_render_mode_inheritance(PyObject *self, PyObject *args) {
-    const char *rendermode;
-    PyObject *parents;
-    unsigned int i;
-    RenderModeInterface *iface = NULL;
-    PyObject *custom;
-    
-    if (!PyArg_ParseTuple(args, "s", &rendermode))
-        return NULL;
-    
-    parents = PyList_New(0);
-    if (!parents)
-        return NULL;
-    
-    /* take care of the chain of custom modes, if there are any */
-    custom = PyDict_GetItemString(custom_render_modes, rendermode);
-    while (custom != NULL) {
-        PyObject *name = PyString_FromString(rendermode);
-        PyList_Append(parents, name);
-        Py_DECREF(name);
-        
-        custom = PyDict_GetItemString(custom, "parent");
-        rendermode = PyString_AsString(custom);
-        custom = PyDict_GetItem(custom_render_modes, custom);
-    }
-    
-    /* now handle concrete modes */
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (strcmp(render_modes[i]->name, rendermode) == 0) {
-            iface = render_modes[i];
-            break;
-        }
-    }
-    
-    if (!iface) {
-        Py_DECREF(parents);
-        return PyErr_Format(PyExc_ValueError, "invalid rendermode: \"%s\"", rendermode);
-    }
-    
-    while (iface) {
-        PyObject *name = PyString_FromString(iface->name);
-        PyList_Append(parents, name);
-        Py_DECREF(name);
-        
-        iface = iface->parent;
-    }
-    
-    PyList_Reverse(parents);
-    return parents;
-}
-
-/* bindings -- get list of (direct) children */
-PyObject *get_render_mode_children(PyObject *self, PyObject *args) {
-    const char *rendermode;
-    PyObject *children;
-    unsigned int i;
-    PyObject *key, *value;
-    Py_ssize_t pos = 0;
-
-    if (!PyArg_ParseTuple(args, "s", &rendermode))
-        return NULL;
-    
-    children = PyList_New(0);
-    if (!children)
-        return NULL;
-    
-    for (i = 0; render_modes[i] != NULL; i++) {
-        if (render_modes[i]->parent && strcmp(render_modes[i]->parent->name, rendermode) == 0) {
-            PyObject *child_name = PyString_FromString(render_modes[i]->name);
-            PyList_Append(children, child_name);
-            Py_DECREF(child_name);
-        }
-    }
-    
-    
-    while (PyDict_Next(custom_render_modes, &pos, &key, &value)) {
-        PyObject *pyparent = PyDict_GetItemString(value, "parent");
-        const char *parent = PyString_AsString(pyparent);
-        
-        if (strcmp(parent, rendermode) == 0) {
-            PyList_Append(children, key);
-        }
-    }
-    
-    return children;
-}
-
-/* helper to decide if a rendermode supports a given option */
-static inline int
-render_mode_supports_option(RenderModeInterface *iface, const char *name) {
-    unsigned int i;
-    
-    if (iface->options != NULL) {
-        for (i = 0; iface->options[i].name != NULL; i++) {
-            if (strcmp(iface->options[i].name, name) == 0) {
-                return 1;
-            }
-        }
-    }
-    
-    if (iface->parent != NULL)
-        return render_mode_supports_option(iface->parent, name);
-    
-    return 0;
-}
-
-/* python rendermode options bindings */
-PyObject *set_render_mode_options(PyObject *self, PyObject *args) {
-    const char *rendermode;
-    PyObject *opts, *key, *value;
-    Py_ssize_t pos = 0;
-    RenderModeInterface *iface = NULL;
-    if (!PyArg_ParseTuple(args, "sO!", &rendermode, &PyDict_Type, &opts))
-        return NULL;
-    
-    iface = render_mode_find_interface(rendermode);
-    
-    if (iface == NULL) {
-        return PyErr_Format(PyExc_ValueError, "'%s' is not a valid rendermode name", rendermode);
-    }
-    
-    /* check options to make sure they're available */
-    while (PyDict_Next(opts, &pos, &key, &value)) {
-        const char *name = PyString_AsString(key);
-        if (name == NULL)
-            return NULL;
-        
-        if (!render_mode_supports_option(iface, name)) {
-            return PyErr_Format(PyExc_ValueError, "'%s' is not a valid option for rendermode '%s'", name, rendermode);
-        }
-    }
-    
-    PyDict_SetItemString(render_mode_options, rendermode, opts);
-    Py_RETURN_NONE;
-}
-
-PyObject *add_custom_render_mode(PyObject *self, PyObject *args) {
-    const char *rendermode, *parentmode;
-    PyObject *opts, *options, *pyparent;
-    if (!PyArg_ParseTuple(args, "sO!", &rendermode, &PyDict_Type, &opts))
-        return NULL;
-
-    /* first, make sure the parent is set correctly */
-    pyparent = PyDict_GetItemString(opts, "parent");
-    if (pyparent == NULL)
-        return PyErr_Format(PyExc_ValueError, "'%s' does not have a parent mode", rendermode);
-    parentmode = PyString_AsString(pyparent);
-    if (parentmode == NULL)
-        return PyErr_Format(PyExc_ValueError, "'%s' does not have a valid parent", rendermode);
-    
-    /* check that parentmode exists */
-    if (PyDict_GetItemString(custom_render_modes, parentmode) == NULL) {
-        unsigned int parent_valid = 0, i;
-        for (i = 0; render_modes[i] != NULL; i++) {
-            if (strcmp(render_modes[i]->name, parentmode) == 0) {
-                parent_valid = 1;
-            }
-        }
-        
-        if (parent_valid == 0)
-            return PyErr_Format(PyExc_ValueError, "'%s' parent '%s' is not valid", rendermode, parentmode);
-    }
-    
-    /* remove and handle options seperately, if needed */
-    options = PyDict_GetItemString(opts, "options");
-    if (options != NULL) {
-        PyObject *opts_copy, *set_opts_args;
-        
-        opts_copy = PyDict_Copy(opts);
-        if (opts_copy == NULL)
-            return NULL;
-        
-        PyDict_DelItemString(opts_copy, "options");
-        PyDict_SetItemString(custom_render_modes, rendermode, opts_copy);
-        Py_DECREF(opts_copy);
-
-        /* call set_render_mode_options */
-        set_opts_args = Py_BuildValue("sO", rendermode, options);
-        if (set_opts_args == NULL)
-            return NULL;
-        if (set_render_mode_options(NULL, set_opts_args) == NULL) {
-            Py_DECREF(set_opts_args);
-            return NULL;
-        }
-        Py_DECREF(set_opts_args);
-    } else {
-        PyDict_SetItemString(custom_render_modes, rendermode, opts);
-    }
-    Py_RETURN_NONE;
-}
diff --git a/overviewer_core/src/rendermodes.h b/overviewer_core/src/rendermodes.h
index 1d94df9..23df5e6 100644
--- a/overviewer_core/src/rendermodes.h
+++ b/overviewer_core/src/rendermodes.h
@@ -15,21 +15,27 @@
  * with the Overviewer.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-/*
- * To make a new render mode (the C part, at least):
+/* To make a new render primitive:
  *
- *     * add a data struct and extern'd interface declaration below
+ *  * add a new class to rendermodes.py
+ *        there are a ton of examples there, the syntax is pretty simple. If
+ *        you need any extra objects that are easy to create in python, this
+ *        is where you put them.
  *
- *     * fill in this interface struct in rendermode-(yourmode).c
- *         (see rendermodes-normal.c for an example: the "normal" mode)
+ *  * create a file in src/primitives with the same name
+ *        so, Nether (named "nether") goes in `nether.c`.
  *
- *     * if you want to derive from (say) the "normal" mode, put
- *       a RenderModeNormal entry at the top of your data struct, and
- *       be sure to call your parent's functions in your own!
- *         (see rendermode-night.c for a simple example derived from
- *          the "lighting" mode)
+ *  * declare a RenderPrimitiveInterface with the name primitive_name
+ *        if you have an underscore in the name, replace it with a
+ *        hyphen. height-fading uses primitive_height_fading.
  *
- *     * add your mode to the list in rendermodes.c
+ *  * fill in the entries of this struct
+ *        the name should match, and you should declare an 'instance' struct
+ *        to use as the self argument to each function. See nether.c and
+ *        height-fading.c for simple examples.
+ *
+ * setup.py will pick up your primitive, add it to the global list, and build
+ * it for you if you follow these conventions.
  */
 
 #ifndef __RENDERMODES_H_INCLUDED__
@@ -38,30 +44,14 @@
 #include <Python.h>
 #include "overviewer.h"
 
+/* render primitive interface */
 typedef struct {
-    const char *name;
-    const char *description;
-} RenderModeOption;
-
-/* rendermode interface */
-typedef struct _RenderModeInterface RenderModeInterface;
-struct _RenderModeInterface {
     /* the name of this mode */
-    const char *name;
-    /* the label to use in the map */
-    const char *label;
-    /* the short description of this render mode */
-    const char *description;
-    
-    /* a NULL-terminated list of render mode options, or NULL */
-    RenderModeOption *options;
-    
-    /* the rendermode this is derived from, or NULL */
-    RenderModeInterface *parent;
+    const char *name;    
     /* the size of the local storage for this rendermode */
     unsigned int data_size;
     
-    /* may return non-zero on error, last arg is options */
+    /* may return non-zero on error, last arg is the python support object */
     int (*start)(void *, RenderState *, PyObject *);
     void (*finish)(void *, RenderState *);
     /* returns non-zero to skip rendering this block because it's not visible */
@@ -71,7 +61,7 @@ struct _RenderModeInterface {
     int (*hidden)(void *, RenderState *, int, int, int);
     /* last two arguments are img and mask, from texture lookup */
     void (*draw)(void *, RenderState *, PyObject *, PyObject *, PyObject *);
-};
+} RenderPrimitiveInterface;
 
 /* A quick note about the difference between occluded and hidden:
  *
@@ -88,57 +78,32 @@ struct _RenderModeInterface {
  * example, in lighting mode it is called at most 4 times per block.
  */
 
+/* convenience wrapper for a single primitive + interface */
+typedef struct {
+    void *primitive;
+    RenderPrimitiveInterface *iface;
+} RenderPrimitive;
+
 /* wrapper for passing around rendermodes */
 struct _RenderMode {
-    void *mode;
-    RenderModeInterface *iface;
+    unsigned int num_primitives;
+    RenderPrimitive **primitives;
     RenderState *state;
 };
 
 /* functions for creating / using rendermodes */
-RenderMode *render_mode_create(const char *mode, RenderState *state);
+RenderMode *render_mode_create(PyObject *mode, RenderState *state);
 void render_mode_destroy(RenderMode *self);
 int render_mode_occluded(RenderMode *self, int x, int y, int z);
 int render_mode_hidden(RenderMode *self, int x, int y, int z);
 void render_mode_draw(RenderMode *self, PyObject *img, PyObject *mask, PyObject *mask_light);
 
 /* helper function for reading in rendermode options
-   works like PyArg_ParseTuple on a dictionary item */
-int render_mode_parse_option(PyObject *dict, const char *name, const char *format, ...);
+   works like PyArg_ParseTuple on a support object */
+int render_mode_parse_option(PyObject *support, const char *name, const char *format, ...);
 
-/* python metadata bindings */
-PyObject *get_render_modes(PyObject *self, PyObject *args);
-PyObject *get_render_mode_info(PyObject *self, PyObject *args);
-PyObject *get_render_mode_inheritance(PyObject *self, PyObject *args);
-PyObject *get_render_mode_children(PyObject *self, PyObject *args);
-
-/* python rendermode options bindings */
-PyObject *set_render_mode_options(PyObject *self, PyObject *args);
-PyObject *add_custom_render_mode(PyObject *self, PyObject *args);
-
-/* individual rendermode interface declarations follow */
-
-/* NORMAL */
-typedef struct {
-    /* coordinates of the chunk, inside its region file */
-    int chunk_x, chunk_y;
-    /* biome data for the region */
-    PyObject *biome_data;
-    /* grasscolor and foliagecolor lookup tables */
-    PyObject *grasscolor, *foliagecolor, *watercolor;
-    /* biome-compatible grass/leaf textures */
-    PyObject *grass_texture;
-    
-    /* black and white colors for height fading */
-    PyObject *black_color, *white_color;
-    
-    float edge_opacity;
-    unsigned int min_depth;
-    unsigned int max_depth;
-    int height_fading;
-    int nether;
-} RenderModeNormal;
-extern RenderModeInterface rendermode_normal;
+/* XXX individual rendermode interface declarations follow */
+#ifdef OLD_MODES
 
 /* OVERLAY */
 typedef struct {
@@ -152,54 +117,6 @@ typedef struct {
 } RenderModeOverlay;
 extern RenderModeInterface rendermode_overlay;
 
-/* LIGHTING */
-typedef struct {
-    /* inherits from normal render mode */
-    RenderModeNormal parent;
-    
-    PyObject *facemasks_py;
-    PyObject *facemasks[3];
-    
-    /* extra data, loaded off the chunk class */
-    PyObject *skylight, *blocklight;
-    PyObject *left_skylight, *left_blocklight;
-    PyObject *right_skylight, *right_blocklight;
-    PyObject *up_left_skylight, *up_left_blocklight;
-    PyObject *up_right_skylight, *up_right_blocklight;
-    
-    /* light color image, loaded if color_light is True */
-    PyObject *lightcolor;
-    
-    /* can be overridden in derived rendermodes to control lighting
-       arguments are data, skylight, blocklight, return RGB */
-    void (*calculate_light_color)(void *, unsigned char, unsigned char, unsigned char *, unsigned char *, unsigned char *);
-    
-    /* can be set to 0 in derived modes to indicate that lighting the chunk
-     * sides is actually important. Right now, this is used in cave mode
-     */
-    int skip_sides;
-    
-    float shade_strength;
-    int color_light;
-    int night;
-} RenderModeLighting;
-extern RenderModeInterface rendermode_lighting;
-
-/* exposed so it can be used in other per-face occlusion checks */
-int rendermode_lighting_is_face_occluded(RenderState *state, int skip_sides, int x, int y, int z);
-
-/* exposed so sub-modes can look at colors directly */
-void get_lighting_color(RenderModeLighting *self, RenderState *state,
-                        int x, int y, int z,
-                        unsigned char *r, unsigned char *g, unsigned char *b);
-
-/* SMOOTH LIGHTING */
-typedef struct {
-    /* inherits from lighting */
-    RenderModeLighting parent;
-} RenderModeSmoothLighting;
-extern RenderModeInterface rendermode_smooth_lighting;
-
 /* SPAWN */
 typedef struct {
     /* inherits from overlay */
@@ -209,34 +126,6 @@ typedef struct {
 } RenderModeSpawn;
 extern RenderModeInterface rendermode_spawn;
 
-/* CAVE */
-typedef struct {
-    /* render blocks with lighting mode */
-    RenderModeLighting parent;
-
-    /* data used to know where the surface is */
-    PyObject *skylight;
-    PyObject *left_skylight;
-    PyObject *right_skylight;
-    PyObject *up_left_skylight;
-    PyObject *up_right_skylight;
-
-    /* data used to know where the surface is */
-    PyObject *blocklight;
-    PyObject *left_blocklight;
-    PyObject *right_blocklight;
-    PyObject *up_left_blocklight;
-    PyObject *up_right_blocklight;
-
-    /* colors used for tinting */
-    PyObject *depth_colors;
-    
-    int depth_tinting;
-    int only_lit;
-    int lighting;
-} RenderModeCave;
-extern RenderModeInterface rendermode_cave;
-
 /* MINERAL */
 typedef struct {
     /* inherits from overlay */
@@ -245,5 +134,6 @@ typedef struct {
     void *minerals;
 } RenderModeMineral;
 extern RenderModeInterface rendermode_mineral;
+#endif /* OLD_MODES */
 
 #endif /* __RENDERMODES_H_INCLUDED__ */
diff --git a/overviewer_core/textures.py b/overviewer_core/textures.py
index d9b5739..4f628e2 100644
--- a/overviewer_core/textures.py
+++ b/overviewer_core/textures.py
@@ -56,8 +56,11 @@ class Textures(object):
     def __getstate__(self):
         # we must get rid of the huge image lists, and other images
         attributes = self.__dict__.copy()
-        for attr in ['terrain_images', 'blockmap', 'biome_grass_texture', 'watertexture', 'lavatexture']:
-            del attributes[attr]
+        for attr in ['terrain_images', 'blockmap', 'biome_grass_texture', 'watertexture', 'lavatexture', 'lightcolor']:
+            try:
+                del attributes[attr]
+            except KeyError:
+                pass
         return attributes
     def __setstate__(self, attrs):
         # regenerate textures, if needed
@@ -245,6 +248,18 @@ class Textures(object):
             lavatexture = self.load_image("lava.png")
         self.lavatexture = lavatexture
         return lavatexture
+    
+    def load_light_color(self):
+        """Helper function to load the light color texture."""
+        if hasattr(self, "lightcolor"):
+            return self.lightcolor
+        try:
+            lightcolor = list(_load_image("light_normal.png").getdata())
+        except Exception:
+            logging.warning("Light color image could not be found.")
+            lightcolor = None
+        self.lightcolor = lightcolor
+        return lightcolor
 
     def _split_terrain(self, terrain):
         """Builds and returns a length 256 array of each 16x16 chunk
@@ -650,24 +665,6 @@ def getBiomeData(worlddir, chunkX, chunkY):
     currentBiomeData = data
     return data
 
-##
-## Color Light
-##
-
-lightcolor = None
-lightcolor_checked = False
-def loadLightColor():
-    global lightcolor, lightcolor_checked
-    
-    if not lightcolor_checked:
-        lightcolor_checked = True
-        try:
-            lightcolor = list(_load_image("light_normal.png").getdata())
-        except Exception:
-            logging.warning("Light color image could not be found.")
-            lightcolor = None
-    return lightcolor
-
 ##
 ## The other big one: @material and associated framework
 ##
diff --git a/overviewer_core/util.py b/overviewer_core/util.py
index 3be41ad..48485e6 100644
--- a/overviewer_core/util.py
+++ b/overviewer_core/util.py
@@ -21,6 +21,7 @@ import imp
 import os
 import os.path
 import sys
+import platform
 from subprocess import Popen, PIPE
 import logging
 from cStringIO import StringIO
@@ -88,6 +89,33 @@ def findGitVersion():
         except Exception:
             return "unknown"
 
+def is_bare_console():
+    """Returns true if Overviewer is running in a bare console in
+    Windows, that is, if overviewer wasn't started in a cmd.exe
+    session.
+    """
+    if platform.system() == 'Windows':
+        try:
+            import ctypes
+            GetConsoleProcessList = ctypes.windll.kernel32.GetConsoleProcessList
+            num = GetConsoleProcessList(ctypes.byref(ctypes.c_int(0)), ctypes.c_int(1))
+            if (num == 1):
+                return True
+                
+        except Exception:
+            pass
+    return False
+
+def exit(ret=0):
+    """Drop-in replacement for sys.exit that will automatically detect
+    bare consoles and wait for user input before closing.
+    """
+    if ret and is_bare_console():
+        print
+        print "Press [Enter] to close this window."
+        raw_input()
+    sys.exit(ret)
+
 # http://docs.python.org/library/itertools.html
 def roundrobin(iterables):
     "roundrobin('ABC', 'D', 'EF') --> A D E B F C"
diff --git a/setup.py b/setup.py
index db2c3d9..7a20a3d 100755
--- a/setup.py
+++ b/setup.py
@@ -15,6 +15,7 @@ import glob
 import platform
 import time
 import overviewer_core.util as util
+import numpy
 
 try:
     import py2exe
@@ -133,7 +134,6 @@ if py2exe is None:
 #
 
 # Third-party modules - we depend on numpy for everything
-import numpy
 # Obtain the numpy include directory.  This logic works across numpy versions.
 try:
     numpy_include = numpy.get_include()
@@ -149,11 +149,16 @@ except Exception:
         
 
 # used to figure out what files to compile
-render_modes = ['normal', 'lighting', 'smooth-lighting', 'cave']
-render_modes += ['overlay', 'spawn', 'mineral']
+# auto-created from files in primitives/, but we need the raw names so
+# we can use them later.
+primitives = []
+for name in glob.glob("overviewer_core/src/primitives/*.c"):
+    name = os.path.split(name)[-1]
+    name = os.path.splitext(name)[0]
+    primitives.append(name)
 
 c_overviewer_files = ['main.c', 'composite.c', 'iterate.c', 'endian.c', 'rendermodes.c']
-c_overviewer_files += map(lambda mode: 'rendermode-%s.c' % (mode,), render_modes)
+c_overviewer_files += map(lambda mode: 'primitives/%s.c' % (mode,), primitives)
 c_overviewer_files += ['Draw.c']
 c_overviewer_includes = ['overviewer.h', 'rendermodes.h']
 
@@ -168,7 +173,7 @@ setup_kwargs['ext_modules'].append(Extension('overviewer_core.c_overviewer', c_o
 setup_kwargs['options']['build_ext'] = {'inplace' : 1}
 
 # custom clean command to remove in-place extension
-# and the version file
+# and the version file, primitives header
 class CustomClean(clean):
     def run(self):
         # do the normal cleanup
@@ -177,31 +182,24 @@ class CustomClean(clean):
         # try to remove '_composite.{so,pyd,...}' extension,
         # regardless of the current system's extension name convention
         build_ext = self.get_finalized_command('build_ext')
-        pretty_fname = build_ext.get_ext_filename('overviewer_core.c_overviewer')
-        fname = pretty_fname
-        if os.path.exists(fname):
-            try:
-                if not self.dry_run:
-                    os.remove(fname)
-                log.info("removing '%s'", pretty_fname)
-            except OSError:
-                log.warn("'%s' could not be cleaned -- permission denied",
-                         pretty_fname)
-        else:
-            log.debug("'%s' does not exist -- can't clean it",
-                      pretty_fname)
-        
+        ext_fname = build_ext.get_ext_filename('overviewer_core.c_overviewer')
         versionpath = os.path.join("overviewer_core", "overviewer_version.py")
-        if os.path.exists(versionpath):
-            try:
-                if not self.dry_run:
-                    os.remove(versionpath)
-                log.info("removing '%s'", versionpath)
-            except OSError:
-                log.warn("'%s' could not be cleaned -- permission denied", versionpath)
-        else:
-            log.debug("'%s' does not exist -- can't clean it", versionpath)
-
+        primspath = os.path.join("overviewer_core", "src", "primitives.h")
+        
+        for fname in [ext_fname, versionpath, primspath]:
+            if os.path.exists(fname):
+                try:
+                    log.info("removing '%s'", fname)
+                    if not self.dry_run:
+                        os.remove(fname)
+                        
+                except OSError:
+                    log.warn("'%s' could not be cleaned -- permission denied",
+                             fname)
+            else:
+                log.debug("'%s' does not exist -- can't clean it",
+                          fname)
+        
         # now try to purge all *.pyc files
         for root, dirs, files in os.walk(os.path.join(os.path.dirname(__file__), ".")):
             for f in files:
@@ -225,16 +223,34 @@ def generate_version_py():
     except Exception:
         print "WARNING: failed to build overviewer_version file"
 
+def generate_primitives_h():
+    global primitives
+    prims = [p.lower().replace('-', '_') for p in primitives]
+    
+    outstr = "/* this file is auto-generated by setup.py */\n"
+    for p in prims:
+        outstr += "extern RenderPrimitiveInterface primitive_{0};\n".format(p)
+    outstr += "static RenderPrimitiveInterface *render_primitives[] = {\n"
+    for p in prims:
+        outstr += "    &primitive_{0},\n".format(p)
+    outstr += "    NULL\n"
+    outstr += "};\n"
+    
+    with open("overviewer_core/src/primitives.h", "w") as f:
+        f.write(outstr)
+
 class CustomSDist(sdist):
     def run(self):
         # generate the version file
         generate_version_py()
+        generate_primitives_h()
         sdist.run(self)
 
 class CustomBuild(build):
     def run(self):
         # generate the version file
         generate_version_py()
+        generate_primitives_h()
         build.run(self)
         print "\nBuild Complete"