Minecraft-Overviewer/chunk.py

333 lines
14 KiB
Python

# 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/>.
import numpy
from PIL import Image, ImageDraw
from itertools import izip, count
import os.path
import hashlib
import nbt
import textures
"""
This module has routines related to rendering one particular chunk into an
image
"""
# General note about pasting transparent image objects onto an image with an
# alpha channel:
# If you use the image as its own mask, it will work fine only if the alpha
# channel is binary. If there's any translucent parts, then the alpha channel
# of the dest image will have its alpha channel modified. To prevent this:
# first use im.split() and take the third item which is the alpha channel and
# use that as the mask. Then take the image and use im.convert("RGB") to strip
# the image from its alpha channel, and use that as the source to paste()
def get_lvldata(filename):
"""Takes a filename and returns the Level struct, which contains all the
level info"""
return nbt.load(filename)[1]['Level']
def get_blockarray(level):
"""Takes the level struct as returned from get_lvldata, and returns the
Block array, which just contains all the block ids"""
return numpy.frombuffer(level['Blocks'], dtype=numpy.uint8).reshape((16,16,128))
def get_blockarray_fromfile(filename):
"""Same as get_blockarray except takes a filename and uses get_lvldata to
open it. This is a shortcut"""
level = get_lvldata(filename)
return get_blockarray(level)
def get_skylight_array(level):
"""Returns the skylight array. Remember this is 4 bits per block, so divide
the z component by 2 when accessing the array. and mask off the top or
bottom 4 bits if it's odd or even respectively
"""
return numpy.frombuffer(level['SkyLight'], dtype=numpy.uint8).reshape((16,16,64))
# This set holds blocks ids that can be seen through, for occlusion calculations
transparent_blocks = set([0, 6, 8, 9, 18, 20, 37, 38, 39, 40, 50, 51, 52, 53,
59, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 74, 75, 76, 77, 79, 83, 85])
def render_and_save(chunkfile, cave=False):
"""Used as the entry point for the multiprocessing workers (since processes
can't target bound methods) or to easily render and save one chunk
Returns the image file location"""
a = ChunkRenderer(chunkfile)
try:
return a.render_and_save(cave)
except Exception, e:
import traceback
traceback.print_exc()
raise
except KeyboardInterrupt:
print
print "You pressed Ctrl-C. Exiting..."
# Raise an exception that is an instance of Exception. Unlike
# KeyboardInterrupt, that will kill the process instead of having it
# propagate the exception back to the parent process.
raise Exception()
class ChunkRenderer(object):
def __init__(self, chunkfile):
if not os.path.exists(chunkfile):
raise ValueError("Could not find chunkfile")
self.chunkfile = chunkfile
destdir, filename = os.path.split(self.chunkfile)
self.destdir = os.path.abspath(destdir)
self.blockid = ".".join(filename.split(".")[1:3])
def _load_level(self):
"""Loads and returns the level structure"""
if not hasattr(self, "_level"):
self._level = get_lvldata(self.chunkfile)
return self._level
level = property(_load_level)
def _load_blocks(self):
"""Loads and returns the block array"""
if not hasattr(self, "_blocks"):
self._blocks = get_blockarray(self._load_level())
return self._blocks
blocks = property(_load_blocks)
def _hash_blockarray(self):
"""Finds a hash of the block array"""
if hasattr(self, "_digest"):
return self._digest
h = hashlib.md5()
h.update(self.level['Blocks'])
# If the render algorithm changes, change this line to re-generate all
# the chunks automatically:
h.update("1")
digest = h.hexdigest()
# 6 digits ought to be plenty
self._digest = digest[:6]
return self._digest
def _find_oldimage(self, cave):
# Get the name of the existing image. No way to do this but to look at
# all the files
oldimg = oldimg_path = None
for filename in os.listdir(self.destdir):
if filename.startswith("img.{0}.{1}.".format(self.blockid,
"cave" if cave else "nocave")) and \
filename.endswith(".png"):
oldimg = filename
oldimg_path = os.path.join(self.destdir, oldimg)
break
return oldimg, oldimg_path
def render_and_save(self, cave=False):
"""Render the chunk using chunk_render, and then save it to a file in
the same directory as the source image. If the file already exists and
is up to date, this method doesn't render anything.
"""
destdir = self.destdir
blockid = self.blockid
oldimg, oldimg_path = self._find_oldimage(cave)
if oldimg:
# An image exists? Instead of checking the hash which is kinda
# expensive (for tens of thousands of chunks, yes it is) check if
# the mtime of the chunk file is newer than the mtime of oldimg
if os.path.getmtime(self.chunkfile) < os.path.getmtime(oldimg_path):
# chunkfile is older than the image, don't even bother checking
# the hash
return oldimg_path
# Reasons for the code to get to this point:
# 1) An old image doesn't exist
# 2) An old image exists, but the chunk was more recently modified (the
# image was NOT checked if it was valid)
# 3) An old image exists, the chunk was not modified more recently, but
# the image was invalid and deleted (sort of the same as (1))
# What /should/ the image be named, go ahead and hash the block array
dest_filename = "img.{0}.{1}.{2}.png".format(
blockid,
"cave" if cave else "nocave",
self._hash_blockarray(),
)
dest_path = os.path.join(destdir, dest_filename)
if oldimg:
if dest_filename == oldimg:
# There is an existing file, the chunk has a newer mtime, but the
# hashes match.
return dest_path
else:
# Remove old image for this chunk. Anything already existing is
# either corrupt or out of date
os.unlink(oldimg_path)
# Render the chunk
img = self.chunk_render(cave=cave)
# Save it
try:
img.save(dest_path)
except:
os.unlink(dest_path)
raise
# Return its location
return dest_path
def chunk_render(self, img=None, xoff=0, yoff=0, cave=False):
"""Renders a chunk with the given parameters, and returns the image.
If img is given, the chunk is rendered to that image object. Otherwise,
a new one is created. xoff and yoff are offsets in the image.
For cave mode, all blocks that have any direct sunlight are not
rendered, and blocks are drawn with a color tint depending on their
depth."""
blocks = self.blocks
if cave:
skylight = get_skylight_array(self.level)
# Cave mode. Actually go through and 0 out all blocks that are not in a
# cave, so that it only renders caves.
# 1st task: this array is 2 blocks per byte, expand it so we can just
# do a bitwise and on the arrays
skylight_expanded = numpy.empty((16,16,128), dtype=numpy.uint8)
# Even elements get the lower 4 bits
skylight_expanded[:,:,::2] = skylight & 0x0F
# Odd elements get the upper 4 bits
skylight_expanded[:,:,1::2] = skylight >> 4
# Places where the skylight is not 0 (there's some amount of skylight
# touching it) change it to something that won't get rendered, AND
# won't get counted as "transparent".
blocks = blocks.copy()
blocks[skylight_expanded != 0] = 21
# Each block is 24x24
# The next block on the X axis adds 12px to x and subtracts 6px from y in the image
# The next block on the Y axis adds 12px to x and adds 6px to y in the image
# The next block up on the Z axis subtracts 12 from y axis in the image
# Since there are 16x16x128 blocks in a chunk, the image will be 384x1728
# (height is 128*12 high, plus the size of the horizontal plane: 16*12)
if not img:
img = Image.new("RGBA", (384, 1728), (38,92,255,0))
for x in xrange(15,-1,-1):
for y in xrange(16):
imgx = xoff + x*12 + y*12
imgy = yoff - x*6 + y*6 + 128*12 + 16*12//2
for z in xrange(128):
try:
blockid = blocks[x,y,z]
t = textures.blockmap[blockid]
if not t:
continue
# Check if this block is occluded
if cave and (
x == 0 and y != 15 and z != 127
):
# If it's on the x face, only render if there's a
# transparent block in the y+1 direction OR the z-1
# direction
if (
blocks[x,y+1,z] not in transparent_blocks and
blocks[x,y,z+1] not in transparent_blocks
):
continue
elif cave and (
y == 15 and x != 0 and z != 127
):
# If it's on the facing y face, only render if there's
# a transparent block in the x-1 direction OR the z-1
# direction
if (
blocks[x-1,y,z] not in transparent_blocks and
blocks[x,y,z+1] not in transparent_blocks
):
continue
elif cave and (
y == 15 and x == 0
):
# If it's on the facing edge, only render if what's
# above it is transparent
if (
blocks[x,y,z+1] not in transparent_blocks
):
continue
elif (
# Normal block or not cave mode, check sides for
# transparentcy or render unconditionally if it's
# on a shown face
x != 0 and y != 15 and z != 127 and
blocks[x-1,y,z] not in transparent_blocks and
blocks[x,y+1,z] not in transparent_blocks and
blocks[x,y,z+1] not in transparent_blocks
):
# Don't render if all sides aren't transparent and
# we're not on the edge
continue
# Draw the actual block on the image. For cave images,
# tint the block with a color proportional to its depth
if cave:
img.paste(Image.blend(t[0],depth_colors[z],0.3), (imgx, imgy), t[1])
else:
img.paste(t[0], (imgx, imgy), t[1])
# Draw edge lines
if blockid not in transparent_blocks:
draw = ImageDraw.Draw(img)
if x != 15 and blocks[x+1,y,z] == 0:
draw.line(((imgx+12,imgy), (imgx+22,imgy+5)), fill=(0,0,0), width=1)
if y != 0 and blocks[x,y-1,z] == 0:
draw.line(((imgx,imgy+6), (imgx+12,imgy)), fill=(0,0,0), width=1)
finally:
# Do this no mater how the above block exits
imgy -= 12
return img
# 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):
img = Image.new("RGB", (24,24), (r,g,b))
depth_colors.append(img)
if z < 32:
g += 7
elif z < 64:
r -= 7
elif z < 96:
b += 7
else:
g -= 7
return depth_colors
depth_colors = generate_depthcolors()