refactored c extensions into one

.gitignore

@@ -7,11 +7,11 @@ cachedir*
 ImPlatform.h
 Imaging.h
 
-# various forms of compiled _composite extensions
+# various forms of compiled c_overviewer extensions
-_composite.so
+c_overviewer.so
-_composite.pyd
+c_overviewer.pyd
-_composite_d.pyd
+c_overviewer_d.pyd
-_composite.dylib
+c_overviewer.dylib
 
 # Mac OS X noise
 .DS_Store

chunk.py

@@ -25,7 +25,7 @@ import nbt
 import textures
 import world
 import composite
-import _iterate
+import c_overviewer
 
 """
 This module has routines related to rendering one particular chunk into an
@@ -545,7 +545,7 @@ class ChunkRenderer(object):
         if not img:
             img = Image.new("RGBA", (384, 1728), (38,92,255,0))
 
-        _iterate.render_loop(self, img, xoff, yoff, blockData_expanded)
+        c_overviewer.render_loop(self, img, xoff, yoff, blockData_expanded)
 
         for entity in tileEntities:
             if entity['id'] == 'Sign':

composite.py

@@ -25,7 +25,7 @@ alpha-over extension cannot be found.
 
 extension_alpha_over = None
 try:
-    from _composite import alpha_over as _extension_alpha_over
+    from c_overviewer import alpha_over as _extension_alpha_over
     extension_alpha_over = _extension_alpha_over
 except ImportError:
     pass

setup.py

@@ -32,11 +32,11 @@ if py2exe != None:
     setup_kwargs['options']['py2exe'] = {'bundle_files' : 1, 'excludes': 'Tkinter'}
 
 #
-# _composite.c extension
+# c_overviewer extension
 #
 
-setup_kwargs['ext_modules'].append(Extension('_composite', ['src/composite.c'], include_dirs=['.'], extra_link_args=["/MANIFEST"] if platform.system() == "Windows" else []))
+c_overviewer_files = ['src/main.c', 'src/composite.c', 'src/iterate.c']
-setup_kwargs['ext_modules'].append(Extension('_iterate', ['src/iterate.c'], include_dirs=['.'], extra_link_args=["/MANIFEST"] if platform.system() == "Windows" else []))
+setup_kwargs['ext_modules'].append(Extension('c_overviewer', c_overviewer_files, include_dirs=['.'], extra_link_args=["/MANIFEST"] if platform.system() == "Windows" else []))
 # tell build_ext to build the extension in-place
 # (NOT in build/)
 setup_kwargs['options']['build_ext'] = {'inplace' : 1}
@@ -52,7 +52,7 @@ 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('_composite')
+        pretty_fname = build_ext.get_ext_filename('c_overviewer')
         fname = pretty_fname
         if os.path.exists(fname):
             try:

src/composite.c

@@ -22,8 +22,7 @@
  * PIL paste if this extension is not found.
  */
 
-#include <Python.h>
+#include "overviewer.h"
-#include <Imaging.h>
 
 /* like (a * b + 127) / 255), but much faster on most platforms
    from PIL's _imaging.c */
@@ -36,7 +35,7 @@ typedef struct
 	Imaging image;
 } ImagingObject;
 
-static Imaging imaging_python_to_c(PyObject* obj)
+Imaging imaging_python_to_c(PyObject* obj)
 {
 	PyObject* im;
 	Imaging image;
@@ -59,26 +58,22 @@ static Imaging imaging_python_to_c(PyObject* obj)
 	return image;
 }
 
-static PyObject* _composite_alpha_over(PyObject* self, PyObject* args)
+/* the alpha_over function, in a form that can be called from C */
+/* if xsize, ysize are negative, they are instead set to the size of the image in src */
+/* returns NULL on error, dest on success. You do NOT need to decref the return! */
+PyObject* alpha_over(PyObject* dest, PyObject* src, PyObject* mask, int dx, int dy, int xsize, int ysize)
 {
-	/* raw input python variables */
-	PyObject* dest, * src, * pos, * mask;
 	/* libImaging handles */
 	Imaging imDest, imSrc, imMask;
 	/* cached blend properties */
 	int src_has_alpha, mask_offset, mask_stride;
-	/* destination position and size */
-	int dx, dy, xsize, ysize;
 	/* source position */
 	int sx, sy;
 	/* iteration variables */
 	unsigned int x, y, i;
 	/* temporary calculation variables */
 	int tmp1, tmp2, tmp3;
-	
+		
-	if (!PyArg_ParseTuple(args, "OOOO", &dest, &src, &pos, &mask))
-		return NULL;
-	
 	imDest = imaging_python_to_c(dest);
 	imSrc = imaging_python_to_c(src);
 	imMask = imaging_python_to_c(mask);
@@ -119,11 +114,11 @@ static PyObject* _composite_alpha_over(PyObject* self, PyObject* args)
 	/* how many bytes to skip to get to the next alpha byte */
 	mask_stride = imMask->pixelsize;
 	
-	/* destination position read */
+	/* handle negative/zero sizes appropriately */
-	if (!PyArg_ParseTuple(pos, "iiii", &dx, &dy, &xsize, &ysize))
+	if (xsize <= 0 || ysize <= 0)
 	{
-		PyErr_SetString(PyExc_TypeError, "given blend destination rect is not valid");
+		xsize = imSrc->xsize;
-		return NULL;
+		ysize = imSrc->ysize;
 	}
 	
 	/* set up the source position, size and destination position */
@@ -158,7 +153,6 @@ static PyObject* _composite_alpha_over(PyObject* self, PyObject* args)
 	if (xsize <= 0 || ysize <= 0)
 	{
 		/* nothing to do, return */
-		Py_INCREF(dest);
 		return dest;
 	}
 	
@@ -208,17 +202,39 @@ static PyObject* _composite_alpha_over(PyObject* self, PyObject* args)
 		}
 	}
 	
-	Py_INCREF(dest);
 	return dest;
 }
 
-static PyMethodDef _CompositeMethods[] =
+/* wraps alpha_over so it can be called directly from python */
+/* properly refs the return value when needed: you DO need to decref the return */
+PyObject* alpha_over_wrap(PyObject* self, PyObject* args)
 {
-	{"alpha_over", _composite_alpha_over, METH_VARARGS, "alpha over composite function"},
+	/* raw input python variables */
-	{NULL, NULL, 0, NULL}
+	PyObject* dest, * src, * pos, * mask;
-};
+	/* destination position and size */
-
+	int dx, dy, xsize, ysize;
-PyMODINIT_FUNC init_composite(void)
+	
-{
+	if (!PyArg_ParseTuple(args, "OOOO", &dest, &src, &pos, &mask))
-	(void) Py_InitModule("_composite", _CompositeMethods);
+		return NULL;
+	
+	/* destination position read */
+	if (!PyArg_ParseTuple(pos, "iiii", &dx, &dy, &xsize, &ysize))
+	{
+		/* try again, but this time try to read a point */
+		xsize = 0;
+		ysize = 0;
+		if (!PyArg_ParseTuple(pos, "ii", &dx, &dy))
+		{
+			PyErr_SetString(PyExc_TypeError, "given blend destination rect is not valid");
+			return NULL;
+		}
+	}
+	
+	PyObject* ret = alpha_over(dest, src, mask, dx, dy, xsize, ysize);
+	if (ret == dest)
+	{
+		/* Python needs us to own our return value */
+		Py_INCREF(dest);
+	}
+	return ret;
 }

src/iterate.c

@@ -1,19 +1,6 @@
-#include <Python.h>
+#include "overviewer.h"
 
 #include <numpy/arrayobject.h>
-#include <Imaging.h>
-
-
-/* like (a * b + 127) / 255), but much faster on most platforms
-   from PIL's _imaging.c */
-#define MULDIV255(a, b, tmp)								\
-	(tmp = (a) * (b) + 128, ((((tmp) >> 8) + (tmp)) >> 8))
-
-typedef struct
-{
-	PyObject_HEAD
-	Imaging image;
-} ImagingObject;
 
 // macro for getting blockID from a chunk of memory
 #define getBlock(blockThing, x,y,z) blockThing[ y + ( z * 128 + ( x * 128 * 16) ) ]
@@ -24,213 +11,22 @@ static inline int isTransparent(unsigned char b) {
 
 }
 
-
+// helper to handle alpha_over calls involving a texture tuple
-static Imaging imaging_python_to_c(PyObject* obj)
+static inline PyObject* texture_alpha_over(PyObject* dest, PyObject* t, int imgx, int imgy)
 {
-	PyObject* im;
+	PyObject* src, * mask;
-	Imaging image;
-
-	/* first, get the 'im' attribute */
-	im = PyObject_GetAttrString(obj, "im");
-	if (!im)
-		return NULL;
 	
-	/* make sure 'im' is the right type */
+	src = PyTuple_GET_ITEM(t, 0);
-	if (strcmp(im->ob_type->tp_name, "ImagingCore") != 0)
+	mask = PyTuple_GET_ITEM(t, 1);
-	{
+	if (mask == Py_None) {
-		/* it's not -- raise an error and exit */
+		mask = src;
-		PyErr_SetString(PyExc_TypeError, "image attribute 'im' is not a core Imaging type");
-		return NULL;
 	}
 	
-	image = ((ImagingObject*)im)->image;
+	return alpha_over(dest, src, mask, imgx, imgy, 0, 0);
-	Py_DECREF(im);
-	return image;
 }
 
-
-
-// TODO refact iterate.c and _composite.c so share implementations
-static PyObject* alpha_over(PyObject* dest, PyObject* t, int imgx, int imgy)
-{
-	/* raw input python variables */
-	PyObject * src, * mask;
-	/* libImaging handles */
-	Imaging imDest, imSrc, imMask;
-	/* cached blend properties */
-	int src_has_alpha, mask_offset, mask_stride;
-	/* destination position and size */
-	int dx, dy, xsize, ysize;
-	/* source position */
-	int sx, sy;
-	/* iteration variables */
-	unsigned int x, y, i;
-	/* temporary calculation variables */
-	int tmp1, tmp2, tmp3;
-	
-    src = PyTuple_GET_ITEM(t, 0);
-    mask = PyTuple_GET_ITEM(t, 1);
-    if (mask == Py_None) {
-        printf("mask is none\n");
-        Py_INCREF(mask);
-        mask = src;
-    }
-	//if (!PyArg_ParseTuple(args, "OOOO", &dest, &src, &pos, &mask))
-	//	return NULL;
-	
-	imDest = imaging_python_to_c(dest);
-	imSrc = imaging_python_to_c(src);
-	imMask = imaging_python_to_c(mask);
-
-    //printf("alpha1\n");    
-	if (!imDest || !imSrc || !imMask) {
-		PyErr_SetString(PyExc_ValueError, "dest, src, or mask is missing");
-		return NULL;
-    }
-    //printf("alpha2\n");    
-	
-	/* check the various image modes, make sure they make sense */
-	if (strcmp(imDest->mode, "RGBA") != 0)
-	{
-		PyErr_SetString(PyExc_ValueError, "given destination image does not have mode \"RGBA\"");
-		return NULL;
-	}
-	
-	if (strcmp(imSrc->mode, "RGBA") != 0 && strcmp(imSrc->mode, "RGB") != 0)
-	{
-		PyErr_SetString(PyExc_ValueError, "given source image does not have mode \"RGBA\" or \"RGB\"");
-		return NULL;
-	}
-	
-	if (strcmp(imMask->mode, "RGBA") != 0 && strcmp(imMask->mode, "L") != 0)
-	{
-		PyErr_SetString(PyExc_ValueError, "given mask image does not have mode \"RGBA\" or \"L\"");
-		return NULL;
-	}
-	
-	/* make sure mask size matches src size */
-	if (imSrc->xsize != imMask->xsize || imSrc->ysize != imMask->ysize)
-	{
-		PyErr_SetString(PyExc_ValueError, "mask and source image sizes do not match");
-		return NULL;
-	}
-	
-    //printf("alpha3\n");    
-	/* set up flags for the src/mask type */
-    src_has_alpha = (imSrc->pixelsize == 4 ? 1 : 0);
-	/* how far into image the first alpha byte resides */
-	mask_offset = (imMask->pixelsize == 4 ? 3 : 0);
-	/* how many bytes to skip to get to the next alpha byte */
-	mask_stride = imMask->pixelsize;
-	
-    //printf("alpha4\n");    
-	/* destination position read */
-	//if (!PyArg_ParseTuple(pos, "iiii", &dx, &dy, &xsize, &ysize))
-	//{
-	//	PyErr_SetString(PyExc_TypeError, "given blend destination rect is not valid");
-	//	return NULL;
-	//}
-    dx = imgx;
-    dy = imgy;
-
-    xsize = imSrc->xsize;
-    ysize = imSrc->ysize;
-    //printf("xsize/ysize %d/%d\n", xsize, ysize);
-
-    //printf("alpha5\n");    
-	
-	/* set up the source position, size and destination position */
-	/* handle negative dest pos */
-	if (dx < 0)
-	{
-		sx = -dx;
-		dx = 0;
-	} else {
-		sx = 0;
-	}
-	
-	if (dy < 0)
-	{
-		sy = -dy;
-		dy = 0;
-	} else {
-		sy = 0;
-	}
-	
-	/* set up source dimensions */
-	xsize -= sx;
-	ysize -= sy;
-   
-    //printf("imDest->xsize=%d imDest->yize=%d\n", imDest->xsize, imDest->ysize); 
-	
-	/* clip dimensions, if needed */
-	if (dx + xsize > imDest->xsize)
-		xsize = imDest->xsize - dx;
-	if (dy + ysize > imDest->ysize)
-		ysize = imDest->ysize - dy;
-	
-	/* check that there remains any blending to be done */
-	if (xsize <= 0 || ysize <= 0)
-	{
-		/* nothing to do, return */
-		Py_INCREF(dest);
-		return dest;
-	}
-	
-	for (y = 0; y < ysize; y++)
-	{
-		UINT8* out = (UINT8*) imDest->image[dy + y] + dx*4;
-		UINT8* outmask = (UINT8*) imDest->image[dy + y] + dx*4 + 3;
-		UINT8* in = (UINT8*) imSrc->image[sy + y] + sx*(imSrc->pixelsize);
-		UINT8* inmask = (UINT8*) imMask->image[sy + y] + sx*mask_stride + mask_offset;
-		
-		for (x = 0; x < xsize; x++)
-		{
-			/* special cases */
-			if (*inmask == 255 || *outmask == 0)
-			{
-				*outmask = *inmask;
-				
-				*out = *in;
-				out++, in++;
-				*out = *in;
-				out++, in++;
-				*out = *in;
-				out++, in++;
-			} else if (*inmask == 0) {
-				/* do nothing -- source is fully transparent */
-				out += 3;
-				in += 3;
-			} else {
-				/* general case */
-				int alpha = *inmask + MULDIV255(*outmask, 255 - *inmask, tmp1);
-				for (i = 0; i < 3; i++)
-				{
-					/* general case */
-					*out = MULDIV255(*in, *inmask, tmp1) + MULDIV255(MULDIV255(*out, *outmask, tmp2), 255 - *inmask, tmp3);
-					*out = (*out * 255) / alpha;
-					out++, in++;
-				}
-				
-				*outmask = alpha;
-			}
-			
-			out++;
-			if (src_has_alpha)
-				in++;
-			outmask += 4;
-			inmask += mask_stride;
-		}
-	}
-	
-	Py_INCREF(dest);
-	return dest;
-}
-
-
-
 // TODO triple check this to make sure reference counting is correct
-static PyObject*
+PyObject*
 chunk_render(PyObject *self, PyObject *args) {
 
     PyObject *chunk;
@@ -324,7 +120,7 @@ chunk_render(PyObject *self, PyObject *args) {
 
                     // note that this version of alpha_over has a different signature than the 
                     // version in _composite.c
-                    alpha_over(img, t, imgx, imgy );
+                    texture_alpha_over(img, t, imgx, imgy );
 
                 } else {
                     // this should be a pointer to a unsigned char
@@ -342,7 +138,7 @@ chunk_render(PyObject *self, PyObject *args) {
                     PyObject *t = PyDict_GetItem(specialblockmap, tmp);  // this is a borrowed reference.  no need to decref
                     Py_DECREF(tmp);
                     if (t != NULL) 
-                        alpha_over(img, t, imgx, imgy );
+                        texture_alpha_over(img, t, imgx, imgy );
                     imgy -= 12;
                     continue;
                 }
@@ -357,17 +153,3 @@ chunk_render(PyObject *self, PyObject *args) {
 
     return Py_BuildValue("i",2);
 }
-
-static PyMethodDef IterateMethods[] = {
-    {"render_loop", chunk_render, METH_VARARGS,
-        "Renders stuffs"},
-    {NULL, NULL, 0, NULL}        /* Sentinel */
-};
-
-
-PyMODINIT_FUNC
-init_iterate(void)
-{
-        (void) Py_InitModule("_iterate", IterateMethods);
-        import_array();  // for numpy
-}

src/main.c

@@ -0,0 +1,18 @@
+#include "overviewer.h"
+
+#include <numpy/arrayobject.h>
+
+static PyMethodDef COverviewerMethods[] = {
+	{"alpha_over", alpha_over_wrap, METH_VARARGS,
+        "alpha over composite function"},
+    {"render_loop", chunk_render, METH_VARARGS,
+        "Renders stuffs"},
+    {NULL, NULL, 0, NULL}        /* Sentinel */
+};
+
+PyMODINIT_FUNC
+initc_overviewer(void)
+{
+        (void) Py_InitModule("c_overviewer", COverviewerMethods);
+        import_array();  // for numpy
+}

src/overviewer.h

@@ -0,0 +1,39 @@
+/* 
+ * 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/>.
+ */
+
+/*
+ * This is a general include file for the Overviewer C extension. It
+ * lists useful, defined functions as well as those that are exported
+ * to python, so all files can use them.
+ */
+
+#ifndef __OVERVIEWER_H_INCLUDED__
+#define __OVERVIEWER_H_INCLUDED__
+
+/* Python and PIL headers */
+#include <Python.h>
+#include <Imaging.h>
+
+/* in composite.c */
+Imaging imaging_python_to_c(PyObject* obj);
+PyObject* alpha_over(PyObject* dest, PyObject* src, PyObject* mask, int dx, int dy, int xsize, int ysize);
+PyObject* alpha_over_wrap(PyObject* self, PyObject* args);
+
+/* in iterate.c */
+PyObject* chunk_render(PyObject *self, PyObject *args);
+
+#endif /* __OVERVIEWER_H_INCLUDED__ */