From 0446e89bfeca59e587529d27e43fe0b883259dd4 Mon Sep 17 00:00:00 2001
From: Virgil Dupras <hsoft@hardcoded.net>
Date: Sun, 31 Jan 2010 10:27:59 +0100
Subject: [PATCH] Converted core_pe's "block" module from Cython to C.

---
 .hgignore                       |   1 -
 core_pe/modules/block/block.c   | 277 ++++++++++++++++++++++++++++++++
 core_pe/modules/block/block.pyx |  96 -----------
 core_pe/modules/block/setup.py  |   4 +-
 4 files changed, 278 insertions(+), 100 deletions(-)
 create mode 100644 core_pe/modules/block/block.c
 delete mode 100644 core_pe/modules/block/block.pyx

diff --git a/.hgignore b/.hgignore
index a7e41fd4..fda43040 100644
--- a/.hgignore
+++ b/.hgignore
@@ -8,7 +8,6 @@ syntax: glob
 *.tm_build_errors
 conf.yaml
 build
-core_pe/modules/block/block.c
 cocoa/*/Info.plist
 cocoa/*/build
 cocoa/*/dg_cocoa.plugin
diff --git a/core_pe/modules/block/block.c b/core_pe/modules/block/block.c
new file mode 100644
index 00000000..968d7ae7
--- /dev/null
+++ b/core_pe/modules/block/block.c
@@ -0,0 +1,277 @@
+/* Created By: Virgil Dupras
+ * Created On: 2010-01-30
+ * Copyright 2010 Hardcoded Software (http://www.hardcoded.net)
+ */
+
+#define PY_SSIZE_T_CLEAN
+#include "Python.h"
+
+/* avgdiff/maxdiff has been called with empty lists */
+static PyObject *NoBlocksError;
+/* avgdiff/maxdiff has been called with 2 block lists of different size. */
+static PyObject *DifferentBlockCountError;
+
+static inline int
+max(int a, int b)
+{
+    return b > a ? b : a;
+}
+
+static inline int
+min(int a, int b)
+{
+    return b < a ? b : a;
+}
+
+/* Create a tuple out of an array of integers. */
+static PyObject*
+inttuple(int numbers[], int count)
+{
+    int i;
+    PyObject *pnumber;
+    PyObject *result;
+    
+    result = PyTuple_New(count);
+    
+    for (i=0; i<count; i++) {
+        pnumber = PyInt_FromLong(numbers[i]);
+        if (pnumber == NULL) {
+            Py_DECREF(result);
+            return NULL;
+        }
+        PyTuple_SET_ITEM(result, i, pnumber);
+    }
+    
+    return result;
+}
+
+/* Returns a 3 sized tuple containing the mean color of 'image'.    
+ * image: a PIL image or crop.
+ */
+static PyObject*
+getblock(PyObject *image)
+{
+    int i, totals[3] = {0, 0, 0};
+    Py_ssize_t pixel_count;
+    PyObject *ppixels;
+    
+    ppixels = PyObject_CallMethod(image, "getdata", NULL);
+    if (ppixels == NULL) {
+        return NULL;
+    }
+    
+    pixel_count = PySequence_Length(ppixels);
+    for (i=0; i<pixel_count; i++) {
+        PyObject *ppixel, *pr, *pg, *pb;
+        int r, g, b;
+        
+        ppixel = PySequence_ITEM(ppixels, i);
+        pr = PySequence_ITEM(ppixel, 0);
+        pg = PySequence_ITEM(ppixel, 1);
+        pb = PySequence_ITEM(ppixel, 2);
+        Py_DECREF(ppixel);
+        r = PyInt_AsSsize_t(pr);
+        g = PyInt_AsSsize_t(pg);
+        b = PyInt_AsSsize_t(pb);
+        Py_DECREF(pr);
+        Py_DECREF(pg);
+        Py_DECREF(pb);
+        
+        totals[0] += r;
+        totals[1] += g;
+        totals[2] += b;
+    }
+    
+    Py_DECREF(ppixels);
+    
+    if (pixel_count) {
+        totals[0] /= pixel_count;
+        totals[1] /= pixel_count;
+        totals[2] /= pixel_count;
+    }
+    
+    return inttuple(totals, 3);
+}
+
+/* Returns the difference between the first block and the second.
+ * It returns an absolute sum of the 3 differences (RGB).
+ */
+static inline int
+diff(PyObject *first, PyObject *second)
+{
+    Py_ssize_t r1, g1, b1, r2, b2, g2;
+    PyObject *pr, *pg, *pb;
+    pr = PySequence_ITEM(first, 0);
+    pg = PySequence_ITEM(first, 1);
+    pb = PySequence_ITEM(first, 2);
+    r1 = PyInt_AsSsize_t(pr);
+    g1 = PyInt_AsSsize_t(pg);
+    b1 = PyInt_AsSsize_t(pb);
+    Py_DECREF(pr);
+    Py_DECREF(pg);
+    Py_DECREF(pb);
+    
+    pr = PySequence_ITEM(second, 0);
+    pg = PySequence_ITEM(second, 1);
+    pb = PySequence_ITEM(second, 2);
+    r2 = PyInt_AsSsize_t(pr);
+    g2 = PyInt_AsSsize_t(pg);
+    b2 = PyInt_AsSsize_t(pb);
+    Py_DECREF(pr);
+    Py_DECREF(pg);
+    Py_DECREF(pb);
+    
+    return abs(r1 - r2) + abs(g1 - g2) + abs(b1 - b2);
+}
+
+PyDoc_STRVAR(block_getblocks2_doc,
+"Returns a list of blocks (3 sized tuples).\n\
+\n\
+image: A PIL image to base the blocks on.\n\
+block_count_per_side: This integer determine the number of blocks the function will return.\n\
+If it is 10, for example, 100 blocks will be returns (10 width, 10 height). The blocks will not\n\
+necessarely cover square areas. The area covered by each block will be proportional to the image\n\
+itself.\n");
+
+static PyObject*
+block_getblocks2(PyObject *self, PyObject *args)
+{
+    int block_count_per_side, width, height, block_width, block_height, ih;
+    PyObject *image;
+    PyObject *pimage_size, *pwidth, *pheight;
+    PyObject *result;
+    
+    if (!PyArg_ParseTuple(args, "Oi", &image, &block_count_per_side)) {
+        return NULL;
+    }
+    
+    pimage_size = PyObject_GetAttrString(image, "size");
+    pwidth = PySequence_ITEM(pimage_size, 0);
+    pheight = PySequence_ITEM(pimage_size, 1);
+    width = PyInt_AsSsize_t(pwidth);
+    height = PyInt_AsSsize_t(pheight);
+    Py_DECREF(pimage_size);
+    Py_DECREF(pwidth);
+    Py_DECREF(pheight);
+    
+    if (!(width && height)) {
+        return PyList_New(0);
+    }
+    
+    block_width = max(width / block_count_per_side, 1);
+    block_height = max(height / block_count_per_side, 1);
+    
+    result = PyList_New(block_count_per_side * block_count_per_side);
+    if (result == NULL) {
+        return NULL;
+    }
+    
+    for (ih=0; ih<block_count_per_side; ih++) {
+        int top, bottom, iw;
+        top = min(ih*block_height, height-block_height);
+        bottom = top + block_height;
+        for (iw=0; iw<block_count_per_side; iw++) {
+            int left, right, box[4];
+            PyObject *pbox;
+            PyObject *pmethodname;
+            PyObject *pcrop;
+            PyObject *pblock;
+            
+            left = min(iw*block_width, width-block_width);
+            right = left + block_width;
+            box[0] = left;
+            box[1] = top;
+            box[2] = right;
+            box[3] = bottom;
+            pbox = inttuple(box, 4);
+            pmethodname = PyString_FromString("crop");
+            pcrop = PyObject_CallMethodObjArgs(image, pmethodname, pbox);
+            Py_DECREF(pmethodname);
+            Py_DECREF(pbox);
+            if (pcrop == NULL) {
+                Py_DECREF(result);
+                return NULL;
+            }
+            pblock = getblock(pcrop);
+            Py_DECREF(pcrop);
+            if (pblock == NULL) {
+                Py_DECREF(result);
+                return NULL;
+            }
+            PyList_SET_ITEM(result, ih*block_count_per_side+iw, pblock);
+        }
+    }
+    
+    return result;
+}
+
+PyDoc_STRVAR(block_avgdiff_doc,
+"Returns the average diff between first blocks and seconds.\n\
+\n\
+If the result surpasses limit, limit + 1 is returned, except if less than min_iterations\n\
+iterations have been made in the blocks.\n");
+
+static PyObject*
+block_avgdiff(PyObject *self, PyObject *args)
+{
+    PyObject *first, *second;
+    int limit, min_iterations;
+    Py_ssize_t count;
+    int sum, i, result;
+    
+    if (!PyArg_ParseTuple(args, "OOii", &first, &second, &limit, &min_iterations)) {
+        return NULL;
+    }
+    
+    count = PySequence_Length(first);
+    if (count != PySequence_Length(second)) {
+        PyErr_SetString(DifferentBlockCountError, "");
+        return NULL;
+    }
+    if (!count) {
+        PyErr_SetString(NoBlocksError, "");
+        return NULL;
+    }
+    
+    sum = 0;
+    for (i=0; i<count; i++) {
+        int iteration_count;
+        PyObject *item1, *item2;
+        
+        iteration_count = i + 1;
+        item1 = PySequence_ITEM(first, i);
+        item2 = PySequence_ITEM(second, i);
+        sum += diff(item1, item2);
+        Py_DECREF(item1);
+        Py_DECREF(item2);
+        if ((sum > limit*iteration_count) && (iteration_count >= min_iterations)) {
+            return PyInt_FromSsize_t(limit + 1);
+        }
+    }
+    
+    result = sum / count;
+    if (!result && sum) {
+        result = 1;
+    }
+    return PyInt_FromSsize_t(result);
+}
+
+static PyMethodDef BlockMethods[] = {
+    {"getblocks2",  block_getblocks2, METH_VARARGS, block_getblocks2_doc},
+    {"avgdiff",  block_avgdiff, METH_VARARGS, block_avgdiff_doc},
+    {NULL, NULL, 0, NULL} /* Sentinel */
+};
+
+PyMODINIT_FUNC
+init_block(void)
+{
+    PyObject *m = Py_InitModule("_block", BlockMethods);
+    if (m == NULL) {
+        return;
+    }
+    
+    NoBlocksError = PyErr_NewException("_block.NoBlocksError", NULL, NULL);
+    PyModule_AddObject(m, "NoBlocksError", NoBlocksError);
+    DifferentBlockCountError = PyErr_NewException("_block.DifferentBlockCountError", NULL, NULL);
+    PyModule_AddObject(m, "DifferentBlockCountError", DifferentBlockCountError);
+}
\ No newline at end of file
diff --git a/core_pe/modules/block/block.pyx b/core_pe/modules/block/block.pyx
deleted file mode 100644
index eb7a5758..00000000
--- a/core_pe/modules/block/block.pyx
+++ /dev/null
@@ -1,96 +0,0 @@
-# Created By: Virgil Dupras
-# Created On: 2009-04-23
-# Copyright 2010 Hardcoded Software (http://www.hardcoded.net)
-# 
-# This software is licensed under the "HS" License as described in the "LICENSE" file, 
-# which should be included with this package. The terms are also available at 
-# http://www.hardcoded.net/licenses/hs_license
-
-cdef extern from "stdlib.h":
-    int abs(int n) # required so that abs() is applied on ints, not python objects
-
-class NoBlocksError(Exception):
-    """avgdiff/maxdiff has been called with empty lists"""
-
-class DifferentBlockCountError(Exception):
-    """avgdiff/maxdiff has been called with 2 block lists of different size."""
-
-
-cdef object getblock(object image):
-    """Returns a 3 sized tuple containing the mean color of 'image'.
-    
-    image: a PIL image or crop.
-    """
-    cdef int pixel_count, red, green, blue, r, g, b
-    if image.size[0]:
-        pixel_count = image.size[0] * image.size[1]
-        red = green = blue = 0
-        for r, g, b in image.getdata():
-            red += r
-            green += g
-            blue += b
-        return (red // pixel_count, green // pixel_count, blue // pixel_count)
-    else:
-        return (0, 0, 0)
-
-def getblocks2(image, int block_count_per_side):
-    """Returns a list of blocks (3 sized tuples).
-    
-    image: A PIL image to base the blocks on.
-    block_count_per_side: This integer determine the number of blocks the function will return.
-    If it is 10, for example, 100 blocks will be returns (10 width, 10 height). The blocks will not
-    necessarely cover square areas. The area covered by each block will be proportional to the image
-    itself.
-    """
-    if not image.size[0]:
-        return []
-    cdef int width, height, block_width, block_height, ih, iw, top, bottom, left, right
-    width, height = image.size
-    block_width = max(width // block_count_per_side, 1)
-    block_height = max(height // block_count_per_side, 1)
-    result = []
-    for ih in range(block_count_per_side):
-        top = min(ih * block_height, height - block_height)
-        bottom = top + block_height
-        for iw in range(block_count_per_side):
-            left = min(iw * block_width, width - block_width)
-            right = left + block_width
-            box = (left, top, right, bottom)
-            crop = image.crop(box)
-            result.append(getblock(crop))
-    return result
-
-cdef int diff(first, second):
-    """Returns the difference between the first block and the second.
-    
-    It returns an absolute sum of the 3 differences (RGB).
-    """
-    cdef int r1, g1, b1, r2, g2, b2
-    r1, g1, b1 = first
-    r2, g2, b2 = second
-    return abs(r1 - r2) + abs(g1 - g2) + abs(b1 - b2)
-
-def avgdiff(first, second, int limit, int min_iterations):
-    """Returns the average diff between first blocks and seconds.
-    
-    If the result surpasses limit, limit + 1 is returned, except if less than min_iterations
-    iterations have been made in the blocks.
-    """
-    cdef int count, sum, i, iteration_count
-    count = len(first)
-    if count != len(second):
-        raise DifferentBlockCountError()
-    if not count:
-        raise NoBlocksError()
-    sum = 0
-    for i in range(count):
-        iteration_count = i + 1
-        item1 = first[i]
-        item2 = second[i]
-        sum += diff(item1, item2)
-        if sum > limit * iteration_count and iteration_count >= min_iterations:
-            return limit + 1
-    result = sum // count
-    if (not result) and sum:
-        result = 1
-    return result
\ No newline at end of file
diff --git a/core_pe/modules/block/setup.py b/core_pe/modules/block/setup.py
index 9502488a..97a95657 100644
--- a/core_pe/modules/block/setup.py
+++ b/core_pe/modules/block/setup.py
@@ -8,9 +8,7 @@
 
 from distutils.core import setup
 from distutils.extension import Extension
-from Cython.Distutils import build_ext
 
 setup(
-    cmdclass = {'build_ext': build_ext},
-    ext_modules = [Extension("_block", ["block.pyx"])]
+    ext_modules = [Extension("_block", ["block.c"])]
 )
\ No newline at end of file