[Matplotlib-checkins] SF.net SVN: matplotlib: [3589] trunk/matplotlib/src/ft2font.cpp

[<md...@us...>]

Revision: 3589
          http://matplotlib.svn.sourceforge.net/matplotlib/?rev=3589&view=rev
Author:   mdboom
Date:     2007-07-20 07:15:29 -0700 (Fri, 20 Jul 2007)

Log Message:
-----------
Improve performance of inner loop and prevent segfaults with negative x or y in draw_bitmap.

Modified Paths:
--------------
    trunk/matplotlib/src/ft2font.cpp

Modified: trunk/matplotlib/src/ft2font.cpp
===================================================================
--- trunk/matplotlib/src/ft2font.cpp	2007-07-20 14:08:58 UTC (rev 3588)
+++ trunk/matplotlib/src/ft2font.cpp	2007-07-20 14:15:29 UTC (rev 3589)
@@ -876,25 +876,28 @@
   return Py::Int(- bbox.yMin);;
 }
 
+#undef	CLAMP
+#define CLAMP(x, low, high)  (((x) > (high)) ? (high) : (((x) < (low)) ? (low) : (x)))
+
 void
 FT2Font::draw_bitmap( FT_Bitmap*  bitmap,
 		      FT_Int      x,
 		      FT_Int      y) {
   _VERBOSE("FT2Font::draw_bitmap");
   FT_Int  i, j, p, q;
-  FT_Int  x_max = x + bitmap->width;
-  FT_Int  y_max = y + bitmap->rows;
-
   FT_Int width = (FT_Int)image.width;
   FT_Int height = (FT_Int)image.height;
-  for ( i = x, p = 0; i < x_max; i++, p++ )
+
+  FT_Int x1 = CLAMP(x, 0, width);
+  FT_Int y1 = CLAMP(y, 0, height);
+  FT_Int x2 = CLAMP(x + bitmap->width, 0, width);
+  FT_Int y2 = CLAMP(y + bitmap->rows, 0, height);
+
+  for ( i = x1, p = 0; i < x2; ++i, ++p )
     {
-      for ( j = y, q = 0; j < y_max; j++, q++ )
+      for ( j = y1, q = 0; j < y2; ++j, ++q )
 	{
-	  if ( i >= width || j >= height )
-	    continue;
-	  image.buffer[i + j*width] |= bitmap->buffer[p + q*bitmap->width];
-
+	  image.buffer[i + j*width] |= bitmap->buffer[p + q*bitmap->pitch];
 	}
     }
 }


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