+// VZ: we use a separate function to do the actual colour mapping because
+// otherwise VC++ optimizer seems to mangle the code in MapBitmap(): with
+// optimization on, the code produces incorrect result (but it's ok in
+// debug mode, i.e. globally without optimizations or if you insert a
+// #pragma optimize("", off) just before the function!)
+//
+// This will also make it simpler to replace MapColours() later with
+// something more efficient...
+static void MapColours(HDC hdc, int width, int height,
+ size_t numColours, COLORMAP *cmap)
+{
+ for ( int i = 0; i < width; i++ )
+ {
+ for ( int j = 0; j < height; j++ )
+ {
+ COLORREF pixel = ::GetPixel(hdc, i, j);
+
+ for ( size_t k = 0; k < numColours; k++ )
+ {
+ COLORREF col = cmap[k].from;
+ if ( abs(GetRValue(pixel) - GetRValue(col)) < 10 &&
+ abs(GetGValue(pixel) - GetGValue(col)) < 10 &&
+ abs(GetBValue(pixel) - GetBValue(col)) < 10 )
+ {
+ ::SetPixel(hdc, i, j, cmap[k].to);
+ break;
+ }
+ }
+ }
+ }
+}
+