+bool wxImage::ConvertAlphaToMask(unsigned char threshold)
+{
+ if (!HasAlpha())
+ return true;
+
+ unsigned char mr, mg, mb;
+ if (!FindFirstUnusedColour(&mr, &mg, &mb))
+ {
+ wxLogError( _("No unused colour in image being masked.") );
+ return false;
+ }
+
+ SetMask(true);
+ SetMaskColour(mr, mg, mb);
+
+ unsigned char *imgdata = GetData();
+ unsigned char *alphadata = GetAlpha();
+
+ int w = GetWidth();
+ int h = GetHeight();
+
+ for (int y = 0; y < h; y++)
+ {
+ for (int x = 0; x < w; x++, imgdata += 3, alphadata++)
+ {
+ if (*alphadata < threshold)
+ {
+ imgdata[0] = mr;
+ imgdata[1] = mg;
+ imgdata[2] = mb;
+ }
+ }
+ }
+
+ free(M_IMGDATA->m_alpha);
+ M_IMGDATA->m_alpha = NULL;
+
+ return true;
+}
+