SftOptions 1.0 - ActiveX Options Control

Bitmap Transparency

SftOptions automatically uses bitmap transparency for all bitmaps used throughout an options control. When a bitmap is displayed, the background can show through portions of the bitmap. SftOptions accomplishes this by dynamically modifying a copy of the bitmap to adjust for the background.

The top, left pixel of each bitmap is inspected as the bitmap is painted. The color of that pixel represents the bitmap's background color. This color is replaced throughout the bitmap with the actual background.

If the bitmap image includes the top, left pixel, add an extra row or column of pixels to the bitmap, so the image does not include the top, left pixel.

Bitmap transparency is not used for icons, Windows metafiles or images in an ImageList control.

Bitmap transparency is fully automatic and cannot be turned off.