SftTabs/OCX 6.5 - Tab Control for VB6

Bitmap Transparency

SftTabs/OCX automatically uses bitmap transparency for all bitmaps used throughout a tab control, defined using the Image.Picture and Tab.Picture properties. When a bitmap is displayed, the background can show through portions of the bitmap. SftTabs/OCX accomplishes this by dynamically modifying a copy of the bitmap to adjust for the background color. While icons and ImageLists are also supported by SftTabs/OCX, these image formats already define transparency, based on how the image was created. These image formats receive no special processing by SftTabs/OCX.

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 color.

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 fully automatic and cannot be turned off.

Bitmap transparency is fully automatic (for images based on bitmaps, defined using the Tab.Picture property) and cannot be turned off. Icons, ImageLists, GDI+ images are not affected by bitmap transparency.