| Transparency is one of the most used features of logiBITBLT. The source bitmap is conditionally transferred to the destination bitmap. Some pixels in the destination bitmap area (rectangle) keep the destination pixel value, while others are assigned by source pixel value (color). logiBITBLT uses color-keyed transparency operation method. One color in the source bitmap is declared the transparency key. Whenever this color occurs in the source bitmap, the source pixel is not transferred to the destination bitmap. Instead this destination bitmap pixel remains unaltered. The background color register (BG_COL_REG) is used as color key setup for the transparent logiBITBLT operations. |