Draws a bitmap, replacing its background with a dithered (checker) pattern.
Points to the destination DC.
The destination x-coordinate.
The destination y-coordinate.
The source bitmap.
One of the two dither colors, typically white.
The other dither color, typically light gray (COLOR_MENU).
The source bitmap is drawn on the destination DC with a two-color (cr1 and cr2) checkered pattern replacing the bitmap's background. The background of the source bitmap is defined as its white pixels and all pixels matching the color of the pixel in the upper-left corner of the bitmap.