Posted by Brian Levantine on September 12, 2007 at 10:14:37:
In Reply to: Wallpaper posted by Stephen Auerbach on September 11, 2007 at 08:45:09:
In order to display a proper background wallpaper, the "field" part (vs "text") of any QCRT character must be made transparent so it will blend into the background. Otherwise, you'd end up punching holes into the wallpaper with each character. Most QCRT applications use the "field" color to distinguish between prompts (SB) and entry areas (SF). When using wallpaper I found that screens look much better if QCRT foreground characters were allowed to punch through the wallpaper, clearly identifying entry areas, and the background areas were left transparent. In order to do the blending, COSW needs to have some way to distinguish those QCRT characters that we want to blend from any others. This is done using the only QCRT character attribute available - the "field" color (upper 4 bits of the configured color). If you want all characters to blend, then you can specify that all colors will blend, and that's the end of it (more or less). Otherwise you must tell COSW which one (and only one) field color will be the transparent color.
While this mechanism works well enough once you figure it all out, it can be very difficult to implement due to varying color configurations in both Windows and Comet. If you still want to proceed with this, let me know what kind of screen(s) you would like to try this on and I'll put something together to get you going.