8th
Raster bars demo done
Furiously preparing for gameboy class. I’m super-psyched (two times) about it. Last night I got the old skoolest of ‘tro routines working, good old raster bars. I’ll up a screenshot later tonight.
Raster bars are one of my favorite effects because they’re quite a hack. It looks like they’re moving, but in reality you’re not drawing anything at all. They take advantage of the palette modes and of the horizontal and vertical blank interrupts. During each vertical blank you adjust an array of colors the length of the screen. During each horizontal blank you set the color of palette 0 to a color stored in the array (according to the vertical line register). The color changes while the horizontal line is drawn to the actual screen, and repeat.
Tonight I work in one of the tiled modes and will put together the simple elements of a an actual game. I think that’s where the class will leave off for next time. I’m documenting stuff on a wiki, but it’s not 100% up to date.