Fix Mac OS 8.6 ATI Rage drawing artifacts - #202
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Mac OS 8.6 programs GUI_TRAJ_CNTL to set draw-engine direction and issues fills through several destination register initiators. Model the composite register, destination initiators, signed inclusive scissors, tiling side effects, and Always_1 source selection. Accept source mix 7 independently of the unused background mix for solid fills, and consume 8-bit HOST_DATA writes in trajectory order. This lets the desktop paint and prevents host uploads from being reversed or clipped. References: - ATI 3D Rage LT Pro Register Reference Guide, pp. 5-8--5-12, 5-33, 5-39--5-42, 5-47--5-51, 5-58, and 5-64--5-65. - ATI Rage Pro and Derivatives Programmer's Guide, pp. 6-5, 6-11--6-19, and 6-27--6-29.
Mac OS 8.6 uses general and rotated source trajectories when drawing Finder icons and the Control Strip. Preserve both source size/start composites and repeat their first and second rectangles according to SRC_CNTL. Use the documented signed source coordinates and inclusive scissors while advancing the source for clipped destination pixels. Unbounded blits continue to use the existing linear trajectory. References: - ATI 3D Rage LT Pro Register Reference Guide, pp. 5-21--5-31 and 5-39--5-42. - ATI Rage Pro and Derivatives Programmer's Guide, pp. 6-11--6-19, 6-31--6-33, and 6-42.
The Mac OS 8.6 driver enables color-register writes without enabling block writes to update SGRAM state. Treat that command as a register-only operation instead of sending it through the VRAM blitter, while retaining the documented destination tiling side effects. This prevents the command from producing stray pixels near the menu bar and Control Strip. References: - ATI 3D Rage LT Pro Register Reference Guide, pp. 5-21--5-24. - ATI Rage Pro and Derivatives Programmer's Guide, pp. 6-11--6-19.
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Aug 8, 2026
Includes dingusdev/dingusppc#202 which implements more ATI Rage features. For #219
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Fix rendering glitches when enabling all the ATI extensions and booting with the Beige G3 ROM.
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