When using Aleph One's software renderer in Marathon 1's scenario, the blue/white texture in "Shake Before Using..." does not render the same as the original game, causing a misaligned zigzag-like pattern. But, only when it's a floor or ceiling - walls are accurate.
Marathon 1 Original:
Aleph One software rendering:
Renders correctly in Aleph One's OpenGL rendering:
OpenGL is default so most people will never see this bug.
This is because that texture has a size of 129x130, with a bytes per row of 130 - it's not a standard 128x128. Aleph One's renderer is from Marathon 2, and it expects a power-of-two texture. There's another texture from that set that's 129x128, with a bytes per row of 128, but I do not know if it renders correctly on the floor/ceiling.
Here's the texture in the Marathon 2 engine, as suggested by treellama:
It does indeed render the exact same buggy way, since A1's renderer is a slightly extended version of M2's.
I imagine M1's renderer must have been more permissive, and someone at Bungie didn't crop the texture properly.
Fixing it might require a separate code path in texture_horizontal_polygon_lines() (low_level_textures.h) and maybe _pretexture_horizontal_polygon_lines() (scottish_textures.cpp), specifically when rendering a non-POW2 textures. The math here is arcane and old so that might not be terribly easy.
texture_vertical_polygon_lines() (low_level_textures.h) renders this texture correctly on the walls.
When using Aleph One's software renderer in Marathon 1's scenario, the blue/white texture in "Shake Before Using..." does not render the same as the original game, causing a misaligned zigzag-like pattern. But, only when it's a floor or ceiling - walls are accurate.
Marathon 1 Original:
Aleph One software rendering:
Renders correctly in Aleph One's OpenGL rendering:
OpenGL is default so most people will never see this bug.
This is because that texture has a size of 129x130, with a bytes per row of 130 - it's not a standard 128x128. Aleph One's renderer is from Marathon 2, and it expects a power-of-two texture. There's another texture from that set that's 129x128, with a bytes per row of 128, but I do not know if it renders correctly on the floor/ceiling.
Here's the texture in the Marathon 2 engine, as suggested by treellama:
It does indeed render the exact same buggy way, since A1's renderer is a slightly extended version of M2's.
I imagine M1's renderer must have been more permissive, and someone at Bungie didn't crop the texture properly.
Fixing it might require a separate code path in texture_horizontal_polygon_lines() (low_level_textures.h) and maybe _pretexture_horizontal_polygon_lines() (scottish_textures.cpp), specifically when rendering a non-POW2 textures. The math here is arcane and old so that might not be terribly easy.
texture_vertical_polygon_lines() (low_level_textures.h) renders this texture correctly on the walls.