Yes some time in the future it might be nice if Jonathan and
Philippe could team up on the rendering code. Philippeqc hasn't posted in a while but he was reading up on the opengl documentation (is there both a red book and a blue book?).
Me I'm just planning on getting to learn blender well at some point in the future (it won't be soon, nothing is ever "soon" for me lol). Which brings up a question: does opengl or sdl have (m)any standard filetypes for models/meshes? If they do maybe we should use one of them?
On the color problem with the alpha layering in dual textured floor, I'll share my experiences, and the solution I've finally found
The examples below are used with moviepack_floor_red/green/blue values of 0.5.
Current method one:
Make floor_a.png with the highest ten pixels white (FFFFFF) and the rest red (FF0000).
Make floor_b.png with the leftmost ten pixels white (FFFFFF) and the rest red (FF0000).
Result:
Grid line intersections = FFFFFF (intersection of the white parts of both floor_a and _b).
Grid lines assuming 50% opacity in the rendering of the layers and moviepack_floor rgb values of 0.5 = (FFFFFF/2)+(FF0000/2) = 777777+770000 = FF7777 i.e. a pale red.
Grid tiles = FF0000 (intersection of the red parts of both floor_a and _b).
Current method two:
Make floor_a.png as above.
Make floor_b.png with the leftmost ten pixels white and the rest 100% transparent.
Result:
Grid line intersections = FFFFFF.
Grid lines created from _a = FFFFFF as the 100% transparent part of _b doesn't affect them.
Grid lines created from _b = FF7777 as above because the red part of _a affects them.
Grid tiles = as above.
Note that this method will create lines with differing "brightness" and might be what you were thinking of Johnatan. Keep in mind the lines might also look like they have different brightness depending on the direction you're travelling: lines parallel to the direction will seem brighter than those crossing it for optical reasons (depending on speed) and this is entirely correct.
Current method three:
Make floor_a.png with the top ten pixels white and the rest 100% transparent.
Make floor_b.png with the leftmost ten pixels white and the rest 100% transparent.
Result:
Grid line intersections = FFFFFF.
Grid lines = 777777 because each layer is 50% opaque and the base value of the grid is pure black 000000.
Grid tiles = 000000 (base colour).
Note that if you try to use moviepack_floor_red/green/blue you will only change the values applied to the grid lines and not the base color in this situation.
If we change moviepack_floor_red/green/blue to 1 we will in method three above get a pure black floor with pure white lines (so this is indeed possible).
In method two above we get pure white lines with lighter red tiles than the texture red.
In method one above we get the same as with method two.
So one gets to choose if one wants pure gridlines or the correct (in relation to texture color) floor color, or neither
you can't have both in a simple way.
The solution:
What possible workarounds are there? The solution if you go for both pure gridlines and correct floor color using method one or two above with moviepack_floor_red/green/blue of 1 is to try to preempt the problem with the floor color by making texture floor color darker than it should be. For both floor_a.png and floor_b.png add a 50% transparent layer with a pure black fill over the red parts only. This seems to work correctly for me I've tested it with wall textures which have the correct color and the modified floor textures gave the same color tone to the unshaded walls.
of course it would be 7F7F7Fh (I added the h on there because I wonder if this is international hex notation or just norwegian? At uni they used to add a small h, o, d or b depending). Remember to count the zero as first value (so it's 7F and 127, both are half of 256 values in total including 0 and up to and including 255) 