Only GLES 3.2 supports glColorMaski, which would exclude any platforms only supporting GLES 3.0 or 3.1, so we simply change the color attachment accordingly. This change also improves VRAM usage, as now there's only a single u/v texture used for both framebuffers as required.
Milkdrop shaders are now read from .vert/.frag and .inc files, then copied into a generated code file by CMake. Makes editing easier, as many IDEs can properly syntax-highlight the shader code.
The class was also moved into MilkdropPreset, as it's the only preset type which will ever make use of those shaders.
Deleted the now fully "dissolved" ShaderEngine class.
Idle preset doesn't render the same way as before, as it was presumably adapted to projectM's previous math. It's now a bit more complex, with the M tilting, a sine waveform at the bottom and some other tweaks.
The filter mesh was broken, so the effects didn't render at all.
Main issue was a wrong -, replaced with + in the rotation calculation. Plus we shouldn't negate the Y pos, as this may mess up UV calculations done in HLSL.
Have to do the motion reverse-propagation on the GPU, as the warp mesh is also calculated there. This is done storing the U/V warp coordinates in a separate texture attachment and then read the (already interpolated) coordinate in the next frame.
Added a second color buffer output to the HLSL shader to accomplish it with both the default warp shader and preset-supplied ones. Luckily, the HLSL transpiler knows what to do.
Since all framebuffer textures must match in size, this adds a bit more VRAM usage. We also need to mask all other draw calls from writing to the second texture expect in the warp shader.
Fixed a transpile issue with a hack used by some preset authors to set a texture sampler to a different filter/wrap mode, removing the "sampler_state" block entirely now as there's no GLSL equivalent (samplers are solely configured on the application side).
Also consolidated a few vertex types into RenderItem and fixed a few old-school effects like DarkenCenter.
Moved per-pixel mesh texture coordinate calculations into the vertex shader. This is probably more performant than the SSE2 code in the old PresetFrameIO class, as the GPU is better at running this stuff in parallel.
All the texture management also needs some refactoring, so now that I've already broken everything, I can just do it as well.
Now using Milkdrop's DX9 coordinate system for all vertex positions and have the vertex shader take care of transforming these into the OpenGL screen space. Makes calculations easier.
Also continued implementing per-pixel mesh and shader stuff.
Don't skip lines with no data after "=", as there are many presets with empty code lines. skipping it would create a gap in the line numbers, aborting the loop in GetCode() early.
