[WIP] Fixes to make voxel tracinig compatible with Angle

[kvark]

UAV error

ERR: Context11.cpp:1029 (rx::Context11::triggerDrawCallProgramRecompilation): Error compiling dynamic pixel executable: error X8000: D3D11 Internal Compiler Error: Invalid Bytecode: PS ouputs must be declared in slots less than UAVs.  Output declared in slot 0 while UAV declared in slot 0.  Opcode #10 (count is 1-based). 
error X8000: D3D11 Internal Compiler Error: Invalid Bytecode: Can't continue validation - aborting.

[2024-11-10T08:39:40Z ERROR wgpu_hal::gles::egl] GLES: [API/Error] ID 1282 : Error: 0x00000502, in ..\..\src\libANGLE\renderer\d3d\d3d11\Context11.cpp, rx::Context11::triggerDrawCallProgramRecompilation:1030. Internal D3D11 error: HRESULT: 0x80004005: Error compiling dynamic pixel executable
ERR: Context11.cpp:1029 (rx::Context11::triggerDrawCallProgramRecompilation): Error compiling dynamic pixel executable: C:\fakepath(598,12-121): error X3662: gradient operation uses a value that may not be defined for all pixels (in ps_5_0 UAV loads can not participate in gradient operations)
C:\fakepath(544,26-45): error X3662: this memory access dependent on potentially UAV-related data
C:\fakepath(545,6-19): error X3662: this variable dependent on potentially UAV-related data: result
C:\fakepath(845,6-96): error X3662: this variable dependent on potentially UAV-related data: _Load_uint_std430_cm_x
C:\fakepath(846,10-36): error X3662: this variable dependent on potentially UAV-related data: __e222808
C:\fakepath(969,6-66): error X3662: this variable dependent on potentially UAV-related data: f_check_occupancy_int3_uint
C:\fakepath(1001,6-35): error X3662: this variable dependent on potentially UAV-related data: __e762893
C:\fakepath(478,12-19): error X3662: this variable dependent on potentially UAV-related data: x0
C:\fakepath(1004,30-87): error X3662: this variable dependent on potentially UAV-related data: uint_ctor
C:\fakepath(1006,28-61): error X3662: this variable dependent on potentially UAV-related data: _num_linear_steps2919
C:\fakepath(1018,6-40): error X3662: this variable dependent on potentially UAV-related data: _num_inner_steps_12872
C:\fakepath(1019,6-20): error X3662: this variable dependent on potentially UAV-related data: __e1582925
C:\fakepath(605,57-74): error X3662: this variable dependent on potentially UAV-related data: a
C:\fakepath(605,57-74): error X3662: this variable dependent on potentially UAV-related data: mix_emu
C:\fakepath(1027,6-102): error X3662: this variable dependent on potentially UAV-related data: mix_emu
C:\fakepath(1042,24-52): error X3662: this variable dependent on potentially UAV-related data: _voxel_shift2927
C:\fakepath(1044,5-37): error X3662: this variable dependent on potentially UAV-related data: _lod_voxel_pos2875
C:\fakepath(1045,28-41): error X3662: this variable dependent on potentially UAV-related data: __e2232938
C:\fakepath(965,3-15): error X3662: this loop dependent on potentially UAV-related data
C:\fakepath(1014,1-18): error X3662: this variable depends on potentially UAV-related data on loop exit: _pos_112873
C:\fakepath(1075,8-31): error X3662: this variable dependent on potentially UAV-related data: _pos_112873
C:\fakepath(1076,8-45): error X3662: this variable dependent on potentially UAV-related data: __e2522948
C:\fakepath(408,16-36): error X3662: this variable dependent on potentially UAV-related data: x0
C:\fakepath(409,5-21): error X3662: this variable dependent on potentially UAV-related data: structure
C:\fakepath(1076,1-46): error X3662: this variable dependent on potentially UAV-related data: _CastPoint_ctor
C:\fakepath(1076,46): error X3662: this variable dependent on potentially UAV-related data: f_cast_ray_through_voxels
C:\fakepath(1076,46): error X3662: this variable dependent on potentially UAV-related data: f_cast_ray_through_voxels
C:\fakepath(1076,46): error X3662: this variable dependent on potentially UAV-related data: f_cast_ray_through_voxels
C:\fakepath(748,34-82): error X3662: this variable dependent on potentially UAV-related data: f_cast_ray_through_voxels
C:\fakepath(754,101-153): error X3662: this variable dependent on potentially UAV-related data: _homogeneous_coords2744
C:\fakepath(438,5-26): error X3662: this variable dependent on potentially UAV-related data: x1
C:\fakepath(754,21-161): error X3662: this variable dependent on potentially UAV-related data: vec3_ctor
C:\fakepath(598,12-121): error X3662: this variable dependent on potentially UAV-related data: t

[kvark]

Angle keeps disappointing:

    float gl_texture2D_comparisonLod(uint samplerIndex, float3 t, float lod)
    {
        const uint textureIndex = samplerIndex - textureIndexOffset2D_comparison;
        const uint samplerArrayIndex = samplerIndex - samplerIndexOffset2D_comparison;
        return textures2D_comparison[textureIndex].SampleCmp(samplers2D_comparison[samplerArrayIndex], float2(t.x, t.y), t.z);
    }

This is supposed to be a fixed-LOD sample, but Angle just ignored the LOD.

Ok, this is a real bummer.
I tried sampling LOD without comparison:

let depth = textureSampleLevel(
        t_Shadow, s_PaletteSampler,
        light_local, 0.0,
    );
let shadow = step(homogeneous_coords.z / homogeneous_coords.w, depth);

Gives me

Internal error in ShaderStages(FRAGMENT) shader: ERROR: 0:121: 'textureLod' : no matching overloaded function found

I tried loading from the texture

    let dim = vec2<f32>(textureDimensions(t_Shadow, 0).xy);
    let depth = textureLoad(t_Shadow, vec2<i32>(light_local * dim), 0);

Gives me:

Internal error in ShaderStages(FRAGMENT) shader: WGSL textureLoad from depth textures is not supported in GLSL