Hey !
I’m working on a vulkan game engine where my shaders are compiled from HLSL or GLSL using glslang.
Problem : the spirv generated from hlsl code seems to be broken : it doesn’t write to the framebuffers, and there are some weird behaviors when I use the RenderDoc mesh viewer :
=> With a HLSL shader, RenderDoc seems to fail to determine the view’s frustum (the left pannel is grayed out)
The render pipeline is exactly the same, the code is equivalent. The only difference is the shader language. Am i missing something or should I post an issue on the glslang github ?
(This is the first time i use HLSL with vulkan so i maybe missed something obvious)
This is the glsl code (working) :
#pragma shader_language GLSL
// NOTE : this file is not directly sent to the compiller,
// the "global" and "vertex" blocks are merged into the vertex shader code,
// and the "global" and "fragment" blocks are merged into the fragment shader code.
global(gbuffer)
[
#version 450
]
vertex(gbuffer)
[
layout(location = 0) in vec3 inPos;
layout(binding = 0) uniform UBO
{
mat4 projection;
mat4 view;
} view_ubo;
void main()
{
vec2 uv = vec2((gl_VertexIndex << 1) & 2, gl_VertexIndex & 2);
gl_Position = vec4(uv * 2.0f - 1.0f, 0.0f, 1.0f);
//view_ubo.projection * view_ubo.view * vec4(inPos, 0);
}
]
fragment(gbuffer)
[
layout (location = 0) out vec4 outPosition;
layout (location = 1) out vec4 outNormal;
layout (location = 2) out vec4 outAlbedo;
void main()
{
outPosition = vec4(1, 1, 1, 1.0);
outNormal = vec4(1, 1, 1, 1.0);
outAlbedo = vec4(1, 1, 1, 1.0);
}
]
and the hlsl version (broken)
#pragma shader_language HLSL
// NOTE : this file is not directly sent to the compiller,
// the "global" and "vertex" blocks are merged into the vertex shader code,
// and the "global" and "fragment" blocks are merged into the fragment shader code.
global(gbuffer)
[
int _Subdivision = 4;
int _Width = 1;
struct VsToFsStruct
{
[[vk::location(0)]] float4 Pos : POSITION0;
};
]
vertex(gbuffer)
[
struct ViewUbo
{
float4x4 projection;
float4x4 view;
float end;
};
cbuffer view_ubo : register(b0)
{
ViewUbo view_ubo;
}
struct VsInput
{
float3 pos : POSITION0;
uint vertex_index : SV_VertexID;
};
VsToFsStruct main(VsInput input)
{
VsToFsStruct output = (VsToFsStruct) 0;
float2 uv = float2((input.vertex_index << 1) & 2, input.vertex_index & 2);
output.Pos = float4(uv * 2.0f - 1.0f, 0.0f, 1.0f);
return output;
}
];
fragment(gbuffer)
[
struct FSOutput
{
float4 Color1 : SV_TARGET0;
float4 Color2 : SV_TARGET1;
float4 Color3 : SV_TARGET2;
};
FSOutput main(VsToFsStruct input)
{
FSOutput output = (FSOutput) 0;
output.Color1 = float4(1, 10, 5, 1);
output.Color2 = float4(1, 1, 1, 1);
output.Color3 = float4(1, 1, 1, 1);
return output;
}
];
The function that generate the TShader :
And the TProgram : https://github.com/PierreEVEN/HeadlessEngine/blob/2d97b3d6a87d3cd3b9ba88afe47a16a56315ffd6/src/engine/shader_builder/private/compiler.cpp#L263
