Shader reflection API issues #4259
Description
Hi,
I don't know if it's the right place to ask questions but I will post it here and if it is not appropriate, I can move the discussion elsewhere.
I am using slang reflection API to feed my engine but I have some troubles.
For some UTs, I have this shader in slang:
struct Stuff
{
int a;
float b;
};
struct Things
{
Texture2D t;
ParameterBlock<Stuff> stuff;
};
ParameterBlock<Stuff> gStuff;
Texture2D gTex;
ConstantBuffer<Things> gThings;
SamplerState s;
RWStructuredBuffer<float> result;
[shader("compute")]
[numthreads(16, 16, 1)]
void main(uint3 threadId: SV_DispatchThreadID)
{
result[0] = (float)gStuff.a + gStuff.b + gTex.SampleLevel(s, float2(0, 0), 0).x + (float)gThings.stuff.a+ gThings.stuff.b + gThings.t.SampleLevel(s, float2(0, 0), 0).x;
}
This is just for unit testing so don't look at the stuff in main.
That will compil into this : (with latest branch 2024.1.18
#version 450
layout(row_major) uniform;
layout(row_major) buffer;
#line 18 0
layout(std430, binding = 3) buffer StructuredBuffer_float_t_0 {
float _data[];
} result_0;
#line 4
struct Stuff_std140_0
{
int a_0;
float b_0;
};
layout(binding = 0, set = 1)
layout(std140) uniform _S1
{
int a_0;
float b_0;
}gStuff_0;
#line 14
layout(binding = 0)
uniform texture2D gTex_0;
#line 16
layout(binding = 2)
uniform sampler s_0;
#line 16
layout(binding = 1)
uniform texture2D gThings_t_0;
#line 16
layout(binding = 0, set = 2)
layout(std140) uniform _S2
{
int a_0;
float b_0;
}gThings_stuff_0;
layout(local_size_x = 16, local_size_y = 16, local_size_z = 1) in;
void main()
{
#line 24
const vec2 _S3 = vec2(0.0, 0.0);
#line 24
result_0._data[0U] = float(gStuff_0.a_0) + gStuff_0.b_0 + (textureLod(sampler2D(gTex_0,s_0), (_S3), (0.0))).x + float(gThings_stuff_0.a_0) + gThings_stuff_0.b_0 + (textureLod(sampler2D(gThings_t_0,s_0), (_S3), (0.0))).x;
return;
}
What I am trying to achieve is to get the correct binding and set for Vulkan for each variable. This shader is basded on an old comment I found in your repo when you were still using childSet in SimpleBindingOffset.
I am using this to compute the relative binding and set of variable
/// Create an offset based on offset information in the given Slang `varLayout`
SimpleBindingOffset(slang::VariableLayoutReflection* varLayout)
{
if (varLayout)
{
bindingSet = varLayout->getBindingSpace() + (Uint32)varLayout->getOffset(SLANG_PARAMETER_CATEGORY_SUB_ELEMENT_REGISTER_SPACE);
binding = (Uint32)(varLayout->getOffset(SLANG_PARAMETER_CATEGORY_DESCRIPTOR_TABLE_SLOT));
pushConstantRange =
(uint32_t)varLayout->getOffset(SLANG_PARAMETER_CATEGORY_PUSH_CONSTANT_BUFFER);
}
}
And I am adding recursively the offset with the parent. THe thing is that I get binding = 1 and set = 2 for gThings. But the gThings.t is in set 0 as the GLSL is showing (and binding 1). How am I supposed to get the right result ?
I read the documentation but I still have trouble understanding everything.
You can see part of my code here! I modified it a bit since last time but nothing fancy. #3318
Thanks,
Baptiste