LLGL::CombinedTextureSamplerDescriptor Struct Reference

Descriptor structure for a combined texture-sampler. More...

#include <PipelineLayoutFlags.h>

Public Attributes
StringLiteral	name
	Specifies the name of an individual shader uniform. This must not be empty.
StringLiteral	textureName
	Specifies the name of the texture binding that is meant to be combined with a sampler binding.
StringLiteral	samplerName
	Specifies the name of the sampler binding that is meant to be combined with a texture binding.
BindingSlot	slot
	Specifies the binding slot of the combined texture-sampler.

Detailed Description

Descriptor structure for a combined texture-sampler.

Remarks

Combined texture-samplers are only required for OpenGL when a sampler is meant to be used for more than one texture in a shader. The following example of an HLSL (Direct3D) shader illustrates how these descriptors are meant to be used:

SamplerState linearSampler;
SamplerState nearestSampler;
 
Texture2D colorMapA;
Texture2D colorMapB;
Texture2D colorMapC;
 
float4 PSMain(float2 tc : TEXCOORD) : SV_Target {
    // Use each sampler with two textures
    return
        colorMapA.Sample(linearSampler,  tc) + // Tex A with Sampler A
        colorMapB.Sample(linearSampler,  tc) + // Tex B with Sampler A
        colorMapB.Sample(nearestSampler, tc) + // Tex B with Sampler B
        colorMapC.Sample(nearestSampler, tc);  // Tex C with Sampler B
}

This could be translated to GLSL as follows:

#version 330
 
uniform sampler2D colorMapA_linearSampler;
uniform sampler2D colorMapB_linearSampler;
uniform sampler2D colorMapB_nearestSampler;
uniform sampler2D colorMapC_nearestSampler;
 
in vec2 tc;
out vec4 fragColor;
 
void main() {
    fragColor =
        texture(colorMapA_linearSampler,  tc) +
        texture(colorMapB_linearSampler,  tc) +
        texture(colorMapB_nearestSampler, tc) +
        texture(colorMapC_nearestSampler, tc);
}

For GLSL, this requires four combined texture-sampler descriptors:

LLGL::PipelineLayoutDescriptor myPSOLayout;
 
myPSOLayout.bindings = {
    LLGL::BindingDescriptor{ "linearSampler",  LLGL::ResourceType::Sampler, ... },
    LLGL::BindingDescriptor{ "nearestSampler", LLGL::ResourceType::Sampler, ... },
    LLGL::BindingDescriptor{ "colorMapA",      LLGL::ResourceType::Texture, ... },
    LLGL::BindingDescriptor{ "colorMapB",      LLGL::ResourceType::Texture, ... },
    LLGL::BindingDescriptor{ "colorMapC",      LLGL::ResourceType::Texture, ... },
};
 
myPSOLayout.combinedTextureSampler = {
    LLGL::CombinedTextureSamplerDescriptor{ "colorMapA_linearSampler",  "colorMapA", "linearSampler",  1 },
    LLGL::CombinedTextureSamplerDescriptor{ "colorMapB_linearSampler",  "colorMapB", "linearSampler",  2 },
    LLGL::CombinedTextureSamplerDescriptor{ "colorMapB_nearestSampler", "colorMapB", "nearestSampler", 3 },
    LLGL::CombinedTextureSamplerDescriptor{ "colorMapC_nearestSampler", "colorMapC", "nearestSampler", 4 },
};

Note

Only supported with: OpenGL, Vulkan.

See also

PipelineLayoutDescriptor::combinedTextureSamplers

Member Data Documentation

name

StringLiteral LLGL::CombinedTextureSamplerDescriptor::name

Specifies the name of an individual shader uniform. This must not be empty.

Remarks

This is the name of the combined texture-sampler in the shader, e.g. "myTex" for uniform sampler2D myTex; in GLSL.

samplerName

StringLiteral LLGL::CombinedTextureSamplerDescriptor::samplerName

Specifies the name of the sampler binding that is meant to be combined with a texture binding.

Remarks

This can refer to either an entry in heapBindings, bindings, or staticSamplers of PipelineLayoutDescriptor.

See also

BindingDescriptor::name

slot

BindingSlot LLGL::CombinedTextureSamplerDescriptor::slot

Specifies the binding slot of the combined texture-sampler.

Remarks

This overrides the binding slot for both the texture and sampler binding that this combined texture-sampler refers to. The binding and stage flags are each a bitwise OR combination of the texture and sampler respectively.

textureName

StringLiteral LLGL::CombinedTextureSamplerDescriptor::textureName

Specifies the name of the texture binding that is meant to be combined with a sampler binding.

Remarks

This can refer to either an entry in heapBindings or bindings of PipelineLayoutDescriptor.

See also

BindingDescriptor::name

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The documentation for this struct was generated from the following file:

• PipelineLayoutFlags.h