HCSLLib

HCSLLib is a library that can be included in HCSL. By using a library, convenient functions and frequently used functions are grouped into a library file so that they can be easily reused.

The basic syntax is the same as HCSL, consisting of the following elements. Inside the hcsllib block, functions can be implemented using the same syntax as the shader block in HCSL.

• Version Preprocessor
• hcsllib block (this takes the place of hcsl in an hcsllib file)

#version 1

hcsllib "LibraryName"
{
    // Implement functions the same way as in the shader block
}

The file extension is .hcsl just like regular HCSL files. When including a library in HCSL, specify the library name assigned inside HCSLLib.

Built-in HCSLLib

These are standard HCSLLibs provided by the engine. You can include and use them the same way as user-defined HCSLLibs.

Built-in HCSLLib and Useable Function List

Library Name	Function	Description
"HCSLCore/Texture"	vec2 helCalcUVTransform(vec2 SrcUV, vec4 TexST)	Calculates UV coordinates incorporating the scale and offset of the texture.
"HCSLCore/Lighting"	vec3 helComputeDirectLight(vec3 worldNormal, vec3 worldPos, vec3 cameraPos, vec3 surfaceColor, float roughness, float metallic, vec3 lightColor, vec3 lightDir)	Calculates direct light lighting in PBR.
"HCSLCore/Lighting"	vec3 helComputeIndirectLight(vec3 worldNormal, vec3 worldPos, vec3 cameraPos, vec3 surfaceColor, float roughness, float metallic, vec3 lightColor, vec3 lightDir)	Calculates indirect light (environment map) lighting in PBR.
"HCSLCore/Lighting"	vec3 helComputeIBLLight(vec3 worldNormal, vec3 worldPos, vec3 cameraPos, vec3 surfaceColor, float roughness, float metallic)	Calculates lighting via IBL. Cannot be previewed in Unity.

Implementation Examples

HCSLLib Creation Example

// HCSLLibTest.hcsl

#version 1

// Library Name
hcsllib "TestLib"
{
    float helRand(vec2 st)
    {
        return fract(sin( dot(st, vec2(12.9898,78.233)) ) * 43758.5453);
    }
}

Using HCSLLib in HCSL Example

pass Geometry_Opaque
{
    attribute
    {
        vec3 _Position : VS_POSITION;
    }

    output vertex
    {
        vec4 outPos : VS_OUT_POSITION;
    }

    shader vertex
    {
        void main()
        {
            outPos = HEL_MATRIX_P * HEL_MATRIX_V * HEL_MATRIX_W * vec4(_Position, 1.0);
        }
    }

    output fragment
    {
        vec4 outColor : FS_COLOR;
    }

    uniform fragment
    {
        sampler2D _MainTex;
        vec4 _MainTex_ST;
    }

    shader fragment
    {
        // Include to use helRand function
        // helRand is defined in another file named TestLib
        #include "TestLib"

        // Include to use helCalcUVTransform function
        // HCSLCore/Texture is a built-in library
        #include "HCSLCore/Texture"

        void main()
        {
            vec2 st = helCalcUVTransform(uv, _MainTex_ST);
            vec4 col = helTexture(_MainTex, st) * helRand(vec2(0.5));

            outColor = col;
        }
    }
}

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