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Reuse HLSL code

Include or duplicate HLSL in different places, or share pragma directives across different shaders.
Read time 2 minutesLast updated a month ago
To tell the compiler to include existing High-Level Shader Language (HLSL) code in another file or section, use the following methods:
  • Include an HLSL file in another, using the standard HLSL 
    #include
    directive.
  • Duplicate HLSL in multiple places using the 
    HLSLINCLUDE
    and 
    ENDHLSL
    macros.
  • Apply a 
    #pragma
    directive to multiple HLSL files, using the Unity 
    #include_with_pragmas
    directive.

Include an HLSL file in another

Unity supports the standard HLSL 
#include
directive. For more information, refer to include directive in the Microsoft HLSL documentation.

Duplicate HLSL in multiple places

To duplicate HLSL code in all the sections of your code, for example to add the same variables in multiple 
Pass
blocks, wrap the code you want to reuse in 
HLSLINCLUDE
and 
ENDHLSL
macros. Unity adds the code at the top of every 
HLSLPROGRAM
block.
For example:
Shader "Examples/ExampleShader"{    HLSLINCLUDE        // Add HLSL code you want to share across the file.    ENDHLSL    SubShader    {        Pass        {                              ...              HLSLPROGRAM                // Unity pastes the contents of the HLSLINCLUDE block here.              ENDHLSL        }        Pass        {                              ...              HLSLPROGRAM                // Unity pastes the contents of the HLSLINCLUDE block here.              ENDHLSL        }    }}

Apply a pragma directive to multiple files

To apply a 
#pragma
directive to multiple shader files, use the Unity 
#include_with_pragmas
directive.
You can use this method to add an argument in multiple files, but toggle the arguments on and off by updating only one file. For example, you can create and toggle a debugging keyword that enables and disables conditional debugging code in multiple shaders.
  1. Add a 
    #pragma
    directive to a separate shader file. For example, create a one-line HLSL file with a pragma that enables shader debug symbols:
#pragma enable_debug_symbols
  1. In each shader you want to include the directive in, add an 
    #include_with_pragmas
    directive to include the file. For example:
#include_with_pragmas "path-to-include-file"
Note
If a shader file uses 
#include
to import a file that contains an 
#include_with_pragmas
directive, Unity ignores the 
#pragma
directives in the file the 
#include_with_pragmas
directive references. Unity warns you about this in the console.

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