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Branch based on platform or graphics API

Use SHADER_API macros to make shader behaviour conditional on the platform or graphics API.
Read time 2 minutesLast updated a month ago
To create optimized shader code for a platform, branch in your shader code using one of the preprocessor macros Unity defines.
#if defined(SHADER_API_DX11)    // Shader code for when the target graphics API is DirectX 11#endif

Branch based on the build target

Unity defines the following macros when you make the corresponding platform the target for your build.

Macro

Platform

UNITY_PLATFORM_ANDROID
Android devices
UNITY_PLATFORM_EMBEDDED_LINUX
Embedded Linux devices
UNITY_PLATFORM_GAMECORE_XBOXONE
XBOX One Game Core
UNITY_PLATFORM_IOS
iOS devices
UNITY_PLATFORM_LINUX
Linux devices
UNITY_PLATFORM_META_QUEST
Meta Quest devices. If you target Meta Quest, Unity also defines the 
UNITY_PLATFORM_ANDROID
macro.
UNITY_PLATFORM_OSX
macOS devices
UNITY_PLATFORM_PS4
PlayStation®4
UNITY_PLATFORM_PS5
PlayStation®5
UNITY_PLATFORM_QNX
QNX devices
UNITY_PLATFORM_SWITCH
Nintendo Switch™
UNITY_PLATFORM_SWITCH2
Nintendo Switch™ 2
UNITY_PLATFORM_TVOS
tvOS devices
UNITY_PLATFORM_UWP
Universal Windows Platform (UWP) devices
UNITY_PLATFORM_VISIONOS
visionOS devices
UNITY_PLATFORM_WEBGL
WebGL devices
UNITY_PLATFORM_WINDOWS
Windows devices
UNITY_PLATFORM_XBOXONE
XBOX One

Branch within a platform branch

To branch again within platform-specific branching code, declare a shader keyword after you test for the platform, then branch using the keyword. For example:
// Test if the build target is Meta Quest#if defined(UNITY_PLATFORM_META_QUEST)    // Add a keyword only if the build target is Meta Quest    #pragma shader_feature _ META_QUEST_REFLECTIONS#endif...fixed4 frag (v2f i) : SV_Target    {        // Test if the build target is Meta Quest        #if defined(UNITY_PLATFORM_META_QUEST)            // Test if your custom keyword is enabled            #if META_QUEST_REFLECTIONS                // Shader code for Meta Quest with reflections            #else                // Shader code for Meta Quest without reflections            #endif        #endif    ...    }
For more information, refer to Changing how shaders work using keywords.

Branch based on the target graphics API

Unity defines the following macros when Unity compiles shaders for the corresponding graphics API.

Macro

Graphics API

SHADER_API_DX11
Direct3D 11
SHADER_API_DX12
Direct3D 12
SHADER_API_D3D11
Direct3D 11 and Direct3D 12 (marked for deprecation)
SHADER_API_D3D11_9X
DirectX 11 feature level 9, for Universal Windows Platform (UWP) devices
SHADER_API_DESKTOP
Graphics APIs used by Windows devices, macOS devices, Linux desktop platforms, and web devices
SHADER_API_GLCORE
OpenGL 3.x, OpenGL 4.x
SHADER_API_GLES3
OpenGL ES 3.x
SHADER_API_METAL
Metal on iOS or macOS
SHADER_API_MOBILE
Graphics APIs used by iOS and Android mobile devices, and tvOS devices
SHADER_API_VULKAN
Vulkan
SHADER_API_WEBGPU
WebGPU
SHADER_TARGET_GLSL
OpenGL and GLES platforms where Unity compiles HLSL to GLSL

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