unity_native_render_plugin/Packages/com.unity.render-pipelines.universal@14.0.11/Shaders/Utils/ScreenSpaceShadows.shader

Shader "Hidden/Universal Render Pipeline/ScreenSpaceShadows"
{
    SubShader
    {
        Tags{ "RenderPipeline" = "UniversalPipeline" "IgnoreProjector" = "True"}

        HLSLINCLUDE

        //Keep compiler quiet about Shadows.hlsl.
        #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/Common.hlsl"
        #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/EntityLighting.hlsl"
        #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/ImageBasedLighting.hlsl"
        // Core.hlsl for XR dependencies
        #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
        #include "Packages/com.unity.render-pipelines.core/Runtime/Utilities/Blit.hlsl"
        #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Shadows.hlsl"
        #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/DeclareDepthTexture.hlsl"

        half4 Fragment(Varyings input) : SV_Target
        {
            UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);

#if defined(_SCREEN_SPACE_SHADOW_LOW_RESOLUTION)
            float4 depths = GATHER_RED_TEXTURE2D(_CameraDepthTexture, sampler_PointClamp, input.texcoord.xy);
#if !defined(UNITY_REVERSED_Z)
            depths = depths * 2.0 - 1.0;
#endif

            half shadow = 0;
            for (int i = 0; i < 4; ++i)
            {
                float depth = depths[i];
                float3 wpos = ComputeWorldSpacePosition(input.texcoord.xy, depth, unity_MatrixInvVP);
                float4 coords = TransformWorldToShadowCoord(wpos);
                shadow += SAMPLE_TEXTURE2D_SHADOW(_MainLightShadowmapTexture, sampler_LinearClampCompare, coords.xyz );
            }
            
            return shadow * 0.25;
#else
            
#if UNITY_REVERSED_Z
            float deviceDepth = SAMPLE_TEXTURE2D_X(_CameraDepthTexture, sampler_PointClamp, input.texcoord.xy).r;
#else
            float deviceDepth = SAMPLE_TEXTURE2D_X(_CameraDepthTexture, sampler_PointClamp, input.texcoord.xy).r;
            deviceDepth = deviceDepth * 2.0 - 1.0;
#endif

            //Fetch shadow coordinates for cascade.
            float3 wpos = ComputeWorldSpacePosition(input.texcoord.xy, deviceDepth, unity_MatrixInvVP);
            float4 coords = TransformWorldToShadowCoord(wpos);

            // Screenspace shadowmap is only used for directional lights which use orthogonal projection.
            half realtimeShadow = MainLightRealtimeShadow(coords);

            return realtimeShadow;
            #endif
        }

        ENDHLSL

        Pass
        {
            Name "ScreenSpaceShadows"
            ZTest Always
            ZWrite Off
            Cull Off
            HLSLPROGRAM
            #pragma multi_compile _MAIN_LIGHT_SHADOWS _MAIN_LIGHT_SHADOWS_CASCADE
            #pragma multi_compile_fragment _ _SHADOWS_SOFT _SHADOWS_SOFT_LOW _SHADOWS_SOFT_MEDIUM _SHADOWS_SOFT_HIGH
            #pragma multi_compile_fragment _ _SCREEN_SPACE_SHADOW_LOW_RESOLUTION

            #pragma target 5.0

            #pragma vertex   Vert
            #pragma fragment Fragment
            ENDHLSL
        }
    }
}