rendering: formalize main light shadow params

project/Assets/Shaders/XCCharacterToon.shader

@@ -65,6 +65,21 @@ Shader "XC Character Toon"
         float4 spotAnglesAndFlags;
     };
 
+    struct ShadowMapMetrics
+    {
+        float2 inverseMapSize;
+        float worldTexelSize;
+        float padding;
+    };
+
+    struct ShadowSamplingData
+    {
+        float enabled;
+        float receiverDepthBias;
+        float normalBiasScale;
+        float shadowStrength;
+    };
+
     cbuffer LightingConstants
     {
         float4 gMainLightDirectionAndIntensity;
@@ -116,8 +131,8 @@ Shader "XC Character Toon"
     cbuffer ShadowReceiverConstants
     {
         float4x4 gWorldToShadowMatrix;
-        float4 gShadowBiasAndTexelSize;
-        float4 gShadowOptions;
+        ShadowMapMetrics gShadowMapMetrics;
+        ShadowSamplingData gShadowSampling;
     };
 
     Texture2D BaseColorTexture;
@@ -250,7 +265,7 @@ Shader "XC Character Toon"
     #ifndef XC_MAIN_LIGHT_SHADOWS
         return 1.0f;
     #else
-        if (gShadowOptions.x < 0.5f) {
+        if (gShadowSampling.enabled < 0.5f) {
             return 1.0f;
         }
 
@@ -258,7 +273,8 @@ Shader "XC Character Toon"
         const float3 resolvedLightDirectionWS =
             NormalizeSafe(lightDirectionWS, float3(0.0f, -1.0f, 0.0f));
         const float nDotL = saturate(dot(resolvedNormalWS, resolvedLightDirectionWS));
-        const float normalBiasWorld = gShadowOptions.y * gShadowOptions.z * (1.0f - nDotL);
+        const float normalBiasWorld =
+            gShadowMapMetrics.worldTexelSize * gShadowSampling.normalBiasScale * (1.0f - nDotL);
         const float3 shadowPositionWS = positionWS + resolvedNormalWS * normalBiasWorld;
         const float4 shadowClip = mul(gWorldToShadowMatrix, float4(shadowPositionWS, 1.0f));
         if (shadowClip.w <= 0.0f) {
@@ -279,7 +295,7 @@ Shader "XC Character Toon"
             return 1.0f;
         }
 
-        const float receiverDepth = shadowNdc.z * 0.5f + 0.5f - gShadowBiasAndTexelSize.x;
+        const float receiverDepth = shadowNdc.z * 0.5f + 0.5f - gShadowSampling.receiverDepthBias;
     #else
         if (shadowUv.x < 0.0f || shadowUv.x > 1.0f ||
             shadowUv.y < 0.0f || shadowUv.y > 1.0f ||
@@ -287,9 +303,9 @@ Shader "XC Character Toon"
             return 1.0f;
         }
 
-        const float receiverDepth = shadowNdc.z - gShadowBiasAndTexelSize.x;
+        const float receiverDepth = shadowNdc.z - gShadowSampling.receiverDepthBias;
     #endif
-        const float2 shadowTexelSize = gShadowBiasAndTexelSize.yz;
+        const float2 shadowTexelSize = gShadowMapMetrics.inverseMapSize;
         float visibility = 0.0f;
         [unroll]
         for (int offsetY = -1; offsetY <= 1; ++offsetY) {
@@ -309,7 +325,7 @@ Shader "XC Character Toon"
         }
 
         visibility *= (1.0f / 9.0f);
-        const float shadowStrength = saturate(gShadowBiasAndTexelSize.w);
+        const float shadowStrength = saturate(gShadowSampling.shadowStrength);
         return lerp(1.0f - shadowStrength, 1.0f, visibility);
     #endif
     }