fix spot light angle strength (#18945)

Author: star-e

editor/assets/chunks/common/lighting/attenuation.chunk

@@ -58,3 +58,11 @@ float CalculateAngleAttenuation(vec3 spotLightDir, vec3 L, float cosAngleOuter)
   float litAngleOffset = -cosAngleOuter * litAngleScale;
   return GetAngleAtt(L, spotLightDir, litAngleScale, litAngleOffset);
 }
+
+float CalculateAngleAttenuationWithStrength(vec3 spotLightDir, vec3 L, float cosAngleOuter, float strength)
+{
+  float cosInner = max(dot(spotLightDir, L), 0.01);
+  float litAngleScale = 1.0 / max(0.001, mix(cosInner, 1.0, strength) - cosAngleOuter);
+  float litAngleOffset = -cosAngleOuter * litAngleScale;
+  return GetAngleAtt(L, spotLightDir, litAngleScale, litAngleOffset);
+}

editor/assets/chunks/lighting-models/lighting-flow/common-flow.chunk

@@ -78,7 +78,7 @@
 
         float angleAtt = 1.0;
         if (IS_SPOT_LIGHT(cc_lightPos[i].w)) {
-          angleAtt = CCSurfacesLightingCalculateAngleAttenuation(lightingData, cc_lightSizeRangeAngle[i], -cc_lightDir[i].xyz);
+          angleAtt = CCSurfacesLightingCalculateAngleAttenuationWithStrength(lightingData, cc_lightSizeRangeAngle[i], -cc_lightDir[i].xyz, cc_lightBoundingSizeVS[i].w);
         }
 
         float multiplier = distAtt * angleAtt;

editor/assets/chunks/lighting-models/model-functions/standard.chunk

@@ -27,6 +27,11 @@ float CCSurfacesLightingCalculateAngleAttenuation(in LightingIntermediateData li
   return CalculateAngleAttenuation(spotLightDir, lightingData.L, lightSizeRangeAngle.z);
 }
 
+float CCSurfacesLightingCalculateAngleAttenuationWithStrength(in LightingIntermediateData lightingData, in vec4 lightSizeRangeAngle, in vec3 spotLightDir, in float strength)
+{
+  return CalculateAngleAttenuationWithStrength(spotLightDir, lightingData.L, lightSizeRangeAngle.z, strength);
+}
+
 void CCSurfacesLightingCalculateDirect(out vec3 lightingDiffuse, out vec3 lightingSpecular, in LightingIntermediateData lightingData, in vec4 lightSourceColorAndIntensity)
 {
 #if !CC_SURFACES_LIGHTING_DISABLE_DIFFUSE

editor/assets/chunks/lighting-models/model-functions/toon.chunk

@@ -17,6 +17,11 @@ float CCSurfacesLightingCalculateAngleAttenuation(in LightingIntermediateData li
   return CalculateAngleAttenuation(spotLightDir, lightingData.L, lightSizeRangeAngle.z);
 }
 
+float CCSurfacesLightingCalculateAngleAttenuationWithStrength(in LightingIntermediateData lightingData, in vec4 lightSizeRangeAngle, in vec3 spotLightDir, in float strength)
+{
+  return CalculateAngleAttenuationWithStrength(spotLightDir, lightingData.L, lightSizeRangeAngle.z, strength);
+}
+
 void CCSurfacesLightingCalculateDirect(out vec3 lightingDiffuse, out vec3 lightingSpecular, in LightingIntermediateData lightingData, in vec4 lightSourceColorAndIntensity)
 {
     vec3 irradiance = lightSourceColorAndIntensity.rgb * lightSourceColorAndIntensity.w;