Pre bindless

res/shaders/lib/LightEnv.slang

@@ -10,11 +10,26 @@ struct DirectionalLight : ILightEnv
 {
     float4 color;
     float4 direction;
+    float4x4 lightSpaceMatrix;
+    Texture2D shadowMap;
+    SamplerState shadowSampler;
 
     float3 illuminate<B:IBRDF>(LightingParameter params, B brdf)
     {
         float3 dir_WS = -normalize(direction.xyz);
-        return brdf.evaluate(params.viewDir_WS, dir_WS, color.xyz * color.w);
+        float3 color = brdf.evaluate(params.viewDir_WS, dir_WS, color.xyz * color.w);
+
+        float4 lightSpacePos = mul(lightSpaceMatrix, float4(params.position_WS, 1));
+        float3 projCoords = lightSpacePos.xyz / lightSpacePos.w;
+        projCoords = projCoords * 0.5 + 0.5;
+        float closestDepth = shadowMap.Sample(shadowSampler, projCoords.xy).r;
+        float currentDepth = projCoords.z;
+        float bias = max(0.05 * (1.0 - dot(brdf.getNormal(), direction.xyz)), 0.005);
+        float shadow = currentDepth - bias > closestDepth ? 1.0 : 0.0;
+        if (projCoords.z > 1.0)
+            shadow = 0;
+
+        return shadow * color;
     }
 };