More ray tracing changes

res/shaders/raytracing/Callable.slang

@@ -0,0 +1,28 @@
+import Common;
+import RayTracingData;
+import MaterialParameter;
+import LightEnv;
+import MATERIAL_FILE_NAME;
+
+[shader("callable")]
+void callable(inout CallablePayload payload)
+{
+    LightingParameter lightingParams = payload.params.getLightingParameter();
+    MaterialParameter materialParams = payload.params.getMaterialParameter();
+	let brdf = Material.prepare(materialParams);
+    
+    float3 result = float3(0, 0, 0);
+    for(int i = 0; i < pLightEnv.numDirectionalLights; ++i)
+    {
+        result += pLightEnv.directionalLights[i].illuminate(lightingParams, brdf);
+    }
+    for(uint i = 0; i < pLightEnv.numPointLights; ++i)
+    {
+        result += pLightEnv.pointLights[i].illuminate(lightingParams, brdf);
+    }
+    result += brdf.evaluateAmbient();
+    // gamma correction
+    result = result / (result + float3(1.0));
+    result = pow(result, float3(1.0/2.2));
+    payload.color = float3(0, 0, 1);
+}