1 files changed, 51 insertions, 0 deletions
diff --git a/NvBlast/samples/resources/shaders/lighting.hlsl b/NvBlast/samples/resources/shaders/lighting.hlsl
new file mode 100644
index 0000000..2dacc14
--- /dev/null
+++ b/NvBlast/samples/resources/shaders/lighting.hlsl
@@ -0,0 +1,51 @@
+#include "common_buffers.hlsl"
+
+static const float att_c = 1.0f;
+static const float att_l = 0.014f;
+static const float att_q = 0.0007f;
+
+
+float CalcAttenuation(float distance)
+{
+	return 1 / (att_c + att_l * distance + att_q * distance * distance);
+};
+
+
+float3 CalcLight(float3 textureColor, float3 lightDir, float3 viewDir, float3 normal, float3 lightColor, float specPower, float specIntensity, float attenuation)
+{
+	normal = normalize(normal);
+
+	// diffuse
+	float3 dirToLight = normalize(-lightDir);
+	float diffuseFactor = max(dot(normal, dirToLight), 0.0);
+	float3 diffuse = lightColor * textureColor * diffuseFactor * attenuation;
+
+	// specular (Blinn-Phong)
+	float3 halfwayDir = normalize(dirToLight + viewDir);
+	float specFactor = pow(max(dot(viewDir, halfwayDir), 0.0), specPower);
+	float3 spec = lightColor * specFactor * attenuation * specIntensity;
+	
+	return diffuse + spec;
+};
+
+float3 CalcPixelLight(float3 diffuseColor, float3 worldPos, float3 normal)
+{
+	float3 viewDir = normalize(viewPos - worldPos);
+
+	// ambient
+	float3 ambient = ambientColor * diffuseColor;
+
+	// dir light
+	float3 dirLight = CalcLight(diffuseColor, dirLightDir, viewDir, normal, dirLightColor, specularPower, specularIntensity, 1);
+
+	// point light
+	float3 pointLightDir = worldPos - pointLightPos;
+	float distance = length(pointLightDir);
+    float attenuation = CalcAttenuation(distance);
+	float3 pointLight = CalcLight(diffuseColor, pointLightDir, viewDir, normal, pointLightColor, specularPower, specularIntensity, attenuation);
+	
+	// hacky hack: ambient attenuates within point light distance
+	ambient *= attenuation;
+
+	return ambient + dirLight + pointLight;
+};
+\ No newline at end of file