Add code

Implement basic diffuse and specular BRDF based heavily on silent's
filamented shader.

1 files changed, 39 insertions, 0 deletions

diff --git a/yum_pbr.cginc b/yum_pbr.cginc
new file mode 100644
index 0000000..b895cd0
--- /dev/null
+++ b/yum_pbr.cginc
@@ -0,0 +1,39 @@
+#ifndef __YUM_PBR
+#define __YUM_PBR
+
+#include "filamented.cginc"
+#include "globals.cginc"
+
+struct YumPbr {
+  float4 albedo;
+  float3 normal;
+  float smoothness;
+  float roughness;
+  float roughness_perceptual;
+  float metallic;
+  float ao;
+};
+
+YumPbr GetYumPbr(v2f i) {
+  YumPbr result;
+
+  result.albedo = tex2D(_MainTex, i.uv) * _Color;
+
+  float3 normal_raw = UnpackScaleNormal(tex2D(_BumpMap, i.uv), _BumpScale);
+  float3x3 tangentToWorld = float3x3(i.tangent, i.bitangent, i.normal);
+  result.normal = normalize(mul(normal_raw, tangentToWorld));
+
+  result.smoothness = _Smoothness;
+  result.roughness_perceptual =
+    normalFiltering(1.0 - result.smoothness, result.normal);
+  result.roughness = result.roughness_perceptual * result.roughness_perceptual;
+
+  result.metallic = _Metallic;
+
+  result.ao = lerp(1, tex2D(_OcclusionMap, i.uv), _OcclusionStrength);
+
+  return result;
+}
+
+#endif
+