Refactor & credit glitter

1 files changed, 88 insertions, 31 deletions

diff --git a/brdf.cginc b/brdf.cginc
index fcc2594..92fd8bb 100755
--- a/brdf.cginc
+++ b/brdf.cginc
@@ -101,6 +101,43 @@ float G_Estevez(float roughness, float NoL, float NoV) {
   return 1.0 / ((1.0 + lambda_l + lambda_v) * 4.0 * NoL * NoV);
 }
 
+#if defined(_GLITTER)
+struct GlitterData {
+  float2 uv;
+  float2x2 uv_J;
+  float N;
+};
+
+struct GlitterDFG {
+  float d;
+  float3 f;
+  float g;
+};
+
+GlitterData GetGlitterData(v2f i) {
+  GlitterData data;
+  data.uv = i.uv01.xy;
+  data.uv_J = uv_ellipsoid(transpose(float2x2(ddx(data.uv), ddy(data.uv))));
+  data.N = 8.0e5f * pow(10.0f, _Glitter_Amount * 6.0f - 2.0f);
+  return data;
+}
+
+GlitterDFG GetGlitterDFG(GlitterData data,
+    float3x3 world_to_tangent, float roughness, float3 H, float LoH,
+    float NoL, float NoV) {
+  GlitterDFG dfg;
+  const float glitter_filter_size = 0.7f;
+  float3 H_tangent = mul(H, world_to_tangent);
+  float f0 = 0.15f;
+  float f90 = 1.0f;
+  dfg.f = F_Schlick(LoH, f0, f90);
+  dfg.d = D_Kemppinen(H_tangent, roughness, _Glitter_Roughness,
+      data.uv, data.uv_J, data.N, glitter_filter_size);
+  dfg.g = G_GGXSmith(roughness, NoL, NoV);
+  return dfg;
+}
+#endif
+
 float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
   bd = (BrdfData)0;
   float3 specular = 0;
@@ -144,6 +181,11 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
   float3 cc_energy_comp = 1.0f + cc_f0_color * (1.0f / (bd.ibl_dfg_cc.xxx + bd.ibl_dfg_cc.yyy) - 1.0f);
 #endif
 
+#if defined(_GLITTER)
+  GlitterData glitter_data = GetGlitterData(i);
+  float3x3 glitter_world_to_tangent = transpose(pbr.tbn);
+#endif
+
   // Direct
   {
     float3 remainder = 1.0f;
@@ -161,51 +203,56 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
     remainder *= saturate(1.0f - bd.direct_f_cc * pbr.cc_strength);
 #endif
 
-#if defined(_GLITTER)
-    float2 glitter_uv = i.uv01.xy;
-    float2x2 glitter_uv_J = uv_ellipsoid(mat2_from_cols(ddx(glitter_uv), ddy(glitter_uv)));
-    float3 H_tangent = mul(data.direct.H, transpose(pbr.tbn));
-    const float glitter_filter_size = 0.7f;
-    float glitter_N = 8.0e5f * pow(10.0f, _Glitter_Amount * 6.0f - 2.0f);
-    bd.direct_f = F_Schlick(data.direct.LoH, 0.96f, 1.0f);
-    bd.direct_d = D_Kemppinen(H_tangent, pbr.roughness, _Glitter_Roughness,
-        glitter_uv, glitter_uv_J, glitter_N, glitter_filter_size);
-    bd.direct_g = G_GGXSmith(pbr.roughness, data.direct.NoL, data.common.NoV);
-    float3 direct_specular_glitter = (bd.direct_d * bd.direct_g) * bd.direct_f;
-    direct_specular_glitter *= data.direct.color * data.direct.NoL;
-    direct_specular_glitter *= remainder;
-    specular += direct_specular_glitter;
-    remainder *= saturate(1.0f - direct_specular_glitter);
-#else
-
 #if defined(_CLOTH)
     float3 cloth_f0 = _Cloth_Sheen.rgb;
     bd.direct_f = F_Schlick(data.direct.LoH, cloth_f0, f90);
     bd.direct_d = D_Estevez(pbr.roughness, data.direct.NoH);
     bd.direct_g = G_Estevez(pbr.roughness, data.direct.NoL, data.common.NoV);
 
-    float3 direct_specular = (bd.direct_d * bd.direct_g) * bd.direct_f;
-    direct_specular *= data.direct.color * data.direct.NoL;
-    direct_specular *= remainder;
-    specular += direct_specular;
-
+    float3 direct_specular_cloth = (bd.direct_d * bd.direct_g) * bd.direct_f;
+    direct_specular_cloth *= data.direct.color * data.direct.NoL;
+    direct_specular_cloth *= remainder;
+    specular += direct_specular_cloth;
+    /*
     float Fd = Fd_Lambertian(data.direct.NoL) / PI;
     float3 direct_diffuse = Fd * pbr.albedo.xyz * data.direct.color;
     direct_diffuse *= remainder;
     direct_diffuse = max(0, direct_diffuse);
     diffuse += direct_diffuse;
+    */
+#endif  // _CLOTH
+
+#if defined(_GLITTER)
+    GlitterDFG direct_glitter = GetGlitterDFG(glitter_data,
+        glitter_world_to_tangent, pbr.roughness, data.direct.H,
+        data.direct.LoH, data.direct.NoL, data.common.NoV);
+    bd.direct_f = direct_glitter.f;
+    bd.direct_d = direct_glitter.d;
+    bd.direct_g = direct_glitter.g;
+    float3 direct_specular_glitter = (direct_glitter.d * direct_glitter.g)
+        * direct_glitter.f * data.direct.color * data.direct.NoL
+        * _Glitter_Tint;
+    // No spec ao for glitter, please.
+    direct_specular_glitter *= remainder;
+    specular += direct_specular_glitter;
+
+    float direct_g = G_GGXSmith(pbr.roughness, data.direct.NoL, data.common.NoV);
+    float3 direct_f = F_Schlick(data.direct.LoH, f0_color, f90);
+    float direct_d = D_GGX(pbr.roughness, data.direct.NoH);
 #else
-    float3 direct_energy = energy_comp;
     bd.direct_g = G_GGXSmith(pbr.roughness, data.direct.NoL, data.common.NoV);
     bd.direct_f = F_Schlick(data.direct.LoH, f0_color, f90);
     bd.direct_d = D_GGX(pbr.roughness, data.direct.NoH);
+    float direct_g = bd.direct_g;
+    float3 direct_f = bd.direct_f;
+    float direct_d = bd.direct_d;
 #endif
 
-    float3 direct_specular = (bd.direct_d * bd.direct_g) * bd.direct_f;
+    float3 direct_specular = (direct_d * direct_g) * direct_f;
     direct_specular *= data.direct.color * data.direct.NoL;
-    direct_specular *= direct_energy;
+    direct_specular *= energy_comp;
     direct_specular *= remainder;
-    specular += direct_specular;
+    specular += direct_specular * data.common.spec_ao;
 
 #if defined(F_OREN_NAYAR)
     float Fd = Fd_OrenNayar(pbr.roughness, data.common.NoV, data.direct.NoL, data.direct.LoV);
@@ -216,7 +263,6 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
     direct_diffuse *= remainder;
     direct_diffuse = max(0, direct_diffuse);
     diffuse += direct_diffuse;
-#endif
   }
 
   // Indirect
@@ -227,23 +273,35 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
     float3 cc_specular_dfg = bd.ibl_dfg_cc.xxx * cc_f0_color + bd.ibl_dfg_cc.yyy;  // filament 5.3.4.6
     float3 cc_indirect_specular = data.indirect.specular_cc * cc_specular_dfg;
     cc_indirect_specular *= cc_energy_comp;
-    specular += cc_indirect_specular;
+    specular += cc_indirect_specular * data.common.spec_ao;
     remainder -= cc_specular_dfg;
 #endif
 
 #if defined(_CLOTH)
     float3 specular_dfg = _Cloth_Sheen.rgb * bd.ibl_dfg.zzz;
     float3 indirect_specular = data.indirect.specular * specular_dfg;
-    specular += indirect_specular * remainder;
+    specular += indirect_specular * remainder * data.common.spec_ao;
 
     float3 indirect_diffuse = pbr.albedo.xyz * data.indirect.diffuse;
     diffuse  += indirect_diffuse * remainder;
 #else
+#if defined(_GLITTER)
+    GlitterDFG indirect_glitter = GetGlitterDFG(glitter_data,
+        glitter_world_to_tangent, pbr.roughness, data.indirect.H,
+        data.indirect.LoH, data.indirect.NoL, data.common.NoV);
+    float3 indirect_specular_glitter = (indirect_glitter.d * indirect_glitter.g)
+        * indirect_glitter.f * data.indirect.specular * data.indirect.NoL
+        * _Glitter_Tint;
+    // No spec ao for glitter, please.
+    specular += indirect_specular_glitter * remainder;
+    remainder *= saturate(1 - indirect_specular_glitter * remainder);
+#endif
+
     float3 specular_dfg = bd.ibl_dfg.xxx * f0_color + bd.ibl_dfg.yyy;  // filament 5.3.4.6
     float3 indirect_specular = data.indirect.specular * specular_dfg;
 
     indirect_specular *= energy_comp;
-    specular += indirect_specular * remainder;
+    specular += indirect_specular * remainder * data.common.spec_ao;
 
     float3 indirect_diffuse = pbr.albedo.xyz * data.indirect.diffuse * (1.0 - pbr.metallic);
     diffuse  += indirect_diffuse * remainder;
@@ -263,7 +321,6 @@ float4 brdf(v2f i, Pbr pbr, LightData data, out BrdfData bd) {
 #endif
 
   diffuse  *= data.common.ao;
-  specular *= data.common.spec_ao;
 
 #if (defined(_EMISSIONS) || defined(_LETTER_GRID)) && defined(FORWARD_BASE_PASS)
   float3 emission = pbr.emission;