From b42d785afebd313f8a531dc8cf832d80ecd50910 Mon Sep 17 00:00:00 2001
From: Daniel Hritzkiv <daniel.hritzkiv@gmail.com>
Date: Sun, 27 Aug 2017 23:47:54 -0400
Subject: [PATCH] Start managing and importing gltf2 pbr materials

---
 code/glTF2Asset.h   | 40 +++++++++++++++++++++++++++++-----------
 code/glTF2Asset.inl | 19 +++++++++++++++----
 2 files changed, 44 insertions(+), 15 deletions(-)

diff --git a/code/glTF2Asset.h b/code/glTF2Asset.h
index 2b37d6a0e..5d99735b2 100644
--- a/code/glTF2Asset.h
+++ b/code/glTF2Asset.h
@@ -671,11 +671,18 @@ namespace glTF2
         inline void SetData(uint8_t* data, size_t length, Asset& r);
     };
 
-    //! Holds a material property that can be a texture or a color
-    struct TexProperty
+    struct ColorProperty
+    {
+        union {
+            vec4, vec3
+        } color;
+    }
+
+    //! Holds a material property that can be a texture or a color (fallback for glTF 1)
+    struct FallbackTexProperty
     {
         Ref<Texture> texture;
-        vec4 color;
+        ColorProperty color;
     };
 
     //! The material appearance of a primitive.
@@ -694,16 +701,27 @@ namespace glTF2
             Technique_CONSTANT
         };
 
-        TexProperty ambient;
-        TexProperty diffuse;
-        TexProperty specular;
-        TexProperty emission;
-        Ref<Texture> normal;
+        //PBR metallic roughness properties
+        ColorProperty baseColor;
+        Ref<Texture> baseColorTexture;
+        Ref<Texture> metallicRoughnessTexture;
+        float metallicFactor;
+        float roughnessFactor;
 
+        //other basic material properties
+        Ref<Texture> normalTexture;
+        Ref<Texture> occlusionTexture;
+        Ref<Texture> emissiveTexture;
+        ColorProperty emissiveFactor;
+        std::string alphaMode;
+        float alphaCutoff;
         bool doubleSided;
-        bool transparent;
-        float transparency;
-        float shininess;
+
+        //fallback material properties (compatible with non-pbr defintions)
+        FallbackTexProperty diffuse;
+        FallbackTexProperty emissive;
+        FallbackTexProperty specular;
+        Ref<Texture> normal;
 
         Technique technique;
 
diff --git a/code/glTF2Asset.inl b/code/glTF2Asset.inl
index 27fdd1c01..bf8cb5a36 100644
--- a/code/glTF2Asset.inl
+++ b/code/glTF2Asset.inl
@@ -725,18 +725,29 @@ inline void Material::Read(Value& material, Asset& r)
     SetDefaults();
 
     if (Value* values = FindObject(material, "values")) {
-        ReadMaterialProperty(r, *values, "ambient", this->ambient);
-        ReadMaterialProperty(r, *values, "diffuse", this->diffuse);
-        ReadMaterialProperty(r, *values, "specular", this->specular);
+
 
         ReadMember(*values, "transparency", transparency);
-        ReadMember(*values, "shininess", shininess);
     }
 
     if (Value* values = FindObject(material, "pbrMetallicRoughness")) {
+        //pbr
+        ReadMaterialProperty(r, *values, "baseColorFactor", this->baseColor);
+        ReadMaterialProperty(r, *values, "baseColorTexture", this->baseColorTexture);
+
+        //non-pbr fallback
         ReadMaterialProperty(r, *values, "baseColorFactor", this->diffuse);
+        ReadMaterialProperty(r, *values, "baseColorTexture", this->diffuse);
+
+        ReadMember(*values, "metallicFactor", metallicFactor);
     }
 
+    ReadMaterialProperty(r, *values, "normalTexture", this->normalTexture);
+    ReadMaterialProperty(r, *values, "normalTexture", this->normal);
+    ReadMaterialProperty(r, *values, "occlusionTexture", this->occlusionTexture);
+    ReadMaterialProperty(r, *values, "emissiveTexture", this->emissiveTexture);
+    ReadMember(*values, "metallicFactor", emissiveFactor);
+
     ReadMember(material, "doubleSided", doubleSided);
 
     if (Value* extensions = FindObject(material, "extensions")) {