Merge pull request #3893 from thomasbiang/wangyi_basisu

Support basis universal to GLTF2 format

code/AssetLib/glTF2/glTF2Asset.h

@@ -1118,11 +1118,13 @@ public:
         bool KHR_materials_transmission;
         bool KHR_draco_mesh_compression;
         bool FB_ngon_encoding;
+        bool KHR_texture_basisu;
     } extensionsUsed;
 
     //! Keeps info about the required extensions
     struct RequiredExtensions {
         bool KHR_draco_mesh_compression;
+        bool KHR_texture_basisu;
     } extensionsRequired;
 
     AssetMetadata asset;

code/AssetLib/glTF2/glTF2Asset.inl

@@ -1144,6 +1144,7 @@ inline Image::Image() :
 }
 
 inline void Image::Read(Value &obj, Asset &r) {
+    //basisu: no need to handle .ktx2, .basis, load as is
     if (!mDataLength) {
         Value *curUri = FindString(obj, "uri");
         if (nullptr != curUri) {
@@ -2124,6 +2125,7 @@ inline void Asset::ReadExtensionsUsed(Document &doc) {
     CHECK_EXT(KHR_materials_clearcoat);
     CHECK_EXT(KHR_materials_transmission);
     CHECK_EXT(KHR_draco_mesh_compression);
+    CHECK_EXT(KHR_texture_basisu);
 
 #undef CHECK_EXT
 }

code/AssetLib/glTF2/glTF2AssetWriter.inl

@@ -250,6 +250,7 @@ namespace glTF2 {
 
     inline void Write(Value& obj, Image& img, AssetWriter& w)
     {
+        //basisu: no need to handle .ktx2, .basis, write as is
         if (img.bufferView) {
             obj.AddMember("bufferView", img.bufferView->index, w.mAl);
             obj.AddMember("mimeType", Value(img.mimeType, w.mAl).Move(), w.mAl);
@@ -892,10 +893,22 @@ namespace glTF2 {
             if (this->mAsset.extensionsUsed.FB_ngon_encoding) {
                 exts.PushBack(StringRef("FB_ngon_encoding"), mAl);
             }
+            
+            if (this->mAsset.extensionsUsed.KHR_texture_basisu) {
+                exts.PushBack(StringRef("KHR_texture_basisu"), mAl);
+            }
         }
 
         if (!exts.Empty())
             mDoc.AddMember("extensionsUsed", exts, mAl);
+            
+        //basisu extensionRequired
+        Value extsReq;
+        extsReq.SetArray();
+        if (this->mAsset.extensionsUsed.KHR_texture_basisu) {
+            extsReq.PushBack(StringRef("KHR_texture_basisu"), mAl);
+            mDoc.AddMember("extensionsRequired", extsReq, mAl);
+        }
     }
 
     template<class T>

code/AssetLib/glTF2/glTF2Exporter.cpp

@@ -494,7 +494,6 @@ void glTF2Exporter::GetMatTexProp(const aiMaterial* mat, float& prop, const char
 
 void glTF2Exporter::GetMatTex(const aiMaterial* mat, Ref<Texture>& texture, aiTextureType tt, unsigned int slot = 0)
 {
-
     if (mat->GetTextureCount(tt) > 0) {
         aiString tex;
 
@@ -507,6 +506,7 @@ void glTF2Exporter::GetMatTex(const aiMaterial* mat, Ref<Texture>& texture, aiTe
                     texture = mAsset->textures.Get(it->second);
                 }
 
+                bool useBasisUniversal = false;
                 if (!texture) {
                     std::string texId = mAsset->FindUniqueID("", "texture");
                     texture = mAsset->textures.Create(texId);
@@ -519,18 +519,46 @@ void glTF2Exporter::GetMatTex(const aiMaterial* mat, Ref<Texture>& texture, aiTe
                         aiTexture* curTex = mScene->mTextures[atoi(&path[1])];
 
                         texture->source->name = curTex->mFilename.C_Str();
-
-                        // The asset has its own buffer, see Image::SetData
-                        texture->source->SetData(reinterpret_cast<uint8_t *>(curTex->pcData), curTex->mWidth, *mAsset);
-
+                        
+                        //basisu: embedded ktx2, bu
                         if (curTex->achFormatHint[0]) {
                             std::string mimeType = "image/";
-                            mimeType += (memcmp(curTex->achFormatHint, "jpg", 3) == 0) ? "jpeg" : curTex->achFormatHint;
+                            if(memcmp(curTex->achFormatHint, "jpg", 3) == 0)
+                                mimeType += "jpeg";
+                            else if(memcmp(curTex->achFormatHint, "ktx", 3) == 0) {
+                                useBasisUniversal = true;
+                                mimeType += "ktx";
+                            }
+                            else if(memcmp(curTex->achFormatHint, "kx2", 3) == 0) {
+                                useBasisUniversal = true;
+                                mimeType += "ktx2";
+                            }
+                            else if(memcmp(curTex->achFormatHint, "bu", 2) == 0) {
+                                useBasisUniversal = true;
+                                mimeType += "basis";
+                            }
+                            else
+                                mimeType += curTex->achFormatHint;
                             texture->source->mimeType = mimeType;
                         }
+                        
+                        // The asset has its own buffer, see Image::SetData
+                        //basisu: "image/ktx2", "image/basis" as is
+                        texture->source->SetData(reinterpret_cast<uint8_t *>(curTex->pcData), curTex->mWidth, *mAsset);
                     }
                     else {
                         texture->source->uri = path;
+                        if(texture->source->uri.find(".ktx")!=std::string::npos ||
+                           texture->source->uri.find(".basis")!=std::string::npos)
+                        {
+                            useBasisUniversal = true;
+                        }
+                    }
+                    
+                    //basisu
+                    if(useBasisUniversal) {
+                        mAsset->extensionsUsed.KHR_texture_basisu = true;
+                        mAsset->extensionsRequired.KHR_texture_basisu = true;
                     }
 
                     GetTexSampler(mat, texture, tt, slot);

code/AssetLib/glTF2/glTF2Importer.cpp

@@ -1476,6 +1476,12 @@ void glTF2Importer::ImportEmbeddedTextures(glTF2::Asset &r) {
                 if (strcmp(ext, "jpeg") == 0) {
                     ext = "jpg";
                 }
+                else if(strcmp(ext, "ktx2") == 0) { //basisu: ktx remains
+                    ext = "kx2";
+                }
+                else if(strcmp(ext, "basis") == 0) { //basisu
+                    ext = "bu";
+                }
 
                 size_t len = strlen(ext);
                 if (len <= 3) {