Add TINYGLTF_ENABLE_DRACO flag to README.

Fix out-of-bounds access when calling DrawMesh().
Fix potential out-of-bounds access when filling window title string.

README.md

@@ -46,11 +46,14 @@ v2.0.0 release(22 Aug, 2018)!
 * Load from memory
 * Custom callback handler
   * [x] Image load
+* Extensions
+  * [x] Draco mesh decoding
 
 ## Examples
 
 * [glview](examples/glview) : Simple glTF geometry viewer.
 * [validator](examples/validator) : Simple glTF validator with JSON schema.
+* [basic](examples/basic) : Basic glTF viewer with texturing support.
 
 ## Projects using TinyGLTF
 
@@ -64,7 +67,8 @@ v2.0.0 release(22 Aug, 2018)!
 
 * [ ] Write C++ code generator which emits C++ code from JSON schema for robust parsing.
 * [ ] Mesh Compression/decompression(Open3DGC, etc)
-  * [ ] Load Draco compressed mesh
+  * [x] Load Draco compressed mesh
+  * [x] Save Draco compressed mesh
 * [ ] Support `extensions` and `extras` property
 * [ ] HDR image?
   * [ ] OpenEXR extension through TinyEXR.
@@ -128,6 +132,8 @@ if (!ret) {
 * `TINYGLTF_NO_STB_IMAGE` : Do not load images with stb_image. Instead use `TinyGLTF::SetImageLoader(LoadimageDataFunction LoadImageData, void *user_data)` to set a callback for loading images.
 * `TINYGLTF_NO_STB_IMAGE_WRITE` : Do not write images with stb_image_write. Instead use `TinyGLTF::SetImageWriter(WriteimageDataFunction WriteImageData, void *user_data)` to set a callback for writing images.
 * `TINYGLTF_NO_EXTERNAL_IMAGE` : Do not try to load external image file. This option woulde be helpful if you do not want load image file during glTF parsing.
+* `TINYGLTF_ANDROID_LOAD_FROM_ASSETS`: Load all files from packaged app assets instead of the regular file system. **Note:** You must pass a valid asset manager from your android app to `tinygltf::asset_manager` beforehand.
+* `TINYGLTF_ENABLE_DRACO`: Enable Draco compression. User must provide include path and link correspnding libraries in your project file.
 
 ### Saving gltTF 2.0 model
 * [ ] Buffers.

examples/basic/README.md

@@ -0,0 +1,21 @@
+# Basic glTF viewer
+
+## Requirements
+
+* glew
+* glfw3
+* premake5(linux)
+* OpenGL 3.3+ GPU
+
+## Build on Linux and macOS
+
+```
+$ premake5 gmake
+$ make
+```
+
+## Build on Visual Studio
+
+Plese use solution file located at `basic` folder.
+
+

examples/basic/premake5.lua

@@ -0,0 +1,44 @@
+solution "basic_viewer"
+   -- location ( "build" )
+   configurations { "Debug", "Release" }
+   platforms {"native", "x64", "x32"}
+   
+   project "basic_viewer"
+
+      kind "ConsoleApp"
+      language "C++"
+	  cppdialect "C++11"
+      files { "main.cpp", "shaders.cpp", "window.cpp" }
+      includedirs { "./" }
+      includedirs { "../../" }
+      includedirs { "../common/glm" }
+
+      configuration { "linux" }
+         linkoptions { "`pkg-config --libs glfw3`" }
+         links { "GL", "GLU", "m", "GLEW", "X11", "Xrandr", "Xinerama", "Xi", "Xxf86vm", "Xcursor", "dl" }
+
+      configuration { "windows" }
+         -- Edit path to glew and GLFW3 fit to your environment.
+         includedirs { "../../../../local/glew-1.13.0/include/" }
+         includedirs { "../../../../local/glfw-3.2.bin.WIN32/include/" }
+         libdirs { "../../../../local/glew-1.13.0/lib/Release/Win32/" }
+         libdirs { "../../../../local/glfw-3.2.bin.WIN32/lib-vc2013/" }
+         links { "glfw3", "gdi32", "winmm", "user32", "glew32", "glu32","opengl32", "kernel32" }
+         defines { "_CRT_SECURE_NO_WARNINGS" }
+
+      configuration { "macosx" }
+         includedirs { "/usr/local/include" }
+         buildoptions { "-Wno-deprecated-declarations" }
+         libdirs { "/usr/local/lib" }
+         links { "glfw", "GLEW" }
+         linkoptions { "-framework OpenGL", "-framework Cocoa", "-framework IOKit", "-framework CoreVideo" }
+
+      configuration "Debug"
+         defines { "DEBUG" }
+		 symbols "On"
+		 warnings "Extra"
+
+      configuration "Release"
+         defines { "NDEBUG" }
+		 optimize "On"
+		 warnings "Extra"

examples/basic/shaders.cpp

@@ -19,7 +19,7 @@ uniform vec3 sun_color; \n\
 out vec4 color;\n\
 void main() {\n\
 	float lum = max(dot(normal, normalize(sun_position)), 0.0);\n\
-	color = texture2D(tex, texcoord) * vec4((0.3 + 0.7 * lum) * sun_color, 1.0);\n\
+	color = texture(tex, texcoord) * vec4((0.3 + 0.7 * lum) * sun_color, 1.0);\n\
 }\n\
 ";
 

examples/glview/CMakeLists.txt

@@ -1,8 +1,10 @@
-cmake_minimum_required(VERSION 3.6)
+cmake_minimum_required(VERSION 3.5)
 project(glview)
 
 set ( CMAKE_PREFIX_PATH cmake )
 
+set ( DRACO_DIR "" CACHE STRING "Path to draco" )
+
 find_package ( GLEW REQUIRED )
 find_package ( GLFW3 REQUIRED )
 find_package ( OpenGL REQUIRED )
@@ -21,6 +23,16 @@ endif (APPLE)
 
 set(CMAKE_CXX_STANDARD 11)
 
+if (${DRACO_DIR} STREQUAL "")
+else ()
+  # TODO(syoyo): better CMake script for draco
+  add_definitions(-DTINYGLTF_ENABLE_DRACO)
+  include_directories(${DRACO_DIR}/include)
+
+  link_directories(${DRACO_DIR}/lib)
+  set(DRACO_LIBRARY draco)
+endif ()
+
 include_directories(
   ../../
   ../common
@@ -35,6 +47,7 @@ add_executable(glview
   )
 
 target_link_libraries ( glview
+  ${DRACO_LIBRARY} 
   ${GLFW3_UNIX_LINK_LIBRARIES}
   ${GLEW_LIBRARY}
   ${GLFW3_glfw_LIBRARY}

examples/glview/README.md

@@ -27,6 +27,17 @@ Open .sln in Visual Studio 2013
 
 When running .exe, glew and glfw dll must exist in the working directory.
 
+#### Build with Draco(optional)
+
+Assume CMake build.
+
+```
+$ mkdir build
+$ cd build
+$ cmake -DDRACO_DIR=/path/to/draco ../
+$ make
+```
+
 ## TODO
 
 * [ ] PBR Material

examples/glview/glview.cc

@@ -677,10 +677,14 @@ static void DrawNode(tinygltf::Model &model, const tinygltf::Node &node) {
   // std::cout << it->first << std::endl;
   // FIXME(syoyo): Refactor.
   // DrawCurves(scene, it->second);
-  DrawMesh(model, model.meshes[node.mesh]);
+  if (node.mesh > -1) {
+    assert(node.mesh < model.meshes.size());
+    DrawMesh(model, model.meshes[node.mesh]);
+  }
 
   // Draw child nodes.
   for (size_t i = 0; i < node.children.size(); i++) {
+    assert(node.children[i] < model.nodes.size());
     DrawNode(model, model.nodes[node.children[i]]);
   }
 
@@ -786,10 +790,12 @@ int main(int argc, char **argv) {
     return -1;
   }
 
-  char title[1024];
-  sprintf(title, "Simple glTF viewer: %s", input_filename.c_str());
+  std::stringstream ss;
+  ss << "Simple glTF viewer: " << input_filename;
 
-  window = glfwCreateWindow(width, height, title, NULL, NULL);
+  std::string title = ss.str();
+
+  window = glfwCreateWindow(width, height, title.c_str(), NULL, NULL);
   if (window == NULL) {
     std::cerr << "Failed to open GLFW window. " << std::endl;
     glfwTerminate();

tiny_gltf.h

@@ -26,6 +26,7 @@
 // THE SOFTWARE.
 
 // Version:
+//  - v2.1.0 Add draco compression.
 //  - v2.0.1 Add comparsion feature(Thanks to @Selmar).
 //  - v2.0.0 glTF 2.0!.
 //
@@ -47,6 +48,12 @@
 #include <string>
 #include <vector>
 
+#ifdef __ANDROID__
+#ifdef TINYGLTF_ANDROID_LOAD_FROM_ASSETS
+#include <android/asset_manager.h>
+#endif
+#endif
+
 namespace tinygltf {
 
 #define TINYGLTF_MODE_POINTS (0)
@@ -139,6 +146,12 @@ namespace tinygltf {
 #define TINYGLTF_DOUBLE_EPS (1.e-12)
 #define TINYGLTF_DOUBLE_EQUAL(a, b) (std::fabs((b) - (a)) < TINYGLTF_DOUBLE_EPS)
 
+#ifdef __ANDROID__
+#ifdef TINYGLTF_ANDROID_LOAD_FROM_ASSETS
+  AAssetManager* asset_manager = nullptr;
+#endif
+#endif
+
 typedef enum {
   NULL_TYPE = 0,
   NUMBER_TYPE = 1,
@@ -526,8 +539,9 @@ struct BufferView {
                       // understood to be tightly packed
   int target;         // ["ARRAY_BUFFER", "ELEMENT_ARRAY_BUFFER"]
   Value extras;
+  bool dracoDecoded;  // Flag indicating this has been draco decoded
 
-  BufferView() : byteOffset(0), byteStride(0) {}
+  BufferView() : byteOffset(0), byteStride(0), dracoDecoded(false) {}
   bool operator==(const BufferView &) const;
 };
 
@@ -646,6 +660,7 @@ struct Primitive {
   // where each target is a dict with attribues in ["POSITION, "NORMAL",
   // "TANGENT"] pointing
   // to their corresponding accessors
+  ExtensionMap extensions;
   Value extras;
 
   Primitive() {
@@ -789,7 +804,7 @@ enum SectionCheck {
 ///
 /// LoadImageDataFunction type. Signature for custom image loading callbacks.
 ///
-typedef bool (*LoadImageDataFunction)(Image *, std::string *, std::string *,
+typedef bool (*LoadImageDataFunction)(Image *, const int, std::string *, std::string *,
                                       int, int, const unsigned char *, int,
                                       void *);
 
@@ -801,7 +816,7 @@ typedef bool (*WriteImageDataFunction)(const std::string *, const std::string *,
 
 #ifndef TINYGLTF_NO_STB_IMAGE
 // Declaration of default image loader callback
-bool LoadImageData(Image *image, std::string *err, std::string *warn,
+bool LoadImageData(Image *image, const int image_idx, std::string *err, std::string *warn,
                    int req_width, int req_height, const unsigned char *bytes,
                    int size, void *);
 #endif
@@ -1048,14 +1063,19 @@ class TinyGLTF {
 #endif
 #endif
 
-#include "./json.hpp"
+#include "json.hpp"
+
+#ifdef TINYGLTF_ENABLE_DRACO
+#include "draco/core/decoder_buffer.h"
+#include "draco/compression/decode.h"
+#endif
 
 #ifndef TINYGLTF_NO_STB_IMAGE
-#include "./stb_image.h"
+#include "stb_image.h"
 #endif
 
 #ifndef TINYGLTF_NO_STB_IMAGE_WRITE
-#include "./stb_image_write.h"
+#include "stb_image_write.h"
 #endif
 
 #ifdef __clang__
@@ -1180,7 +1200,8 @@ bool BufferView::operator==(const BufferView &other) const {
   return this->buffer == other.buffer && this->byteLength == other.byteLength &&
          this->byteOffset == other.byteOffset &&
          this->byteStride == other.byteStride && this->name == other.name &&
-         this->target == other.target && this->extras == other.extras;
+         this->target == other.target && this->extras == other.extras &&
+         this->dracoDecoded == other.dracoDecoded;
 }
 bool Camera::operator==(const Camera &other) const {
   return this->name == other.name && this->extensions == other.extensions &&
@@ -1576,9 +1597,9 @@ void TinyGLTF::SetImageLoader(LoadImageDataFunction func, void *user_data) {
 }
 
 #ifndef TINYGLTF_NO_STB_IMAGE
-bool LoadImageData(Image *image, std::string *err, std::string *warn,
+bool LoadImageData(Image *image, const int image_idx, std::string *err, std::string *warn,
                    int req_width, int req_height, const unsigned char *bytes,
-                   int size, void *) {
+                   int size, void *user_data) {
   (void)warn;
 
   int w, h, comp, req_comp;
@@ -1598,7 +1619,7 @@ bool LoadImageData(Image *image, std::string *err, std::string *warn,
   if (!data) {
     // NOTE: you can use `warn` instead of `err`
     if (err) {
-      (*err) += "Unknown image format.\n";
+      (*err) += "Unknown image format. STB cannot decode image data for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\". Proably 16bit PNG?\n";
     }
     return false;
   }
@@ -1606,7 +1627,7 @@ bool LoadImageData(Image *image, std::string *err, std::string *warn,
   if (w < 1 || h < 1) {
     free(data);
     if (err) {
-      (*err) += "Invalid image data.\n";
+      (*err) += "Invalid image data for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
     }
     return false;
   }
@@ -1615,7 +1636,7 @@ bool LoadImageData(Image *image, std::string *err, std::string *warn,
     if (req_width != w) {
       free(data);
       if (err) {
-        (*err) += "Image width mismatch.\n";
+        (*err) += "Image width mismatch for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
       }
       return false;
     }
@@ -1625,7 +1646,7 @@ bool LoadImageData(Image *image, std::string *err, std::string *warn,
     if (req_height != h) {
       free(data);
       if (err) {
-        (*err) += "Image height mismatch.\n";
+        (*err) += "Image height mismatch. for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
       }
       return false;
     }
@@ -1729,6 +1750,18 @@ void TinyGLTF::SetFsCallbacks(FsCallbacks callbacks) { fs = callbacks; }
 
 bool FileExists(const std::string &abs_filename, void *) {
   bool ret;
+#ifdef TINYGLTF_ANDROID_LOAD_FROM_ASSETS
+    if (asset_manager) {
+        AAsset* asset = AAssetManager_open(asset_manager, abs_filename.c_str(), AASSET_MODE_STREAMING);
+        if (!asset) {
+            return false;
+        }
+        AAsset_close(asset);
+        ret = true;
+    } else {
+      return false;
+    }
+#else
 #ifdef _WIN32
   FILE *fp;
   errno_t err = fopen_s(&fp, abs_filename.c_str(), "rb");
@@ -1744,6 +1777,7 @@ bool FileExists(const std::string &abs_filename, void *) {
   } else {
     ret = false;
   }
+#endif
 
   return ret;
 }
@@ -1797,6 +1831,33 @@ std::string ExpandFilePath(const std::string &filepath, void *) {
 
 bool ReadWholeFile(std::vector<unsigned char> *out, std::string *err,
                    const std::string &filepath, void *) {
+#ifdef TINYGLTF_ANDROID_LOAD_FROM_ASSETS
+  if (asset_manager) {
+    AAsset* asset = AAssetManager_open(asset_manager, filepath.c_str(), AASSET_MODE_STREAMING);
+    if (!asset) {
+      if (err) {
+        (*err) += "File open error : " + filepath + "\n";
+      }
+      return false;
+    }
+    size_t size = AAsset_getLength(asset);
+    if (size <= 0) {
+      if (err) {
+        (*err) += "Invalid file size : " + filepath +
+                  " (does the path point to a directory?)";
+      }
+    }
+    out->resize(size);
+    AAsset_read(asset, reinterpret_cast<char *>(&out->at(0)), size);
+    AAsset_close(asset);
+    return true;
+  } else {
+    if (err) {
+      (*err) += "No asset manager specified : " + filepath + "\n";
+    }
+    return false;
+  }
+#else
   std::ifstream f(filepath.c_str(), std::ifstream::binary);
   if (!f) {
     if (err) {
@@ -1828,6 +1889,7 @@ bool ReadWholeFile(std::vector<unsigned char> *out, std::string *err,
   f.close();
 
   return true;
+#endif
 }
 
 bool WriteWholeFile(std::string *err, const std::string &filepath,
@@ -2374,7 +2436,7 @@ static bool ParseAsset(Asset *asset, std::string *err, const json &o) {
   return true;
 }
 
-static bool ParseImage(Image *image, std::string *err, std::string *warn,
+static bool ParseImage(Image *image, const int image_idx, std::string *err, std::string *warn,
                        const json &o, const std::string &basedir,
                        FsCallbacks *fs,
                        LoadImageDataFunction *LoadImageData = nullptr,
@@ -2386,24 +2448,25 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
   bool hasBufferView = (o.find("bufferView") != o.end());
   bool hasURI = (o.find("uri") != o.end());
 
+  ParseStringProperty(&image->name, err, o, "name", false);
+
   if (hasBufferView && hasURI) {
     // Should not both defined.
     if (err) {
       (*err) +=
           "Only one of `bufferView` or `uri` should be defined, but both are "
-          "defined for Image.\n";
+          "defined for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
     }
     return false;
   }
 
   if (!hasBufferView && !hasURI) {
     if (err) {
-      (*err) += "Neither required `bufferView` nor `uri` defined for Image.\n";
+      (*err) += "Neither required `bufferView` nor `uri` defined for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
     }
     return false;
   }
 
-  ParseStringProperty(&image->name, err, o, "name", false);
   ParseExtensionsProperty(&image->extensions, err, o);
   ParseExtrasProperty(&image->extras, o);
 
@@ -2411,7 +2474,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
     double bufferView = -1;
     if (!ParseNumberProperty(&bufferView, err, o, "bufferView", true)) {
       if (err) {
-        (*err) += "Failed to parse `bufferView` for Image.\n";
+        (*err) += "Failed to parse `bufferView` for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
       }
       return false;
     }
@@ -2441,7 +2504,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
   std::string tmp_err;
   if (!ParseStringProperty(&uri, &tmp_err, o, "uri", true)) {
     if (err) {
-      (*err) += "Failed to parse `uri` for Image.\n";
+      (*err) += "Failed to parse `uri` for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\".\n";
     }
     return false;
   }
@@ -2451,7 +2514,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
   if (IsDataURI(uri)) {
     if (!DecodeDataURI(&img, image->mimeType, uri, 0, false)) {
       if (err) {
-        (*err) += "Failed to decode 'uri' for image parameter.\n";
+        (*err) += "Failed to decode 'uri' for image[" + std::to_string(image_idx) + "] name = [" + image->name + "]\n";
       }
       return false;
     }
@@ -2464,7 +2527,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
 #endif
     if (!LoadExternalFile(&img, err, warn, uri, basedir, false, 0, false, fs)) {
       if (warn) {
-        (*warn) += "Failed to load external 'uri' for image parameter\n";
+        (*warn) += "Failed to load external 'uri' for image[" + std::to_string(image_idx) + "] name = [" + image->name + "]\n";
       }
       // If the image cannot be loaded, keep uri as image->uri.
       return true;
@@ -2472,7 +2535,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
 
     if (img.empty()) {
       if (warn) {
-        (*warn) += "Image is empty.\n";
+        (*warn) += "Image data is empty for image[" + std::to_string(image_idx) + "] name = [" + image->name + "] \n";
       }
       return false;
     }
@@ -2484,7 +2547,7 @@ static bool ParseImage(Image *image, std::string *err, std::string *warn,
     }
     return false;
   }
-  return (*LoadImageData)(image, err, warn, 0, 0, &img.at(0),
+  return (*LoadImageData)(image, image_idx, err, warn, 0, 0, &img.at(0),
                           static_cast<int>(img.size()), load_image_user_data);
 }
 
@@ -2674,10 +2737,7 @@ static bool ParseBufferView(BufferView *bufferView, std::string *err,
 
 static bool ParseAccessor(Accessor *accessor, std::string *err, const json &o) {
   double bufferView = -1.0;
-  if (!ParseNumberProperty(&bufferView, err, o, "bufferView", true,
-                           "Accessor")) {
-    return false;
-  }
+  ParseNumberProperty(&bufferView, err, o, "bufferView", false, "Accessor");
 
   double byteOffset = 0.0;
   ParseNumberProperty(&byteOffset, err, o, "byteOffset", false, "Accessor");
@@ -2759,7 +2819,184 @@ static bool ParseAccessor(Accessor *accessor, std::string *err, const json &o) {
   return true;
 }
 
-static bool ParsePrimitive(Primitive *primitive, std::string *err,
+#ifdef TINYGLTF_ENABLE_DRACO
+
+static void DecodeIndexBuffer(draco::Mesh* mesh, size_t componentSize, std::vector<uint8_t>& outBuffer)
+{
+  if (componentSize == 4)
+  {
+    assert(sizeof(mesh->face(draco::FaceIndex(0))[0]) == componentSize);
+    memcpy(outBuffer.data(), &mesh->face(draco::FaceIndex(0))[0], outBuffer.size());
+  }
+  else
+  {
+    size_t faceStride = componentSize * 3;
+    for (draco::FaceIndex f(0); f < mesh->num_faces(); ++f)
+    {
+      const draco::Mesh::Face& face = mesh->face(f);
+      if (componentSize == 2)
+      {
+        uint16_t indices[3] = { (uint16_t)face[0].value(), (uint16_t)face[1].value(), (uint16_t)face[2].value() };
+        memcpy(outBuffer.data() + f.value() * faceStride, &indices[0], faceStride);
+      }
+      else
+      {
+        uint8_t indices[3] = { (uint8_t)face[0].value(), (uint8_t)face[1].value(), (uint8_t)face[2].value() };
+        memcpy(outBuffer.data() + f.value() * faceStride, &indices[0], faceStride);
+      }
+    }
+  }
+}
+
+template<typename T>
+static bool GetAttributeForAllPoints(draco::Mesh* mesh, const draco::PointAttribute* pAttribute, std::vector<uint8_t>& outBuffer)
+{
+  size_t byteOffset = 0;
+  T values[4] = { 0, 0, 0, 0 };
+  for (draco::PointIndex i(0); i < mesh->num_points(); ++i)
+  {
+    const draco::AttributeValueIndex val_index = pAttribute->mapped_index(i);
+    if (!pAttribute->ConvertValue<T>(val_index, pAttribute->num_components(), values))
+      return false;
+
+    memcpy(outBuffer.data() + byteOffset, &values[0], sizeof(T) * pAttribute->num_components());
+    byteOffset += sizeof(T) * pAttribute->num_components();
+  }
+
+  return true;
+}
+
+static bool GetAttributeForAllPoints(uint32_t componentType, draco::Mesh* mesh, const draco::PointAttribute* pAttribute, std::vector<uint8_t>& outBuffer)
+{
+  bool decodeResult = false;
+  switch (componentType)
+  {
+  case TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE:
+    decodeResult = GetAttributeForAllPoints<uint8_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_BYTE:
+    decodeResult = GetAttributeForAllPoints<int8_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT:
+    decodeResult = GetAttributeForAllPoints<uint16_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_SHORT:
+    decodeResult = GetAttributeForAllPoints<int16_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_INT:
+    decodeResult = GetAttributeForAllPoints<int32_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT:
+    decodeResult = GetAttributeForAllPoints<uint32_t>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_FLOAT:
+    decodeResult = GetAttributeForAllPoints<float>(mesh, pAttribute, outBuffer);
+    break;
+  case TINYGLTF_COMPONENT_TYPE_DOUBLE:
+    decodeResult = GetAttributeForAllPoints<double>(mesh, pAttribute, outBuffer);
+    break;
+  default:
+    return false;
+  }
+
+  return decodeResult;
+}
+
+static bool ParseDracoExtension(Primitive *primitive, Model *model, std::string *err, const Value &dracoExtensionValue)
+{
+  auto bufferViewValue = dracoExtensionValue.Get("bufferView");
+  if (!bufferViewValue.IsInt())
+    return false;
+  auto attributesValue = dracoExtensionValue.Get("attributes");
+  if (!attributesValue.IsObject())
+    return false;
+
+  auto attributesObject = attributesValue.Get<Value::Object>();
+  int bufferView = bufferViewValue.Get<int>();
+
+  BufferView& view = model->bufferViews[bufferView];
+  Buffer& buffer = model->buffers[view.buffer];
+  // BufferView has already been decoded
+  if (view.dracoDecoded)
+    return true;
+  view.dracoDecoded = true;
+
+  const char* bufferViewData = reinterpret_cast<const char*>(buffer.data.data() + view.byteOffset);
+  size_t bufferViewSize = view.byteLength;
+
+  // decode draco
+  draco::DecoderBuffer decoderBuffer;
+  decoderBuffer.Init(bufferViewData, bufferViewSize);
+  draco::Decoder decoder;
+  auto decodeResult = decoder.DecodeMeshFromBuffer(&decoderBuffer);
+  if (!decodeResult.ok()) {
+    return false;
+  }
+  const std::unique_ptr<draco::Mesh>& mesh = decodeResult.value();
+
+  // create new bufferView for indices
+  if (primitive->indices >= 0)
+  {
+    int32_t componentSize = GetComponentSizeInBytes(model->accessors[primitive->indices].componentType);
+    Buffer decodedIndexBuffer;
+    decodedIndexBuffer.data.resize(mesh->num_faces() * 3 * componentSize);
+
+    DecodeIndexBuffer(mesh.get(), componentSize, decodedIndexBuffer.data);
+
+    model->buffers.emplace_back(std::move(decodedIndexBuffer));
+
+    BufferView decodedIndexBufferView;
+    decodedIndexBufferView.buffer = int(model->buffers.size() - 1);
+    decodedIndexBufferView.byteLength = int(mesh->num_faces() * 3 * componentSize);
+    decodedIndexBufferView.byteOffset = 0;
+    decodedIndexBufferView.byteStride = 0;
+    decodedIndexBufferView.target = TINYGLTF_TARGET_ARRAY_BUFFER;
+    model->bufferViews.emplace_back(std::move(decodedIndexBufferView));
+
+    model->accessors[primitive->indices].bufferView = int(model->bufferViews.size() - 1);
+    model->accessors[primitive->indices].count = int(mesh->num_faces() * 3);
+  }
+
+  for (const auto& attribute : attributesObject)
+  {
+    if (!attribute.second.IsInt())
+      return false;
+    auto primitiveAttribute = primitive->attributes.find(attribute.first);
+    if (primitiveAttribute == primitive->attributes.end())
+      return false;
+
+    int dracoAttributeIndex = attribute.second.Get<int>();
+    const auto pAttribute = mesh->GetAttributeByUniqueId(dracoAttributeIndex);
+    const auto pBuffer = pAttribute->buffer();
+    const auto componentType = model->accessors[primitiveAttribute->second].componentType;
+
+    // Create a new buffer for this decoded buffer
+    Buffer decodedBuffer;
+    size_t bufferSize = mesh->num_points() * pAttribute->num_components() * GetComponentSizeInBytes(componentType);
+    decodedBuffer.data.resize(bufferSize);
+
+    if (!GetAttributeForAllPoints(componentType, mesh.get(), pAttribute, decodedBuffer.data))
+      return false;
+
+    model->buffers.emplace_back(std::move(decodedBuffer));
+
+    BufferView decodedBufferView;
+    decodedBufferView.buffer = int(model->buffers.size() - 1);
+    decodedBufferView.byteLength = bufferSize;
+    decodedBufferView.byteOffset = pAttribute->byte_offset();
+    decodedBufferView.byteStride = pAttribute->byte_stride();
+    decodedBufferView.target = primitive->indices >= 0 ? TINYGLTF_TARGET_ELEMENT_ARRAY_BUFFER : TINYGLTF_TARGET_ARRAY_BUFFER;
+    model->bufferViews.emplace_back(std::move(decodedBufferView));
+
+    model->accessors[primitiveAttribute->second].bufferView = int(model->bufferViews.size() - 1);
+    model->accessors[primitiveAttribute->second].count = int(mesh->num_points());
+  }
+
+  return true;
+}
+#endif
+
+static bool ParsePrimitive(Primitive *primitive, Model *model, std::string *err,
                            const json &o) {
   double material = -1.0;
   ParseNumberProperty(&material, err, o, "material", false);
@@ -2799,10 +3036,20 @@ static bool ParsePrimitive(Primitive *primitive, std::string *err,
 
   ParseExtrasProperty(&(primitive->extras), o);
 
+  ParseExtensionsProperty(&primitive->extensions, err, o);
+
+#ifdef TINYGLTF_ENABLE_DRACO
+  auto dracoExtension = primitive->extensions.find("KHR_draco_mesh_compression");
+  if (dracoExtension != primitive->extensions.end())
+  {
+      ParseDracoExtension(primitive, model, err, dracoExtension->second);
+  }
+#endif
+
   return true;
 }
 
-static bool ParseMesh(Mesh *mesh, std::string *err, const json &o) {
+static bool ParseMesh(Mesh *mesh, Model *model, std::string *err, const json &o) {
   ParseStringProperty(&mesh->name, err, o, "name", false);
 
   mesh->primitives.clear();
@@ -2811,7 +3058,7 @@ static bool ParseMesh(Mesh *mesh, std::string *err, const json &o) {
     for (json::const_iterator i = primObject.value().begin();
          i != primObject.value().end(); i++) {
       Primitive primitive;
-      if (ParsePrimitive(&primitive, err, i.value())) {
+      if (ParsePrimitive(&primitive, model, err, i.value())) {
         // Only add the primitive if the parsing succeeds.
         mesh->primitives.push_back(primitive);
       }
@@ -3470,7 +3717,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
           return false;
         }
         Mesh mesh;
-        if (!ParseMesh(&mesh, err, it->get<json>())) {
+        if (!ParseMesh(&mesh, model, err, it->get<json>())) {
           return false;
         }
 
@@ -3612,15 +3859,16 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
 
       json::const_iterator it(root.begin());
       json::const_iterator itEnd(root.end());
-      for (; it != itEnd; it++) {
+      int idx = 0;
+      for (; it != itEnd; it++, idx++) {
         if (!it.value().is_object()) {
           if (err) {
-            (*err) += "`images' does not contain an JSON object.";
+            (*err) += "image[" + std::to_string(idx) + "] is not a JSON object.";
           }
           return false;
         }
         Image image;
-        if (!ParseImage(&image, err, warn, it.value(), base_dir, &fs,
+        if (!ParseImage(&image, idx, err, warn, it.value(), base_dir, &fs,
                         &this->LoadImageData, load_image_user_data_)) {
           return false;
         }
@@ -3630,7 +3878,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
           if (size_t(image.bufferView) >= model->bufferViews.size()) {
             if (err) {
               std::stringstream ss;
-              ss << "bufferView \"" << image.bufferView
+              ss << "image[" << idx << "] bufferView \"" << image.bufferView
                  << "\" not found in the scene." << std::endl;
               (*err) += ss.str();
             }
@@ -3647,7 +3895,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
             }
             return false;
           }
-          bool ret = LoadImageData(&image, err, warn, image.width, image.height,
+          bool ret = LoadImageData(&image, idx, err, warn, image.width, image.height,
                                    &buffer.data[bufferView.byteOffset],
                                    static_cast<int>(bufferView.byteLength),
                                    load_image_user_data_);
@@ -4575,14 +4823,14 @@ static void WriteBinaryGltfFile(const std::string &output,
   const int padding_size = content.size() % 4;
 
   // 12 bytes for header, JSON content length, 8 bytes for JSON chunk info, padding
-  const int length = 12 + 8 + content.size() + padding_size;
+  const int length = 12 + 8 + int(content.size()) + padding_size;
   
   gltfFile.write(header.c_str(), header.size());
   gltfFile.write(reinterpret_cast<const char *>(&version), sizeof(version));
   gltfFile.write(reinterpret_cast<const char *>(&length), sizeof(length));
 
   // JSON chunk info, then JSON data
-  const int model_length = content.size() + padding_size;
+  const int model_length = int(content.size()) + padding_size;
   const int model_format = 0x4E4F534A;
   gltfFile.write(reinterpret_cast<const char *>(&model_length), sizeof(model_length));
   gltfFile.write(reinterpret_cast<const char *>(&model_format), sizeof(model_format));