Introduce tiny_gltf_util.h header file which contains some useful helper/util functions.

Add an utility function to get buffer byte address.

README.md

@@ -46,14 +46,11 @@ 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
 
@@ -65,10 +62,10 @@ v2.0.0 release(22 Aug, 2018)!
 
 ## TODOs
 
+* [ ] Sparse accesors(e.g. for efficient morph targets)
 * [ ] Write C++ code generator which emits C++ code from JSON schema for robust parsing.
 * [ ] Mesh Compression/decompression(Open3DGC, etc)
-  * [x] Load Draco compressed mesh
-  * [x] Save Draco compressed mesh
+  * [ ] Load Draco compressed mesh
 * [ ] Support `extensions` and `extras` property
 * [ ] HDR image?
   * [ ] OpenEXR extension through TinyEXR.
@@ -132,8 +129,6 @@ 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/anim-dump/Makefile

@@ -0,0 +1,6 @@
+# Use this for strict compilation check(will work on clang 3.8+)
+#EXTRA_CXXFLAGS := -fsanitize=address -Wall -Werror -Weverything -Wno-c++11-long-long -Wno-c++98-compat
+
+all:
+	clang++ -I../../ $(EXTRA_CXXFLAGS) -std=c++11 -g -O0 -o anim-dump anim-dump.cc
+

examples/anim-dump/README.md

@@ -0,0 +1,2 @@
+# Simple animation value dumper
+

examples/anim-dump/anim-dump.cc

@@ -0,0 +1,178 @@
+//
+// TODO(syoyo): Print extensions and extras for each glTF object.
+//
+#include "tiny_gltf_util.h"
+
+#define TINYGLTF_IMPLEMENTATION
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "tiny_gltf.h"
+
+
+#include <cstdio>
+#include <fstream>
+#include <iostream>
+
+static std::string GetFilePathExtension(const std::string &FileName) {
+  if (FileName.find_last_of(".") != std::string::npos)
+    return FileName.substr(FileName.find_last_of(".") + 1);
+  return "";
+}
+
+static std::string Indent(const int indent) {
+  std::string s;
+  for (int i = 0; i < indent; i++) {
+    s += "  ";
+  }
+
+  return s;
+}
+
+
+
+static void ProcessAnimation(const tinygltf::Animation &animation, const tinygltf::Model &model)
+{
+#if 0
+  if (animaton_channel.target_path.compare("translation") == 0) {
+  } else if (animaton_channel.target_path.compare("rotation") == 0) {
+  } else if (animaton_channel.target_path.compare("scale") == 0) {
+  } else if (animaton_channel.target_path.compare("weights") == 0) {
+  }
+#endif
+
+
+  for (size_t j = 0; j < animation.samplers.size(); j++) {
+    std::cout << "== samplers[" << j << "] ===============" << std::endl;
+    const tinygltf::AnimationSampler &sampler = animation.samplers[j];
+    std::cout << Indent(1) << "interpolation = " << sampler.interpolation<< std::endl;
+    std::cout << Indent(1) << "input = " << sampler.input << std::endl;
+    std::cout << Indent(1) << "output = " << sampler.output << std::endl;
+    
+    // input accessor must have min/max property.
+    const tinygltf::Accessor &accessor = model.accessors[sampler.input];
+    
+    for (size_t i = 0; i < accessor.minValues.size(); i++) {
+      std::cout << Indent(1) << "input min[" << i << "] = " << accessor.minValues[i] << std::endl;
+    }
+    for (size_t i = 0; i < accessor.maxValues.size(); i++) {
+      std::cout << Indent(1) << "input max[" << i << "] = " << accessor.maxValues[i] << std::endl;
+    }
+
+    std::cout << Indent(1) << "input count = " << accessor.count << std::endl;
+
+    for (size_t i = 0; i < accessor.count; i++) {
+      if (accessor.type == TINYGLTF_TYPE_SCALAR) {
+        float v;
+        if (tinygltf::util::DecodeScalarAnimationValue(i, accessor, model, &v)) {
+          std::cout << Indent(2) << "input value[" << i << "] = " << v << std::endl;
+        }
+      }
+    }
+
+
+    //const tinygltf::Accessor &accessor = model.accessors[sampler.output];
+    //std::cout << Indent(2) << "output        : " << sampler.output
+    //          << std::endl;
+  }
+  
+}
+
+static void DumpAnim(const tinygltf::Model &model) {
+  std::cout << "=== Dump glTF ===" << std::endl;
+  std::cout << "asset.copyright          : " << model.asset.copyright
+            << std::endl;
+  std::cout << "asset.generator          : " << model.asset.generator
+            << std::endl;
+  std::cout << "asset.version            : " << model.asset.version
+            << std::endl;
+  std::cout << "asset.minVersion         : " << model.asset.minVersion
+            << std::endl;
+  std::cout << std::endl;
+
+  std::cout << "=== Dump scene ===" << std::endl;
+  std::cout << "defaultScene: " << model.defaultScene << std::endl;
+
+  {
+    std::cout << "animations(items=" << model.animations.size() << ")"
+              << std::endl;
+    for (size_t i = 0; i < model.animations.size(); i++) {
+      const tinygltf::Animation &animation = model.animations[i];
+      std::cout << Indent(1) << "name         : " << animation.name
+                << std::endl;
+
+      std::cout << Indent(1) << "channels : [ " << std::endl;
+      for (size_t j = 0; i < animation.channels.size(); i++) {
+        std::cout << Indent(2)
+                  << "sampler     : " << animation.channels[j].sampler
+                  << std::endl;
+        std::cout << Indent(2)
+                  << "target.id   : " << animation.channels[j].target_node
+                  << std::endl;
+        std::cout << Indent(2)
+                  << "target.path : " << animation.channels[j].target_path
+                  << std::endl;
+        std::cout << ((i != (animation.channels.size() - 1)) ? "  , " : "");
+      }
+      std::cout << "  ]" << std::endl;
+
+      std::cout << Indent(1) << "samplers(items=" << animation.samplers.size()
+                << ")" << std::endl;
+      for (size_t j = 0; j < animation.samplers.size(); j++) {
+        const tinygltf::AnimationSampler &sampler = animation.samplers[j];
+        std::cout << Indent(2) << "input         : " << sampler.input
+                  << std::endl;
+        std::cout << Indent(2) << "interpolation : " << sampler.interpolation
+                  << std::endl;
+        std::cout << Indent(2) << "output        : " << sampler.output
+                  << std::endl;
+      }
+
+      ProcessAnimation(animation, model);
+    }
+
+  }
+
+}
+
+int main(int argc, char **argv) {
+  if (argc < 2) {
+    printf("Needs input.gltf\n");
+    exit(1);
+  }
+
+  tinygltf::Model model;
+  tinygltf::TinyGLTF gltf_ctx;
+  std::string err;
+  std::string warn; 
+  std::string input_filename(argv[1]);
+  std::string ext = GetFilePathExtension(input_filename);
+
+  bool ret = false;
+  if (ext.compare("glb") == 0) {
+    std::cout << "Reading binary glTF" << std::endl;
+    // assume binary glTF.
+    ret = gltf_ctx.LoadBinaryFromFile(&model, &err, &warn, input_filename.c_str());
+  } else {
+    std::cout << "Reading ASCII glTF" << std::endl;
+    // assume ascii glTF.
+    ret = gltf_ctx.LoadASCIIFromFile(&model, &err, &warn, input_filename.c_str());
+  }
+
+  if (!warn.empty()) {
+    printf("Warn: %s\n", warn.c_str());
+  }
+
+
+  if (!err.empty()) {
+    printf("Err: %s\n", err.c_str());
+  }
+
+  if (!ret) {
+    printf("Failed to parse glTF\n");
+    return -1;
+  }
+
+  DumpAnim(model);
+
+  return 0;
+}

examples/basic/README.md

@@ -1,21 +0,0 @@
-# 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

@@ -1,44 +0,0 @@
-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 = texture(tex, texcoord) * vec4((0.3 + 0.7 * lum) * sun_color, 1.0);\n\
+	color = texture2D(tex, texcoord) * vec4((0.3 + 0.7 * lum) * sun_color, 1.0);\n\
 }\n\
 ";
 

examples/glview/CMakeLists.txt

@@ -1,10 +1,8 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.6)
 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 )
@@ -23,16 +21,6 @@ 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
@@ -47,7 +35,6 @@ add_executable(glview
   )
 
 target_link_libraries ( glview
-  ${DRACO_LIBRARY} 
   ${GLFW3_UNIX_LINK_LIBRARIES}
   ${GLEW_LIBRARY}
   ${GLFW3_glfw_LIBRARY}

examples/glview/README.md

@@ -27,17 +27,6 @@ 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

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

tiny_gltf.h

@@ -26,7 +26,6 @@
 // THE SOFTWARE.
 
 // Version:
-//  - v2.1.0 Add draco compression.
 //  - v2.0.1 Add comparsion feature(Thanks to @Selmar).
 //  - v2.0.0 glTF 2.0!.
 //
@@ -48,12 +47,6 @@
 #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)
@@ -63,6 +56,7 @@ namespace tinygltf {
 #define TINYGLTF_MODE_TRIANGLE_STRIP (5)
 #define TINYGLTF_MODE_TRIANGLE_FAN (6)
 
+#define TINYGLTF_COMPONENT_TYPE_INVALID (-1)
 #define TINYGLTF_COMPONENT_TYPE_BYTE (5120)
 #define TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE (5121)
 #define TINYGLTF_COMPONENT_TYPE_SHORT (5122)
@@ -113,6 +107,7 @@ namespace tinygltf {
 
 // End parameter types
 
+#define TINYGLTF_TYPE_INVALID (-1)
 #define TINYGLTF_TYPE_VEC2 (2)
 #define TINYGLTF_TYPE_VEC3 (3)
 #define TINYGLTF_TYPE_VEC4 (4)
@@ -146,12 +141,6 @@ 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,
@@ -429,6 +418,7 @@ struct AnimationSampler {
 
   AnimationSampler() : input(-1), output(-1), interpolation("LINEAR") {}
   bool operator==(const AnimationSampler &) const;
+
 };
 
 struct Animation {
@@ -539,9 +529,8 @@ 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), dracoDecoded(false) {}
+  BufferView() : byteOffset(0), byteStride(0) {}
   bool operator==(const BufferView &) const;
 };
 
@@ -549,11 +538,11 @@ struct Accessor {
   int bufferView;  // optional in spec but required here since sparse accessor
                    // are not supported
   std::string name;
-  size_t byteOffset;
-  bool normalized;    // optinal.
-  int componentType;  // (required) One of TINYGLTF_COMPONENT_TYPE_***
-  size_t count;       // required
-  int type;           // (required) One of TINYGLTF_TYPE_***   ..
+  size_t byteOffset = 0;
+  bool normalized = false;    // optinal.
+  int componentType = TINYGLTF_COMPONENT_TYPE_INVALID;  // (required) One of TINYGLTF_COMPONENT_TYPE_***
+  size_t count = 0;       // required
+  int type = TINYGLTF_TYPE_INVALID;           // (required) One of TINYGLTF_TYPE_***   ..
   Value extras;
 
   std::vector<double> minValues;  // optional
@@ -602,6 +591,7 @@ struct Accessor {
   bool operator==(const tinygltf::Accessor &) const;
 };
 
+
 struct PerspectiveCamera {
   double aspectRatio;  // min > 0
   double yfov;         // required. min > 0
@@ -660,7 +650,6 @@ struct Primitive {
   // where each target is a dict with attribues in ["POSITION, "NORMAL",
   // "TANGENT"] pointing
   // to their corresponding accessors
-  ExtensionMap extensions;
   Value extras;
 
   Primitive() {
@@ -790,6 +779,14 @@ class Model {
   Value extras;
 };
 
+///
+/// Utility function to get an address of underlying buffer for i'th element.
+/// Returns nullptr for invalid parameter or invalid data.
+/// Assume `buffer` parameter = model.buffers[bufferViewObject.buffer]
+///
+const uint8_t *GetBufferAddress(const int i, const Accessor &accessor, const BufferView &bufferViewObject, const Buffer &buffer);
+
+
 enum SectionCheck {
   NO_REQUIRE = 0x00,
   REQUIRE_SCENE = 0x01,
@@ -804,7 +801,7 @@ enum SectionCheck {
 ///
 /// LoadImageDataFunction type. Signature for custom image loading callbacks.
 ///
-typedef bool (*LoadImageDataFunction)(Image *, const int, std::string *, std::string *,
+typedef bool (*LoadImageDataFunction)(Image *, std::string *, std::string *,
                                       int, int, const unsigned char *, int,
                                       void *);
 
@@ -816,7 +813,7 @@ typedef bool (*WriteImageDataFunction)(const std::string *, const std::string *,
 
 #ifndef TINYGLTF_NO_STB_IMAGE
 // Declaration of default image loader callback
-bool LoadImageData(Image *image, const int image_idx, std::string *err, std::string *warn,
+bool LoadImageData(Image *image, std::string *err, std::string *warn,
                    int req_width, int req_height, const unsigned char *bytes,
                    int size, void *);
 #endif
@@ -1063,19 +1060,14 @@ class TinyGLTF {
 #endif
 #endif
 
-#include "json.hpp"
-
-#ifdef TINYGLTF_ENABLE_DRACO
-#include "draco/core/decoder_buffer.h"
-#include "draco/compression/decode.h"
-#endif
+#include "./json.hpp"
 
 #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__
@@ -1200,8 +1192,7 @@ 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->dracoDecoded == other.dracoDecoded;
+         this->target == other.target && this->extras == other.extras;
 }
 bool Camera::operator==(const Camera &other) const {
   return this->name == other.name && this->extensions == other.extensions &&
@@ -1597,9 +1588,9 @@ void TinyGLTF::SetImageLoader(LoadImageDataFunction func, void *user_data) {
 }
 
 #ifndef TINYGLTF_NO_STB_IMAGE
-bool LoadImageData(Image *image, const int image_idx, std::string *err, std::string *warn,
+bool LoadImageData(Image *image, std::string *err, std::string *warn,
                    int req_width, int req_height, const unsigned char *bytes,
-                   int size, void *user_data) {
+                   int size, void *) {
   (void)warn;
 
   int w, h, comp, req_comp;
@@ -1619,7 +1610,7 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err, std::str
   if (!data) {
     // NOTE: you can use `warn` instead of `err`
     if (err) {
-      (*err) += "Unknown image format. STB cannot decode image data for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\". Proably 16bit PNG?\n";
+      (*err) += "Unknown image format.\n";
     }
     return false;
   }
@@ -1627,7 +1618,7 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err, std::str
   if (w < 1 || h < 1) {
     free(data);
     if (err) {
-      (*err) += "Invalid image data for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+      (*err) += "Invalid image data.\n";
     }
     return false;
   }
@@ -1636,7 +1627,7 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err, std::str
     if (req_width != w) {
       free(data);
       if (err) {
-        (*err) += "Image width mismatch for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+        (*err) += "Image width mismatch.\n";
       }
       return false;
     }
@@ -1646,7 +1637,7 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err, std::str
     if (req_height != h) {
       free(data);
       if (err) {
-        (*err) += "Image height mismatch. for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+        (*err) += "Image height mismatch.\n";
       }
       return false;
     }
@@ -1750,18 +1741,6 @@ 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");
@@ -1777,7 +1756,6 @@ bool FileExists(const std::string &abs_filename, void *) {
   } else {
     ret = false;
   }
-#endif
 
   return ret;
 }
@@ -1831,33 +1809,6 @@ 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) {
@@ -1889,7 +1840,6 @@ bool ReadWholeFile(std::vector<unsigned char> *out, std::string *err,
   f.close();
 
   return true;
-#endif
 }
 
 bool WriteWholeFile(std::string *err, const std::string &filepath,
@@ -2070,6 +2020,21 @@ bool DecodeDataURI(std::vector<unsigned char> *out, std::string &mime_type,
   return true;
 }
 
+const uint8_t *GetBufferAddress(const int i, const Accessor &accessor, const BufferView &bufferViewObject, const Buffer &buffer) {
+
+  if (i >= int(accessor.count)) return nullptr;
+
+  int byte_stride = accessor.ByteStride(bufferViewObject);
+  if (byte_stride == -1) {
+    return nullptr;
+  }
+
+  // TODO(syoyo): Bounds check.
+  const uint8_t *base_addr = buffer.data.data() + bufferViewObject.byteOffset + accessor.byteOffset;
+  const uint8_t *addr = base_addr + i * byte_stride;
+  return addr;
+}
+
 static bool ParseJsonAsValue(Value *ret, const json &o) {
   Value val{};
   switch (o.type()) {
@@ -2436,7 +2401,7 @@ static bool ParseAsset(Asset *asset, std::string *err, const json &o) {
   return true;
 }
 
-static bool ParseImage(Image *image, const int image_idx, std::string *err, std::string *warn,
+static bool ParseImage(Image *image, std::string *err, std::string *warn,
                        const json &o, const std::string &basedir,
                        FsCallbacks *fs,
                        LoadImageDataFunction *LoadImageData = nullptr,
@@ -2448,25 +2413,24 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
   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[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+          "defined for Image.\n";
     }
     return false;
   }
 
   if (!hasBufferView && !hasURI) {
     if (err) {
-      (*err) += "Neither required `bufferView` nor `uri` defined for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+      (*err) += "Neither required `bufferView` nor `uri` defined for Image.\n";
     }
     return false;
   }
 
+  ParseStringProperty(&image->name, err, o, "name", false);
   ParseExtensionsProperty(&image->extensions, err, o);
   ParseExtrasProperty(&image->extras, o);
 
@@ -2474,7 +2438,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
     double bufferView = -1;
     if (!ParseNumberProperty(&bufferView, err, o, "bufferView", true)) {
       if (err) {
-        (*err) += "Failed to parse `bufferView` for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\"\n";
+        (*err) += "Failed to parse `bufferView` for Image.\n";
       }
       return false;
     }
@@ -2504,7 +2468,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
   std::string tmp_err;
   if (!ParseStringProperty(&uri, &tmp_err, o, "uri", true)) {
     if (err) {
-      (*err) += "Failed to parse `uri` for image[" + std::to_string(image_idx) + "] name = \"" + image->name + "\".\n";
+      (*err) += "Failed to parse `uri` for Image.\n";
     }
     return false;
   }
@@ -2514,7 +2478,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
   if (IsDataURI(uri)) {
     if (!DecodeDataURI(&img, image->mimeType, uri, 0, false)) {
       if (err) {
-        (*err) += "Failed to decode 'uri' for image[" + std::to_string(image_idx) + "] name = [" + image->name + "]\n";
+        (*err) += "Failed to decode 'uri' for image parameter.\n";
       }
       return false;
     }
@@ -2527,7 +2491,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
 #endif
     if (!LoadExternalFile(&img, err, warn, uri, basedir, false, 0, false, fs)) {
       if (warn) {
-        (*warn) += "Failed to load external 'uri' for image[" + std::to_string(image_idx) + "] name = [" + image->name + "]\n";
+        (*warn) += "Failed to load external 'uri' for image parameter\n";
       }
       // If the image cannot be loaded, keep uri as image->uri.
       return true;
@@ -2535,7 +2499,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
 
     if (img.empty()) {
       if (warn) {
-        (*warn) += "Image data is empty for image[" + std::to_string(image_idx) + "] name = [" + image->name + "] \n";
+        (*warn) += "Image is empty.\n";
       }
       return false;
     }
@@ -2547,7 +2511,7 @@ static bool ParseImage(Image *image, const int image_idx, std::string *err, std:
     }
     return false;
   }
-  return (*LoadImageData)(image, image_idx, err, warn, 0, 0, &img.at(0),
+  return (*LoadImageData)(image, err, warn, 0, 0, &img.at(0),
                           static_cast<int>(img.size()), load_image_user_data);
 }
 
@@ -2737,7 +2701,10 @@ static bool ParseBufferView(BufferView *bufferView, std::string *err,
 
 static bool ParseAccessor(Accessor *accessor, std::string *err, const json &o) {
   double bufferView = -1.0;
-  ParseNumberProperty(&bufferView, err, o, "bufferView", false, "Accessor");
+  if (!ParseNumberProperty(&bufferView, err, o, "bufferView", true,
+                           "Accessor")) {
+    return false;
+  }
 
   double byteOffset = 0.0;
   ParseNumberProperty(&byteOffset, err, o, "byteOffset", false, "Accessor");
@@ -2819,184 +2786,7 @@ static bool ParseAccessor(Accessor *accessor, std::string *err, const json &o) {
   return true;
 }
 
-#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,
+static bool ParsePrimitive(Primitive *primitive, std::string *err,
                            const json &o) {
   double material = -1.0;
   ParseNumberProperty(&material, err, o, "material", false);
@@ -3036,20 +2826,10 @@ static bool ParsePrimitive(Primitive *primitive, Model *model, 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, Model *model, std::string *err, const json &o) {
+static bool ParseMesh(Mesh *mesh, std::string *err, const json &o) {
   ParseStringProperty(&mesh->name, err, o, "name", false);
 
   mesh->primitives.clear();
@@ -3058,7 +2838,7 @@ static bool ParseMesh(Mesh *mesh, Model *model, std::string *err, const json &o)
     for (json::const_iterator i = primObject.value().begin();
          i != primObject.value().end(); i++) {
       Primitive primitive;
-      if (ParsePrimitive(&primitive, model, err, i.value())) {
+      if (ParsePrimitive(&primitive, err, i.value())) {
         // Only add the primitive if the parsing succeeds.
         mesh->primitives.push_back(primitive);
       }
@@ -3717,7 +3497,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
           return false;
         }
         Mesh mesh;
-        if (!ParseMesh(&mesh, model, err, it->get<json>())) {
+        if (!ParseMesh(&mesh, err, it->get<json>())) {
           return false;
         }
 
@@ -3735,7 +3515,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
     {
       if (primitive.indices > -1) // has indices from parsing step, must be Element Array Buffer
       {
-        model->bufferViews[model->accessors[primitive.indices].bufferView]
+        model->bufferViews[size_t(model->accessors[size_t(primitive.indices)].bufferView)]
             .target = TINYGLTF_TARGET_ELEMENT_ARRAY_BUFFER;
         // we could optionally check if acessors' bufferView type is Scalar, as it should be
       }
@@ -3859,16 +3639,15 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
 
       json::const_iterator it(root.begin());
       json::const_iterator itEnd(root.end());
-      int idx = 0;
-      for (; it != itEnd; it++, idx++) {
+      for (; it != itEnd; it++) {
         if (!it.value().is_object()) {
           if (err) {
-            (*err) += "image[" + std::to_string(idx) + "] is not a JSON object.";
+            (*err) += "`images' does not contain an JSON object.";
           }
           return false;
         }
         Image image;
-        if (!ParseImage(&image, idx, err, warn, it.value(), base_dir, &fs,
+        if (!ParseImage(&image, err, warn, it.value(), base_dir, &fs,
                         &this->LoadImageData, load_image_user_data_)) {
           return false;
         }
@@ -3878,7 +3657,7 @@ 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 << "image[" << idx << "] bufferView \"" << image.bufferView
+              ss << "bufferView \"" << image.bufferView
                  << "\" not found in the scene." << std::endl;
               (*err) += ss.str();
             }
@@ -3895,7 +3674,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
             }
             return false;
           }
-          bool ret = LoadImageData(&image, idx, err, warn, image.width, image.height,
+          bool ret = LoadImageData(&image, err, warn, image.width, image.height,
                                    &buffer.data[bufferView.byteOffset],
                                    static_cast<int>(bufferView.byteLength),
                                    load_image_user_data_);
@@ -4825,7 +4604,7 @@ static void WriteBinaryGltfFile(const std::string &output,
   // 12 bytes for header, JSON content length, 8 bytes for JSON chunk info, padding
   const int length = 12 + 8 + int(content.size()) + padding_size;
   
-  gltfFile.write(header.c_str(), header.size());
+  gltfFile.write(header.c_str(), std::streamsize(header.size()));
   gltfFile.write(reinterpret_cast<const char *>(&version), sizeof(version));
   gltfFile.write(reinterpret_cast<const char *>(&length), sizeof(length));
 
@@ -4834,12 +4613,12 @@ static void WriteBinaryGltfFile(const std::string &output,
   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));
-  gltfFile.write(content.c_str(), content.size());
+  gltfFile.write(content.c_str(), std::streamsize(content.size()));
 
   // Chunk must be multiplies of 4, so pad with spaces
   if (padding_size > 0) {
-    const std::string padding = std::string(padding_size, ' ');
-    gltfFile.write(padding.c_str(), padding.size());
+    const std::string padding = std::string(size_t(padding_size), ' ');
+    gltfFile.write(padding.c_str(), std::streamsize(padding.size()));
   }
 }
 

tiny_gltf_util.h

@@ -0,0 +1,294 @@
+//
+// TinyGLTF utility functions
+//
+//
+// The MIT License (MIT)
+//
+// Copyright (c) 2015 - 2018 Syoyo Fujita, Aurélien Chatelain and many
+// contributors.
+//
+
+#include <iostream>
+
+#include "tiny_gltf.h"
+
+namespace tinygltf {
+
+namespace util {
+
+static std::string PrintMode(int mode) {
+  if (mode == TINYGLTF_MODE_POINTS) {
+    return "POINTS";
+  } else if (mode == TINYGLTF_MODE_LINE) {
+    return "LINE";
+  } else if (mode == TINYGLTF_MODE_LINE_LOOP) {
+    return "LINE_LOOP";
+  } else if (mode == TINYGLTF_MODE_TRIANGLES) {
+    return "TRIANGLES";
+  } else if (mode == TINYGLTF_MODE_TRIANGLE_FAN) {
+    return "TRIANGLE_FAN";
+  } else if (mode == TINYGLTF_MODE_TRIANGLE_STRIP) {
+    return "TRIANGLE_STRIP";
+  }
+  return "**UNKNOWN**";
+}
+
+static std::string PrintTarget(int target) {
+  if (target == 34962) {
+    return "GL_ARRAY_BUFFER";
+  } else if (target == 34963) {
+    return "GL_ELEMENT_ARRAY_BUFFER";
+  } else {
+    return "**UNKNOWN**";
+  }
+}
+
+static std::string PrintType(int ty) {
+  if (ty == TINYGLTF_TYPE_SCALAR) {
+    return "SCALAR";
+  } else if (ty == TINYGLTF_TYPE_VECTOR) {
+    return "VECTOR";
+  } else if (ty == TINYGLTF_TYPE_VEC2) {
+    return "VEC2";
+  } else if (ty == TINYGLTF_TYPE_VEC3) {
+    return "VEC3";
+  } else if (ty == TINYGLTF_TYPE_VEC4) {
+    return "VEC4";
+  } else if (ty == TINYGLTF_TYPE_MATRIX) {
+    return "MATRIX";
+  } else if (ty == TINYGLTF_TYPE_MAT2) {
+    return "MAT2";
+  } else if (ty == TINYGLTF_TYPE_MAT3) {
+    return "MAT3";
+  } else if (ty == TINYGLTF_TYPE_MAT4) {
+    return "MAT4";
+  }
+  return "**UNKNOWN**";
+}
+
+static std::string PrintComponentType(int ty) {
+  if (ty == TINYGLTF_COMPONENT_TYPE_BYTE) {
+    return "BYTE";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE) {
+    return "UNSIGNED_BYTE";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_SHORT) {
+    return "SHORT";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT) {
+    return "UNSIGNED_SHORT";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_INT) {
+    return "INT";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_UNSIGNED_INT) {
+    return "UNSIGNED_INT";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_FLOAT) {
+    return "FLOAT";
+  } else if (ty == TINYGLTF_COMPONENT_TYPE_DOUBLE) {
+    return "DOUBLE";
+  }
+
+  return "**UNKNOWN**";
+}
+
+static std::string PrintWrapMode(int mode) {
+  if (mode == TINYGLTF_TEXTURE_WRAP_REPEAT) {
+    return "REPEAT";
+  } else if (mode == TINYGLTF_TEXTURE_WRAP_CLAMP_TO_EDGE) {
+    return "CLAMP_TO_EDGE";
+  } else if (mode == TINYGLTF_TEXTURE_WRAP_MIRRORED_REPEAT) {
+    return "MIRRORED_REPEAT";
+  }
+
+  return "**UNKNOWN**";
+}
+
+static std::string PrintFilterMode(int mode) {
+  if (mode == TINYGLTF_TEXTURE_FILTER_NEAREST) {
+    return "NEAREST";
+  } else if (mode == TINYGLTF_TEXTURE_FILTER_LINEAR) {
+    return "LINEAR";
+  } else if (mode == TINYGLTF_TEXTURE_FILTER_NEAREST_MIPMAP_NEAREST) {
+    return "NEAREST_MIPMAP_NEAREST";
+  } else if (mode == TINYGLTF_TEXTURE_FILTER_NEAREST_MIPMAP_LINEAR) {
+    return "NEAREST_MIPMAP_LINEAR";
+  } else if (mode == TINYGLTF_TEXTURE_FILTER_LINEAR_MIPMAP_NEAREST) {
+    return "LINEAR_MIPMAP_NEAREST";
+  } else if (mode == TINYGLTF_TEXTURE_FILTER_LINEAR_MIPMAP_LINEAR) {
+    return "LINEAR_MIPMAP_LINEAR";
+  }
+  return "**UNKNOWN**";
+}
+
+static int GetAnimationSamplerInputCount(const tinygltf::AnimationSampler &sampler, const tinygltf::Model &model)
+{
+  const tinygltf::Accessor &accessor = model.accessors[sampler.input];
+  return accessor.count;
+}
+
+static int GetAnimationSamplerOutputCount(const tinygltf::AnimationSampler &sampler, const tinygltf::Model &model)
+{
+  const tinygltf::Accessor &accessor = model.accessors[sampler.output];
+  return accessor.count;
+}
+
+static bool GetAnimationSamplerInputMinMax(const tinygltf::AnimationSampler &sampler, const tinygltf::Model &model, float *min_value, float *max_value)
+{
+  const tinygltf::Accessor &accessor = model.accessors[sampler.input];
+
+  // Assume scalar value.
+  if ((accessor.minValues.size() > 0) &&
+      (accessor.maxValues.size() > 0)) {
+    (*min_value) = accessor.minValues[0];
+    (*max_value) = accessor.maxValues[0];
+    return true;
+  } else {
+    (*min_value) = 0.0f;
+    (*max_value) = 0.0f;
+    return false;
+  }
+}
+
+// Utility function for decoding animation value
+static inline float DecodeAnimationChannelValue(int8_t c) {
+  return std::max(float(c) / 127.0f, -1.0f);
+}
+static inline float DecodeAnimationChannelValue(uint8_t c) {
+  return float(c) / 255.0f;
+}
+static inline float DecodeAnimationChannelValue(int16_t c) {
+  return std::max(float(c) / 32767.0f, -1.0f);
+}
+static inline float DecodeAnimationChannelValue(uint16_t c) {
+  return float(c) / 65525.0f;
+}
+
+static bool DecodeScalarAnimationValue(const size_t i, const tinygltf::Accessor &accessor, const tinygltf::Model &model, float *scalar)
+{
+  const BufferView &bufferView = model.bufferViews[accessor.bufferView];
+  const Buffer &buffer = model.buffers[bufferView.buffer];
+
+  const uint8_t *addr = GetBufferAddress(i, accessor, bufferView, buffer);
+  if (addr == nullptr) {
+    std::cerr << "Invalid glTF data?" << std::endl;
+    return false;
+  }
+
+  float value = 0.0f;
+
+  if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_BYTE) {
+    value = DecodeAnimationChannelValue(*(reinterpret_cast<const int8_t*>(addr)));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE) {
+    value = DecodeAnimationChannelValue(*(reinterpret_cast<const uint8_t*>(addr)));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_SHORT) {
+    value = DecodeAnimationChannelValue(*(reinterpret_cast<const int16_t*>(addr)));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT) {
+    value = DecodeAnimationChannelValue(*(reinterpret_cast<const uint16_t*>(addr)));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_FLOAT) {
+    value = *(reinterpret_cast<const float*>(addr));
+  } else {
+    std::cerr << "??? Unknown componentType : " << PrintComponentType(accessor.componentType) << std::endl;
+    return false;
+  }
+
+  (*scalar) = value;
+
+  return true;
+}
+
+static bool DecodeTranslationAnimationValue(const size_t i, const tinygltf::Accessor &accessor, const tinygltf::Model &model, float *xyz)
+{
+  if (accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+    std::cerr << "`translation` must be float type." << std::endl;
+    return false;
+  }
+
+  const BufferView &bufferView = model.bufferViews[accessor.bufferView];
+  const Buffer &buffer = model.buffers[bufferView.buffer];
+
+  const uint8_t *addr = GetBufferAddress(i, accessor, bufferView, buffer);
+  if (addr == nullptr) {
+    std::cerr << "Invalid glTF data?" << std::endl;
+    return 0.0f;
+  }
+
+  const float *ptr = reinterpret_cast<const float*>(addr);
+
+  xyz[0] = *(ptr + 0);
+  xyz[1] = *(ptr + 1);
+  xyz[2] = *(ptr + 2);
+
+  return true;
+}
+
+static bool DecodeScaleAnimationValue(const size_t i, const tinygltf::Accessor &accessor, const tinygltf::Model &model, float *xyz)
+{
+  if (accessor.componentType != TINYGLTF_COMPONENT_TYPE_FLOAT) {
+    std::cerr << "`scale` must be float type." << std::endl;
+    return false;
+  }
+
+  const BufferView &bufferView = model.bufferViews[accessor.bufferView];
+  const Buffer &buffer = model.buffers[bufferView.buffer];
+
+  const uint8_t *addr = GetBufferAddress(i, accessor, bufferView, buffer);
+  if (addr == nullptr) {
+    std::cerr << "Invalid glTF data?" << std::endl;
+    return 0.0f;
+  }
+
+  const float *ptr = reinterpret_cast<const float*>(addr);
+
+  xyz[0] = *(ptr + 0);
+  xyz[1] = *(ptr + 1);
+  xyz[2] = *(ptr + 2);
+
+  return true;
+}
+
+static bool DecodeRotationAnimationValue(const size_t i, const tinygltf::Accessor &accessor, const tinygltf::Model &model, float *xyzw)
+{
+  const BufferView &bufferView = model.bufferViews[accessor.bufferView];
+  const Buffer &buffer = model.buffers[bufferView.buffer];
+
+  const uint8_t *addr = GetBufferAddress(i, accessor, bufferView, buffer);
+  if (addr == nullptr) {
+    std::cerr << "Invalid glTF data?" << std::endl;
+    return false;
+  }
+
+  float value = 0.0f;
+
+  if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_BYTE) {
+    xyzw[0] = DecodeAnimationChannelValue(*(reinterpret_cast<const int8_t*>(addr) + 0));
+    xyzw[1] = DecodeAnimationChannelValue(*(reinterpret_cast<const int8_t*>(addr) + 1));
+    xyzw[2] = DecodeAnimationChannelValue(*(reinterpret_cast<const int8_t*>(addr) + 2));
+    xyzw[3] = DecodeAnimationChannelValue(*(reinterpret_cast<const int8_t*>(addr) + 3));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE) {
+    xyzw[0] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint8_t*>(addr) + 0));
+    xyzw[1] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint8_t*>(addr) + 1));
+    xyzw[2] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint8_t*>(addr) + 2));
+    xyzw[3] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint8_t*>(addr) + 3));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_SHORT) {
+    xyzw[0] = DecodeAnimationChannelValue(*(reinterpret_cast<const int16_t*>(addr) + 0));
+    xyzw[1] = DecodeAnimationChannelValue(*(reinterpret_cast<const int16_t*>(addr) + 1));
+    xyzw[2] = DecodeAnimationChannelValue(*(reinterpret_cast<const int16_t*>(addr) + 2));
+    xyzw[3] = DecodeAnimationChannelValue(*(reinterpret_cast<const int16_t*>(addr) + 3));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT) {
+    xyzw[0] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint16_t*>(addr) + 0));
+    xyzw[1] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint16_t*>(addr) + 1));
+    xyzw[2] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint16_t*>(addr) + 2));
+    xyzw[3] = DecodeAnimationChannelValue(*(reinterpret_cast<const uint16_t*>(addr) + 3));
+  } else if (accessor.componentType == TINYGLTF_COMPONENT_TYPE_FLOAT) {
+    xyzw[0] = *(reinterpret_cast<const float*>(addr) + 0);
+    xyzw[1] = *(reinterpret_cast<const float*>(addr) + 1);
+    xyzw[2] = *(reinterpret_cast<const float*>(addr) + 2);
+    xyzw[3] = *(reinterpret_cast<const float*>(addr) + 3);
+  } else {
+    std::cerr << "??? Unknown componentType : " << PrintComponentType(accessor.componentType) << std::endl;
+    return false;
+  }
+
+  return true;
+}
+
+} // namespace util
+
+} // namespace tinygltf