VS2019 seems gone. Use VS2022.

add missing switch case for binary

.github/workflows/c-cpp.yml

@@ -47,7 +47,8 @@ jobs:
             sudo apt-get install -y mingw-w64
             x86_64-w64-mingw32-g++ -std=c++11 -o loader_example loader_example.cc
 
-  # Windows(x64) + Visual Studio 2019 build
+  # Windows(x64) + Visual Studio 2022 build
+  # Assume windows-latest have VS2022 installed
   build-windows-msvc:
 
     runs-on: windows-latest
@@ -62,7 +63,8 @@ jobs:
         run: |
           mkdir build
           cd build
-          cmake -G "Visual Studio 16 2019" -DTINYGLTF_BUILD_LOADER_EXAMPLE=On -DTINYGLTF_BUILD_GL_EXAMPLES=Off -DTINYGLTF_BUILD_VALIDATOR_EXAMPLE=On ..
+          cmake --help
+          cmake -G "Visual Studio 17 2022" -A x64 -DTINYGLTF_BUILD_LOADER_EXAMPLE=On -DTINYGLTF_BUILD_GL_EXAMPLES=Off -DTINYGLTF_BUILD_VALIDATOR_EXAMPLE=On ..
           cd ..
       - name: Build
         run: cmake --build build --config Release

CMakeLists.txt

@@ -4,9 +4,12 @@ PROJECT (tinygltf)
 
 SET(CMAKE_CXX_STANDARD 11)
 
-option(TINYGLTF_BUILD_LOADER_EXAMPLE "Build loader_example" ON)
+option(TINYGLTF_BUILD_LOADER_EXAMPLE "Build loader_example(load glTF and dump infos)" ON)
 option(TINYGLTF_BUILD_GL_EXAMPLES "Build GL exampels(requires glfw, OpenGL, etc)" OFF)
 option(TINYGLTF_BUILD_VALIDATOR_EXAMPLE "Build validator exampe" OFF)
+option(TINYGLTF_BUILD_BUILDER_EXAMPLE "Build glTF builder example" OFF)
+option(TINYGLTF_HEADER_ONLY "On: header-only mode. Off: create tinygltf library(No TINYGLTF_IMPLEMENTATION required in your project)" OFF)
+option(TINYGLTF_INSTALL "Install tinygltf files during install step. Usually set to OFF if you include tinygltf through add_subdirectory()" ON)
 
 if (TINYGLTF_BUILD_LOADER_EXAMPLE)
   ADD_EXECUTABLE ( loader_example
@@ -22,20 +25,52 @@ endif (TINYGLTF_BUILD_GL_EXAMPLES)
 if (TINYGLTF_BUILD_VALIDATOR_EXAMPLE)
   ADD_SUBDIRECTORY ( examples/validator )
 endif (TINYGLTF_BUILD_VALIDATOR_EXAMPLE)
+
+if (TINYGLTF_BUILD_BUILDER_EXAMPLE)
+  ADD_SUBDIRECTORY ( examples/build-gltf )
+endif (TINYGLTF_BUILD_BUILDER_EXAMPLE)
+
 #
-# TinuGLTF is a header-only library, so no library build. just install header files.
+# for add_subdirectory and standalone build
 #
-INSTALL ( FILES
+if (TINYGLTF_HEADER_ONLY)
-  json.hpp
+  add_library(tinygltf INTERFACE)
-  stb_image.h
+
-  stb_image_write.h
+  target_include_directories(tinygltf
-  tiny_gltf.h
+          INTERFACE
-  DESTINATION
+          $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
-  include
+          $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
   )
 
-INSTALL ( FILES
+else (TINYGLTF_HEADER_ONLY)
-  cmake/TinyGLTFConfig.cmake
+  add_library(tinygltf)
-  DESTINATION
+  target_sources(tinygltf PRIVATE
-  cmake
+          ${CMAKE_CURRENT_SOURCE_DIR}/tiny_gltf.cc)
-  )
+  target_include_directories(tinygltf
+          INTERFACE
+          $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}>
+          $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
+          )
+endif (TINYGLTF_HEADER_ONLY)
+
+if (TINYGLTF_INSTALL)
+
+  # Do not install .lib even if !TINYGLTF_HEADER_ONLY
+
+  INSTALL ( FILES
+    json.hpp
+    stb_image.h
+    stb_image_write.h
+    tiny_gltf.h
+    ${TINYGLTF_EXTRA_SOUECES}
+    DESTINATION
+    include
+    )
+
+  INSTALL ( FILES
+    cmake/TinyGLTFConfig.cmake
+    DESTINATION
+    cmake
+    )
+
+endif(TINYGLTF_INSTALL)

README.md

@@ -7,6 +7,8 @@ If you are looking for old, C++03 version, please use `devel-picojson` branch(bu
 
 ## Status
 
+Currently TinyGLTF is stable and maintainance mode. No drastic changes and feature addition planned.
+
  - v2.4.0 Experimental RapidJSON support. Experimental C++14 support(C++14 may give better performance)
  - v2.3.0 Modified Material representation according to glTF 2.0 schema(and introduced TextureInfo class)
  - v2.2.0 release(Support loading 16bit PNG. Sparse accessor support)
@@ -77,6 +79,7 @@ In extension(`ExtensionMap`), JSON number value is parsed as int or float(number
 * [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.
+* [build-gltf](examples/build-gltf) : Build simple glTF scene from a scratch.
 
 ## Projects using TinyGLTF
 
@@ -90,6 +93,7 @@ In extension(`ExtensionMap`), JSON number value is parsed as int or float(number
 * [GlslViewer](https://github.com/patriciogonzalezvivo/glslViewer) - live GLSL coding for MacOS and Linux
 * [Vulkan-Samples](https://github.com/KhronosGroup/Vulkan-Samples) - The Vulkan Samples is collection of resources to help you develop optimized Vulkan applications.
 * [TDME2](https://github.com/andreasdr/tdme2) - TDME2 - ThreeDeeMiniEngine2 is a lightweight 3D engine including tools suited for 3D game development using C++11
+* [SanityEngine](https://github.com/DethRaid/SanityEngine) - A C++/D3D12 renderer focused on the personal and proessional development of its developer
 * Your projects here! (Please send PR)
 
 ## TODOs
@@ -155,6 +159,10 @@ if (!ret) {
 }
 ```
 
+#### Loader options
+
+* `TinyGLTF::SetPreserveimageChannels(bool onoff)`. `true` to preserve image channels as stored in image file for loaded image. `false` by default for backward compatibility(image channels are widen to `RGBA` 4 channels). Effective only when using builtin image loader(STB image loader).
+
 ## Compile options
 
 * `TINYGLTF_NOEXCEPTION` : Disable C++ exception in JSON parsing. You can use `-fno-exceptions` or by defining the symbol `JSON_NOEXCEPTION` and `TINYGLTF_NOEXCEPTION`  to fully remove C++ exception codes when compiling TinyGLTF.
@@ -164,11 +172,26 @@ if (!ret) {
 * `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.
 * `TINYGLTF_NO_INCLUDE_JSON `: Disable including `json.hpp` from within `tiny_gltf.h` because it has been already included before or you want to include it using custom path before including `tiny_gltf.h`.
+* `TINYGLTF_NO_INCLUDE_RAPIDJSON `: Disable including RapidJson's header files from within `tiny_gltf.h` because it has been already included before or you want to include it using custom path before including `tiny_gltf.h`.
 * `TINYGLTF_NO_INCLUDE_STB_IMAGE `: Disable including `stb_image.h` from within `tiny_gltf.h` because it has been already included before or you want to include it using custom path before including `tiny_gltf.h`.
 * `TINYGLTF_NO_INCLUDE_STB_IMAGE_WRITE `: Disable including `stb_image_write.h` from within `tiny_gltf.h` because it has been already included before or you want to include it using custom path before including `tiny_gltf.h`.
-* `TINYGLTF_USE_RAPIDJSON` : Use RapidJSON as a JSON parser/serializer. RapidJSON files are not included in TinyGLTF repo. Please set an include path to RapidJSON if you enable this featrure.
+* `TINYGLTF_USE_RAPIDJSON` : Use RapidJSON as a JSON parser/serializer. RapidJSON files are not included in TinyGLTF repo. Please set an include path to RapidJSON if you enable this feature.
 * `TINYGLTF_USE_CPP14` : Use C++14 feature(requires C++14 compiler). This may give better performance than C++11.
 
+## CMake options
+
+You can add tinygltf using `add_subdirectory` feature.
+If you add tinygltf to your project using `add_subdirectory`, it would be better to set `TINYGLTF_HEADER_ONLY` on(just add an include path to tinygltf) and `TINYGLTF_INSTALL` off(Which does not install tinygltf files).
+
+```
+// Your project's CMakeLists.txt
+...
+
+set(TINYGLTF_HEADER_ONLY ON CACHE INTERNAL "" FORCE)
+set(TINYGLTF_INSTALL OFF CACHE INTERNAL "" FORCE)
+add_subdirectory(/path/to/tinygltf)
+```
+
 
 ### Saving gltTF 2.0 model
 

examples/build-gltf/Makefile

@@ -0,0 +1,2 @@
+all:
+	$(CXX) -o create_triangle_gltf -I../../ create_triangle_gltf.cpp

examples/build-gltf/create_triangle_gltf.cpp

@@ -0,0 +1,121 @@
+// An example of how to generate a gltf file from scratch. This example
+// was translated from the pygltlib documentation in the pypi project page,
+// which in turn is based on the Khronos Sample Models at:
+//
+// https://github.com/KhronosGroup/glTF-Sample-Models
+//
+// This example is released under the MIT license. 
+//
+// 2021-02-25 Thu
+// Dov Grobgeld <dov.grobgeld@gmail.com>
+
+
+// Define these only in *one* .cc file.
+#define TINYGLTF_IMPLEMENTATION
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+
+// #define TINYGLTF_NOEXCEPTION // optional. disable exception handling.
+#include "tiny_gltf.h"
+
+int main(int argc, char **argv)
+{
+  // Create a model with a single mesh and save it as a gltf file
+  tinygltf::Model m;
+  tinygltf::Scene scene;
+  tinygltf::Mesh mesh;
+  tinygltf::Primitive primitive;
+  tinygltf::Node node;
+  tinygltf::Buffer buffer;
+  tinygltf::BufferView bufferView1;
+  tinygltf::BufferView bufferView2;
+  tinygltf::Accessor accessor1;
+  tinygltf::Accessor accessor2;
+  tinygltf::Asset asset;
+
+  // This is the raw data buffer. 
+  buffer.data = {
+    // 6 bytes of indices and two bytes of padding
+    0x00,0x00,0x01,0x00,0x02,0x00,0x00,0x00,
+    // 36 bytes of floating point numbers
+    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+    0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x3f,
+    0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
+    0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x3f,
+    0x00,0x00,0x00,0x00};
+
+  // "The indices of the vertices (ELEMENT_ARRAY_BUFFER) take up 6 bytes in the
+  // start of the buffer.
+  bufferView1.buffer = 0;
+  bufferView1.byteOffset=0;
+  bufferView1.byteLength=6;
+  bufferView1.target = TINYGLTF_TARGET_ELEMENT_ARRAY_BUFFER;
+
+  // The vertices take up 36 bytes (3 vertices * 3 floating points * 4 bytes)
+  // at position 8 in the buffer and are of type ARRAY_BUFFER
+  bufferView2.buffer = 0;
+  bufferView2.byteOffset=8;
+  bufferView2.byteLength=36;
+  bufferView2.target = TINYGLTF_TARGET_ARRAY_BUFFER;
+
+  // Describe the layout of bufferView1, the indices of the vertices
+  accessor1.bufferView = 0;
+  accessor1.byteOffset = 0;
+  accessor1.componentType = TINYGLTF_COMPONENT_TYPE_UNSIGNED_SHORT;
+  accessor1.count = 3;
+  accessor1.type = TINYGLTF_TYPE_SCALAR;
+  accessor1.maxValues.push_back(2);
+  accessor1.minValues.push_back(0);
+
+  // Describe the layout of bufferView2, the vertices themself
+  accessor2.bufferView = 1;
+  accessor2.byteOffset = 0;
+  accessor2.componentType = TINYGLTF_COMPONENT_TYPE_FLOAT;
+  accessor2.count = 3;
+  accessor2.type = TINYGLTF_TYPE_VEC3;
+  accessor2.maxValues = {1.0, 1.0, 0.0};
+  accessor2.minValues = {0.0, 0.0, 0.0};
+
+  // Build the mesh primitive and add it to the mesh
+  primitive.indices = 0;                 // The index of the accessor for the vertex indices
+  primitive.attributes["POSITION"] = 1;  // The index of the accessor for positions
+  primitive.material = 0;
+  primitive.mode = TINYGLTF_MODE_TRIANGLES;
+  mesh.primitives.push_back(primitive);
+
+  // Other tie ups
+  node.mesh = 0;
+  scene.nodes.push_back(0); // Default scene
+
+  // Define the asset. The version is required
+  asset.version = "2.0";
+  asset.generator = "tinygltf";
+
+  // Now all that remains is to tie back all the loose objects into the
+  // our single model.
+  m.scenes.push_back(scene);
+  m.meshes.push_back(mesh);
+  m.nodes.push_back(node);
+  m.buffers.push_back(buffer);
+  m.bufferViews.push_back(bufferView1);
+  m.bufferViews.push_back(bufferView2);
+  m.accessors.push_back(accessor1);
+  m.accessors.push_back(accessor2);
+  m.asset = asset;
+
+  // Create a simple material
+  tinygltf::Material mat;
+  mat.pbrMetallicRoughness.baseColorFactor = {1.0f, 0.9f, 0.9f, 1.0f};  
+  mat.doubleSided = true;
+  m.materials.push_back(mat);
+
+  // Save it to a file
+  tinygltf::TinyGLTF gltf;
+  gltf.WriteGltfSceneToFile(&m, "triangle.gltf",
+                           true, // embedImages
+                           true, // embedBuffers
+                           true, // pretty print
+                           false); // write binary
+  
+  exit(0);
+}

examples/dxview/src/Viewer.cc

@@ -610,7 +610,7 @@ void Viewer::buildSamplerDescs() {
 
     samplerDesc.AddressU = toTextureAddressMode(glTFSampler.wrapS);
     samplerDesc.AddressV = toTextureAddressMode(glTFSampler.wrapT);
-    samplerDesc.AddressW = toTextureAddressMode(glTFSampler.wrapR);
+    samplerDesc.AddressW = D3D12_TEXTURE_ADDRESS_MODE_WRAP;
     samplerDesc.MaxLOD = 256;
 
     samplerDescs_.push_back(samplerDesc);

examples/glview/CMakeLists.txt

@@ -51,7 +51,7 @@ add_executable(glview
 target_link_libraries ( glview
   ${DRACO_LIBRARY}
   ${GLFW3_UNIX_LINK_LIBRARIES}
-  ${GLEW_LIBRARY}
+  ${GLEW_LIBRARIES}
   ${GLFW3_glfw_LIBRARY}
   ${OPENGL_gl_LIBRARY}
   ${OPENGL_glu_LIBRARY}

loader_example.cc

@@ -524,7 +524,7 @@ static void Dump(const tinygltf::Model &model) {
                 << std::endl;
 
       std::cout << Indent(1) << "channels : [ " << std::endl;
-      for (size_t j = 0; i < animation.channels.size(); i++) {
+      for (size_t j = 0; j < animation.channels.size(); j++) {
         std::cout << Indent(2)
                   << "sampler     : " << animation.channels[j].sampler
                   << std::endl;

tests/tester.cc

@@ -432,11 +432,40 @@ TEST_CASE("serialize-empty-material", "[issue-294]") {
   nlohmann::json j = nlohmann::json::parse(os.str());
 
   REQUIRE(1 == j["materials"].size());
-  REQUIRE(j["asset"].is_null());
   REQUIRE(j["materials"][0].is_object());
 
 }
 
+TEST_CASE("empty-skeleton-id", "[issue-321]") {
+
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  bool ret = ctx.LoadASCIIFromFile(&model, &err, &warn, "../models/regression/unassigned-skeleton.gltf");
+  if (!err.empty()) {
+    std::cerr << err << std::endl;
+  }
+  REQUIRE(true == ret);
+
+  REQUIRE(model.skins.size() == 1);
+  REQUIRE(model.skins[0].skeleton == -1); // unassigned
+
+  std::stringstream os;
+
+  ctx.WriteGltfSceneToStream(&model, os, false, false);
+
+  // use nlohmann json
+  nlohmann::json j = nlohmann::json::parse(os.str());
+
+  // Ensure `skeleton` property is not written to .gltf(was serialized as -1)
+  REQUIRE(1 == j["skins"].size());
+  REQUIRE(j["skins"][0].is_object());
+  REQUIRE(j["skins"][0].count("skeleton") == 0);
+
+}
+
 #ifndef TINYGLTF_NO_FS
 TEST_CASE("expandpath-utf-8", "[pr-226]") {
 

tiny_gltf.cc

@@ -0,0 +1,4 @@
+#define TINYGLTF_IMPLEMENTATION
+#define STB_IMAGE_IMPLEMENTATION
+#define STB_IMAGE_WRITE_IMPLEMENTATION
+#include "tiny_gltf.h"

tiny_gltf.h

@@ -4,7 +4,7 @@
 //
 // The MIT License (MIT)
 //
-// Copyright (c) 2015 - 2020 Syoyo Fujita, Aurélien Chatelain and many
+// Copyright (c) 2015 - Present Syoyo Fujita, Aurélien Chatelain and many
 // contributors.
 //
 // Permission is hereby granted, free of charge, to any person obtaining a copy
@@ -26,7 +26,9 @@
 // THE SOFTWARE.
 
 // Version:
-//  - v2.4.3 Fix null object output when when material has all default parameters.
+//  - v2.5.0 Add SetPreserveImageChannels() option to load image data as is.
+//  - v2.4.3 Fix null object output when when material has all default
+//  parameters.
 //  - v2.4.2 Decode percent-encoded URI.
 //  - v2.4.1 Fix some glTF object class does not have `extensions` and/or
 //  `extras` property.
@@ -189,14 +191,14 @@ AAssetManager *asset_manager = nullptr;
 #endif
 
 typedef enum {
-  NULL_TYPE = 0,
+  NULL_TYPE,
-  REAL_TYPE = 1,
+  REAL_TYPE,
-  INT_TYPE = 2,
+  INT_TYPE,
-  BOOL_TYPE = 3,
+  BOOL_TYPE,
-  STRING_TYPE = 4,
+  STRING_TYPE,
-  ARRAY_TYPE = 5,
+  ARRAY_TYPE,
-  BINARY_TYPE = 6,
+  BINARY_TYPE,
-  OBJECT_TYPE = 7
+  OBJECT_TYPE
 } Type;
 
 static inline int32_t GetComponentSizeInBytes(uint32_t componentType) {
@@ -251,7 +253,6 @@ bool DecodeDataURI(std::vector<unsigned char> *out, std::string &mime_type,
 #ifdef __clang__
 #pragma clang diagnostic push
 // Suppress warning for : static Value null_value
-// https://stackoverflow.com/questions/15708411/how-to-deal-with-global-constructor-warning-in-clang
 #pragma clang diagnostic ignored "-Wexit-time-destructors"
 #pragma clang diagnostic ignored "-Wpadded"
 #endif
@@ -296,7 +297,7 @@ class Value {
 
   DEFAULT_METHODS(Value)
 
-  char Type() const { return static_cast<const char>(type_); }
+  char Type() const { return static_cast<char>(type_); }
 
   bool IsBool() const { return (type_ == BOOL_TYPE); }
 
@@ -602,7 +603,7 @@ struct Sampler {
   // `magFilter`. Set -1 in TinyGLTF(issue #186)
   int minFilter =
       -1;  // optional. -1 = no filter defined. ["NEAREST", "LINEAR",
-           // "NEAREST_MIPMAP_LINEAR", "LINEAR_MIPMAP_NEAREST",
+           // "NEAREST_MIPMAP_NEAREST", "LINEAR_MIPMAP_NEAREST",
            // "NEAREST_MIPMAP_LINEAR", "LINEAR_MIPMAP_LINEAR"]
   int magFilter =
       -1;  // optional. -1 = no filter defined. ["NEAREST", "LINEAR"]
@@ -612,7 +613,7 @@ struct Sampler {
   int wrapT =
       TINYGLTF_TEXTURE_WRAP_REPEAT;  // ["CLAMP_TO_EDGE", "MIRRORED_REPEAT",
                                      // "REPEAT"], default "REPEAT"
-  int wrapR = TINYGLTF_TEXTURE_WRAP_REPEAT;  // TinyGLTF extension
+  //int wrapR = TINYGLTF_TEXTURE_WRAP_REPEAT;  // TinyGLTF extension. currently not used.
 
   Value extras;
   ExtensionMap extensions;
@@ -625,8 +626,7 @@ struct Sampler {
       : minFilter(-1),
         magFilter(-1),
         wrapS(TINYGLTF_TEXTURE_WRAP_REPEAT),
-        wrapT(TINYGLTF_TEXTURE_WRAP_REPEAT),
+        wrapT(TINYGLTF_TEXTURE_WRAP_REPEAT) {}
-        wrapR(TINYGLTF_TEXTURE_WRAP_REPEAT) {}
   DEFAULT_METHODS(Sampler)
   bool operator==(const Sampler &) const;
 };
@@ -849,8 +849,10 @@ struct Accessor {
   std::string extras_json_string;
   std::string extensions_json_string;
 
-  std::vector<double> minValues;  // optional
+  std::vector<double>
-  std::vector<double> maxValues;  // optional
+      minValues;  // optional. integer value is promoted to double
+  std::vector<double>
+      maxValues;  // optional. integer value is promoted to double
 
   struct {
     int count;
@@ -1068,7 +1070,7 @@ struct Buffer {
 };
 
 struct Asset {
-  std::string version;  // required
+  std::string version = "2.0";  // required
   std::string generator;
   std::string minVersion;
   std::string copyright;
@@ -1190,7 +1192,8 @@ enum SectionCheck {
 ///
 typedef bool (*LoadImageDataFunction)(Image *, const int, std::string *,
                                       std::string *, int, int,
-                                      const unsigned char *, int, void *);
+                                      const unsigned char *, int,
+                                      void *user_pointer);
 
 ///
 /// WriteImageDataFunction type. Signature for custom image writing callbacks.
@@ -1255,7 +1258,7 @@ bool FileExists(const std::string &abs_filename, void *);
 
 ///
 /// Expand file path(e.g. `~` to home directory on posix, `%APPDATA%` to
-/// `C:\Users\tinygltf\AppData`)
+/// `C:\\Users\\tinygltf\\AppData`)
 ///
 /// @param[in] filepath File path string. Assume UTF-8
 /// @param[in] userdata User data. Set to `nullptr` if you don't need it.
@@ -1346,6 +1349,11 @@ class TinyGLTF {
   ///
   void SetImageLoader(LoadImageDataFunction LoadImageData, void *user_data);
 
+  ///
+  /// Unset(remove) callback of loading image data
+  ///
+  void RemoveImageLoader();
+
   ///
   /// Set callback to use for writing image data
   ///
@@ -1384,6 +1392,16 @@ class TinyGLTF {
     return store_original_json_for_extras_and_extensions_;
   }
 
+  ///
+  /// Specify whether preserve image channales when loading images or not.
+  /// (Not effective when the user suppy their own LoadImageData callbacks)
+  ///
+  void SetPreserveImageChannels(bool onoff) {
+    preserve_image_channels_ = onoff;
+  }
+
+  bool GetPreserveImageChannels() const { return preserve_image_channels_; }
+
  private:
   ///
   /// Loads glTF asset from string(memory).
@@ -1403,6 +1421,9 @@ class TinyGLTF {
 
   bool store_original_json_for_extras_and_extensions_ = false;
 
+  bool preserve_image_channels_ = false;  /// Default false(expand channels to
+                                          /// RGBA) for backward compatibility.
+
   FsCallbacks fs = {
 #ifndef TINYGLTF_NO_FS
       &tinygltf::FileExists, &tinygltf::ExpandFilePath,
@@ -1422,7 +1443,8 @@ class TinyGLTF {
 #else
       nullptr;
 #endif
-  void *load_image_user_data_ = reinterpret_cast<void *>(&fs);
+  void *load_image_user_data_{nullptr};
+  bool user_image_loader_{false};
 
   WriteImageDataFunction WriteImageData =
 #ifndef TINYGLTF_NO_STB_IMAGE_WRITE
@@ -1430,7 +1452,7 @@ class TinyGLTF {
 #else
       nullptr;
 #endif
-  void *write_image_user_data_ = reinterpret_cast<void *>(&fs);
+  void *write_image_user_data_{nullptr};
 };
 
 #ifdef __clang__
@@ -1515,6 +1537,7 @@ class TinyGLTF {
 #ifndef TINYGLTF_USE_RAPIDJSON
 #include "json.hpp"
 #else
+#ifndef TINYGLTF_NO_INCLUDE_RAPIDJSON
 #include "document.h"
 #include "prettywriter.h"
 #include "rapidjson.h"
@@ -1522,6 +1545,7 @@ class TinyGLTF {
 #include "writer.h"
 #endif
 #endif
+#endif
 
 #ifdef TINYGLTF_ENABLE_DRACO
 #include "draco/compression/decode.h"
@@ -1580,7 +1604,7 @@ class TinyGLTF {
 
 #endif
 
-#elif !defined(__ANDROID__)
+#elif !defined(__ANDROID__) && !defined(__OpenBSD__)
 #include <wordexp.h>
 #endif
 
@@ -1684,6 +1708,19 @@ void JsonParse(JsonDocument &doc, const char *str, size_t length,
 
 namespace tinygltf {
 
+///
+/// Internal LoadImageDataOption struct.
+/// This struct is passed through `user_pointer` in LoadImageData.
+/// The struct is not passed when the user supply their own LoadImageData
+/// callbacks.
+///
+struct LoadImageDataOption {
+  // true: preserve image channels(e.g. load as RGB image if the image has RGB
+  // channels) default `false`(channels are expanded to RGBA for backward
+  // compatiblity).
+  bool preserve_channels{false};
+};
+
 // Equals function for Value, for recursivity
 static bool Equals(const tinygltf::Value &one, const tinygltf::Value &other) {
   if (one.Type() != other.Type()) return false;
@@ -1896,8 +1933,9 @@ bool Sampler::operator==(const Sampler &other) const {
   return this->extensions == other.extensions && this->extras == other.extras &&
          this->magFilter == other.magFilter &&
          this->minFilter == other.minFilter && this->name == other.name &&
-         this->wrapR == other.wrapR && this->wrapS == other.wrapS &&
          this->wrapT == other.wrapT;
+
+         //this->wrapR == other.wrapR && this->wrapS == other.wrapS &&
 }
 bool Scene::operator==(const Scene &other) const {
   return this->extensions == other.extensions && this->extras == other.extras &&
@@ -2001,9 +2039,12 @@ static std::string GetBaseDir(const std::string &filepath) {
   return "";
 }
 
-// https://stackoverflow.com/questions/8520560/get-a-file-name-from-a-path
 static std::string GetBaseFilename(const std::string &filepath) {
-  return filepath.substr(filepath.find_last_of("/\\") + 1);
+  constexpr char path_separators[2] = { '/', '\\' };
+  auto idx = filepath.find_last_of(path_separators);
+  if (idx != std::string::npos)
+    return filepath.substr(idx + 1);
+  return filepath;
 }
 
 std::string base64_encode(unsigned char const *, unsigned int len);
@@ -2149,47 +2190,35 @@ std::string base64_decode(std::string const &encoded_string) {
 // TODO(syoyo): Use uriparser https://uriparser.github.io/ for stricter Uri
 // decoding?
 //
-// https://stackoverflow.com/questions/18307429/encode-decode-url-in-c
+// Uri Decoding from DLIB
 // http://dlib.net/dlib/server/server_http.cpp.html
-
+// --- dlib begin ------------------------------------------------------------
-// --- dlib beign ------------------------------------------------------------
 // Copyright (C) 2003  Davis E. King (davis@dlib.net)
-// License: Boost Software License   See LICENSE.txt for the full license.
+// License: Boost Software License
+// Boost Software License - Version 1.0 - August 17th, 2003
 
+// Permission is hereby granted, free of charge, to any person or organization
+// obtaining a copy of the software and accompanying documentation covered by
+// this license (the "Software") to use, reproduce, display, distribute,
+// execute, and transmit the Software, and to prepare derivative works of the
+// Software, and to permit third-parties to whom the Software is furnished to
+// do so, all subject to the following:
+// The copyright notices in the Software and this entire statement, including
+// the above license grant, this restriction and the following disclaimer,
+// must be included in all copies of the Software, in whole or in part, and
+// all derivative works of the Software, unless such copies or derivative
+// works are solely in the form of machine-executable object code generated by
+// a source language processor.
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
+// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
+// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
+// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+// 
 namespace dlib {
 
-#if 0
-        inline unsigned char to_hex( unsigned char x )
-        {
-            return x + (x > 9 ? ('A'-10) : '0');
-        }
-
-        const std::string urlencode( const std::string& s )
-        {
-            std::ostringstream os;
-
-            for ( std::string::const_iterator ci = s.begin(); ci != s.end(); ++ci )
-            {
-                if ( (*ci >= 'a' && *ci <= 'z') ||
-                     (*ci >= 'A' && *ci <= 'Z') ||
-                     (*ci >= '0' && *ci <= '9') )
-                { // allowed
-                    os << *ci;
-                }
-                else if ( *ci == ' ')
-                {
-                    os << '+';
-                }
-                else
-                {
-                    os << '%' << to_hex(static_cast<unsigned char>(*ci >> 4)) << to_hex(static_cast<unsigned char>(*ci % 16));
-                }
-            }
-
-            return os.str();
-        }
-#endif
-
 inline unsigned char from_hex(unsigned char ch) {
   if (ch <= '9' && ch >= '0')
     ch -= '0';
@@ -2298,22 +2327,40 @@ static bool LoadExternalFile(std::vector<unsigned char> *out, std::string *err,
 void TinyGLTF::SetImageLoader(LoadImageDataFunction func, void *user_data) {
   LoadImageData = func;
   load_image_user_data_ = user_data;
+  user_image_loader_ = true;
+}
+
+void TinyGLTF::RemoveImageLoader() {
+  LoadImageData =
+#ifndef TINYGLTF_NO_STB_IMAGE
+      &tinygltf::LoadImageData;
+#else
+      nullptr;
+#endif
+
+  load_image_user_data_ = nullptr;
+  user_image_loader_ = false;
 }
 
 #ifndef TINYGLTF_NO_STB_IMAGE
 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 *user_data) {
-  (void)user_data;
   (void)warn;
 
+  LoadImageDataOption option;
+  if (user_data) {
+    option = *reinterpret_cast<LoadImageDataOption *>(user_data);
+  }
+
   int w = 0, h = 0, comp = 0, req_comp = 0;
 
   unsigned char *data = nullptr;
 
-  // force 32-bit textures for common Vulkan compatibility. It appears that
+  // preserve_channels true: Use channels stored in the image file.
-  // some GPU drivers do not support 24-bit images for Vulkan
+  // false: force 32-bit textures for common Vulkan compatibility. It appears
-  req_comp = 4;
+  // that some GPU drivers do not support 24-bit images for Vulkan
+  req_comp = option.preserve_channels ? 0 : 4;
   int bits = 8;
   int pixel_type = TINYGLTF_COMPONENT_TYPE_UNSIGNED_BYTE;
 
@@ -2385,13 +2432,18 @@ bool LoadImageData(Image *image, const int image_idx, std::string *err,
     }
   }
 
+  if (req_comp != 0) {
+    // loaded data has `req_comp` channels(components)
+    comp = req_comp;
+  }
+
   image->width = w;
   image->height = h;
-  image->component = req_comp;
+  image->component = comp;
   image->bits = bits;
   image->pixel_type = pixel_type;
-  image->image.resize(static_cast<size_t>(w * h * req_comp) * size_t(bits / 8));
+  image->image.resize(static_cast<size_t>(w * h * comp) * size_t(bits / 8));
-  std::copy(data, data + w * h * req_comp * (bits / 8), image->image.begin());
+  std::copy(data, data + w * h * comp * (bits / 8), image->image.begin());
   stbi_image_free(data);
 
   return true;
@@ -2567,7 +2619,7 @@ std::string ExpandFilePath(const std::string &filepath, void *) {
 #else
 
 #if defined(TARGET_OS_IPHONE) || defined(TARGET_IPHONE_SIMULATOR) || \
-    defined(__ANDROID__) || defined(__EMSCRIPTEN__)
+    defined(__ANDROID__) || defined(__EMSCRIPTEN__) || defined(__OpenBSD__)
   // no expansion
   std::string s = filepath;
 #else
@@ -3140,6 +3192,7 @@ static bool ParseJsonAsValue(Value *ret, const json &o) {
       break;
     case json::value_t::null:
     case json::value_t::discarded:
+    case json::value_t::binary:
       // default:
       break;
   }
@@ -4410,6 +4463,7 @@ static bool GetAttributeForAllPoints(uint32_t componentType, draco::Mesh *mesh,
 static bool ParseDracoExtension(Primitive *primitive, Model *model,
                                 std::string *err,
                                 const Value &dracoExtensionValue) {
+  (void)err;
   auto bufferViewValue = dracoExtensionValue.Get("bufferView");
   if (!bufferViewValue.IsInt()) return false;
   auto attributesValue = dracoExtensionValue.Get("attributes");
@@ -4470,7 +4524,6 @@ static bool ParseDracoExtension(Primitive *primitive, Model *model,
 
     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;
 
@@ -5029,12 +5082,12 @@ static bool ParseSampler(Sampler *sampler, std::string *err, const json &o,
   int magFilter = -1;
   int wrapS = TINYGLTF_TEXTURE_WRAP_REPEAT;
   int wrapT = TINYGLTF_TEXTURE_WRAP_REPEAT;
-  int wrapR = TINYGLTF_TEXTURE_WRAP_REPEAT;
+  //int wrapR = TINYGLTF_TEXTURE_WRAP_REPEAT;
   ParseIntegerProperty(&minFilter, err, o, "minFilter", false);
   ParseIntegerProperty(&magFilter, err, o, "magFilter", false);
   ParseIntegerProperty(&wrapS, err, o, "wrapS", false);
   ParseIntegerProperty(&wrapT, err, o, "wrapT", false);
-  ParseIntegerProperty(&wrapR, err, o, "wrapR", false);  // tinygltf extension
+  //ParseIntegerProperty(&wrapR, err, o, "wrapR", false);  // tinygltf extension
 
   // TODO(syoyo): Check the value is alloed one.
   // (e.g. we allow 9728(NEAREST), but don't allow 9727)
@@ -5043,7 +5096,7 @@ static bool ParseSampler(Sampler *sampler, std::string *err, const json &o,
   sampler->magFilter = magFilter;
   sampler->wrapS = wrapS;
   sampler->wrapT = wrapT;
-  sampler->wrapR = wrapR;
+  //sampler->wrapR = wrapR;
 
   ParseExtensionsProperty(&(sampler->extensions), err, o);
   ParseExtrasProperty(&(sampler->extras), o);
@@ -5770,13 +5823,13 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
         {
           json_const_iterator it;
           if (FindMember(o, "extensions", it)) {
-            model->extensions_json_string = JsonToString(GetValue(it));
+            scene.extensions_json_string = JsonToString(GetValue(it));
           }
         }
         {
           json_const_iterator it;
           if (FindMember(o, "extras", it)) {
-            model->extras_json_string = JsonToString(GetValue(it));
+            scene.extras_json_string = JsonToString(GetValue(it));
           }
         }
       }
@@ -5826,6 +5879,18 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
   }
 
   // 11. Parse Image
+  void *load_image_user_data{nullptr};
+
+  LoadImageDataOption load_image_option;
+
+  if (user_image_loader_) {
+    // Use user supplied pointer
+    load_image_user_data = load_image_user_data_;
+  } else {
+    load_image_option.preserve_channels = preserve_image_channels_;
+    load_image_user_data = reinterpret_cast<void *>(&load_image_option);
+  }
+
   {
     int idx = 0;
     bool success = ForEachInArray(v, "images", [&](const json &o) {
@@ -5838,7 +5903,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
       Image image;
       if (!ParseImage(&image, idx, err, warn, o,
                       store_original_json_for_extras_and_extensions_, base_dir,
-                      &fs, &this->LoadImageData, load_image_user_data_)) {
+                      &fs, &this->LoadImageData, load_image_user_data)) {
         return false;
       }
 
@@ -5876,7 +5941,7 @@ bool TinyGLTF::LoadFromString(Model *model, std::string *err, std::string *warn,
         bool ret = LoadImageData(
             &image, idx, err, warn, image.width, image.height,
             &buffer.data[bufferView.byteOffset],
-            static_cast<int>(bufferView.byteLength), load_image_user_data_);
+            static_cast<int>(bufferView.byteLength), load_image_user_data);
         if (!ret) {
           return false;
         }
@@ -6552,8 +6617,33 @@ static void SerializeGltfAccessor(Accessor &accessor, json &o) {
 
   SerializeNumberProperty<int>("componentType", accessor.componentType, o);
   SerializeNumberProperty<size_t>("count", accessor.count, o);
-  SerializeNumberArrayProperty<double>("min", accessor.minValues, o);
+
-  SerializeNumberArrayProperty<double>("max", accessor.maxValues, o);
+  if ((accessor.componentType == TINYGLTF_COMPONENT_TYPE_FLOAT) ||
+      (accessor.componentType == TINYGLTF_COMPONENT_TYPE_DOUBLE)) {
+    SerializeNumberArrayProperty<double>("min", accessor.minValues, o);
+    SerializeNumberArrayProperty<double>("max", accessor.maxValues, o);
+  } else {
+    // Issue #301. Serialize as integer.
+    // Assume int value is within [-2**31-1, 2**31-1]
+    {
+      std::vector<int> values;
+      std::transform(accessor.minValues.begin(), accessor.minValues.end(),
+                     std::back_inserter(values),
+                     [](double v) { return static_cast<int>(v); });
+
+      SerializeNumberArrayProperty<int>("min", values, o);
+    }
+
+    {
+      std::vector<int> values;
+      std::transform(accessor.maxValues.begin(), accessor.maxValues.end(),
+                     std::back_inserter(values),
+                     [](double v) { return static_cast<int>(v); });
+
+      SerializeNumberArrayProperty<int>("max", values, o);
+    }
+  }
+
   if (accessor.normalized)
     SerializeValue("normalized", Value(accessor.normalized), o);
   std::string type;
@@ -6663,10 +6753,15 @@ static void SerializeGltfAsset(Asset &asset, json &o) {
     SerializeStringProperty("copyright", asset.copyright, o);
   }
 
-  if (!asset.version.empty()) {
+  if (asset.version.empty()) {
-    SerializeStringProperty("version", asset.version, o);
+    // Just in case
+    // `version` must be defined
+    asset.version = "2.0";
   }
 
+  // TODO(syoyo): Do we need to check if `version` is greater or equal to 2.0?
+  SerializeStringProperty("version", asset.version, o);
+
   if (asset.extras.Keys().size()) {
     SerializeValue("extras", asset.extras, o);
   }
@@ -7064,7 +7159,7 @@ static void SerializeGltfSampler(Sampler &sampler, json &o) {
   if (sampler.minFilter != -1) {
     SerializeNumberProperty("minFilter", sampler.minFilter, o);
   }
-  SerializeNumberProperty("wrapR", sampler.wrapR, o);
+  //SerializeNumberProperty("wrapR", sampler.wrapR, o);
   SerializeNumberProperty("wrapS", sampler.wrapS, o);
   SerializeNumberProperty("wrapT", sampler.wrapT, o);
 
@@ -7139,11 +7234,17 @@ static void SerializeGltfScene(Scene &scene, json &o) {
 }
 
 static void SerializeGltfSkin(Skin &skin, json &o) {
-  if (skin.inverseBindMatrices != -1)
+  // required
-    SerializeNumberProperty("inverseBindMatrices", skin.inverseBindMatrices, o);
-
   SerializeNumberArrayProperty<int>("joints", skin.joints, o);
-  SerializeNumberProperty("skeleton", skin.skeleton, o);
+
+  if (skin.inverseBindMatrices >= 0) {
+    SerializeNumberProperty("inverseBindMatrices", skin.inverseBindMatrices, o);
+  }
+
+  if (skin.skeleton >= 0) {
+    SerializeNumberProperty("skeleton", skin.skeleton, o);
+  }
+
   if (skin.name.size()) {
     SerializeStringProperty("name", skin.name, o);
   }
@@ -7230,7 +7331,8 @@ static void SerializeGltfModel(Model *model, json &o) {
       if (JsonIsNull(material)) {
         // Issue 294.
         // `material` does not have any required parameters
-        // so the result may be null(unmodified) when all material parameters have default value.
+        // so the result may be null(unmodified) when all material parameters
+        // have default value.
         //
         // null is not allowed thus we create an empty JSON object.
         JsonSetObject(material);
@@ -7373,7 +7475,7 @@ static void SerializeGltfModel(Model *model, json &o) {
   }
 
   // Extensions used
-  if (model->extensionsUsed.size()) {
+  if (extensionsUsed.size()) {
     SerializeStringArrayProperty("extensionsUsed", extensionsUsed, o);
   }
 
@@ -7417,31 +7519,24 @@ static void WriteBinaryGltfStream(std::ostream &stream,
   const std::string header = "glTF";
   const int version = 2;
 
-  // https://stackoverflow.com/questions/3407012/c-rounding-up-to-the-nearest-multiple-of-a-number
+  const uint32_t content_size = uint32_t(content.size());
-  auto roundUp = [](uint32_t numToRound, uint32_t multiple) {
+  const uint32_t binBuffer_size = uint32_t(binBuffer.size());
-    if (multiple == 0) return numToRound;
+  // determine number of padding bytes required to ensure 4 byte alignment
-
+  const uint32_t content_padding_size = content_size % 4 == 0 ? 0 : 4 - content_size % 4;
-    uint32_t remainder = numToRound % multiple;
+  const uint32_t bin_padding_size = binBuffer_size % 4 == 0 ? 0 : 4 - binBuffer_size % 4;
-    if (remainder == 0) return numToRound;
-
-    return numToRound + multiple - remainder;
-  };
-
-  const uint32_t padding_size =
-      roundUp(uint32_t(content.size()), 4) - uint32_t(content.size());
 
   // 12 bytes for header, JSON content length, 8 bytes for JSON chunk info.
-  // Chunk data must be located at 4-byte boundary.
+  // Chunk data must be located at 4-byte boundary, which may require padding
   const uint32_t length =
-      12 + 8 + roundUp(uint32_t(content.size()), 4) +
+      12 + 8 + content_size + content_padding_size +
-      (binBuffer.size() ? (8 + roundUp(uint32_t(binBuffer.size()), 4)) : 0);
+      (binBuffer_size ? (8 + binBuffer_size + bin_padding_size) : 0);
 
   stream.write(header.c_str(), std::streamsize(header.size()));
   stream.write(reinterpret_cast<const char *>(&version), sizeof(version));
   stream.write(reinterpret_cast<const char *>(&length), sizeof(length));
 
   // JSON chunk info, then JSON data
-  const uint32_t model_length = uint32_t(content.size()) + padding_size;
+  const uint32_t model_length = uint32_t(content.size()) + content_padding_size;
   const uint32_t model_format = 0x4E4F534A;
   stream.write(reinterpret_cast<const char *>(&model_length),
                sizeof(model_length));
@@ -7450,13 +7545,11 @@ static void WriteBinaryGltfStream(std::ostream &stream,
   stream.write(content.c_str(), std::streamsize(content.size()));
 
   // Chunk must be multiplies of 4, so pad with spaces
-  if (padding_size > 0) {
+  if (content_padding_size > 0) {
-    const std::string padding = std::string(size_t(padding_size), ' ');
+    const std::string padding = std::string(size_t(content_padding_size), ' ');
     stream.write(padding.c_str(), std::streamsize(padding.size()));
   }
   if (binBuffer.size() > 0) {
-    const uint32_t bin_padding_size =
-        roundUp(uint32_t(binBuffer.size()), 4) - uint32_t(binBuffer.size());
     // BIN chunk info, then BIN data
     const uint32_t bin_length = uint32_t(binBuffer.size()) + bin_padding_size;
     const uint32_t bin_format = 0x004e4942;