Add CMake test target and fix Windows test failure

- Add TINYGLTF_BUILD_TESTS option to build unit tests via CMake
- Test runs from tests/ directory so relative paths work correctly
- Fix Windows file sharing violation in images-as-is test by closing
  fstream before stbi_load attempts to open the same file

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.github/instructions/copilot-instructions.md

@@ -0,0 +1,92 @@
+# Copilot Review Instructions for TinyGLTF
+
+This document provides guidelines for reviewing code changes in the TinyGLTF repository.
+
+## Memory Safety
+
+- **Buffer Overflows**: Check for proper bounds checking when accessing arrays, vectors, and buffers. Verify that buffer sizes are validated before read/write operations.
+- **Null Pointer Dereferences**: Ensure all pointers are checked for null before dereferencing, especially when handling optional glTF fields.
+- **Memory Leaks**: Verify proper resource management, including RAII patterns for file handles, image data, and dynamically allocated memory.
+- **Use-After-Free**: Check for proper lifetime management of objects, especially when dealing with callbacks and asynchronous operations.
+
+## Error Handling
+
+- **File I/O**: Verify that all file operations have proper error checking and meaningful error messages.
+- **JSON Parsing**: Ensure JSON parsing errors are caught and reported with helpful context about the location and nature of the error.
+- **Resource Loading**: Check that failures in loading images, buffers, and other resources are properly handled and don't cause crashes.
+- **Error Propagation**: Verify that errors are properly propagated through the call stack with appropriate error messages.
+
+## glTF 2.0 Specification Compliance
+
+- **Required Fields**: Ensure all required glTF fields are validated and present.
+- **Data Types**: Verify that data types match the glTF specification (e.g., component types, accessor types).
+- **Constraints**: Check that glTF constraints are enforced (e.g., valid ranges for enums, buffer stride requirements).
+- **Extensions**: Verify proper handling of glTF extensions and that unknown extensions are handled gracefully.
+- **Validation**: Ensure new features align with the glTF 2.0 specification from the Khronos Group.
+
+## Cross-Platform Compatibility
+
+- **Windows**: Check for proper handling of Windows-specific issues (path separators, line endings, file operations).
+- **Linux**: Verify compatibility with various Linux distributions and compilers (GCC, Clang).
+- **macOS**: Ensure macOS-specific considerations are addressed (case-sensitive filesystems, Clang compatibility).
+- **Mobile Platforms**: Consider Android and iOS compatibility where applicable.
+- **Endianness**: Verify proper handling of byte order when reading binary data.
+- **Compiler Compatibility**: Ensure code compiles with C++11 standard and supported compilers (MSVC, GCC, Clang).
+
+## Edge Cases in glTF Parsing
+
+- **Empty/Minimal Files**: Verify handling of minimal valid glTF files.
+- **Large Files**: Check for proper handling of large glTF files and buffers without memory exhaustion.
+- **Malformed Data**: Ensure graceful handling of malformed or invalid glTF data.
+- **Missing Optional Fields**: Verify correct behavior when optional glTF fields are absent.
+- **Edge Values**: Check handling of boundary values (e.g., maximum buffer sizes, extreme floating-point values).
+- **Base64 Encoding**: Verify proper handling of base64-encoded data URIs and invalid encodings.
+
+## Backwards Compatibility
+
+- **API Changes**: Ensure public API changes maintain backwards compatibility or are properly deprecated.
+- **Breaking Changes**: Flag any breaking changes for major version updates and document migration paths.
+- **Binary Compatibility**: Consider ABI stability for header-only library changes.
+- **Default Behavior**: Verify that default behavior of existing functionality remains unchanged.
+
+## Performance Considerations
+
+- **Parsing Performance**: Check for unnecessary copies, redundant allocations, and inefficient algorithms in parsing logic.
+- **Memory Usage**: Verify efficient memory usage, especially when loading large glTF files.
+- **I/O Operations**: Ensure efficient file reading and minimize unnecessary disk access.
+- **String Operations**: Check for efficient string handling (use of string_view, move semantics).
+- **STL Usage**: Verify appropriate use of STL containers and algorithms.
+
+## Documentation
+
+- **Public API**: Ensure all public functions, classes, and methods have clear documentation comments.
+- **Parameters**: Verify that function parameters are documented, including expected ranges and constraints.
+- **Return Values**: Document return values and possible error conditions.
+- **Examples**: Check that complex features include usage examples.
+- **Changelog**: Verify that significant changes are documented in release notes or changelog.
+
+## Testing
+
+- **Test Coverage**: Ensure new features include appropriate unit tests or integration tests.
+- **Edge Cases**: Verify that tests cover edge cases and error conditions.
+- **Cross-Platform Tests**: Check that tests run on all supported platforms.
+- **Regression Tests**: Ensure bug fixes include regression tests to prevent recurrence.
+- **Sample Files**: Verify that changes are tested with various valid and invalid glTF sample files.
+
+## Code Style Consistency
+
+- **Header-Only Pattern**: Maintain the header-only library structure.
+- **Naming Conventions**: Follow existing naming conventions (CamelCase for types, snake_case for functions where applicable).
+- **Formatting**: Adhere to the existing code formatting style (check `.clang-format` if available).
+- **Include Guards**: Verify proper include guards and header organization.
+- **Namespace Usage**: Ensure proper use of the `tinygltf` namespace.
+- **Comments**: Maintain consistent comment style with existing code.
+- **C++11 Compliance**: Verify that code uses C++11 features appropriately and doesn't require newer standards unless specified.
+
+## Additional Considerations
+
+- **Third-Party Dependencies**: Minimize new dependencies; prefer existing dependencies (json.hpp, stb_image).
+- **Warnings**: Ensure code compiles without warnings on supported compilers.
+- **const Correctness**: Verify proper use of const for parameters and methods.
+- **RAII**: Prefer RAII patterns for resource management over manual cleanup.
+- **noexcept**: Use noexcept appropriately for move constructors and move assignment operators.

.travis-before-install.sh

@@ -1,10 +0,0 @@
-#!/bin/bash
-
-if [[ "$TRAVIS_OS_NAME" == "osx" ]]
-then
-    brew upgrade
-    curl -o premake5.tar.gz https://github.com/premake/premake-core/releases/download/v5.0.0-alpha12/premake-5.0.0-alpha12-macosx.tar.gz
-else
-    wget https://github.com/premake/premake-core/releases/download/v5.0.0-alpha12/premake-5.0.0-alpha12-linux.tar.gz -O premake5.tar.gz
-fi
-tar xzf premake5.tar.gz

.travis.yml

@@ -1,63 +0,0 @@
-language: cpp
-sudo: false
-matrix:
-  include:
-  - addons: &1
-      apt:
-        sources:
-        - george-edison55-precise-backports
-        - ubuntu-toolchain-r-test
-        - llvm-toolchain-trusty-3.9
-        packages:
-        - g++-4.9
-        - clang-3.9
-    compiler: clang
-    env: COMPILER_VERSION=3.9 BUILD_TYPE=Debug
-  - addons: *1
-    compiler: clang
-    env: COMPILER_VERSION=3.9 BUILD_TYPE=Release
-  - addons: &2
-      apt:
-        sources:
-        - george-edison55-precise-backports
-        - ubuntu-toolchain-r-test
-        packages:
-        - g++-4.9
-    compiler: gcc
-    env: COMPILER_VERSION=4.9 BUILD_TYPE=Debug EXTRA_CXXFLAGS="-fsanitize=address"
-  - addons: *2
-    compiler: gcc
-    env: COMPILER_VERSION=4.9 BUILD_TYPE=Release EXTRA_CXXFLAGS="-fsanitize=address"
-  - addons: *1
-    compiler: clang
-    env: COMPILER_VERSION=3.9 BUILD_TYPE=Debug CFLAGS="-O0" CXXFLAGS="-O0"
-  - addons: &3
-      apt:
-        sources:
-        - ubuntu-toolchain-r-test
-        packages:
-        - g++-4.8
-    compiler: gcc
-    env: COMPILER_VERSION=4.8 BUILD_TYPE=Debug
-  - addons: *3
-    compiler: gcc
-    env: COMPILER_VERSION=4.8 BUILD_TYPE=Release
-
-before_install:
-  - ./.travis-before-install.sh
-
-
-script:
-  - export CC="${CC}-${COMPILER_VERSION}"
-  - export CXX="${CXX}-${COMPILER_VERSION}"
-  - ${CC} -v
-  - ${CXX} ${EXTRA_CXXFLAGS} -std=c++11 -Wall -g -o loader_example loader_example.cc
-  - ./loader_example ./models/Cube/Cube.gltf
-  - cd tests
-  - clang++ -v
-  - make
-  - ./tester
-  - ./tester_noexcept
-  - cd ../examples/raytrace
-  - ../../premake5 gmake
-  - make

CMakeLists.txt

@@ -14,8 +14,10 @@ option(TINYGLTF_BUILD_LOADER_EXAMPLE "Build loader_example(load glTF and dump in
 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_BUILD_TESTS "Build unit tests" 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)
+option(TINYGLTF_INSTALL_VENDOR "Install vendored nlohmann/json and nothings/stb headers" ON)
 
 if (TINYGLTF_BUILD_LOADER_EXAMPLE)
   add_executable(loader_example
@@ -36,6 +38,16 @@ if (TINYGLTF_BUILD_BUILDER_EXAMPLE)
   add_subdirectory ( examples/build-gltf )
 endif (TINYGLTF_BUILD_BUILDER_EXAMPLE)
 
+if (TINYGLTF_BUILD_TESTS)
+  enable_testing()
+  add_executable(tester tests/tester.cc)
+  target_include_directories(tester PRIVATE
+    ${CMAKE_CURRENT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/tests
+  )
+  add_test(NAME tester COMMAND tester WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/tests)
+endif (TINYGLTF_BUILD_TESTS)
+
 #
 # for add_subdirectory and standalone build
 #
@@ -61,19 +73,26 @@ endif (TINYGLTF_HEADER_ONLY)
 
 if (TINYGLTF_INSTALL)
   install(TARGETS tinygltf EXPORT tinygltfTargets)
-  install(EXPORT tinygltfTargets NAMESPACE tinygltf:: FILE TinyGLTFTargets.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake)
+  install(EXPORT tinygltfTargets NAMESPACE tinygltf:: FILE TinyGLTFTargets.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/tinygltf)
   configure_package_config_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/TinyGLTFConfig.cmake.in ${CMAKE_CURRENT_BINARY_DIR}/TinyGLTFConfig.cmake INSTALL_DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake)
-  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/TinyGLTFConfig.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake)
+  install(FILES ${CMAKE_CURRENT_BINARY_DIR}/TinyGLTFConfig.cmake DESTINATION ${CMAKE_INSTALL_LIBDIR}/cmake/tinygltf)
   # 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
     )
 
+    if(TINYGLTF_INSTALL_VENDOR)
+      INSTALL ( FILES
+        json.hpp
+        stb_image.h
+        stb_image_write.h
+        DESTINATION
+        include
+        )
+    endif()
+
 endif(TINYGLTF_INSTALL)

README.md

@@ -9,7 +9,7 @@ If you are looking for old, C++03 version, please use `devel-picojson` branch (b
 ## Status
 
 Currently TinyGLTF is stable and maintenance mode. No drastic changes and feature additions planned.
-
+ - v2.9.0 Various fixes and improvements. Filesystem callback API change.
  - v2.8.0 Add URICallbacks for custom URI handling in Buffer and Image. PR#397
  - v2.7.0 Change WriteImageDataFunction user callback function signature. PR#393
  - v2.6.0 Support serializing sparse accessor(Thanks to @fynv).
@@ -26,8 +26,6 @@ Currently TinyGLTF is stable and maintenance mode. No drastic changes and featur
 
 ## Builds
 
-[![Build Status](https://travis-ci.org/syoyo/tinygltf.svg?branch=devel)](https://travis-ci.org/syoyo/tinygltf)
-
 [![Build status](https://ci.appveyor.com/api/projects/status/warngenu9wjjhlm8?svg=true)](https://ci.appveyor.com/project/syoyo/tinygltf)
 
 ![C/C++ CI](https://github.com/syoyo/tinygltf/workflows/C/C++%20CI/badge.svg)
@@ -109,7 +107,7 @@ WASI build example is located in [wasm](wasm) .
 * [SanityEngine](https://github.com/DethRaid/SanityEngine) - A C++/D3D12 renderer focused on the personal and professional development of its developer
 * [Open3D](http://www.open3d.org/) - A Modern Library for 3D Data Processing
 * [Supernova Engine](https://github.com/supernovaengine/supernova) - Game engine for 2D and 3D projects with Lua or C++ in data oriented design.
-* [Wicked Engine<img src="https://github.com/turanszkij/WickedEngine/blob/master/Content/logo_small.png" width="28px" align="center"/>](https://github.com/turanszkij/WickedEngine) - 3D engine with modern graphics 
+* [Wicked Engine<img src="https://github.com/turanszkij/WickedEngine/blob/master/Content/logo_small.png" width="28px" align="center"/>](https://github.com/turanszkij/WickedEngine) - 3D engine with modern graphics
 * Your projects here! (Please send PR)
 
 ## TODOs
@@ -161,9 +159,10 @@ Model model;
 TinyGLTF loader;
 std::string err;
 std::string warn;
+std::string filename = "input.gltf";
 
-bool ret = loader.LoadASCIIFromFile(&model, &err, &warn, argv[1]);
-//bool ret = loader.LoadBinaryFromFile(&model, &err, &warn, argv[1]); // for binary glTF(.glb)
+bool ret = loader.LoadASCIIFromFile(&model, &err, &warn, filename);
+//bool ret = loader.LoadBinaryFromFile(&model, &err, &warn, filename); // for binary glTF(.glb)
 
 if (!warn.empty()) {
   printf("Warn: %s\n", warn.c_str());
@@ -174,8 +173,7 @@ if (!err.empty()) {
 }
 
 if (!ret) {
-  printf("Failed to parse glTF\n");
-  return -1;
+  printf("Failed to parse glTF: %s\n", filename.c_str());
 }
 ```
 
@@ -196,7 +194,6 @@ if (!ret) {
 * `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 feature.
-* `TINYGLTF_USE_CPP14` : Use C++14 feature(requires C++14 compiler). This may give better performance than C++11.
 
 
 ## CMake options
@@ -213,6 +210,11 @@ set(TINYGLTF_INSTALL OFF CACHE INTERNAL "" FORCE)
 add_subdirectory(/path/to/tinygltf)
 ```
 
+NOTE: Using tinygltf as a submodule doesn't automatically add the headers to your include path (as standard for many libraries). To get this functionality, add the following to the CMakeLists.txt file from above:
+
+```
+target_include_directories(${PROJECT_NAME} PRIVATE "/path/to/tinygltf")
+```
 
 ### Saving gltTF 2.0 model
 

examples/glview/glview.cc

@@ -788,8 +788,10 @@ static void QuatToAngleAxis(const std::vector<double> quaternion,
     return;
   }
 
+  constexpr double pi = 3.14159265358979323846;
+
   double denom = sqrt(1-qw*qw);
-  outAngleDegrees = angleRadians * 180.0 / M_PI;
+  outAngleDegrees = angleRadians * 180.0 / pi;
   axis[0] = qx / denom;
   axis[1] = qy / denom;
   axis[2] = qz / denom;

tests/tester.cc

@@ -474,7 +474,7 @@ TEST_CASE("image-uri-spaces", "[issue-236]") {
     }
     REQUIRE(true == ret);
     REQUIRE(err.empty());
-    REQUIRE(!warn.empty());  // relative image path won't exist in tests/
+    REQUIRE(warn.empty());
     REQUIRE(saved.images.size() == model.images.size());
 
     // The image uri in CubeImageUriMultipleSpaces.gltf is not encoded and
@@ -662,10 +662,11 @@ TEST_CASE("serialize-image-callback", "[issue-394]") {
 
   auto writer = [](const std::string *basepath, const std::string *filename,
                    const tinygltf::Image *image, bool embedImages,
-                   const tinygltf::URICallbacks *uri_cb, std::string *out_uri,
-                   void *user_pointer) -> bool {
+                   const tinygltf::FsCallbacks* fs, const tinygltf::URICallbacks *uri_cb,
+                   std::string *out_uri, void *user_pointer) -> bool {
     (void)basepath;
     (void)image;
+    (void)fs;
     (void)uri_cb;
     REQUIRE(*filename == "foo");
     REQUIRE(embedImages == true);
@@ -699,12 +700,13 @@ TEST_CASE("serialize-image-failure", "[issue-394]") {
 
   auto writer = [](const std::string *basepath, const std::string *filename,
                    const tinygltf::Image *image, bool embedImages,
-                   const tinygltf::URICallbacks *uri_cb, std::string *out_uri,
-                   void *user_pointer) -> bool {
+                   const tinygltf::FsCallbacks* fs, const tinygltf::URICallbacks *uri_cb,
+                   std::string *out_uri, void *user_pointer) -> bool {
     (void)basepath;
     (void)filename;
     (void)image;
     (void)embedImages;
+    (void)fs;
     (void)uri_cb;
     (void)out_uri;
     (void)user_pointer;
@@ -902,3 +904,348 @@ TEST_CASE("serialize-empty-scene", "[issue-464]") {
     CHECK(m.scenes[0] == scene);
   }
 }
+
+TEST_CASE("zero-sized-bin-chunk-glb", "[issue-440]") {
+
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  // Input glb has zero-sized data in bin chunk(8 bytes for BIN chunk, and chunksize == 0)
+  // The spec https://registry.khronos.org/glTF/specs/2.0/glTF-2.0.html#binary-buffer says
+  //
+  // When the binary buffer is empty or when it is stored by other means, this chunk SHOULD be omitted.
+  //
+  // 'SHOULD' mean 'RECOMMENDED', so we'll need to allow such zero-sized bin chunk is NOT omitted.
+  bool ret = ctx.LoadBinaryFromFile(&model, &err, &warn, "../models/regression/zero-sized-bin-chunk-issue-440.glb");
+  if (!warn.empty()) {
+    std::cout << "WARN: " << warn << "\n";
+  }
+  if (!err.empty()) {
+    std::cerr << err << std::endl;
+  }
+
+  REQUIRE(true == ret);
+}
+
+TEST_CASE("serialize-node-emitter", "[KHR_audio]") {
+  // Stream to serialize to
+  std::stringstream os;
+
+  {
+    tinygltf::Model m;
+    // Create a default audio emitter
+    m.audioEmitters.resize(1);
+    // Create a single node
+    m.nodes.resize(1);
+    // The node references the single emitter
+    m.nodes[0].emitter = 0;
+    // Create a single scene
+    m.scenes.resize(1);
+    // Make the scene reference the single node
+    m.scenes[0].nodes.push_back(0);
+
+    // Serialize model to output stream
+    tinygltf::TinyGLTF ctx;
+    bool ret = ctx.WriteGltfSceneToStream(&m, os, false, false);
+    REQUIRE(true == ret);
+  }
+
+  {
+    tinygltf::Model m;
+    tinygltf::TinyGLTF ctx;
+    // Parse the serialized model
+    bool ok = ctx.LoadASCIIFromString(&m, nullptr, nullptr, os.str().c_str(), os.str().size(), "");
+    REQUIRE(true == ok);
+
+    // Make sure the single scene is there
+    REQUIRE(1 == m.scenes.size());
+    // Make sure all three nodes are there
+    REQUIRE(1 == m.nodes.size());
+    // Make sure the single root node of the scene is there
+    REQUIRE(1 == m.scenes[0].nodes.size());
+    REQUIRE(0 == m.scenes[0].nodes[0]);
+    // Retrieve the scene root node
+    const tinygltf::Node& node = m.nodes[m.scenes[0].nodes[0]];
+    // Make sure the single root node has both lod nodes
+    REQUIRE(0 == node.emitter);
+  }
+}
+
+TEST_CASE("serialize-lods", "[lods]") {
+  // Stream to serialize to
+  std::stringstream os;
+
+  {
+    tinygltf::Model m;
+
+    m.nodes.resize(4);
+    // Add Node 1 and Node 2 as lods to Node 0
+    m.nodes[0].lods.push_back(1);
+    m.nodes[0].lods.push_back(2);
+
+    // Add Material 1 and Material 2 as lods to Material 0
+    m.materials.resize(4);
+    m.materials[0].lods.push_back(1);
+    m.materials[0].lods.push_back(2);
+
+    tinygltf::Scene scene;
+    // Scene uses Node 0 and 3 as root node
+    scene.nodes.push_back(0);
+    scene.nodes.push_back(3);
+    // Add scene to the model
+    m.scenes.push_back(scene);
+
+    // Serialize model to output stream
+    tinygltf::TinyGLTF ctx;
+    bool ret = ctx.WriteGltfSceneToStream(&m, os, false, false);
+    REQUIRE(true == ret);
+  }
+
+  {
+    tinygltf::Model m;
+    tinygltf::TinyGLTF ctx;
+    // Parse the serialized model
+    bool ok = ctx.LoadASCIIFromString(&m, nullptr, nullptr, os.str().c_str(), os.str().size(), "");
+    REQUIRE(true == ok);
+    // Make sure the model's used extensions hold MSFT_lod
+    CHECK(m.extensionsUsed.size() == 1);
+    CHECK(m.extensionsUsed[0].compare("MSFT_lod") == 0);
+    // MSFT_lod is not a required extension
+    CHECK(m.extensionsRequired.size() == 0);
+
+    // Make sure all four materials are there
+    REQUIRE(4 == m.materials.size());
+    // Make sure the first material has both lod materials
+    REQUIRE(2 == m.materials[0].lods.size());
+    // Make sure the order is still the same after serialization and deserialization
+    CHECK(1 == m.materials[0].lods[0]);
+    CHECK(2 == m.materials[0].lods[1]);
+    // Make sure the material with lods exposes the MSFT_lod extension
+    CHECK(m.materials[0].extensions.size() == 1);
+    CHECK(m.materials[0].extensions.count("MSFT_lod") == 1);
+    // Make sure the last material has no lod materials
+    CHECK(0 == m.materials[3].lods.size());
+    // Make sure the material without lods does not exposes the MSFT_lod extension
+    CHECK(m.materials[3].extensions.size() == 0);
+    CHECK(m.materials[3].extensions.count("MSFT_lod") == 0);
+
+    // Make sure the single scene is there
+    REQUIRE(1 == m.scenes.size());
+    // Make sure all four nodes are there
+    REQUIRE(4 == m.nodes.size());
+    // Make sure the two root nodes of the scene are there
+    REQUIRE(2 == m.scenes[0].nodes.size());
+    REQUIRE(0 == m.scenes[0].nodes[0]);
+    REQUIRE(3 == m.scenes[0].nodes[1]);
+    // Retrieve the node with lods
+    const tinygltf::Node& nodeWithLods = m.nodes[m.scenes[0].nodes[0]];
+    // Make sure the node has both lod nodes
+    REQUIRE(2 == nodeWithLods.lods.size());
+    // Make sure the order is still the same after serialization and deserialization
+    CHECK(1 == nodeWithLods.lods[0]);
+    CHECK(2 == nodeWithLods.lods[1]);
+    // Make sure the node with lods exposes the MSFT_lod extension
+    CHECK(nodeWithLods.extensions.size() == 1);
+    CHECK(nodeWithLods.extensions.count("MSFT_lod") == 1);
+    // Retrieve the node without lods
+    const tinygltf::Node& nodeWithoutLods = m.nodes[m.scenes[0].nodes[1]];
+    // Make sure the node has no lod nodes
+    CHECK(0 == nodeWithoutLods.lods.size());
+    // Make sure the node without lods does not exposes the MSFT_lod extension
+    CHECK(nodeWithoutLods.extensions.size() == 0);
+    CHECK(nodeWithoutLods.extensions.count("MSFT_lod") == 0);
+  }
+}
+
+TEST_CASE("write-image-issue", "[issue-473]") {
+  std::string err;
+  std::string warn;
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  bool ok = ctx.LoadASCIIFromFile(&model, &err, &warn, "../models/Cube/Cube.gltf");
+  REQUIRE(ok);
+  REQUIRE(err.empty());
+  REQUIRE(warn.empty());
+
+  REQUIRE(model.images.size() == 2);
+  REQUIRE(model.images[0].uri == "Cube_BaseColor.png");
+  REQUIRE(model.images[1].uri == "Cube_MetallicRoughness.png");
+
+  REQUIRE_FALSE(model.images[0].image.empty());
+  REQUIRE_FALSE(model.images[1].image.empty());
+
+  ok = ctx.WriteGltfSceneToFile(&model, "Cube.gltf");
+  REQUIRE(ok);
+
+  for (const auto& image : model.images) {
+    std::fstream file(image.uri);
+    CHECK(file.good());
+  }
+}
+
+TEST_CASE("images-as-is", "[issue-487]") {
+  std::string err;
+  std::string warn;
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  ctx.SetImagesAsIs(true);
+  bool ok = ctx.LoadASCIIFromFile(&model, &err, &warn, "../models/Cube/Cube.gltf");
+  REQUIRE(ok);
+  REQUIRE(err.empty());
+  REQUIRE(warn.empty());
+
+  for (const auto& image : model.images) {
+    CHECK(image.as_is == true);
+    CHECK_FALSE(image.uri.empty());
+    CHECK_FALSE(image.image.empty());
+
+#ifndef TINYGLTF_NO_STB_IMAGE
+    // Make sure we can decode the images
+    int w = -1, h = -1, component = -1;
+    unsigned char *data = stbi_load_from_memory(image.image.data(), static_cast<int>(image.image.size()), &w, &h, &component, 0);
+    CHECK(data != nullptr);
+    CHECK(w == 512);
+    CHECK(h == 512);
+    CHECK(component >= 3);
+    stbi_image_free(data);
+#endif
+  }
+
+  // Write glTF model to disk, and images as separate files
+  {
+    ok = ctx.WriteGltfSceneToFile(&model, "Cube_with_image_files.gltf");
+    REQUIRE(ok);
+
+    // All the images should have been written to disk with their original data
+    for (const auto& image : model.images)  {
+      // Make sure the image files exist
+      {
+        std::fstream file(image.uri);
+        CHECK(file.good());
+      } // Close file before stbi_load (Windows sharing violation fix)
+#ifndef TINYGLTF_NO_STB_IMAGE
+      // Make sure we can load the images
+      int w = -1, h = -1, component = -1;
+      unsigned char *data = stbi_load(image.uri.c_str(), &w, &h, &component, 0);
+      CHECK(data != nullptr);
+      CHECK(w == 512);
+      CHECK(h == 512);
+      CHECK(component >= 3);
+      stbi_image_free(data);
+#endif
+    }
+  }
+
+  // Write glTF model to disk, and embed images as data URIs
+  {
+    ok = ctx.WriteGltfSceneToFile(&model, "Cube_with_embedded_images.gltf", true, false);
+    REQUIRE(ok);
+
+    // Load above model again, and check if the images are loaded properly
+    tinygltf::Model embeddedImages;
+    ctx.SetImagesAsIs(false);
+    bool ok = ctx.LoadASCIIFromFile(&embeddedImages, &err, &warn, "Cube_with_embedded_images.gltf");
+    REQUIRE(ok);
+    REQUIRE(err.empty());
+    REQUIRE(warn.empty());
+
+    for (const auto& image : embeddedImages.images) {
+      CHECK(image.as_is == false);
+      CHECK_FALSE(image.mimeType.empty());
+      CHECK_FALSE(image.image.empty());
+      CHECK(image.width == 512);
+      CHECK(image.height == 512);
+      CHECK(image.component >= 3);
+    }
+  }
+
+  // Write glTF model to disk, as GLB
+  {
+    ok = ctx.WriteGltfSceneToFile(&model, "Cube.glb", true, true, true, true);
+    REQUIRE(ok);
+
+    // Load above model again, and check if the images are loaded properly
+    tinygltf::Model glbModel;
+    ctx.SetImagesAsIs(false);
+    bool ok = ctx.LoadBinaryFromFile(&glbModel, &err, &warn, "Cube.glb");
+    REQUIRE(ok);
+    REQUIRE(err.empty());
+    REQUIRE(warn.empty());
+
+    for (const auto& image : glbModel.images) {
+      CHECK(image.as_is == false);
+      CHECK_FALSE(image.mimeType.empty());
+      CHECK_FALSE(image.image.empty());
+      CHECK(image.width == 512);
+      CHECK(image.height == 512);
+      CHECK(image.component >= 3);
+    }
+  }
+}
+
+TEST_CASE("inverse-bind-matrices-optional", "[issue-492]") {
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+  std::string err;
+  std::string warn;
+
+  bool ret = ctx.LoadBinaryFromFile(&model, &err, &warn, "issue-492.glb");
+  if (!warn.empty()) {
+    std::cout << "WARN:" << warn << std::endl;
+  }
+  if (!err.empty()) {
+    std::cerr << "ERR:" << err << std::endl;
+  }
+
+  REQUIRE(true == ret);
+  REQUIRE(err.empty());
+}
+
+bool LoadImageData(tinygltf::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 */) {
+    return true;
+}
+
+bool WriteImageData(const std::string * /* basepath */, const std::string * /* filename */,
+                    const tinygltf::Image *image, bool /* embedImages */,
+                    const tinygltf::FsCallbacks * /* fs_cb */, const tinygltf::URICallbacks * /* uri_cb */,
+                    std::string * /* out_uri */, void * user_pointer) {
+    REQUIRE(user_pointer != nullptr);
+    auto counter = static_cast<int*>(user_pointer);
+    *counter = *counter + 1;
+    return true;
+}
+
+TEST_CASE("empty-images-not-written", "[issue-495]") {
+  std::string err;
+  std::string warn;
+  tinygltf::Model model;
+  tinygltf::TinyGLTF ctx;
+
+  ctx.SetImageLoader(LoadImageData, nullptr);
+  bool ok = ctx.LoadASCIIFromFile(&model, &err, &warn, "../models/Cube/Cube.gltf");
+  REQUIRE(ok);
+  REQUIRE(err.empty());
+  REQUIRE(warn.empty());
+
+  CHECK(model.images.size() == 2);
+  for (const auto& image : model.images) {
+    // No data loaded or decoded
+    CHECK(image.image.empty());
+    // The URI is kept
+    CHECK_FALSE(image.uri.empty());
+    // The URI should not be a data URI
+    CHECK(image.uri.find("data:") != 0);
+  }
+
+  // Now write the loaded model
+  int counter = 0;
+  ctx.SetImageWriter(WriteImageData, &counter);
+  ok = ctx.WriteGltfSceneToFile(&model, "issue-495-external.gltf");
+  CHECK(ok);
+  // WriteImageData should be invoked for both images
+  CHECK(counter == 2);
+}