.github/instructions/copilot-instructions.md - third_party/tinygltf - Git at Google

 # 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.
	# 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.