odin-lang.Odin/vendor/cgltf

:diamond_shape_with_a_dot_inside: cgltf

glTF loader and writer (Single-file/stb-style C glTF loader and writer)

Used in: bgfx, Filament, gltfpack, raylib, Unigine, and more!

Usage: Loading

Loading from file:

package main

import "vendor:cgltf"

main :: proc() {
	options: cgltf.options
	data, result := cgltf.parse_file(&options, "scene.gltf")
	if result != .success {
		/* TODO handle error */
	}
	defer cgltf.free(data)
	/* TODO make awesome stuff */
}

Loading from memory:

package main

import "vendor:cgltf"

main :: proc() {
	buf: []byte = ... // data to glb or gltf file data

	options: cgltf.options
	data, result := cgltf.parse(&options, raw_data(buf), len(buf))
	if result != .success {
		/* TODO handle error */
	}
	defer cgltf.free(data)
	/* TODO make awesome stuff */
}

Note that cgltf does not load the contents of extra files such as buffers or images into memory by default. You'll need to read these files yourself using URIs from data.buffers[] or data.images[] respectively. For buffer data, you can alternatively call cgltf.load_buffers, which will use ^clib.FILE APIs to open and read buffer files. This automatically decodes base64 data URIs in buffers. For data URIs in images, you will need to use cgltf.load_buffer_base64.

For more in-depth documentation and a description of the public interface refer to the top of the cgltf.h file.

Usage: Writing

When writing glTF data, you need a valid cgltf.data structure that represents a valid glTF document. You can construct such a structure yourself or load it using the loader functions described above. The writer functions do not deallocate any memory. So, you either have to do it manually or call cgltf.free() if you got the data by loading it from a glTF document.

Writing to file:

package main

import "vendor:cgltf"

main :: proc() {
	options: cgltf.options
	data: ^cgltf.data = /* TODO must be valid data */
	result := cgltf.write_file(&options, "out.gltf", data)
	if result != .success {
		/* TODO handle error */
	}
}

Writing to memory:

package main

import "vendor:cgltf"

main :: proc() {
	options: cgltf.options
	data: ^cgltf.data = /* TODO must be valid data */

	size := cgltf.write(&options, nil, 0, data)

	buf := make([]byte, size)

	written := cgltf.write(&options, raw_data(buf), size, data)
	if written != size {
		/* TODO handle error */
	}
}

Note that cgltf does not write the contents of extra files such as buffers or images. You'll need to write this data yourself.

For more in-depth documentation and a description of the public interface refer to the top of the cgltf_write.h file.

Features

cgltf supports core glTF 2.0:

• glb (binary files) and gltf (JSON files)
• meshes (including accessors, buffer views, buffers)
• materials (including textures, samplers, images)
• scenes and nodes
• skins
• animations
• cameras
• morph targets
• extras data

cgltf also supports some glTF extensions:

• EXT_mesh_gpu_instancing
• EXT_meshopt_compression
• KHR_draco_mesh_compression (requires a library like Google's Draco for decompression though)
• KHR_lights_punctual
• KHR_materials_clearcoat
• KHR_materials_emissive_strength
• KHR_materials_ior
• KHR_materials_iridescence
• KHR_materials_pbrSpecularGlossiness
• KHR_materials_sheen
• KHR_materials_specular
• KHR_materials_transmission
• KHR_materials_unlit
• KHR_materials_variants
• KHR_materials_volume
• KHR_texture_basisu (requires a library like Binomial Basisu for transcoding to native compressed texture)
• KHR_texture_transform

cgltf does not yet support unlisted extensions. However, unlisted extensions can be accessed via "extensions" member on objects.

Contributing

Everyone is welcome to contribute to the library. If you find any problems, you can submit them using GitHub's issue system. If you want to contribute code, you should fork the project and then send a pull request.

Dependencies

None.

C headers being used by the implementation:

#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <limits.h>
#include <assert.h> // If asserts are enabled.

Note, this library has a copy of the JSMN JSON parser embedded in its source.