A C++14/C++17 header-only library for simple, efficient, and robust serialization/deserialization of glTF 2.0
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Complete support for required glTF 2.0 schema elements
- Full serialization (save) and deserialization (load) capability
- External and embedded resource loading
- Binary .glb files
- Load as text, save as binary etc.
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Modern C++14/C++17 support
- Includes usage of std::string_view internally where appropriate for performance
- Implemented using modern and safe syntax and methodologies
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Small, header-only library
- <2000 lines of high-level, straightforward, generously spaced code including whitespace/comments
- C++20 Module ready (does not leak preprocessor defines/macros beyond its own file)
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Fast, Efficient, and Safe processing
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Useful examples
- DirectX 12 enabled viewer
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gltf.his the single required file available in theinclude/fxrepo path.A typical installation will preserve the directory hierarchy:
#include <fx/gltf.h>
- nlohmann::json (must be referenceable using
#include <nlohmann/json.hpp>)
Example: General usage
// Single header...
#include <fx/gltf.h>
// Loading...
fx::gltf::Document helmet = fx::gltf::LoadFromText("DamagedHelmet.gltf");
// Manipulation...
helmet.asset.generator = "My cool generator";
helmet.buffers.push_back(fx::gltf::Buffer{});
helmet.buffers.back().byteLength = 678;
helmet.buffers.back().data = ...;
helmet.buffers.back().SetAsEmbeddedResource();
// Saving back as text...
fx::gltf::Save(helment, "NewHelmet.gltf", false);Example: Placing a quota on how large files and buffers can be; e.g. when loading files from potentially hostile sources
#include <fx/gltf.h>
// Load at most 3 buffers in total, each as large as 8mb...
// additionally, place a quota on the file size as well
fx::gltf::ReadQuotas readQuotas{};
readQuotas.MaxBufferCount = 3; // default: 8
readQuotas.MaxBufferByteLength = 8 * 1024 * 1024; // default: 32mb
readQuotas.MaxFileSize = 8 * 1024 * 1024; // default: 32mb (applies to binary .glb only)
fx::gltf::Document docFromInternet = fx::gltf::LoadFromBinary("untrusted.glb", readQuotas);See the DirectX 12 enabled viewer example for a demonstration of how to leverage fx-gltf in a full application context.
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Robust automated testing
- Roundtrip testing for all models inside glTF-Sample-Models
- Testing of Base64 encoding and decoding routines, including invalid Base64 inputs
- Strict required vs. optional element loading and saving
| Model Type | Status: glTF-Sample-Models |
|---|---|
| .gltf files w/external resources | 100% complete and passing |
| .gltf files w/embedded resources | 100% complete and passing (2 models excluded due to out-of-spec mimetypes) |
| .gltf files w/pbrSpecularGlossiness extension | 100% complete and passing |
| .glb files | 100% complete and passing |
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Safety
- Built-in protection against directory traversal when loading external resource URIs from malicious files
- Enforced quotas on maximum files sizes and buffers to prevent DOS's from malicious files
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Developed using both clang-tidy and MSVC CppCoreCheck toolsets
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Faster than other full-featured loaders
- Improvement ranges from 1.1x to 2x (!) faster depending on the model.
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Benchmark Time CPU Iterations
-------------------------------------------------------------------------------------
fxgltf_Test/External_Box_mean 261 us 261 us 2358
fxgltf_Test/External_Box_median 253 us 258 us 2358
fxgltf_Test/External_Box_stddev 27 us 28 us 2358
tinygltf_Test/External_Box_mean 321 us 319 us 2133
tinygltf_Test/External_Box_median 312 us 308 us 2133
tinygltf_Test/External_Box_stddev 20 us 20 us 2133
fxgltf_Test/Embedded_Box_mean 192 us 192 us 4073
fxgltf_Test/Embedded_Box_median 192 us 188 us 4073
fxgltf_Test/Embedded_Box_stddev 14 us 16 us 4073
tinygltf_Test/Embedded_Box_mean 274 us 273 us 3200
tinygltf_Test/Embedded_Box_median 281 us 278 us 3200
tinygltf_Test/Embedded_Box_stddev 30 us 30 us 3200
fxgltf_Test/External_2CylinderEngine_mean 6503 us 6563 us 100
fxgltf_Test/External_2CylinderEngine_median 7065 us 7188 us 100
fxgltf_Test/External_2CylinderEngine_stddev 900 us 931 us 100
tinygltf_Test/External_2CylinderEngine_mean 8664 us 8681 us 90
tinygltf_Test/External_2CylinderEngine_median 8490 us 8507 us 90
tinygltf_Test/External_2CylinderEngine_stddev 1034 us 1005 us 90
fxgltf_Test/Embedded_2CylinderEngine_mean 72760 us 72727 us 11
fxgltf_Test/Embedded_2CylinderEngine_median 74147 us 73864 us 11
fxgltf_Test/Embedded_2CylinderEngine_stddev 8219 us 8246 us 11
tinygltf_Test/Embedded_2CylinderEngine_mean 110179 us 110268 us 7
tinygltf_Test/Embedded_2CylinderEngine_median 109267 us 109375 us 7
tinygltf_Test/Embedded_2CylinderEngine_stddev 5324 us 6431 us 7
fxgltf_Test/External_ReciprocatingSaw_mean 12221 us 12333 us 56
fxgltf_Test/External_ReciprocatingSaw_median 11875 us 11998 us 56
fxgltf_Test/External_ReciprocatingSaw_stddev 717 us 666 us 56
tinygltf_Test/External_ReciprocatingSaw_mean 17273 us 17313 us 50
tinygltf_Test/External_ReciprocatingSaw_median 18154 us 18125 us 50
tinygltf_Test/External_ReciprocatingSaw_stddev 2095 us 2205 us 50
fxgltf_Test/Embedded_ReciprocatingSaw_mean 143724 us 144792 us 6
fxgltf_Test/Embedded_ReciprocatingSaw_median 147001 us 148438 us 6
fxgltf_Test/Embedded_ReciprocatingSaw_stddev 14070 us 14096 us 6
tinygltf_Test/Embedded_ReciprocatingSaw_mean 211632 us 210417 us 3
tinygltf_Test/Embedded_ReciprocatingSaw_median 206052 us 208333 us 3
tinygltf_Test/Embedded_ReciprocatingSaw_stddev 20525 us 21663 us 3
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More memory efficient than other full-featured loaders
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Greater than 50% reduction in number of allocations across a variety of models. Sometimes as high as 70%!
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Greater than 40% reduction in total allocation size across a variety of models. Sometimes as high as 67%!
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Benchmark Time CPU Iterations TotalNewCalls TotalNewSize
----------------------------------------------------------------------------------------------------------
fxgltf_Test/External_Box 222 us 0 us 1 201 12.646k
tinygltf_Test/External_Box 664 us 0 us 1 428 36.709k
fxgltf_Test/Embedded_Box 660 us 0 us 1 217 19.958k
tinygltf_Test/Embedded_Box 670 us 0 us 1 452 49.667k
fxgltf_Test/External_2CylinderEngine 11398 us 0 us 1 4.915k 2.15445M
tinygltf_Test/External_2CylinderEngine 11598 us 15625 us 1 14.942k 5.1615M
fxgltf_Test/Embedded_2CylinderEngine 57782 us 62500 us 1 4.968k 23.0764M
tinygltf_Test/Embedded_2CylinderEngine 80368 us 78125 us 1 15.021k 43.5535M
fxgltf_Test/External_ReciprocatingSaw 17415 us 15625 us 1 9.784k 4.2078M
tinygltf_Test/External_ReciprocatingSaw 13825 us 15625 us 1 31.806k 10.5618M
fxgltf_Test/Embedded_ReciprocatingSaw 126205 us 125000 us 1 9.84k 42.5873M
tinygltf_Test/Embedded_ReciprocatingSaw 236703 us 234375 us 1 31.889k 79.4386M
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Using C++17 yields some additional benefits over C++14
- Total number of allocations drops 2-3% and total allocation size drops 1% for external resources and 5-10% for embedded resources!
C++14
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Benchmark Time CPU Iterations TotalNewCalls TotalNewSize
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fxgltf_Test/External_Box 648 us 0 us 1 206 12.806k
fxgltf_Test/Embedded_Box 608 us 0 us 1 223 21k
fxgltf_Test/External_2CylinderEngine 11017 us 15625 us 1 5.052k 2.15883M
fxgltf_Test/Embedded_2CylinderEngine 54864 us 62500 us 1 5.106k 25.4737M
fxgltf_Test/External_ReciprocatingSaw 10434 us 0 us 1 10.045k 4.21615M
fxgltf_Test/Embedded_ReciprocatingSaw 106756 us 109375 us 1 10.102k 47.258M
C++17
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Benchmark Time CPU Iterations TotalNewCalls TotalNewSize
--------------------------------------------------------------------------------------------------------
fxgltf_Test/External_Box 236 us 0 us 1 201 12.646k
fxgltf_Test/Embedded_Box 193 us 0 us 1 217 19.958k
fxgltf_Test/External_2CylinderEngine 6076 us 15625 us 1 4.915k 2.15445M
fxgltf_Test/Embedded_2CylinderEngine 63823 us 78125 us 1 4.968k 23.0764M
fxgltf_Test/External_ReciprocatingSaw 17033 us 15625 us 1 9.784k 4.2078M
fxgltf_Test/Embedded_ReciprocatingSaw 122586 us 109375 us 1 9.84k 42.5873M
- File->Open->CMake
- Point to the
testrepo path
- Point to the
- CMake->Rebuild All
- Inside Test Explorer -> Run All
$ mkdir build
$ cd build
$ cmake ..
$ cmake --build .
$ ctest --output-on-failure -C [Debug or Release]- Microsoft Visual C++ 2017 15.3+ (and possibly earlier)
- Clang 5.0+
- GCC 6.1+
- No known issues or missing features
- No known issues
- TODO: Publish to vcpkg for easier package maintenance within MSVC environments
- TODO: Ship a C++20 Modules file in addition to the header
- API: Improvement: Make creation of objects easier when building documents by hand (C++20 will allow aggregate struct initialization so maybe that's all that is needed...)
Licensed under the MIT License http://opensource.org/licenses/MIT.
Copyright (c) 2018 Jesse Yurkovich
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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 AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
This software would not be possible without the help of these great resources. Thanks a lot!
- nlohmann::json for JSON serialization
- Catch2 for testing
- glTF-Sample-Models for glTF sample models. All 1.2gb of it...