mirror of
https://github.com/Open-Cascade-SAS/OCCT.git
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565baee64b
Handled __EMSCRIPTEN__ macros to:
- Workaround atomics (__GCC_HAVE_SYNC_COMPARE_AND_SWAP_4 is undefined, but GCC atomics are provided).
- Suppress non-standard header <sys/signal.h> warning.
- Return OSD_LinuxREDHAT.
- Avoid inclusion of XLib headers.
- Skip fontconfig library.
- Enable EGL+GLES path (translated by Emscripten into WebGL).
- Skip eglCreatePbufferSurface() not implemented by Emscripten EGL.
Fixed Graphic3d_Vec4.hxx usage within Quantity_ColorRGBA.hxx.
OpenGl_ShaderManager::defaultGlslVersion() now prefers GLSL 300 es when WebGL 2.0 is available,
as there no any OpenGL ES greater than 3.0 emulation so far.
Shaders_Declarations.glsl - added workaround for GLSL compilation on WebGL 1.0
by defining Light properties accessors as macros instead of functions
('[]' : Index expression must be constant).
OpenGl_FrameBuffer::Init() - added workaround for initialization of GL_DEPTH24_STENCIL8
depth-stencil attachment on WebGL 1.0 + GL_WEBGL_depth_texture extension.
OpenGl_Context::Vec4FromQuantityColor() now considers myIsSRgbActive flag
to handle use case, when Immediate Layer is drawn directly into window buffer,
which is not sRGB-ready.
Added new sample - OCCT WebGL viewer.
29 lines
1.6 KiB
Markdown
29 lines
1.6 KiB
Markdown
OCCT WebGL Viewer sample {#occt_samples_webgl}
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==================
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This sample demonstrates simple way of using OCCT libraries in Web application written in C++ and translated into WebAssembly module using Emscripten SDK (emsdk):
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https://emscripten.org/
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Sample consists of the Open CASCADE 3D Viewer with a button for opening a model in BREP format.
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The sample requires a WebGL 2.0 capable browser supporting WebAssembly 1.0 (Wasm).
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Installation and configuration:
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1. Install Emscripten SDK and activate minimal configuration (Python, Java and CLang) following *emsdk* documentation. Activate also MinGW when building sample on Windows host.
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2. Build (using *emsdk*) or download FreeType static library.
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3. Configure CMake for building Open CASCADE Technology (OCCT) static libraries (BUILD_LIBRARY_TYPE="Static").
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For this, activate *emsdk* command prompt, configure CMake for building OCCT using cross-compilation toolchain, disable *BUILD_MODULE_Draw*.
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4. Perform building and installation steps.
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~~~~~
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> ${EMSDK}/fastcomp/emscripten/cmake/Modules/Platform/Emscripten.cmake
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~~~~~
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5. Configure CMake for building this WebGL sample using *emsdk* with paths to OCCT and FreeType. Perform building and installation steps.
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6. Copy data/occ/Ball.brep from OCCT into "samples" folder within WebGL sample installation path.
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7. Navigate to installation folder and start web server from it; Python coming with *emsdk* can be used for this purpose:
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~~~~~
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> python -m SimpleHTTPServer 8080
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~~~~~
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8. Open compatible browser and enter path taking into account your web server settings:
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~~~~~
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> http://localhost:8080/occt-webgl-sample.html
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~~~~~
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