# ANGLE GLES 1.0 Headers The GLES 1.0 headers ANGLE uses are generated using the Khronos tools but modified to include function pointer types and function prototype guards. ### Regenerating gl.h 1. Install **Python 3** (not 2) with the **lxml** addon. You can do this using `pip install lxml` from your Python's Scripts folder. 1. Clone [https://github.com/KhronosGroup/OpenGL-Registry.git](https://github.com/KhronosGroup/OpenGL-Registry.git). 1. Edit `OpenGL-Registry/xml/genheaders.py`: 1. Look for the section titled `# GLES 1.x API + mandatory extensions - GLES/gl.h (no function pointers)` 1. Change `prefixText = prefixStrings + gles1PlatformStrings + genDateCommentString,` to `prefixText = prefixStrings + gles1PlatformStrings + apiEntryPrefixStrings + genDateCommentString,` 1. Change `genFuncPointers = False,` to `genFuncPointers = True,` 1. Change `protectProto = False,` to `protectProto = 'nonzero',` 1. Change `protectProtoStr = 'GL_GLEXT_PROTOTYPES',` to `protectProtoStr = 'GL_GLES_PROTOTYPES',` 1. Set your working directory to `OpenGL-Registry/xml/`. 1. Run `python genheaders.py ../api/GLES/gl.h` 1. The generated header will now be in `OpenGL-Registry/api/GLES/gl.h`. You can copy the header over to this folder. 1. Also update `scripts/gl.xml` with the latest version from `OpenGL-Registry/xml/`.