GL_EXT_clear_texture https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_clear_texture.txt GL_EXT_clear_texture void glClearTexImageEXT (GLuint texture, GLint level, GLenum format, GLenum type, const void *data) void glClearTexSubImageEXT (GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const void *data)