1GL_ARB_get_texture_sub_image 2https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_get_texture_sub_image.txt 3GL_ARB_get_texture_sub_image 4 5 void glGetCompressedTextureSubImage (GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLsizei bufSize, void *pixels) 6 void glGetTextureSubImage (GLuint texture, GLint level, GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, GLsizei bufSize, void *pixels) 7