gl_helpers.py

from OpenGL.EGL.VERSION.EGL_1_0 import EGLNativeDisplayType, eglGetProcAddress, eglQueryString, EGL_EXTENSIONS

from OpenGL.raw.GLES2 import _types as _cs
from OpenGL.GLES2.VERSION.GLES2_2_0 import *
from OpenGL.GLES3.VERSION.GLES3_3_0 import *
from OpenGL import GL as gl

from ctypes import c_int, c_char_p, c_void_p, cdll, POINTER, util, \
	pointer, CFUNCTYPE, c_bool

def getEGLNativeDisplay():
	_x11lib = cdll.LoadLibrary(util.find_library("X11"))
	XOpenDisplay = _x11lib.XOpenDisplay
	XOpenDisplay.argtypes = [c_char_p]
	XOpenDisplay.restype = POINTER(EGLNativeDisplayType)

	xdpy = XOpenDisplay(None)

# Hack. PyOpenGL doesn't seem to manage to find glEGLImageTargetTexture2DOES.
def getglEGLImageTargetTexture2DOES():
	funcptr = eglGetProcAddress("glEGLImageTargetTexture2DOES")
	prototype = CFUNCTYPE(None,_cs.GLenum,_cs.GLeglImageOES)
	return prototype(funcptr)

glEGLImageTargetTexture2DOES = getglEGLImageTargetTexture2DOES()


def str_to_fourcc(str):
	assert(len(str) == 4)
	fourcc = 0
	for i,v in enumerate([ord(c) for c in str]):
		fourcc |= v << (i * 8)
	return fourcc

def get_gl_extensions():
	n = GLint()
	glGetIntegerv(GL_NUM_EXTENSIONS, n)
	gl_extensions = []
	for i in range(n.value):
		gl_extensions.append(gl.glGetStringi(GL_EXTENSIONS, i).decode())
	return gl_extensions

def check_gl_extensions(required_extensions):
	extensions = get_gl_extensions()

	if False:
		print("GL EXTENSIONS: ", " ".join(extensions))

	for ext in required_extensions:
		if not ext in extensions:
			raise Exception(ext + " missing")

def get_egl_extensions(egl_display):
	return eglQueryString(egl_display, EGL_EXTENSIONS).decode().split(" ")

def check_egl_extensions(egl_display, required_extensions):
	extensions = get_egl_extensions(egl_display)

	if False:
		print("EGL EXTENSIONS: ", " ".join(extensions))

	for ext in required_extensions:
		if not ext in extensions:
			raise Exception(ext + " missing")