gistfile1.c

static void test(void)
{
	GLenum glerr;
	bool has_error = false;
	GLuint tex[2];
	PFNGLXCOPYIMAGESUBDATANVPROC p_glXCopyImageSubDataNV;

	#define check() \
		while ((glerr = glGetError()) != GL_NO_ERROR) { \
			has_error = true; \
			blog(LOG_ERROR, "GL error: %x", glerr); \
		} \
		if (has_error) { \
			return; \
		}

	glGenTextures(2, tex);
	check()
	glBindTexture(GL_TEXTURE_2D, tex[0]);
	check()
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1920, 1080, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
	check()
	glBindTexture(GL_TEXTURE_2D, tex[1]);
	check()
	glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 1920, 1080, 0, GL_RGBA, GL_UNSIGNED_INT_8_8_8_8_REV, NULL);
	check()

	p_glXCopyImageSubDataNV = (PFNGLXCOPYIMAGESUBDATANVPROC)glXGetProcAddress((const GLubyte*)"glXCopyImageSubDataNV");
	p_glXCopyImageSubDataNV(
		glXGetCurrentDisplay(),
		NULL, tex[0], GL_TEXTURE_2D, 0, 0, 0, 0,
		NULL, tex[1], GL_TEXTURE_2D, 0, 0, 0, 0,
		1920, 1080, 1
	);
	check()
}