Cairo, GL, SDL together

crsl.cpp

#include <iostream>
#include <cairo/cairo.h>
#include <cairo/cairo-gl.h>
#include <SDL2/SDL.h>
#include <SDL2/SDL_syswm.h>

int main(int argc, char* argv[]) {
	SDL_Init(SDL_INIT_VIDEO);
	auto win = SDL_CreateWindow("crsl", 300, 300, 512, 512, SDL_WINDOW_OPENGL);
	SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
	/*SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK,
			SDL_GL_CONTEXT_PROFILE_CORE);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 2);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 1);
	SDL_GL_SetAttribute(SDL_GL_SHARE_WITH_CURRENT_CONTEXT, 1);*/
	SDL_GL_SetSwapInterval(1);
	auto glcx = SDL_GL_CreateContext(win);

	SDL_SysWMinfo wmifo;
	SDL_GetWindowWMInfo(win, &wmifo);
	auto cd = cairo_glx_device_create(wmifo.info.x11.display,
			(GLXContext)glcx);
	if(!cd) {
		std::cout << "failed to get GLX device" << std::endl;
		return 0;
	}
	auto gl_surf = cairo_gl_surface_create_for_window(cd, wmifo.info.x11.window, 512, 512);
	if(!gl_surf) {
		std::cout << "failed to get GL surface" << std::endl;
		return 0;
	}

	auto cx = cairo_create(gl_surf);

	float t = 0.;
	while(true) {
		cairo_set_source_rgb(cx, 1.0, t, 0.5);
		cairo_fill(cx);
		SDL_GL_SwapWindow(win);
		t += 0.01;
	}

	SDL_GL_DeleteContext(glcx);
	SDL_DestroyWindow(win);
	SDL_Quit();

	return 0;
}