// Compile with:
// c++ layered_renderbuffer.cc $(pkg-config --cflags --libs sdl2 gl)
#define GL_GLEXT_PROTOTYPES 1
#include <GL/gl.h>
#include <SDL.h>
#include <cassert>

int main()
{
	if (SDL_Init(SDL_INIT_VIDEO) < 0)
		assert(false);

	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MAJOR_VERSION, 3);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_MINOR_VERSION, 3);
	SDL_GL_SetAttribute(SDL_GL_CONTEXT_PROFILE_MASK,
		SDL_GL_CONTEXT_PROFILE_CORE);

	SDL_Window * const window = SDL_CreateWindow(
		"", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
		640, 480, SDL_WINDOW_OPENGL);
	assert(window);

	const SDL_GLContext context = SDL_GL_CreateContext(window);
	assert(context);

	GLuint framebuffer;
	glGenFramebuffers(1, &framebuffer);
	glBindFramebuffer(GL_DRAW_FRAMEBUFFER, framebuffer);

	GLuint texture;
	glGenTextures(1, &texture);
	glBindTexture(GL_TEXTURE_2D_ARRAY, texture);
	glTexStorage3D(GL_TEXTURE_2D_ARRAY, 1, GL_RGBA8, 640, 480, 2);
	
	GLuint renderbuffers[2];
	glGenRenderbuffers(2, &renderbuffers[0]);
	glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[0]);
	glRenderbufferStorage(GL_RENDERBUFFER, GL_RGBA8, 640, 480);
	glBindRenderbuffer(GL_RENDERBUFFER, renderbuffers[1]);
	glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, 640, 480);
	
	// This makes GL_COLOR_ATTACHMENT0 layered.
	glFramebufferTexture(GL_DRAW_FRAMEBUFFER,
		GL_COLOR_ATTACHMENT0, texture, 0);

	// Replace the binding on GL_COLOR_ATTACHMENT0. Renderbuffers don't
	// have layred state, but currently the layered state is preserved
	// from the previously bound texture and this is used for framebuffer
	// completeness tests.
	glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER,
		GL_COLOR_ATTACHMENT0, GL_RENDERBUFFER, renderbuffers[0]);
	// This is not layered, so it conflicts with the incorrectly layered
	// GL_COLOR_ATTACHMENT0.
	glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER,
		GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, renderbuffers[1]);

	// The draw framebuffer should be framebuffer complete now.
	const GLenum status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
	assert(glGetError() == GL_NO_ERROR);
	glClear(GL_COLOR_BUFFER_BIT);
	const GLenum error = glGetError();
	assert(status == GL_FRAMEBUFFER_COMPLETE);
	assert(glGetError() == GL_NO_ERROR);
}