// Execute one phase, ie. set up all inputs, effects and outputs, and render the quad.
void execute_phase(Phase *phase, bool last_phase,
// Execute one phase, ie. set up all inputs, effects and outputs, and render the quad.
void execute_phase(Phase *phase, bool last_phase,
std::map<Phase *, GLuint> *output_textures,
std::set<Phase *> *generated_mipmaps);
std::map<Phase *, GLuint> *output_textures,
std::set<Phase *> *generated_mipmaps);