void screen_color(struct color background)

Change the screen background color.

void shake_screen(float stopwatch)

Shake the virtual camera (e.g. for explosions and hits). The screen will keep shaking as long as you call shake_screen(). To return the screen to its normal state, you should complement with calling relax_screen().

void relax_screen(float stopwatch)

Undo the screen shake effect.

void draw_on_screen(void)

Switch back to draw on the actual screen following a call to draw_on_image() on an image.

void set_screen_size(int width, int height)

Change the screen size.

void get_screen_size(int *width, int *height)

Get the screen size.

void set_window_size(int width, int height)

Change the real window size.

void get_window_size(int *width, int *height)

Get the real window size.