# Summary

Drawing:

- Specify points with `pt(x,y)`
- Specify rectangles with `rect(x,y,width,height)`
- Draw using `draw_line, draw_rect, fill_rect` etc.
- Change drawing colour, e.g. `set_colour(g, GREEN);`
- You need a `Graphics` object to draw

Windows:

- Create windows with `new_window`
- You need an `App` object, e.g. `App *app = new_app(argc, argv);`
- E.g. `new_window(app, rect(0,0,400,300), "Name", STANDARD_WINDOW);`
- Add a redraw call-back using `on_window_redraw(w, fn);`
- Redraw call-backs for windows are defined `void fn(Window *w, Graphics *g);`
- Show the window on screen with `show_window(w);`
- Handle events by calling `main_loop(app);`