Render Loop

The render loop is the process by which a UI library continuously copies the Canvas buffer onto the screen surface.

#Two phases

• Logic update: process input, advance state.
• Draw: call primitives like canvas_set_pixel to refresh the buffer, then blit to the window.

A real app's window is kept visible by the OS compositor; we only need to repaint the content each frame.

#How it relates to us

The Canvas we wrote is "what to draw"; the window backend is responsible for pasting it onto the screen surface.