HTML5 Canvas, 2nd Edition

Game Object Physics and Animation

All of our game objects will move on a two-dimensional plane. We will use basic directional movement vectors to calculate the change in the x and y coordinates for each game object. At its very basic level, we will be updating the delta x (dx) and delta y (dy) of each of our game objects on each frame to simulate movement. These dx and dy values will be based on the angle and direction in which we want the object to move. All of our logical display objects will add their respective dx and dy values to their x and y values on each frame of animation. The player ship will not use strict dx and dy because it needs to be able to float and turn independently. Let’s take a closer look at the player movement now.