Pruning collision detection with a 1D sort

Recently I was trying out Phaser.io. It’s a nifty little HTML5/JS game development framework for 2D games with graphics, audio, physics, etc. It’s free, and MIT licensed. Anyway, I ran into a limitation in its physics optimization. You can collide object-to-object, or entire groups of objects to other groups. Colliding entire groups at a time …