jastice / boxes-and-bubbles

A simple-as-possible 2D physics rigid-body physics engine for Elm.

Hello, I'm Justin Kaeser

I work at JetBrains in various capacities. I coordinate development for Bazel support in IntelliJ IDEA through bazel-bsp and the Bazel plugin for IntelliJ, and I was a member of the Scala plugin for IntelliJ IDEA team 2016-2022, focusing on build tool integration, specifically sbt and developing the Build Server Protocol.

Projects I'm currently involved in

• Build Server Protocol - protocol enabling integration of build tools with IDEs
• bazel-bsp - implementation of the build server protocol for Bazel

Some projects I've started or contributed to in the past

• Scala plugin for IntelliJ IDEA - The most popular IDE for Scala.
• Askhole - Android App version of the Askhole card game
• Scredis - Akka-based Redis client for Scala
• Gringotts - Minecraft Bukkit server plugin, supporting an item-based economy
• Boxes and Bubbles - a really simple 2D physics engine in Elm

boxes-and-bubbles's Issues

how about benchmark or performance?

Bounds function incorrect placement

I may not understand what it's supposed to do, or maybe it's a bug, but I can't seem to get them to position correctly. If I change the math a little bit from this:

box (w,thickness) inf restitution (cx, hExt+halfThick) (0,0) meta,
box (w,thickness) inf restitution (cx, -(hExt+halfThick)) (0,0) meta,
box (thickness,h) inf restitution (wExt+halfThick, cy) (0,0) meta,
box (thickness,h) inf restitution (-(wExt+halfThick), cy) (0,0) meta

To this:

box (w,thickness) inf restitution (cx, cy + (hExt+halfThick)) (0,0) meta,
box (w,thickness) inf restitution (cx, cy - (hExt+halfThick)) (0,0) meta,
box (thickness,h) inf restitution (cx + (wExt+halfThick), cy) (0,0) meta,
box (thickness,h) inf restitution (cx - (wExt+halfThick), cy) (0,0) meta

Then it behaves exactly as I expect.

https://github.com/jastice/boxes-and-bubbles/blob/master/src/BoxesAndBubbles.elm#L109-L112