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Elisée Maurer elisee

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@vurtun
vurtun / _GJK.md
Last active July 17, 2024 17:42
3D Gilbert–Johnson–Keerthi (GJK) distance algorithm

Gilbert–Johnson–Keerthi (GJK) 3D distance algorithm

The Gilbert–Johnson–Keerthi (GJK) distance algorithm is a method of determining the minimum distance between two convex sets. The algorithm's stability, speed which operates in near-constant time, and small storage footprint make it popular for realtime collision detection.

Unlike many other distance algorithms, it has no requirments on geometry data to be stored in any specific format, but instead relies solely on a support function to iteratively generate closer simplices to the correct answer using the Minkowski sum (CSO) of two convex shapes.

@rygorous
rygorous / gist:e0f055bfb74e3d5f0af20690759de5a7
Created May 8, 2016 06:54
A bit of background on compilers exploiting signed overflow
Why do compilers even bother with exploiting undefinedness signed overflow? And what are those
mysterious cases where it helps?
A lot of people (myself included) are against transforms that aggressively exploit undefined behavior, but
I think it's useful to know what compiler writers are accomplishing by this.
TL;DR: C doesn't work very well if int!=register width, but (for backwards compat) int is 32-bit on all
major 64-bit targets, and this causes quite hairy problems for code generation and optimization in some
fairly common cases. The signed overflow UB exploitation is an attempt to work around this.
@flibitijibibo
flibitijibibo / FNAWindowExample.cs
Last active April 30, 2022 15:21
Example to hook up an SDL2 window to a Panel for use in a System.Windows.Forms window
#region License
/* FNA GameWindow for System.Windows.Forms Example
* Written by Ethan "flibitijibibo" Lee
* http://www.flibitijibibo.com/
*
* Released under public domain.
* No warranty implied; use at your own risk.
*/
#endregion