scunliffe / game-dev-geometry-math

A Collection of Game Dev Geometry based snippets

game-dev-geometry-math

A Collection of Game Dev Geometry based snippets

Why?

When I started building games in Unity (C#) I found myself needing many functions to calculate common geometry functions. I was hoping such a repo existed somewhere, and I could just use it, but I didn't find one. So I wanted to collect the best, optimized examples from the Internet/experts... and organize them for fellow developers that might want to use them.

Although my focus here is in C#, for Unity development, if this is of any value to others, I will add C++, Java/Kotlin, Python examples as well.

Key Desired Methods

2D

1. Determine which side of a line (2D) a point is on
2. Determine if a point is inside a (2D) shape (rectangle, triangle, circle, polygon)
3. Determine the centroid of a (2D) shape (rectangle, triangle, circle, polygon)
4. Determine the normal for a line
5. Determine the angle between 2 lines
6. Determine if 2 lines intersect, and if so where

3D

1. Determine if a point is within a (3D) shape (rectangular prism/cuboid, sphere, cone, cylinder, pyramid)
2. Determine which side of (3D) plane a point is on
3. Determine the midpoint of a line
4. Determine if a point is on a line (with a fuzz factor)
5. Determine the normal for a plane
6. Determine if 2 lines intersect, and if so where
7. Determine where a line intersects a plane

Yo! This is awesome, but what gives? camelCase method names, OTB brace style, and tabs for indentation?... this isn't the C# way! Yup, this was intentional. I come from a Java/JavaScript world where methods start lowercase and its just so much easier for me to work with... and well the brace/indentaion styling are just my preferences.