VMath - 2d and 3d vector math.

nimble install vmath

API reference

This library has no dependencies other than the Nim standard library.

About

Your one stop shop for vector math routines for 2d and 3d graphics.

Pure Nim with no dependencies.
Very similar to GLSL Shader Language with extra stuff.
Extensively benchmarked.

Has vector functions for GLSL types:

Type	Constructor	Description
BVec#	bvec#	a vector of booleans
IVec#	ivec#	a vector of signed integers
UVec#	uvec#	a vector of unsigned integers
Vec#	vec#	a vector of single-precision floating-point numbers
DVec#	dvec#	a vector of double-precision floating-point numbers

You can use these constructors to make them:

NIM	GLSL	2	3	4	9	16	4
bool	bool	BVec2	BVec3	BVec4
int32	int	IVec2	IVec3	IVec4
uint32	uint	UVec2	UVec3	UVec4
float32	float	Vec2	Vec3	Vec4	Mat3	Mat4	Quat
float64	double	DVec2	DVec3	DVec4	DMat3	DMat4	DQuat

2D & 3D matrix math

You can combine and create 2d and 3d matrices by passing 2d or 3d vectors to matrix functions:

let mat2d = translate(vec2(10, 20)) * rotate(45.toRadians) * scale(vec2(2))
let mat3d = translate(vec3(10, 20, 0)) * rotateZ(45.toRadians) * scale(vec3(2))

Almost equal operator

Easily check if floating point numbers are close, very useful for tests:

1.0 ~= 1.0
vec2(1.0, 2.0) ~= vec2(1.0, 2.0)
dvec2(1) ~= dvec2(1)
quat(1.0, 2.0, 3.0, 4.0) ~= quat(1.0, 2.0, 3.0, 4.0)

Number functions

between - Returns true if value is between min and max or equal to them.
sign - Returns the sign of a number, -1 or 1.
quantize - Makes v be a multiple of n. Rounding to integer quantize by 1.0.
fractional - Returns fractional part of a number. 3.14 -> 0.14
lerp - Interpolates value between a and b.

Angle functions

fixAngle - Make angle be from -PI to PI radians.
angleBetween - Find the angle between angle a and angle b.
turnAngle - Move from angle a to angle b with step of v.

Vector and matrix representation and benchmarks.

C compilers seem to optimize different representations differently. This is very surprising for us and vmath has 3 different implementations:

-d:vmathObjBased - A vector is an object of 3 floats.
-d:vmathArrayBased - A vector is an array of 3 floats.
-d:vmathObjArrayBased (default) - A vector is an object that has an array of 3 floats.

name ............................... min time      avg time    std dv   runs
vmathObjBased ..................... 74.061 ms     74.297 ms    ±0.347   x100
vmathArrayBased ................... 89.498 ms     89.911 ms    ±1.019   x100
vmathObjArrayBased ................ 73.968 ms     74.292 ms    ±0.631   x100

0.x.x to 1.0.0 vmath breaking changes:

vec3(v) no longer works please use vec3(v.x, v.y, 0) instead.
vec3(v, 0) no longer works please use vec3(v.x, v.y, 0) instead.
2 * v no longer works due to more vec types please use v * 2 instead.
m[15] no longer works because matrices are now m[x, y].
Concept of 3x3 rotation 3d matrix was removed.
angleBetween got renamed to angle(a, b)
scaleMat got renamed to scale(v)
rotationMat3 got renamed to rotate(x)

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