gm #

WGSL-style math library for Dart. Vectors, matrices, quaternions, and all the WGSL built-in functions.

Usage #

import 'package:gm/gm.dart';

// Vectors
const a = vec3(1, 2, 3);
const b = vec3(4, 5, 6);
final c = a + b;           // vec3(5, 7, 9)
final d = dot(a, b);       // 32.0
final n = normalize(a);    // unit length
final r = cross(a, b);     // perpendicular

// Scalar multiply/divide
final scaled = a * 2.0;    // vec3(2, 4, 6)

// Matrices
final view = mat4x4.lookAt(
  eye: vec3(0, 5, 10),
  target: vec3.zero,
  up: vec3(0, 1, 0),
);
final proj = mat4x4.perspective(
  fovY: radians(60.0),
  aspect: 16 / 9,
  near: 0.1,
  far: 100,
);
final mvp = proj * view;

// Quaternions
final q = quat.fromRotationY(radians(90.0));
final rotated = q.rotate(vec3(1, 0, 0)); // vec3(0, 0, -1)

// WGSL functions work on scalars and vectors
final x = mix(0.0, 10.0, 0.5);           // 5.0
final v = mix(vec3.zero, a, 0.5);        // vec3(0.5, 1.0, 1.5)
final s = smoothstep(0.0, 1.0, 0.5);     // 0.5
final clamped = clamp(vec3(-1, 2, 0.5), vec3.zero, vec3(1, 1, 1));

What's in the box #

Vectors — vec2, vec3, vec4 (float), vec2i/3i/4i (int), vec2u/3u/4u (uint), vec2b/3b/4b (bool). Indexing, swizzling (v.xy, v.zyx, v.rgb), component replacement (v.withX(5)).

Matrices — all 9 WGSL types (mat2x2 through mat4x4, including non-square), column-major.

Quaternions — quat with slerp, axis-angle, euler, and matrix conversion.

Scalars — f32, i32, u32 extension types.

WGSL built-in functions — dot, cross, normalize, length, mix, clamp, smoothstep, reflect, sin, cos, pow, sqrt, abs, sign, floor, ceil, step, select, and more.

Benchmark #

Compared against vector_math on Dart 3.11.1, Apple M4 Pro.

JIT (dart run) #

AOT (dart compile exe) #

gm wins 7 out of 8 in both modes. AOT benefits more from inline pragmas. vector_math wins batch update where its in-place addScaled avoids allocations.

GC pressure #

Measured with dart --verbose-gc, main isolate only.

gm uses immutable values (plain final double fields, no Float32List backing) with inline pragmas that let the Dart VM scalar-replace intermediates. Batch update and camera setup still allocate, the rest produce zero GC.

dart benchmark/vs_vector_math.dart