Vector

A vector in Zig is a special kind of array compatible with SIMD instructions of modern CPUs. It has a higher memory alignment requirement. For example, @Vector(4, f32) aligns to 16-byte boundary (128-bit), whereas [4]f32 only aligns to 4byte.

pub const Vector = @Vector(3, f32);

pub fn dot(v1: Vector, v2: Vector) f32 {
    return @reduce(.Add, v1 * v2);
}

pub fn cross(v1: Vector, v2: Vector) Vector {
    const p1 = @shuffle(f32, v1, undefined, @Vector(3, i32){ 1, 2, 0 }) * @shuffle(f32, v2, undefined, @Vector(3, i32){ 2, 0, 1 });
    const p2 = @shuffle(f32, v1, undefined, @Vector(3, i32){ 2, 0, 1 }) * @shuffle(f32, v2, undefined, @Vector(3, i32){ 1, 2, 0 });
    return p1 - p2;
}

import { Vector, cross, dot } from './vector-example-1.zig';

const v1 = new Vector([ 0.5, 1, 0 ]);
const v2 = new Vector([ 3, -4, 9 ]);

const p1 = dot(v1, v2);
console.log(`dot product = ${p1}`);
const p2 = cross(v1, v2);
console.log(`cross product = [ ${[ ...p2 ]} ]`);

dot product = -2.5
cross product = [ 9,-4.5,-5 ]

Zigar does not use proxy to implement the bracket operator for vectors. Each element has its own getter/setter so access is fast. Vector objects do not have get() and set().

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Array