herd / files / src / entities / Dog.ts
Dog.ts
| 1 | import { Vec2 } from '../math/Vec2.ts' |
| 2 | |
| 3 | const ARRIVAL_THRESHOLD_SQ = 10 * 10 |
| 4 | |
| 5 | export class Dog { |
| 6 | pos: Vec2 |
| 7 | vel: Vec2 = Vec2.ZERO |
| 8 | target: Vec2 | null = null |
| 9 | speed: number |
| 10 | private facing: number = -Math.PI / 2 |
| 11 | |
| 12 | constructor(x: number, y: number, speed = 160) { |
| 13 | this.pos = new Vec2(x, y) |
| 14 | this.speed = speed |
| 15 | } |
| 16 | |
| 17 | setTarget(worldX: number, worldY: number) { |
| 18 | this.target = new Vec2(worldX, worldY) |
| 19 | } |
| 20 | |
| 21 | update(dt: number) { |
| 22 | if (!this.target) return |
| 23 | const diff = this.target.sub(this.pos) |
| 24 | if (diff.lengthSq() < ARRIVAL_THRESHOLD_SQ) { |
| 25 | this.target = null |
| 26 | this.vel = Vec2.ZERO |
| 27 | return |
| 28 | } |
| 29 | this.vel = diff.normalize().scale(this.speed) |
| 30 | this.facing = Math.atan2(this.vel.y, this.vel.x) |
| 31 | this.pos = this.pos.add(this.vel.scale(dt)) |
| 32 | } |
| 33 | |
| 34 | draw(ctx: CanvasRenderingContext2D, scale = 1) { |
| 35 | const { x, y } = this.pos |
| 36 | const facing = this.facing |
| 37 | |
| 38 | ctx.save() |
| 39 | ctx.translate(x, y) |
| 40 | ctx.rotate(facing) |
| 41 | ctx.scale(scale, scale) |
| 42 | |
| 43 | // tail — curves up from rear, drawn behind body |
| 44 | ctx.strokeStyle = '#111' |
| 45 | ctx.lineWidth = 3 |
| 46 | ctx.lineCap = 'round' |
| 47 | ctx.beginPath() |
| 48 | ctx.moveTo(-10, 0) |
| 49 | ctx.quadraticCurveTo(-16, -5, -12, -13) |
| 50 | ctx.stroke() |
| 51 | |
| 52 | // body — elongated black ellipse, border-collie proportions |
| 53 | ctx.fillStyle = '#111' |
| 54 | ctx.beginPath() |
| 55 | ctx.ellipse(0, 0, 11, 7, 0, 0, Math.PI * 2) |
| 56 | ctx.fill() |
| 57 | |
| 58 | // white chest/belly saddle |
| 59 | ctx.fillStyle = '#eee8d8' |
| 60 | ctx.beginPath() |
| 61 | ctx.ellipse(-1, 0, 5.5, 4.5, 0, 0, Math.PI * 2) |
| 62 | ctx.fill() |
| 63 | |
| 64 | // head at front (+x in local space) |
| 65 | ctx.fillStyle = '#111' |
| 66 | ctx.beginPath() |
| 67 | ctx.arc(13, 0, 5.5, 0, Math.PI * 2) |
| 68 | ctx.fill() |
| 69 | |
| 70 | // white blaze down centre of face |
| 71 | ctx.fillStyle = '#eee8d8' |
| 72 | ctx.beginPath() |
| 73 | ctx.ellipse(14.5, 0, 2, 3.5, 0, 0, Math.PI * 2) |
| 74 | ctx.fill() |
| 75 | |
| 76 | // floppy ears — drop slightly behind/below head centre |
| 77 | ctx.fillStyle = '#111' |
| 78 | for (const side of [-1, 1]) { |
| 79 | ctx.beginPath() |
| 80 | ctx.ellipse(10, side * 6, 3, 4.5, Math.PI * 0.25 * side, 0, Math.PI * 2) |
| 81 | ctx.fill() |
| 82 | } |
| 83 | |
| 84 | // amber eyes |
| 85 | ctx.fillStyle = '#c8860a' |
| 86 | for (const side of [-1, 1]) { |
| 87 | ctx.beginPath() |
| 88 | ctx.arc(15, side * 2.2, 1.6, 0, Math.PI * 2) |
| 89 | ctx.fill() |
| 90 | } |
| 91 | |
| 92 | // pupils |
| 93 | ctx.fillStyle = '#111' |
| 94 | for (const side of [-1, 1]) { |
| 95 | ctx.beginPath() |
| 96 | ctx.arc(15.4, side * 2.2, 0.7, 0, Math.PI * 2) |
| 97 | ctx.fill() |
| 98 | } |
| 99 | |
| 100 | // nose |
| 101 | ctx.fillStyle = '#111' |
| 102 | ctx.beginPath() |
| 103 | ctx.ellipse(18.5, 0, 1.8, 1.3, 0, 0, Math.PI * 2) |
| 104 | ctx.fill() |
| 105 | |
| 106 | ctx.restore() |
| 107 | |
| 108 | // target indicator — world space (not scaled, always thin) |
| 109 | if (this.target) { |
| 110 | ctx.strokeStyle = 'rgba(255,255,255,0.25)' |
| 111 | ctx.lineWidth = 1 |
| 112 | ctx.setLineDash([4, 4]) |
| 113 | ctx.beginPath() |
| 114 | ctx.moveTo(x, y) |
| 115 | ctx.lineTo(this.target.x, this.target.y) |
| 116 | ctx.stroke() |
| 117 | ctx.setLineDash([]) |
| 118 | |
| 119 | ctx.strokeStyle = 'rgba(255,255,255,0.5)' |
| 120 | ctx.lineWidth = 1.5 |
| 121 | ctx.beginPath() |
| 122 | ctx.arc(this.target.x, this.target.y, 5 * scale, 0, Math.PI * 2) |
| 123 | ctx.stroke() |
| 124 | } |
| 125 | } |
| 126 | } |