drawWithAlpha

bundle.js

@@ -5,10 +5,262 @@
 const Constants = {
     TWO_PI: Math.PI * 2
 };
-const init = (opt)=>{
-    window['doodler'] = new Doodler(opt);
-    window['doodler'].init();
-};
+class Vector {
+    x;
+    y;
+    z;
+    constructor(x = 0, y = 0, z = 0){
+        this.x = x;
+        this.y = y;
+        this.z = z;
+    }
+    set(v, y, z) {
+        if (arguments.length === 1 && typeof v !== "number") {
+            this.set(v.x || v[0] || 0, v.y || v[1] || 0, v.z || v[2] || 0);
+        } else {
+            this.x = v;
+            this.y = y || 0;
+            this.z = z || 0;
+        }
+    }
+    get() {
+        return new Vector(this.x, this.y, this.z);
+    }
+    mag() {
+        const x = this.x, y = this.y, z = this.z;
+        return Math.sqrt(x * x + y * y + z * z);
+    }
+    magSq() {
+        const x = this.x, y = this.y, z = this.z;
+        return x * x + y * y + z * z;
+    }
+    setMag(v_or_len, len) {
+        if (len === undefined) {
+            len = v_or_len;
+            this.normalize();
+            this.mult(len);
+        } else {
+            const v = v_or_len;
+            v.normalize();
+            v.mult(len);
+            return v;
+        }
+    }
+    add(v, y, z) {
+        if (arguments.length === 1 && typeof v !== 'number') {
+            this.x += v.x;
+            this.y += v.y;
+            this.z += v.z;
+        } else if (arguments.length === 2) {
+            this.x += v;
+            this.y += y ?? 0;
+        } else {
+            this.x += v;
+            this.y += y ?? 0;
+            this.z += z ?? 0;
+        }
+        return this;
+    }
+    sub(v, y, z) {
+        if (arguments.length === 1 && typeof v !== 'number') {
+            this.x -= v.x;
+            this.y -= v.y;
+            this.z -= v.z;
+        } else if (arguments.length === 2) {
+            this.x -= v;
+            this.y -= y ?? 0;
+        } else {
+            this.x -= v;
+            this.y -= y ?? 0;
+            this.z -= z ?? 0;
+        }
+        return this;
+    }
+    mult(v) {
+        if (typeof v === 'number') {
+            this.x *= v;
+            this.y *= v;
+            this.z *= v;
+        } else {
+            this.x *= v.x;
+            this.y *= v.y;
+            this.z *= v.z;
+        }
+        return this;
+    }
+    div(v) {
+        if (typeof v === 'number') {
+            this.x /= v;
+            this.y /= v;
+            this.z /= v;
+        } else {
+            this.x /= v.x;
+            this.y /= v.y;
+            this.z /= v.z;
+        }
+        return this;
+    }
+    rotate(angle) {
+        const prev_x = this.x;
+        const c = Math.cos(angle);
+        const s = Math.sin(angle);
+        this.x = c * this.x - s * this.y;
+        this.y = s * prev_x + c * this.y;
+        return this;
+    }
+    dist(v) {
+        const dx = this.x - v.x, dy = this.y - v.y, dz = this.z - v.z;
+        return Math.sqrt(dx * dx + dy * dy + dz * dz);
+    }
+    dot(v, y, z) {
+        if (arguments.length === 1 && typeof v !== 'number') {
+            return this.x * v.x + this.y * v.y + this.z * v.z;
+        }
+        return this.x * v + this.y * y + this.z * z;
+    }
+    cross(v) {
+        const x = this.x, y = this.y, z = this.z;
+        return new Vector(y * v.z - v.y * z, z * v.x - v.z * x, x * v.y - v.x * y);
+    }
+    lerp(v_or_x, amt_or_y, z, amt) {
+        const lerp_val = (start, stop, amt)=>{
+            return start + (stop - start) * amt;
+        };
+        let x, y;
+        if (arguments.length === 2 && typeof v_or_x !== 'number') {
+            amt = amt_or_y;
+            x = v_or_x.x;
+            y = v_or_x.y;
+            z = v_or_x.z;
+        } else {
+            x = v_or_x;
+            y = amt_or_y;
+        }
+        this.x = lerp_val(this.x, x, amt);
+        this.y = lerp_val(this.y, y, amt);
+        this.z = lerp_val(this.z, z, amt);
+        return this;
+    }
+    normalize() {
+        const m = this.mag();
+        if (m > 0) {
+            this.div(m);
+        }
+        return this;
+    }
+    limit(high) {
+        if (this.mag() > high) {
+            this.normalize();
+            this.mult(high);
+        }
+        return this;
+    }
+    heading() {
+        return -Math.atan2(-this.y, this.x);
+    }
+    heading2D() {
+        return this.heading();
+    }
+    toString() {
+        return "[" + this.x + ", " + this.y + ", " + this.z + "]";
+    }
+    array() {
+        return [
+            this.x,
+            this.y,
+            this.z
+        ];
+    }
+    copy() {
+        return new Vector(this.x, this.y, this.z);
+    }
+    drawDot() {
+        if (!doodler) return;
+        doodler.dot(this, {
+            weight: 2,
+            color: 'red'
+        });
+    }
+    static fromAngle(angle, v) {
+        if (v === undefined || v === null) {
+            v = new Vector();
+        }
+        v.x = Math.cos(angle);
+        v.y = Math.sin(angle);
+        return v;
+    }
+    static random2D(v) {
+        return Vector.fromAngle(Math.random() * (Math.PI * 2), v);
+    }
+    static random3D(v) {
+        const angle = Math.random() * Constants.TWO_PI;
+        const vz = Math.random() * 2 - 1;
+        const mult = Math.sqrt(1 - vz * vz);
+        const vx = mult * Math.cos(angle);
+        const vy = mult * Math.sin(angle);
+        if (v === undefined || v === null) {
+            v = new Vector(vx, vy, vz);
+        } else {
+            v.set(vx, vy, vz);
+        }
+        return v;
+    }
+    static dist(v1, v2) {
+        return v1.dist(v2);
+    }
+    static dot(v1, v2) {
+        return v1.dot(v2);
+    }
+    static cross(v1, v2) {
+        return v1.cross(v2);
+    }
+    static add(v1, v2) {
+        return new Vector(v1.x + v2.x, v1.y + v2.y, v1.z + v2.z);
+    }
+    static sub(v1, v2) {
+        return new Vector(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z);
+    }
+    static angleBetween(v1, v2) {
+        return Math.acos(v1.dot(v2) / Math.sqrt(v1.magSq() * v2.magSq()));
+    }
+    static lerp(v1, v2, amt) {
+        const retval = new Vector(v1.x, v1.y, v1.z);
+        retval.lerp(v2, amt);
+        return retval;
+    }
+    static vectorProjection(v1, v2) {
+        v2 = v2.copy();
+        v2.normalize();
+        const sp = v1.dot(v2);
+        v2.mult(sp);
+        return v2;
+    }
+    static hypot2(a, b) {
+        return Vector.dot(Vector.sub(a, b), Vector.sub(a, b));
+    }
+}
+class OriginVector extends Vector {
+    origin;
+    get halfwayPoint() {
+        return {
+            x: this.mag() / 2 * Math.sin(this.heading()) + this.origin.x,
+            y: this.mag() / 2 * Math.cos(this.heading()) + this.origin.y
+        };
+    }
+    constructor(origin, p){
+        super(p.x, p.y, p.z);
+        this.origin = origin;
+    }
+    static from(origin, p) {
+        const v = {
+            x: p.x - origin.x,
+            y: p.y - origin.y
+        };
+        return new OriginVector(origin, v);
+    }
+}
+const easeInOut = (x)=>x < 0.5 ? 4 * x * x * x : 1 - Math.pow(-2 * x + 2, 3) / 2;
+const map = (value, x1, y1, x2, y2)=>(value - x1) * (y2 - x2) / (y1 - x1) + x2;
 class Doodler {
     ctx;
     _canvas;
@@ -21,6 +273,9 @@ class Doodler {
     get height() {
         return this.ctx.canvas.height;
     }
+    draggables = [];
+    clickables = [];
+    dragTarget;
     constructor({ width , height , canvas , bg , framerate  }){
         if (!canvas) {
             canvas = document.createElement('canvas');
@@ -32,11 +287,13 @@ class Doodler {
         canvas.height = height;
         this._canvas = canvas;
         const ctx = canvas.getContext('2d');
-        console.log(ctx);
         if (!ctx) throw 'Unable to initialize Doodler: Canvas context not found';
         this.ctx = ctx;
     }
     init() {
+        this._canvas.addEventListener('mousedown', (e)=>this.onClick(e));
+        this._canvas.addEventListener('mouseup', (e)=>this.offClick(e));
+        this._canvas.addEventListener('mousemove', (e)=>this.onDrag(e));
         this.startDrawLoop();
     }
     timer;
@@ -49,6 +306,7 @@ class Doodler {
         for (const [i, l] of (this.layers || []).entries()){
             l(this.ctx, i);
         }
+        this.drawUI();
     }
     createLayer(layer) {
         this.layers.push(layer);
@@ -132,259 +390,426 @@ class Doodler {
         this.ctx.bezierCurveTo(b.x, b.y, c.x, c.y, d.x, d.y);
         this.ctx.stroke();
     }
+    drawRotated(origin, angle, cb) {
+        this.ctx.save();
+        this.ctx.translate(origin.x, origin.y);
+        this.ctx.rotate(angle);
+        this.ctx.translate(-origin.x, -origin.y);
+        cb();
+        this.ctx.restore();
+    }
+    drawScaled(scale, cb) {
+        this.ctx.save();
+        this.ctx.transform(scale, 0, 0, scale, 0, 0);
+        cb();
+        this.ctx.restore();
+    }
+    drawImage(img, at, w, h) {
+        w && h ? this.ctx.drawImage(img, at.x, at.y, w, h) : this.ctx.drawImage(img, at.x, at.y);
+    }
+    drawSprite(img, spritePos, sWidth, sHeight, at, width, height) {
+        this.ctx.drawImage(img, spritePos.x, spritePos.y, sWidth, sHeight, at.x, at.y, width, height);
+    }
     setStyle(style) {
         const ctx = this.ctx;
         ctx.fillStyle = style?.color || style?.fillColor || 'black';
         ctx.strokeStyle = style?.color || style?.strokeColor || 'black';
         ctx.lineWidth = style?.weight || 1;
     }
-}
-class Vector {
-    x;
-    y;
-    z;
-    constructor(x = 0, y = 0, z = 0){
-        this.x = x;
-        this.y = y;
-        this.z = z;
-    }
-    set(v, y, z) {
-        if (arguments.length === 1 && typeof v !== "number") {
-            this.set(v.x || v[0] || 0, v.y || v[1] || 0, v.z || v[2] || 0);
-        } else {
-            this.x = v;
-            this.y = y || 0;
-            this.z = z || 0;
-        }
-    }
-    get() {
-        return new Vector(this.x, this.y, this.z);
-    }
-    mag() {
-        const x = this.x, y = this.y, z = this.z;
-        return Math.sqrt(x * x + y * y + z * z);
-    }
-    magSq() {
-        const x = this.x, y = this.y, z = this.z;
-        return x * x + y * y + z * z;
-    }
-    setMag(v_or_len, len) {
-        if (len === undefined) {
-            len = v_or_len;
-            this.normalize();
-            this.mult(len);
-        } else {
-            const v = v_or_len;
-            v.normalize();
-            v.mult(len);
-            return v;
-        }
-    }
-    add(v, y, z) {
-        if (arguments.length === 1 && typeof v !== 'number') {
-            this.x += v.x;
-            this.y += v.y;
-            this.z += v.z;
-        } else if (arguments.length === 2) {
-            this.x += v;
-            this.y += y ?? 0;
-        } else {
-            this.x += v;
-            this.y += y ?? 0;
-            this.z += z ?? 0;
-        }
-    }
-    sub(v, y, z) {
-        if (arguments.length === 1 && typeof v !== 'number') {
-            this.x -= v.x;
-            this.y -= v.y;
-            this.z -= v.z;
-        } else if (arguments.length === 2) {
-            this.x -= v;
-            this.y -= y ?? 0;
-        } else {
-            this.x -= v;
-            this.y -= y ?? 0;
-            this.z -= z ?? 0;
-        }
-    }
-    mult(v) {
-        if (typeof v === 'number') {
-            this.x *= v;
-            this.y *= v;
-            this.z *= v;
-        } else {
-            this.x *= v.x;
-            this.y *= v.y;
-            this.z *= v.z;
-        }
-        return this;
-    }
-    div(v) {
-        if (typeof v === 'number') {
-            this.x /= v;
-            this.y /= v;
-            this.z /= v;
-        } else {
-            this.x /= v.x;
-            this.y /= v.y;
-            this.z /= v.z;
-        }
-    }
-    rotate(angle) {
-        const prev_x = this.x;
-        const c = Math.cos(angle);
-        const s = Math.sin(angle);
-        this.x = c * this.x - s * this.y;
-        this.y = s * prev_x + c * this.y;
-    }
-    dist(v) {
-        const dx = this.x - v.x, dy = this.y - v.y, dz = this.z - v.z;
-        return Math.sqrt(dx * dx + dy * dy + dz * dz);
-    }
-    dot(v, y, z) {
-        if (arguments.length === 1 && typeof v !== 'number') {
-            return this.x * v.x + this.y * v.y + this.z * v.z;
-        }
-        return this.x * v + this.y * y + this.z * z;
-    }
-    cross(v) {
-        const x = this.x, y = this.y, z = this.z;
-        return new Vector(y * v.z - v.y * z, z * v.x - v.z * x, x * v.y - v.x * y);
-    }
-    lerp(v_or_x, amt_or_y, z, amt) {
-        const lerp_val = (start, stop, amt)=>{
-            return start + (stop - start) * amt;
-        };
-        let x, y;
-        if (arguments.length === 2 && typeof v_or_x !== 'number') {
-            amt = amt_or_y;
-            x = v_or_x.x;
-            y = v_or_x.y;
-            z = v_or_x.z;
-        } else {
-            x = v_or_x;
-            y = amt_or_y;
-        }
-        this.x = lerp_val(this.x, x, amt);
-        this.y = lerp_val(this.y, y, amt);
-        this.z = lerp_val(this.z, z, amt);
-    }
-    normalize() {
-        const m = this.mag();
-        if (m > 0) {
-            this.div(m);
-        }
-        return this;
-    }
-    limit(high) {
-        if (this.mag() > high) {
-            this.normalize();
-            this.mult(high);
-        }
-    }
-    heading() {
-        return -Math.atan2(-this.y, this.x);
-    }
-    heading2D() {
-        return this.heading();
-    }
-    toString() {
-        return "[" + this.x + ", " + this.y + ", " + this.z + "]";
-    }
-    array() {
-        return [
-            this.x,
-            this.y,
-            this.z
-        ];
-    }
-    copy() {
-        return new Vector(this.x, this.y, this.z);
-    }
-    drawDot() {
-        let doodler1 = window['doodler'];
-        if (!doodler1) return;
-        doodler1.dot(this, {
-            weight: 2,
-            color: 'red'
+    mouseX = 0;
+    mouseY = 0;
+    registerDraggable(point, radius, style) {
+        if (this.draggables.find((d)=>d.point === point)) return;
+        const id = this.addUIElement('circle', point, radius, {
+            fillColor: '#5533ff50',
+            strokeColor: '#5533ff50'
+        });
+        this.draggables.push({
+            point,
+            radius,
+            style,
+            id
         });
     }
-    static fromAngle(angle, v) {
-        if (v === undefined || v === null) {
-            v = new Vector();
+    unregisterDraggable(point) {
+        for (const d of this.draggables){
+            if (d.point === point) {
+                this.removeUIElement(d.id);
+            }
         }
-        v.x = Math.cos(angle);
-        v.y = Math.sin(angle);
-        return v;
+        this.draggables = this.draggables.filter((d)=>d.point !== point);
     }
-    static random2D(v) {
-        return Vector.fromAngle(Math.random() * (Math.PI * 2), v);
+    registerClickable(p1, p2, cb) {
+        const top = Math.min(p1.y, p2.y);
+        const left = Math.min(p1.x, p2.x);
+        const bottom = Math.max(p1.y, p2.y);
+        const right = Math.max(p1.x, p2.x);
+        this.clickables.push({
+            onClick: cb,
+            checkBound: (p)=>p.y >= top && p.x >= left && p.y <= bottom && p.x <= right
+        });
     }
-    static random3D(v) {
-        const angle = Math.random() * Constants.TWO_PI;
-        const vz = Math.random() * 2 - 1;
-        const mult = Math.sqrt(1 - vz * vz);
-        const vx = mult * Math.cos(angle);
-        const vy = mult * Math.sin(angle);
-        if (v === undefined || v === null) {
-            v = new Vector(vx, vy, vz);
-        } else {
-            v.set(vx, vy, vz);
+    unregisterClickable(cb) {
+        this.clickables = this.clickables.filter((c)=>c.onClick !== cb);
+    }
+    addDragEvents({ onDragEnd , onDragStart , onDrag , point  }) {
+        const d = this.draggables.find((d)=>d.point === point);
+        if (d) {
+            d.onDragEnd = onDragEnd;
+            d.onDragStart = onDragStart;
+            d.onDrag = onDrag;
         }
-        return v;
     }
-    static dist(v1, v2) {
-        return v1.dist(v2);
+    onClick(e) {
+        const mouse = new Vector(this.mouseX, this.mouseY);
+        for (const d of this.draggables){
+            if (d.point.dist(mouse) <= d.radius) {
+                d.beingDragged = true;
+                d.onDragStart?.call(null);
+                this.dragTarget = d;
+            } else d.beingDragged = false;
+        }
+        for (const c of this.clickables){
+            if (c.checkBound(mouse)) {
+                c.onClick();
+            }
+        }
     }
-    static dot(v1, v2) {
-        return v1.dot(v2);
+    offClick(e) {
+        for (const d of this.draggables){
+            d.beingDragged = false;
+            d.onDragEnd?.call(null);
+        }
+        this.dragTarget = undefined;
     }
-    static cross(v1, v2) {
-        return v1.cross(v2);
+    onDrag(e) {
+        this._canvas.getBoundingClientRect();
+        this.mouseX = e.offsetX;
+        this.mouseY = e.offsetY;
+        for (const d of this.draggables.filter((d)=>d.beingDragged)){
+            d.point.add(e.movementX, e.movementY);
+            d.onDrag && d.onDrag({
+                x: e.movementX,
+                y: e.movementY
+            });
+        }
     }
-    static add(v1, v2) {
-        return new Vector(v1.x + v2.x, v1.y + v2.y, v1.z + v2.z);
+    uiElements = new Map();
+    uiDrawing = {
+        rectangle: (...args)=>{
+            !args[3].noFill && this.fillRect(args[0], args[1], args[2], args[3]);
+            !args[3].noStroke && this.drawRect(args[0], args[1], args[2], args[3]);
+        },
+        square: (...args)=>{
+            !args[2].noFill && this.fillSquare(args[0], args[1], args[2]);
+            !args[2].noStroke && this.drawSquare(args[0], args[1], args[2]);
+        },
+        circle: (...args)=>{
+            !args[2].noFill && this.fillCircle(args[0], args[1], args[2]);
+            !args[2].noStroke && this.drawCircle(args[0], args[1], args[2]);
+        }
+    };
+    drawUI() {
+        for (const [shape, ...args] of this.uiElements.values()){
+            this.uiDrawing[shape].apply(null, args);
+        }
     }
-    static sub(v1, v2) {
-        return new Vector(v1.x - v2.x, v1.y - v2.y, v1.z - v2.z);
+    addUIElement(shape, ...args) {
+        const id = crypto.randomUUID();
+        for (const arg of args){
+            delete arg.color;
+        }
+        this.uiElements.set(id, [
+            shape,
+            ...args
+        ]);
+        return id;
     }
-    static angleBetween(v1, v2) {
-        return Math.acos(v1.dot(v2) / Math.sqrt(v1.magSq() * v2.magSq()));
-    }
-    static lerp(v1, v2, amt) {
-        const retval = new Vector(v1.x, v1.y, v1.z);
-        retval.lerp(v2, amt);
-        return retval;
-    }
-    static vectorProjection(v1, v2) {
-        v2 = v2.copy();
-        v2.normalize();
-        const sp = v1.dot(v2);
-        v2.mult(sp);
-        return v2;
-    }
-    static hypot2(a, b) {
-        return Vector.dot(Vector.sub(a, b), Vector.sub(a, b));
+    removeUIElement(id) {
+        this.uiElements.delete(id);
     }
 }
+class ZoomableDoodler extends Doodler {
+    scale = 1;
+    dragging = false;
+    origin = {
+        x: 0,
+        y: 0
+    };
+    mouse = {
+        x: 0,
+        y: 0
+    };
+    previousTouchLength;
+    touchTimer;
+    hasDoubleTapped = false;
+    zooming = false;
+    scaleAround = {
+        x: 0,
+        y: 0
+    };
+    maxScale = 4;
+    constructor(options){
+        super(options);
+        this._canvas.addEventListener('wheel', (e)=>{
+            this.scaleAtMouse(e.deltaY < 0 ? 1.1 : .9);
+            if (this.scale === 1) {
+                this.origin.x = 0;
+                this.origin.y = 0;
+            }
+        });
+        this._canvas.addEventListener('dblclick', (e)=>{
+            e.preventDefault();
+            this.scale = 1;
+            this.origin.x = 0;
+            this.origin.y = 0;
+            this.ctx.setTransform(1, 0, 0, 1, 0, 0);
+        });
+        this._canvas.addEventListener('mousedown', (e)=>{
+            e.preventDefault();
+            this.dragging = true;
+        });
+        this._canvas.addEventListener('mouseup', (e)=>{
+            e.preventDefault();
+            this.dragging = false;
+        });
+        this._canvas.addEventListener('mouseleave', (e)=>{
+            this.dragging = false;
+        });
+        this._canvas.addEventListener('mousemove', (e)=>{
+            const prev = this.mouse;
+            this.mouse = {
+                x: e.offsetX,
+                y: e.offsetY
+            };
+            if (this.dragging && !this.dragTarget) this.drag(prev);
+        });
+        this._canvas.addEventListener('touchstart', (e)=>{
+            e.preventDefault();
+            if (e.touches.length === 1) {
+                const t1 = e.touches.item(0);
+                if (t1) {
+                    this.mouse = this.getTouchOffset({
+                        x: t1.clientX,
+                        y: t1.clientY
+                    });
+                }
+            } else {
+                clearTimeout(this.touchTimer);
+            }
+        });
+        this._canvas.addEventListener('touchend', (e)=>{
+            if (e.touches.length !== 2) {
+                this.previousTouchLength = undefined;
+            }
+            switch(e.touches.length){
+                case 1:
+                    break;
+                case 0:
+                    if (!this.zooming) {
+                        this.events.get('touchend')?.map((cb)=>cb(e));
+                    }
+                    break;
+            }
+            this.dragging = e.touches.length === 1;
+            clearTimeout(this.touchTimer);
+        });
+        this._canvas.addEventListener('touchmove', (e)=>{
+            e.preventDefault();
+            if (e.touches.length === 2) {
+                const t1 = e.touches.item(0);
+                const t2 = e.touches.item(1);
+                if (t1 && t2) {
+                    const vect = OriginVector.from(this.getTouchOffset({
+                        x: t1.clientX,
+                        y: t1.clientY
+                    }), {
+                        x: t2.clientX,
+                        y: t2.clientY
+                    });
+                    if (this.previousTouchLength) {
+                        const diff = this.previousTouchLength - vect.mag();
+                        this.scaleAt(vect.halfwayPoint, diff < 0 ? 1.01 : .99);
+                        this.scaleAround = {
+                            ...vect.halfwayPoint
+                        };
+                    }
+                    this.previousTouchLength = vect.mag();
+                }
+            }
+            if (e.touches.length === 1) {
+                this.dragging === true;
+                const t11 = e.touches.item(0);
+                if (t11) {
+                    const prev = this.mouse;
+                    this.mouse = this.getTouchOffset({
+                        x: t11.clientX,
+                        y: t11.clientY
+                    });
+                    this.drag(prev);
+                }
+            }
+        });
+        this._canvas.addEventListener('touchstart', (e)=>{
+            if (e.touches.length !== 1) return false;
+            if (!this.hasDoubleTapped) {
+                this.hasDoubleTapped = true;
+                setTimeout(()=>this.hasDoubleTapped = false, 300);
+                return false;
+            }
+            console.log(this.mouse);
+            if (this.scale > 1) {
+                this.frameCounter = map(this.scale, this.maxScale, 1, 0, 59);
+                this.zoomDirection = -1;
+            } else {
+                this.frameCounter = 0;
+                this.zoomDirection = 1;
+            }
+            if (this.zoomDirection > 0) this.scaleAround = {
+                ...this.mouse
+            };
+            this.events.get('doubletap')?.map((cb)=>cb(e));
+        });
+    }
+    worldToScreen(x, y) {
+        x = x * this.scale + this.origin.x;
+        y = y * this.scale + this.origin.y;
+        return {
+            x,
+            y
+        };
+    }
+    screenToWorld(x, y) {
+        x = (x - this.origin.x) / this.scale;
+        y = (y - this.origin.y) / this.scale;
+        return {
+            x,
+            y
+        };
+    }
+    scaleAtMouse(scaleBy) {
+        if (this.scale === this.maxScale && scaleBy > 1) return;
+        this.scaleAt({
+            x: this.mouse.x,
+            y: this.mouse.y
+        }, scaleBy);
+    }
+    scaleAt(p, scaleBy) {
+        this.scale = Math.min(Math.max(this.scale * scaleBy, 1), this.maxScale);
+        this.origin.x = p.x - (p.x - this.origin.x) * scaleBy;
+        this.origin.y = p.y - (p.y - this.origin.y) * scaleBy;
+        this.constrainOrigin();
+    }
+    drag(prev) {
+        if (this.scale > 1) {
+            const xOffset = this.mouse.x - prev.x;
+            const yOffset = this.mouse.y - prev.y;
+            this.origin.x += xOffset;
+            this.origin.y += yOffset;
+            this.constrainOrigin();
+        }
+    }
+    constrainOrigin() {
+        this.origin.x = Math.min(Math.max(this.origin.x, -this._canvas.width * this.scale + this._canvas.width), 0);
+        this.origin.y = Math.min(Math.max(this.origin.y, -this._canvas.height * this.scale + this._canvas.height), 0);
+    }
+    draw() {
+        this.ctx.setTransform(this.scale, 0, 0, this.scale, this.origin.x, this.origin.y);
+        this.animateZoom();
+        this.ctx.fillStyle = this.bg;
+        this.ctx.fillRect(0, 0, this.width / this.scale, this.height / this.scale);
+        super.draw();
+    }
+    getTouchOffset(p) {
+        const { x , y  } = this._canvas.getBoundingClientRect();
+        const offsetX = p.x - x;
+        const offsetY = p.y - y;
+        return {
+            x: offsetX,
+            y: offsetY
+        };
+    }
+    onDrag(e) {
+        const d = {
+            ...e,
+            movementX: e.movementX / this.scale,
+            movementY: e.movementY / this.scale
+        };
+        super.onDrag(d);
+        const { x , y  } = this.screenToWorld(e.offsetX, e.offsetY);
+        this.mouseX = x;
+        this.mouseY = y;
+    }
+    zoomDirection = -1;
+    frameCounter = 60;
+    animateZoom() {
+        if (this.frameCounter < 60) {
+            const frame = easeInOut(map(this.frameCounter, 0, 59, 0, 1));
+            switch(this.zoomDirection){
+                case 1:
+                    {
+                        this.scale = map(frame, 0, 1, 1, this.maxScale);
+                    }
+                    break;
+                case -1:
+                    {
+                        this.scale = map(frame, 0, 1, this.maxScale, 1);
+                    }
+                    break;
+            }
+            this.origin.x = this.scaleAround.x - this.scaleAround.x * this.scale;
+            this.origin.y = this.scaleAround.y - this.scaleAround.y * this.scale;
+            this.constrainOrigin();
+            this.frameCounter++;
+        }
+    }
+    events = new Map();
+    registerEvent(eventName, cb) {
+        let events = this.events.get(eventName);
+        if (!events) events = this.events.set(eventName, []).get(eventName);
+        events.push(cb);
+    }
+}
+const init = (opt, zoomable)=>{
+    if (window.doodler) throw 'Doodler has already been initialized in this window';
+    window.doodler = zoomable ? new ZoomableDoodler(opt) : new Doodler(opt);
+    window.doodler.init();
+};
 init({
     width: 400,
     height: 400
-});
-const movingVector = new Vector(100, 300);
+}, true);
+new Vector(100, 300);
+const v = new Vector(30, 30);
+doodler.registerDraggable(v, 20);
+const img = new Image();
+img.src = './EngineSprites.png';
+img.hidden;
+document.body.append(img);
+const p = new Vector(200, 200);
 doodler.createLayer(()=>{
-    doodler.line(new Vector(100, 100), new Vector(200, 200));
-    doodler.dot(new Vector(300, 300));
-    doodler.fillCircle(movingVector, 6, {
-        color: 'red'
+    doodler.drawScaled(1.5, ()=>{
+        doodler.line(p.copy().add(-8, 10), p.copy().add(8, 10), {
+            color: 'grey',
+            weight: 2
+        });
+        doodler.line(p.copy().add(-8, -10), p.copy().add(8, -10), {
+            color: 'grey',
+            weight: 2
+        });
+        doodler.line(p, p.copy().add(0, 12), {
+            color: 'brown',
+            weight: 4
+        });
+        doodler.line(p, p.copy().add(0, -12), {
+            color: 'brown',
+            weight: 4
+        });
     });
-    doodler.drawRect(new Vector(50, 50), movingVector.x, movingVector.y);
-    doodler.fillRect(new Vector(200, 250), 30, 10);
-    doodler.drawCenteredSquare(new Vector(200, 200), 40, {
-        color: 'purple',
-        weight: 5
-    });
-    doodler.drawBezier(new Vector(100, 150), movingVector, new Vector(150, 300), new Vector(100, 250));
-    movingVector.set((movingVector.x + 1) % 400, movingVector.y);
+});
+document.addEventListener('keyup', (e)=>{
+    e.preventDefault();
+    if (e.key === ' ') {
+        doodler.unregisterDraggable(v);
+    }
 });

canvas.ts

@@ -1,15 +1,18 @@
 /// <reference types="./global.d.ts" />
 
-
 import { Constants } from "./geometry/constants.ts";
 import { Vector } from "./geometry/vector.ts";
+import { ZoomableDoodler } from "./zoomableCanvas.ts";
 
-export const init = (opt: IDoodlerOptions) => {
-  window['doodler'] = new Doodler(opt);
-  window['doodler'].init();
-}
+export const init = (opt: IDoodlerOptions, zoomable: boolean) => {
+  if (window.doodler) {
+    throw "Doodler has already been initialized in this window";
+  }
+  window.doodler = zoomable ? new ZoomableDoodler(opt) : new Doodler(opt);
+  window.doodler.init();
+};
 
-interface IDoodlerOptions {
+export interface IDoodlerOptions {
   width: number;
   height: number;
   canvas?: HTMLCanvasElement;
@@ -20,12 +23,12 @@ interface IDoodlerOptions {
 type layer = (ctx: CanvasRenderingContext2D, index: number) => void;
 
 export class Doodler {
-  private ctx: CanvasRenderingContext2D;
-  private _canvas: HTMLCanvasElement;
+  protected ctx: CanvasRenderingContext2D;
+  protected _canvas: HTMLCanvasElement;
 
   private layers: layer[] = [];
 
-  private bg: string;
+  protected bg: string;
   private framerate: number;
 
   get width() {
@@ -35,19 +38,24 @@ export class Doodler {
     return this.ctx.canvas.height;
   }
 
+  private draggables: Draggable[] = [];
+  private clickables: Clickable[] = [];
+
+  protected dragTarget?: Draggable;
+
   constructor({
     width,
     height,
     canvas,
     bg,
-    framerate
+    framerate,
   }: IDoodlerOptions) {
     if (!canvas) {
-      canvas = document.createElement('canvas');
+      canvas = document.createElement("canvas");
       document.body.append(canvas);
     }
 
-    this.bg = bg || 'white';
+    this.bg = bg || "white";
     this.framerate = framerate || 60;
 
     canvas.width = width;
@@ -55,13 +63,15 @@ export class Doodler {
 
     this._canvas = canvas;
 
-    const ctx = canvas.getContext('2d');
-    console.log(ctx);
-    if (!ctx) throw 'Unable to initialize Doodler: Canvas context not found';
+    const ctx = canvas.getContext("2d");
+    if (!ctx) throw "Unable to initialize Doodler: Canvas context not found";
     this.ctx = ctx;
   }
 
   init() {
+    this._canvas.addEventListener("mousedown", (e) => this.onClick(e));
+    this._canvas.addEventListener("mouseup", (e) => this.offClick(e));
+    this._canvas.addEventListener("mousemove", (e) => this.onDrag(e));
     this.startDrawLoop();
   }
 
@@ -70,30 +80,40 @@ export class Doodler {
     this.timer = setInterval(() => this.draw(), 1000 / this.framerate);
   }
 
-  private draw() {
+  protected draw() {
+    this.ctx.clearRect(0, 0, this.width, this.height);
     this.ctx.fillStyle = this.bg;
     this.ctx.fillRect(0, 0, this.width, this.height);
+    // for (const d of this.draggables.filter(d => d.beingDragged)) {
+    //   d.point.set(this.mouseX,this.mouseY);
+    // }
     for (const [i, l] of (this.layers || []).entries()) {
       l(this.ctx, i);
+      this.drawDeferred();
     }
+    this.drawUI();
   }
 
+  // Layer management
+
   createLayer(layer: layer) {
     this.layers.push(layer);
   }
 
   deleteLayer(layer: layer) {
-    this.layers = this.layers.filter(l => l !== layer);
+    this.layers = this.layers.filter((l) => l !== layer);
   }
 
   moveLayer(layer: layer, index: number) {
-    let temp = this.layers.filter(l => l !== layer);
+    let temp = this.layers.filter((l) => l !== layer);
 
     temp = [...temp.slice(0, index), layer, ...temp.slice(index)];
 
     this.layers = temp;
   }
 
+  // Drawing
+
   line(start: Vector, end: Vector, style?: IStyle) {
     this.setStyle(style);
     this.ctx.beginPath();
@@ -102,7 +122,7 @@ export class Doodler {
     this.ctx.stroke();
   }
   dot(at: Vector, style?: IStyle) {
-    this.setStyle({ ...style, weight: 1 })
+    this.setStyle({ ...style, weight: 1 });
     this.ctx.beginPath();
 
     this.ctx.arc(at.x, at.y, style?.weight || 1, 0, Constants.TWO_PI);
@@ -163,12 +183,249 @@ export class Doodler {
     this.ctx.stroke();
   }
 
+  drawRotated(origin: Vector, angle: number, cb: () => void) {
+    this.ctx.save();
+    this.ctx.translate(origin.x, origin.y);
+    this.ctx.rotate(angle);
+    this.ctx.translate(-origin.x, -origin.y);
+    cb();
+    this.ctx.restore();
+  }
+
+  drawScaled(scale: number, cb: () => void) {
+    this.ctx.save();
+    this.ctx.transform(scale, 0, 0, scale, 0, 0);
+    cb();
+    this.ctx.restore();
+  }
+
+  drawWithAlpha(alpha: number, cb: () => void) {
+    this.ctx.save();
+    this.ctx.globalAlpha = Math.min(Math.max(alpha, 0), 1);
+    cb();
+    this.ctx.restore();
+  }
+
+  drawImage(img: HTMLImageElement, at: Vector): void;
+  drawImage(img: HTMLImageElement, at: Vector, w: number, h: number): void;
+  drawImage(img: HTMLImageElement, at: Vector, w?: number, h?: number) {
+    w && h
+      ? this.ctx.drawImage(img, at.x, at.y, w, h)
+      : this.ctx.drawImage(img, at.x, at.y);
+  }
+  drawSprite(
+    img: HTMLImageElement,
+    spritePos: Vector,
+    sWidth: number,
+    sHeight: number,
+    at: Vector,
+    width: number,
+    height: number,
+  ) {
+    this.ctx.drawImage(
+      img,
+      spritePos.x,
+      spritePos.y,
+      sWidth,
+      sHeight,
+      at.x,
+      at.y,
+      width,
+      height,
+    );
+  }
+
+  private deferredDrawings: (() => void)[] = [];
+
+  deferDrawing(cb: () => void) {
+    this.deferredDrawings.push(cb);
+  }
+
+  drawDeferred() {
+    while (this.deferredDrawings.length) {
+      this.deferredDrawings.pop()?.();
+    }
+  }
+
   setStyle(style?: IStyle) {
     const ctx = this.ctx;
-    ctx.fillStyle = style?.color || style?.fillColor || 'black';
-    ctx.strokeStyle = style?.color || style?.strokeColor || 'black';
+    ctx.fillStyle = style?.color || style?.fillColor || "black";
+    ctx.strokeStyle = style?.color || style?.strokeColor || "black";
 
     ctx.lineWidth = style?.weight || 1;
+
+    ctx.textAlign = style?.textAlign || ctx.textAlign;
+    ctx.textBaseline = style?.textBaseline || ctx.textBaseline;
+  }
+
+  fillText(text: string, pos: Vector, maxWidth: number, style?: IStyle) {
+    this.setStyle(style);
+    // TODO: add text alignment to style
+    this.ctx.fillText(text, pos.x, pos.y, maxWidth);
+  }
+  strokeText(text: string, pos: Vector, maxWidth: number, style?: IStyle) {
+    this.setStyle(style);
+    // TODO: add text alignment to style
+    this.ctx.strokeText(text, pos.x, pos.y, maxWidth);
+  }
+
+  clearRect(at: Vector, width: number, height: number) {
+    this.ctx.clearRect(at.x, at.y, width, height);
+  }
+
+  // Interaction
+
+  mouseX = 0;
+  mouseY = 0;
+
+  registerDraggable(
+    point: Vector,
+    radius: number,
+    style?: IStyle & { shape: "square" | "circle" },
+  ) {
+    if (this.draggables.find((d) => d.point === point)) return;
+    const id = this.addUIElement("circle", point, radius, {
+      fillColor: "#5533ff50",
+      strokeColor: "#5533ff50",
+    });
+    this.draggables.push({ point, radius, style, id });
+  }
+  unregisterDraggable(point: Vector) {
+    for (const d of this.draggables) {
+      if (d.point === point) {
+        this.removeUIElement(d.id);
+      }
+    }
+    this.draggables = this.draggables.filter((d) => d.point !== point);
+  }
+
+  registerClickable(p1: Vector, p2: Vector, cb: () => void) {
+    const top = Math.min(p1.y, p2.y);
+    const left = Math.min(p1.x, p2.x);
+    const bottom = Math.max(p1.y, p2.y);
+    const right = Math.max(p1.x, p2.x);
+
+    this.clickables.push({
+      onClick: cb,
+      checkBound: (p) =>
+        p.y >= top && p.x >= left && p.y <= bottom && p.x <= right,
+    });
+  }
+
+  unregisterClickable(cb: () => void) {
+    this.clickables = this.clickables.filter((c) => c.onClick !== cb);
+  }
+
+  addDragEvents({
+    onDragEnd,
+    onDragStart,
+    onDrag,
+    point,
+  }: {
+    point: Vector;
+    onDragEnd?: () => void;
+    onDragStart?: () => void;
+    onDrag?: (movement: { x: number; y: number }) => void;
+  }) {
+    const d = this.draggables.find((d) => d.point === point);
+    if (d) {
+      d.onDragEnd = onDragEnd;
+      d.onDragStart = onDragStart;
+      d.onDrag = onDrag;
+    }
+  }
+
+  onClick(e: MouseEvent) {
+    const mouse = new Vector(this.mouseX, this.mouseY);
+    for (const d of this.draggables) {
+      if (d.point.dist(mouse) <= d.radius) {
+        d.beingDragged = true;
+        d.onDragStart?.call(null);
+        this.dragTarget = d;
+      } else d.beingDragged = false;
+    }
+
+    for (const c of this.clickables) {
+      if (c.checkBound(mouse)) {
+        c.onClick();
+      }
+    }
+  }
+
+  offClick(e: MouseEvent) {
+    for (const d of this.draggables) {
+      d.beingDragged = false;
+      d.onDragEnd?.call(null);
+    }
+    this.dragTarget = undefined;
+  }
+
+  onDrag(e: MouseEvent) {
+    const rect = this._canvas.getBoundingClientRect();
+    this.mouseX = e.offsetX;
+    this.mouseY = e.offsetY;
+    // this.mouseX = e.clientX - rect.left;
+    // this.mouseY = e.clientY - rect.top;
+
+    for (const d of this.draggables.filter((d) => d.beingDragged)) {
+      d.point.add(e.movementX, e.movementY);
+      d.onDrag && d.onDrag({ x: e.movementX, y: e.movementY });
+    }
+  }
+
+  // UI Layer
+  uiElements: Map<string, [keyof uiDrawing, ...any]> = new Map();
+  private uiDrawing: uiDrawing = {
+    rectangle: (...args: any[]) => {
+      !args[3].noFill && this.fillRect(args[0], args[1], args[2], args[3]);
+      !args[3].noStroke && this.drawRect(args[0], args[1], args[2], args[3]);
+    },
+    square: (...args: any[]) => {
+      !args[2].noFill && this.fillSquare(args[0], args[1], args[2]);
+      !args[2].noStroke && this.drawSquare(args[0], args[1], args[2]);
+    },
+    circle: (...args: any[]) => {
+      !args[2].noFill && this.fillCircle(args[0], args[1], args[2]);
+      !args[2].noStroke && this.drawCircle(args[0], args[1], args[2]);
+    },
+  };
+
+  private drawUI() {
+    for (const [shape, ...args] of this.uiElements.values()) {
+      this.uiDrawing[shape].apply(null, args as []);
+    }
+  }
+
+  addUIElement(
+    shape: "rectangle",
+    at: Vector,
+    width: number,
+    height: number,
+    style?: IStyle,
+  ): string;
+  addUIElement(
+    shape: "square",
+    at: Vector,
+    size: number,
+    style?: IStyle,
+  ): string;
+  addUIElement(
+    shape: "circle",
+    at: Vector,
+    radius: number,
+    style?: IStyle,
+  ): string;
+  addUIElement(shape: keyof uiDrawing, ...args: any[]) {
+    const id = crypto.randomUUID();
+    for (const arg of args) {
+      delete arg.color;
+    }
+    this.uiElements.set(id, [shape, ...args]);
+    return id;
+  }
+
+  removeUIElement(id: string) {
+    this.uiElements.delete(id);
   }
 }
 
@@ -177,8 +434,42 @@ interface IStyle {
   fillColor?: string;
   strokeColor?: string;
   weight?: number;
+
+  noStroke?: boolean;
+  noFill?: boolean;
+
+  textAlign?: "center" | "end" | "left" | "right" | "start";
+  textBaseline?:
+    | "alphabetic"
+    | "top"
+    | "hanging"
+    | "middle"
+    | "ideographic"
+    | "bottom";
 }
 
 interface IDrawable {
   draw: () => void;
 }
+
+type Draggable = {
+  point: Vector;
+  radius: number;
+  style?: IStyle & { shape: "square" | "circle" };
+  beingDragged?: boolean;
+  id: string;
+  onDragStart?: () => void;
+  onDragEnd?: () => void;
+  onDrag?: (dragDistance: { x: number; y: number }) => void;
+};
+
+type Clickable = {
+  onClick: () => void;
+  checkBound: (p: Vector) => boolean;
+};
+
+type uiDrawing = {
+  circle: () => void;
+  square: () => void;
+  rectangle: () => void;
+};

geometry/vector.ts

@@ -2,7 +2,7 @@
 
 import { Constants } from "./constants.ts";
 
-export class Vector {
+export class Vector implements Point {
   x: number;
   y: number;
   z: number;
@@ -56,9 +56,9 @@ export class Vector {
       return v;
     }
   }
-  add(x: number, y: number, z: number): void;
-  add(x: number, y: number): void;
-  add(v: Vector): void;
+  add(x: number, y: number, z: number): Vector;
+  add(x: number, y: number): Vector;
+  add(v: Vector): Vector;
   add(v: Vector | number, y?: number, z?: number) {
     if (arguments.length === 1 && typeof v !== 'number') {
       this.x += v.x;
@@ -73,10 +73,11 @@ export class Vector {
       this.y += y ?? 0;
       this.z += z ?? 0;
     }
+    return this;
   }
-  sub(x: number, y: number, z: number): void;
-  sub(x: number, y: number): void;
-  sub(v: Vector): void;
+  sub(x: number, y: number, z: number): Vector;
+  sub(x: number, y: number): Vector;
+  sub(v: Vector): Vector;
   sub(v: Vector | number, y?: number, z?: number) {
     if (arguments.length === 1 && typeof v !== 'number') {
       this.x -= v.x;
@@ -91,6 +92,7 @@ export class Vector {
       this.y -= y ?? 0;
       this.z -= z ?? 0;
     }
+    return this;
   }
   mult(v: number | Vector) {
     if (typeof v === 'number') {
@@ -114,6 +116,7 @@ export class Vector {
       this.y /= v.y;
       this.z /= v.z;
     }
+    return this;
   }
   rotate(angle: number) {
     const prev_x = this.x;
@@ -121,6 +124,7 @@ export class Vector {
     const s = Math.sin(angle);
     this.x = c * this.x - s * this.y;
     this.y = s * prev_x + c * this.y;
+    return this;
   }
   dist(v: Vector) {
     const dx = this.x - v.x,
@@ -165,6 +169,7 @@ export class Vector {
     this.x = lerp_val(this.x, x, amt!);
     this.y = lerp_val(this.y, y, amt!);
     this.z = lerp_val(this.z, z!, amt!);
+    return this;
   }
   normalize() {
     const m = this.mag();
@@ -178,6 +183,7 @@ export class Vector {
       this.normalize();
       this.mult(high);
     }
+    return this;
   }
   heading() {
     return (-Math.atan2(-this.y, this.x));
@@ -197,7 +203,6 @@ export class Vector {
   }
 
   drawDot() {
-    let doodler = window['doodler'];
     if (!doodler) return;
 
     doodler.dot(this, {weight: 2, color: 'red'});
@@ -273,3 +278,34 @@ export class Vector {
     return Vector.dot(Vector.sub(a, b), Vector.sub(a, b))
   }
 }
+
+export class OriginVector extends Vector {
+  origin: Point;
+
+  get halfwayPoint() {
+    return {
+      x: (this.mag()/2 * Math.sin(this.heading())) + this.origin.x,
+      y: (this.mag()/2 * Math.cos(this.heading())) + this.origin.y
+    }
+  }
+
+  constructor(origin: Point, p: Point) {
+    super(p.x, p.y, p.z);
+    this.origin = origin;
+  }
+
+  static from(origin: Point, p: Point) {
+    const v = {
+      x: p.x - origin.x,
+      y: p.y - origin.y,
+    };
+
+    return new OriginVector(origin, v);
+  }
+}
+
+export interface Point {
+  x: number;
+  y: number;
+  z?: number;
+}

main.ts

@@ -1,4 +1,3 @@
-import { Doodler } from "./canvas.ts";
 /// <reference types="./global.d.ts" />
 
 import { Vector, initializeDoodler } from './mod.ts'
@@ -6,21 +5,51 @@ import { Vector, initializeDoodler } from './mod.ts'
 initializeDoodler({
   width: 400,
   height: 400
-})
-
-// let doodler = window['doodler'];
+}, true);
 
 const movingVector = new Vector(100, 300);
+let angleMultiplier = 0;
+const v = new Vector(30, 30);
+doodler.registerDraggable(v, 20)
+const img = new Image();
+img.src = './EngineSprites.png'
+img.hidden
+document.body.append(img)
+
+const p = new Vector(200, 200);
+
 doodler.createLayer(() => {
 
-  doodler.line(new Vector(100, 100), new Vector(200, 200))
-  doodler.dot(new Vector(300, 300))
-  doodler.fillCircle(movingVector, 6, { color: 'red' });
-  doodler.drawRect(new Vector(50, 50), movingVector.x, movingVector.y);
-  doodler.fillRect(new Vector(200, 250), 30, 10)
+  // doodler.line(new Vector(100, 100), new Vector(200, 200))
+  // doodler.dot(new Vector(300, 300))
+  // doodler.fillCircle(movingVector, 6, { color: 'red' });
+  // doodler.drawRect(new Vector(50, 50), movingVector.x, movingVector.y);
+  // doodler.fillRect(new Vector(200, 250), 30, 10)
 
-  doodler.drawCenteredSquare(new Vector(200, 200), 40, { color: 'purple', weight: 5 })
-  doodler.drawBezier(new Vector(100, 150), movingVector, new Vector(150, 300), new Vector(100, 250))
+  // doodler.drawCenteredSquare(new Vector(200, 200), 40, { color: 'purple', weight: 5 })
+  // doodler.drawBezier(new Vector(100, 150), movingVector, new Vector(150, 300), new Vector(100, 250))
 
-  movingVector.set((movingVector.x + 1) % 400, movingVector.y);
+  // let rotatedOrigin = new Vector(200, 200)
+  // doodler.drawRotated(rotatedOrigin, Math.PI * angleMultiplier, () => {
+  //   doodler.drawCenteredSquare(rotatedOrigin, 30)
+  //   doodler.drawSprite(img, new Vector(0, 40), 80, 20, new Vector(160, 300), 80, 20)
+  // })
+
+
+  // movingVector.set((movingVector.x + 1) % 400, movingVector.y);
+  // angleMultiplier += .001;
+
+  // doodler.drawSprite(img, new Vector(0, 40), 80, 20, new Vector(100, 300), 80, 20)
+
+  doodler.drawScaled(1.5, () => {doodler.line(p.copy().add(-8,10), p.copy().add(8,10), {color: 'grey', weight: 2})
+  doodler.line(p.copy().add(-8,-10), p.copy().add(8,-10), {color: 'grey', weight: 2})
+  doodler.line(p, p.copy().add(0,12), {color: 'brown', weight: 4})
+  doodler.line(p, p.copy().add(0,-12), {color: 'brown', weight: 4})})
 });
+
+document.addEventListener('keyup', e => {
+  e.preventDefault();
+  if (e.key === ' ') {
+    doodler.unregisterDraggable(v);
+  }
+})

timing/EaseInOut.ts

@@ -0,0 +1,2 @@
+export const easeInOut = (x: number) =>
+  x < 0.5 ? 4 * x * x * x : 1 - Math.pow(-2 * x + 2, 3) / 2;

timing/Map.ts

@@ -0,0 +1,2 @@
+export const map = (value: number, x1: number, y1: number, x2: number, y2: number) => 
+  (value - x1) * (y2 - x2) / (y1 - x1) + x2;

zoomableCanvas.ts

@@ -0,0 +1,273 @@
+import { Doodler, IDoodlerOptions } from "./canvas.ts";
+import { OriginVector, Point } from "./geometry/vector.ts";
+import { easeInOut } from "./timing/EaseInOut.ts";
+import { map } from "./timing/Map.ts";
+
+type TouchEventCallback = (e: TouchEvent) => void;
+
+export class ZoomableDoodler extends Doodler {
+
+  private scale = 1;
+  dragging = false;
+  private origin: Point = {
+    x: 0,
+    y: 0
+  }
+
+  mouse = {
+    x: 0,
+    y: 0
+  }
+
+  private previousTouchLength?: number;
+
+  private touchTimer?: number;
+
+  private hasDoubleTapped = false;
+  private zooming = false;
+  scaleAround: Point = { x: 0, y: 0 };
+
+  maxScale = 4;
+  
+  constructor(options: IDoodlerOptions) {
+    super(options)
+
+    this._canvas.addEventListener('wheel', (e) => {
+      this.scaleAtMouse(e.deltaY < 0 ? 1.1 : .9);
+      if (this.scale === 1) {
+        this.origin.x = 0
+        this.origin.y = 0
+      }
+    })
+    this._canvas.addEventListener('dblclick', (e) => {
+      e.preventDefault();
+      this.scale = 1;
+      this.origin.x = 0;
+      this.origin.y = 0;
+      this.ctx.setTransform(1, 0, 0, 1, 0, 0);
+    })
+    this._canvas.addEventListener('mousedown', (e) => {
+      e.preventDefault();
+      this.dragging = true;
+    })
+    this._canvas.addEventListener('mouseup', (e) => {
+      e.preventDefault();
+      this.dragging = false;
+    })
+    this._canvas.addEventListener('mouseleave', (e) => {
+      this.dragging = false;
+    })
+    this._canvas.addEventListener('mousemove', (e) => {
+      const prev = this.mouse;
+      this.mouse = {
+        x: e.offsetX,
+        y: e.offsetY
+      }
+      if (this.dragging && !this.dragTarget) this.drag(prev);
+    })
+
+    this._canvas.addEventListener('touchstart', (e) => {
+      e.preventDefault();
+      if (e.touches.length === 1) {
+        const t1 = e.touches.item(0);
+        if (t1) {
+          this.mouse = this.getTouchOffset({
+            x: t1.clientX,
+            y: t1.clientY
+          })
+        }
+        // this.touchTimer = setTimeout(() => {
+        //   this.dragging = true;
+        // }, 100)
+      } else {
+        clearTimeout(this.touchTimer);
+      }
+    });
+    this._canvas.addEventListener('touchend', (e) => {
+      if (e.touches.length !== 2) {
+        this.previousTouchLength = undefined;
+      }
+
+      switch (e.touches.length) {
+        case 1:
+          break;
+        case 0:
+          if (!this.zooming) {
+            this.events.get('touchend')?.map(cb => cb(e));
+          }
+          break;
+      }
+
+      this.dragging = e.touches.length === 1;
+      clearTimeout(this.touchTimer);
+    });
+    this._canvas.addEventListener('touchmove', (e) => {
+      e.preventDefault();
+
+      if (e.touches.length === 2) {
+        const t1 = e.touches.item(0);
+        const t2 = e.touches.item(1);
+
+        if (t1 && t2) {
+          const vect = OriginVector.from(
+            this.getTouchOffset({
+              x: t1.clientX,
+              y: t1.clientY
+            }),
+            {
+              x: t2.clientX,
+              y: t2.clientY
+            },
+          )
+
+          if (this.previousTouchLength) {
+            const diff = this.previousTouchLength - vect.mag();
+            this.scaleAt(vect.halfwayPoint, diff < 0 ? 1.01 : .99);
+            this.scaleAround = { ...vect.halfwayPoint }
+          }
+          this.previousTouchLength = vect.mag();
+        }
+      }
+
+      if (e.touches.length === 1) {
+        this.dragging === true;
+        const t1 = e.touches.item(0);
+        if (t1) {
+          const prev = this.mouse;
+          this.mouse = this.getTouchOffset({
+            x: t1.clientX,
+            y: t1.clientY
+          })
+          this.drag(prev);
+        }
+      }
+    });
+
+    this._canvas.addEventListener('touchstart', (e) => {
+      if (e.touches.length !== 1) return false;
+
+      if (!this.hasDoubleTapped) {
+        this.hasDoubleTapped = true;
+        setTimeout(() => this.hasDoubleTapped = false, 300);
+        return false;
+      }
+
+      // this.ctx.setTransform(1, 0, 0, 1, 0, 0);
+      // this.scale = 1;
+      // this.origin.x = 0;
+      // this.origin.y = 0;
+
+      console.log(this.mouse);
+
+      if (this.scale > 1) {
+        this.frameCounter = map(this.scale, this.maxScale, 1, 0, 59);
+        this.zoomDirection = -1;
+      } else {
+        this.frameCounter = 0;
+        this.zoomDirection = 1;
+      }
+      if (this.zoomDirection > 0)
+        this.scaleAround = { ...this.mouse };
+
+      this.events.get('doubletap')?.map(cb => cb(e));
+    })
+  }
+
+  worldToScreen(x: number, y: number) {
+    x = x * this.scale + this.origin.x;
+    y = y * this.scale + this.origin.y;
+    return { x, y };
+  }
+  screenToWorld(x: number, y: number) {
+    x = (x - this.origin.x) / this.scale;
+    y = (y - this.origin.y) / this.scale;
+    return { x, y };
+  }
+  scaleAtMouse(scaleBy: number) {
+    if (this.scale === this.maxScale && scaleBy > 1) return;
+    this.scaleAt({
+      x: this.mouse.x,
+      y: this.mouse.y
+    }, scaleBy);
+  }
+  scaleAt(p: Point, scaleBy: number) {
+    this.scale = Math.min(Math.max(this.scale * scaleBy, 1), this.maxScale);
+    this.origin.x = p.x - (p.x - this.origin.x) * scaleBy;
+    this.origin.y = p.y - (p.y - this.origin.y) * scaleBy;
+    this.constrainOrigin();
+  }
+  drag(prev: Point) {
+    if (this.scale > 1) {
+      const xOffset = this.mouse.x - prev.x;
+      const yOffset = this.mouse.y - prev.y;
+      this.origin.x += xOffset;
+      this.origin.y += yOffset;
+      this.constrainOrigin();
+    }
+  }
+  constrainOrigin() {
+    this.origin.x = Math.min(Math.max(this.origin.x, (-this._canvas.width * this.scale) + this._canvas.width), 0);
+    this.origin.y = Math.min(Math.max(this.origin.y, (-this._canvas.height * this.scale) + this._canvas.height), 0);
+  }
+
+  draw() {
+    this.ctx.setTransform(this.scale, 0, 0, this.scale, this.origin.x, this.origin.y)
+    this.animateZoom();
+    this.ctx.fillStyle = this.bg;
+    this.ctx.fillRect(0, 0, this.width/this.scale, this.height/this.scale);
+    super.draw();
+  }
+
+  getTouchOffset(p: Point) {
+    const { x, y } = this._canvas.getBoundingClientRect();
+    const offsetX = p.x - x;
+    const offsetY = p.y - y;
+
+    return {
+      x: offsetX,
+      y: offsetY
+    }
+  }
+
+  onDrag(e: MouseEvent): void {
+    const d = {
+      ...e,
+      movementX: e.movementX/this.scale,
+      movementY: e.movementY/this.scale
+    }
+    super.onDrag(d);
+    const {x, y} = this.screenToWorld(e.offsetX, e.offsetY);
+    this.mouseX = x;
+    this.mouseY = y;
+  }
+
+  zoomDirection = -1;
+  frameCounter = 60;
+  animateZoom() {
+    if (this.frameCounter < 60) {
+      const frame = easeInOut(map(this.frameCounter, 0, 59, 0, 1));
+      switch (this.zoomDirection) {
+        case 1: {
+          this.scale = map(frame, 0, 1, 1, this.maxScale);
+        }
+          break;
+        case -1: {
+          this.scale = map(frame, 0, 1, this.maxScale, 1);
+        }
+          break;
+      }
+      this.origin.x = this.scaleAround.x - (this.scaleAround.x * this.scale);
+      this.origin.y = this.scaleAround.y - (this.scaleAround.y * this.scale);
+      this.constrainOrigin();
+
+      this.frameCounter++;
+    }
+  }
+
+  events: Map<string, TouchEventCallback[]> = new Map();
+  registerEvent(eventName: 'touchend' | 'touchstart' | 'touchmove' | 'doubletap', cb: TouchEventCallback) {
+    let events = this.events.get(eventName);
+    if (!events) events = this.events.set(eventName, []).get(eventName)!;
+    events.push(cb);
+  }
+}