1 files changed, 119 insertions, 0 deletions
diff --git a/src/client/util/Transform.ts b/src/client/util/Transform.ts
new file mode 100644
index 000000000..3e1039166
--- /dev/null
+++ b/src/client/util/Transform.ts
@@ -0,0 +1,119 @@
+export class Transform {
+    private _translateX: number = 0;
+    private _translateY: number = 0;
+    private _scale: number = 1;
+
+    static get Identity(): Transform {
+        return new Transform(0, 0, 1);
+    }
+
+    get TranslateX(): number { return this._translateX; }
+    get TranslateY(): number { return this._translateY; }
+    get Scale(): number { return this._scale; }
+
+    constructor(x: number, y: number, scale: number) {
+        this._translateX = x;
+        this._translateY = y;
+        this._scale = scale;
+    }
+
+    translate = (x: number, y: number): Transform => {
+        this._translateX += x;
+        this._translateY += y;
+        return this;
+    }
+
+    scale = (scale: number): Transform => {
+        this._scale *= scale;
+        this._translateX *= scale;
+        this._translateY *= scale;
+        return this;
+    }
+
+    scaleAbout = (scale: number, x: number, y: number): Transform => {
+        this._translateX += x * this._scale - x * this._scale * scale;
+        this._translateY += y * this._scale - y * this._scale * scale;
+        this._scale *= scale;
+        return this;
+    }
+
+    transform = (transform: Transform): Transform => {
+        this._translateX = transform._translateX + transform._scale * this._translateX;
+        this._translateY = transform._translateY + transform._scale * this._translateY;
+        this._scale *= transform._scale;
+        return this;
+    }
+
+    preTranslate = (x: number, y: number): Transform => {
+        this._translateX += this._scale * x;
+        this._translateY += this._scale * y;
+        return this;
+    }
+
+    preScale = (scale: number): Transform => {
+        this._scale *= scale;
+        return this;
+    }
+
+    preTransform = (transform: Transform): Transform => {
+        this._translateX += transform._translateX * this._scale;
+        this._translateY += transform._translateY * this._scale;
+        this._scale *= transform._scale;
+        return this;
+    }
+
+    translated = (x: number, y: number): Transform => {
+        return this.copy().translate(x, y);
+    }
+
+    preTranslated = (x: number, y: number): Transform => {
+        return this.copy().preTranslate(x, y);
+    }
+
+    scaled = (scale: number): Transform => {
+        return this.copy().scale(scale);
+    }
+
+    scaledAbout = (scale: number, x: number, y: number): Transform => {
+        return this.copy().scaleAbout(scale, x, y);
+    }
+
+    preScaled = (scale: number): Transform => {
+        return this.copy().preScale(scale);
+    }
+
+    transformed = (transform: Transform): Transform => {
+        return this.copy().transform(transform);
+    }
+
+    preTransformed = (transform: Transform): Transform => {
+        return this.copy().preTransform(transform);
+    }
+
+    transformPoint = (x: number, y: number): [number, number] => {
+        x *= this._scale;
+        x += this._translateX;
+        y *= this._scale;
+        y += this._translateY;
+        return [x, y];
+    }
+
+    transformDirection = (x: number, y: number): [number, number] => {
+        return [x * this._scale, y * this._scale];
+    }
+
+    transformBounds(x: number, y: number, width: number, height: number): { x: number, y: number, width: number, height: number } {
+        [x, y] = this.transformPoint(x, y);
+        [width, height] = this.transformDirection(width, height);
+        return { x, y, width, height };
+    }
+
+    inverse = () => {
+        return new Transform(-this._translateX / this._scale, -this._translateY / this._scale, 1 / this._scale)
+    }
+
+    copy = () => {
+        return new Transform(this._translateX, this._translateY, this._scale);
+    }
+
+}
+\ No newline at end of file