Merge branch 'master' of https://github.com/browngraphicslab/Dash-Web into improveText

1 files changed, 94 insertions, 0 deletions

diff --git a/src/client/util/Transform.ts b/src/client/util/Transform.ts
new file mode 100644
index 000000000..7861ed308
--- /dev/null
+++ b/src/client/util/Transform.ts
@@ -0,0 +1,94 @@
+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);
+    }
+
+    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;
+    }
+
+    translated = (x: number, y: number): Transform => {
+        return this.copy().translate(x, y);
+    }
+
+    preTranslate = (x: number, y: number): Transform => {
+        this._translateX += x * this._scale;
+        this._translateY += y * this._scale;
+        return this;
+    }
+
+    preTranslated = (x: number, y: number): Transform => {
+        return this.copy().preTranslate(x, y);
+    }
+
+    scale = (scale: number): Transform => {
+        this._scale *= scale;
+        return this;
+    }
+
+    scaled = (scale: number): Transform => {
+        return this.copy().scale(scale);
+    }
+
+    preScale = (scale: number): Transform => {
+        this._scale *= scale;
+        this._translateX *= scale;
+        this._translateY *= scale;
+        return this;
+    }
+
+    preScaled = (scale: number): Transform => {
+        return this.copy().preScale(scale);
+    }
+
+    transform = (transform: Transform): Transform => {
+        this._translateX += transform._translateX * this._scale;
+        this._translateY += transform._translateY * this._scale;
+        this._scale *= transform._scale;
+        return this;
+    }
+
+    transformed = (transform: Transform): Transform => {
+        return this.copy().transform(transform);
+    }
+
+    preTransform = (transform: Transform): Transform => {
+        this._translateX = transform._translateX + this._translateX * transform._scale;
+        this._translateY = transform._translateY + this._translateY * transform._scale;
+        this._scale *= transform._scale;
+        return this;
+    }
+
+    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];
+    }
+
+    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