Merge pull request #6 from browngraphicslab/transforms

Transforms

1 files changed, 46 insertions, 27 deletions

diff --git a/src/client/util/Transform.ts b/src/client/util/Transform.ts
index 7861ed308..9fd4f7bef 100644
--- a/src/client/util/Transform.ts
+++ b/src/client/util/Transform.ts
@@ -7,6 +7,10 @@ export class 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;
@@ -19,56 +23,67 @@ export class Transform {
         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;
+    scale = (scale: number): Transform => {
+        this._scale *= scale;
+        this._translateX *= scale;
+        this._translateY *= scale;
         return this;
     }
 
-    preTranslated = (x: number, y: number): Transform => {
-        return this.copy().preTranslate(x, y);
+    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;
     }
 
-    scale = (scale: number): Transform => {
-        this._scale *= scale;
+    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;
     }
 
-    scaled = (scale: number): Transform => {
-        return this.copy().scale(scale);
+    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;
-        this._translateX *= scale;
-        this._translateY *= scale;
         return this;
     }
 
-    preScaled = (scale: number): Transform => {
-        return this.copy().preScale(scale);
-    }
-
-    transform = (transform: Transform): Transform => {
+    preTransform = (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);
+    translated = (x: number, y: number): Transform => {
+        return this.copy().translate(x, y);
     }
 
-    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;
+    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 => {
@@ -83,6 +98,10 @@ export class Transform {
         return [x, y];
     }
 
+    transformDirection = (x: number, y: number): [number, number] => {
+        return [x * this._scale, y * this._scale];
+    }
+
     inverse = () => {
         return new Transform(-this._translateX / this._scale, -this._translateY / this._scale, 1 / this._scale)
     }