Use zoom while calculating border limit

I guess it would break backwards-compatibility if user has already fixed zoom himself somehow :) resolves michaschwab#16, resolves michaschwab#12.
sliterok · Oct 29, 2020 · e7f2255 · e7f2255
1 parent b147097
commit e7f2255
Showing 1 changed file with 29 additions and 23 deletions.
diff --git a/easypz.ts b/easypz.ts
@@ -455,29 +455,35 @@ class EasyPZ
 
     private ensureTransformWithinBounds(transformBeforeScale)
     {
-        if(this.options.bounds)
-        {
-            let scale = transformBeforeScale ? this.totalTransform.scale - 1 : 1 - 1 / this.totalTransform.scale;
-            let scaleTopLeft = -1 * Math.max(scale, 0);
-            let scaleBotRight = -1 * Math.min(scale, 0);
-
-            if(this.totalTransform.translateX < scaleTopLeft * this.width + this.options.bounds.left)
-            {
-                this.totalTransform.translateX = scaleTopLeft * this.width + this.options.bounds.left;
-            }
-            if(this.totalTransform.translateX > scaleBotRight * this.width + this.options.bounds.right)
-            {
-                this.totalTransform.translateX = scaleBotRight * this.width + this.options.bounds.right;
-            }
-            if(this.totalTransform.translateY < scaleTopLeft * this.height + this.options.bounds.top)
-            {
-                this.totalTransform.translateY = scaleTopLeft * this.height + this.options.bounds.top;
-            }
-            if(this.totalTransform.translateY > scaleBotRight * this.height + this.options.bounds.bottom)
-            {
-                this.totalTransform.translateY = scaleBotRight * this.height + this.options.bounds.bottom;
-            }
-        }
+        if(!this.options.bounds)
+            return;
+
+        let x = this.totalTransform.translateX,
+            y = this.totalTransform.translateY
+
+        const boundLeft = this.options.bounds.left * this.totalTransform.scale
+        const boundRight = this.options.bounds.right * this.totalTransform.scale
+        const boundTop = this.options.bounds.top * this.totalTransform.scale
+        const boundBottom = this.options.bounds.bottom * this.totalTransform.scale
+
+        const borderX = [boundLeft, this.width - boundRight]
+        const borderLeft = Math.min(...borderX)
+        const borderRight = Math.max(...borderX)
+        if(x < borderLeft)
+            x = borderLeft
+        else if(x > borderRight)
+            x = borderRight
+
+        const borderY = [boundTop, this.height - boundBottom]
+        const borderTop = Math.min(...borderY)
+        const borderBottom = Math.max(...borderY)
+        if(y < borderTop)
+            y = borderTop
+        else if(y > borderBottom)
+            y = borderBottom
+
+        this.totalTransform.translateX = x
+        this.totalTransform.translateY = y
     }
 
     private lastAppliedTransform = { translateX: 0, translateY: 0, scale: 1 };