From 5a6b11ef50480460bc280610598cf4b51997da7a Mon Sep 17 00:00:00 2001
From: Andrea Bogazzi <andreabogazzi79@gmail.com>
Date: Mon, 30 May 2016 23:33:02 +0200
Subject: [PATCH] introduce a parameter to choose behaviour of background and
 overlay (#3019)

* introduce a parameter to choose behaviour of background and overlay
---
 src/static_canvas.class.js | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/static_canvas.class.js b/src/static_canvas.class.js
index 412d81ce..7ba6f027 100644
--- a/src/static_canvas.class.js
+++ b/src/static_canvas.class.js
@@ -147,6 +147,22 @@
      */
     viewportTransform: [1, 0, 0, 1, 0, 0],
 
+    /**
+     * if set to false background image is not affected by viewport transform
+     * @since 1.6.3
+     * @type Boolean
+     * @default
+     */
+    backgroundVpt: true,
+
+    /**
+     * if set to false overlya image is not affected by viewport transform
+     * @since 1.6.3
+     * @type Boolean
+     * @default
+     */
+    overlayVpt: true,
+
     /**
      * Callback; invoked right before object is about to be scaled/rotated
      */
@@ -922,7 +938,12 @@
       }
       object = this[property + 'Image'];
       if (object) {
+        if (this[property + 'Vpt']) {
+          ctx.save();
+          ctx.transform.apply(ctx, this.viewportTransform);
+        }
         object.render(ctx);
+        this[property + 'Vpt'] && ctx.restore();
       }
     },