From 86c105beaa0881be8160bc93bdf7108e4901bee1 Mon Sep 17 00:00:00 2001
From: Tom <tmpearce@gmail.com>
Date: Sat, 10 Dec 2022 06:57:53 -0500
Subject: [PATCH] bugfix in getCenter during zoom animation

---
 src/viewport.js                         |  5 +++--
 test/demo/fitboundswithconstraints.html | 27 +++++++++++++++++++++++--
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/viewport.js b/src/viewport.js
index cbb71429..a0e5a6f1 100644
--- a/src/viewport.js
+++ b/src/viewport.js
@@ -483,7 +483,7 @@ $.Viewport.prototype = {
         );
 
         newZoomPixel = this._pixelFromPoint(this.zoomPoint, bounds);
-        deltaZoomPixels = newZoomPixel.minus( oldZoomPixel );
+        deltaZoomPixels = newZoomPixel.minus( oldZoomPixel ).rotate(-this.getRotation(true));
         deltaZoomPoints = deltaZoomPixels.divide( this._containerInnerSize.x * zoom );
 
         return centerTarget.plus( deltaZoomPoints );
@@ -578,7 +578,7 @@ $.Viewport.prototype = {
         }
 
         var constraintApplied = xConstrained || yConstrained;
-        var newViewportBounds = constraintApplied ? this.viewerElementToViewportRectangle(newBounds) : bounds.clone();
+        var newViewportBounds = constraintApplied ? this.viewerElementToViewportRectangle(newBounds, false) : bounds.clone();
         newViewportBounds.xConstrained = xConstrained;
         newViewportBounds.yConstrained = yConstrained;
         newViewportBounds.constraintApplied = constraintApplied;
@@ -811,6 +811,7 @@ $.Viewport.prototype = {
             constrainedBounds;
 
         bounds = this.getBounds(current);
+        // bounds = this.getBoundsNoRotate(current);
 
         constrainedBounds = this._applyBoundaryConstraints(bounds);
 
diff --git a/test/demo/fitboundswithconstraints.html b/test/demo/fitboundswithconstraints.html
index d91c52e5..5851a424 100644
--- a/test/demo/fitboundswithconstraints.html
+++ b/test/demo/fitboundswithconstraints.html
@@ -81,8 +81,9 @@ setTimeout(() => viewport.applyConstraints(), 1000);</pre>
             tileSources: "../data/testpattern.dzi",
             minZoomImageRatio: 0,
             maxZoomPixelRatio: 10,
-            visibilityRatio:1.0,
+            visibilityRatio:1,
             constrainDuringPan:true,
+            // showNavigationControl:false,
         });
 
         viewer.addHandler("open", function(event) {
@@ -147,7 +148,29 @@ setTimeout(() => viewport.applyConstraints(), 1000);</pre>
                 });
             })
 
-            viewer.viewport.zoomTo(0.5, null, true);
+            viewer.viewport.zoomTo(1/2, null, true);
+
+            // viewer.viewport.panBy(new OpenSeadragon.Point(0.5, 0.5).minus(viewer.viewport.pointFromPixel(new OpenSeadragon.Point(0, 0))))
+            // setTimeout(()=>viewer.viewport.contentCoords(),1500);
+            // // setTimeout(()=>{
+            // //     viewer.viewport.rotateBy(-90, new OpenSeadragon.Point(0.5, 0.5));
+            // //     console.log('Rotated by -90')
+            // //     viewer.viewport.contentCoords();
+            // //     setTimeout(()=>{
+            // //         console.log('After rotation');
+            // //         viewer.viewport.contentCoords();
+            // //     },1500);
+            // // }, 2000)
+
+            // setTimeout(()=>{
+            //     viewer.viewport.zoomBy(2, new OpenSeadragon.Point(0.5, 0.5));
+            //     console.log('Zoomed by 2')
+            //     viewer.viewport.contentCoords();
+            //     setTimeout(()=>{
+            //         console.log('After zoom');
+            //         viewer.viewport.contentCoords();
+            //     },1500);
+            // }, 4500)
 
         });
         $('.method').on('click',function(){