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Fix wrong center point on touch zoom

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When doing pinch to zoom, we need to do pan first and then zoom, so that the center point is correct.
Otherwise, the pan will computed on the unzoomed coordinates, giving an impression of zooming toward the center
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Christophe Avenel 2022-05-12 10:45:47 +02:00 • committed by GitHub
parent 165aaebd4c
commit f1865c3878
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GPG key ID: 4AEE18F83AFDEB23
1 changed files with 3 additions and 3 deletions
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6
src/viewer.js
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@ -3289,9 +3289,6 @@ function onCanvasPinch( event ) {
if ( gestureSettings.pinchToZoom &&
(!canvasPinchEventArgs.preventDefaultPanAction || !canvasPinchEventArgs.preventDefaultZoomAction) ) {
centerPt = this.viewport.pointFromPixel( event.center, true );
if ( !canvasPinchEventArgs.preventDefaultZoomAction ) {
this.viewport.zoomBy( event.distance / event.lastDistance, centerPt, true );
}
if ( gestureSettings.zoomToRefPoint && !canvasPinchEventArgs.preventDefaultPanAction ) {
lastCenterPt = this.viewport.pointFromPixel( event.lastCenter, true );
panByPt = lastCenterPt.minus( centerPt );
@ -3303,6 +3300,9 @@ function onCanvasPinch( event ) {
}
this.viewport.panBy(panByPt, true);
}
if ( !canvasPinchEventArgs.preventDefaultZoomAction ) {
this.viewport.zoomBy( event.distance / event.lastDistance, centerPt, true );
}
this.viewport.applyConstraints();
}
if ( gestureSettings.pinchRotate && !canvasPinchEventArgs.preventDefaultRotateAction ) {