Merge master

CITATION.cff

@@ -0,0 +1,39 @@
+cff-version: 1.2.0
+title: OpenSeadragon
+message: "If you use this software, please cite it using the metadata from this file."
+type: software
+authors:
+  - given-names: Ian
+    family-names: Gilman
+    email: ian@iangilman.com
+  - given-names: Aseem
+    family-names: Kishore
+  - given-names: Chris
+    family-names: Thatcher
+  - given-names: Mark
+    family-names: Salsbery
+  - given-names: Antoine
+    family-names: Vandecreme
+  - given-names: Thomas
+    family-names: Pearce
+identifiers:
+  - type: url
+    value: https://openseadragon.github.io/
+    description: Homepage
+  - type: url
+    value: https://github.com/openseadragon/openseadragon
+    description: Repository
+repository-code: https://github.com/openseadragon/openseadragon
+url: https://openseadragon.github.io/
+abstract: "An open-source, web-based viewer for high-resolution zoomable images, implemented in pure JavaScript, for desktop and mobile."
+keywords:
+  - javascript
+  - image
+  - zooming
+  - viewer
+  - image-viewer
+  - high-resolution
+  - iiif
+license: BSD-3-Clause
+version: 4.1.1
+date-released: 2024-04-01

changelog.txt

@@ -5,18 +5,27 @@ OPENSEADRAGON CHANGELOG
 
 * BREAKING CHANGE: Dropped support for IE11 (#2300, #2361 @AndrewADev)
 * DEPRECATION: The OpenSeadragon.createCallback function is no longer recommended (#2367 @akansjain)
-* The viewer now uses WebGL when available (#2310, #2462, #2466, #2468, #2469, #2472, #2478 @pearcetm, @Aiosa, @thec0keman)
+* The viewer now uses WebGL when available (#2310, #2462, #2466, #2468, #2469, #2472, #2478, #2488, #2492 @pearcetm, @Aiosa, @thec0keman)
 * Added webp to supported image formats (#2455 @BeebBenjamin)
 * Introduced maxTilesPerFrame option to allow loading more tiles simultaneously (#2387 @jetic83)
 * Now when creating a viewer or navigator, we leave its position style alone if possible (#2393 @VIRAT9358)
+* Added getter & setter for Viewport.maxZoomPixelRatio (#2506 @eug-L)
 * Test improvements (#2382 @AndrewADev)
 * MouseTracker options documentation fixes (#2389 @msalsbery)
+* Improved documentation and error message for Viewport.imageToViewportZoom (#2505 @eug-L)
+* Fixed documentation typos (#2507 @frameflare)
 * Fixed: Sometimes if the viewport was flipped and the user zoomed in far enough, it would flip back (#2364 @SebDelile)
-* Fixed: Strange behavior if IIIF sizes were not in ascending order (#2416 @lutzhelm)
 * Fixed: Two-finger tap on a Mac trackpad would zoom you out (#2431 @cavenel)
 * Fixed: dragToPan gesture could not be disabled when flickEnabled was activated (#2464 @jonasengelmann)
 * Fixed: placeholderFillStyle didn't work properly when the image was rotated (#2469 @pearcetm)
 * Fixed: Sometimes exponential springs wouldn't ever settle (#2469 @pearcetm)
+* Fixed: The navigator wouldn't update its tracking rectangle when the navigator was resized (#2491 @pearcetm)
+* Fixed: The drawer would improperly crop when the viewport was flipped and a tiled image was rotated (#2511 @pearcetm, @eug-L)
+* Fixed: Flipped viewport caused image to be flipped again when going fullscreen or resizing (#2518 @pearcetm)
+
+4.1.1:
+
+* Fixed: Strange behavior if IIIF sizes were not in ascending order (#2416 @lutzhelm)
 
 4.1.0:
 

package.json

@@ -1,6 +1,6 @@
 {
     "name": "openseadragon",
-    "version": "4.1.0",
+    "version": "4.1.1",
     "description": "Provides a smooth, zoomable user interface for HTML/Javascript.",
     "keywords": [
         "image",
@@ -48,4 +48,4 @@
         "test": "grunt test",
         "prepare": "grunt build"
     }
-}
+}

src/canvasdrawer.js

@@ -80,7 +80,6 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         // Canvas default is "true", so this will only be changed if user specifies "false" in the options or via setImageSmoothinEnabled.
         this._imageSmoothingEnabled = true;
 
-
         // Since the tile-drawn and tile-drawing events are fired by this drawer, make sure handlers can be added for them
         this.viewer.allowEventHandler("tile-drawn");
         this.viewer.allowEventHandler("tile-drawing");
@@ -119,7 +118,9 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
      */
     draw(tiledImages) {
         this._prepareNewFrame(); // prepare to draw a new frame
-
+        if(this.viewer.viewport.getFlip() !== this._viewportFlipped){
+            this._flip();
+        }
         for(const tiledImage of tiledImages){
             if (tiledImage.opacity !== 0) {
                 this._drawTiles(tiledImage);
@@ -147,10 +148,12 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
     }
 
     /**
+     * @param {TiledImage} tiledImage the tiled image that is calling the function
      * @returns {Boolean} Whether this drawer requires enforcing minimum tile overlap to avoid showing seams.
+     * @private
      */
-    minimumOverlapRequired() {
-       return true;
+    minimumOverlapRequired(tiledImage) {
+        return true;
     }
 
 
@@ -189,6 +192,14 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         context.restore();
     }
 
+    /**
+     * Test whether the current context is flipped or not
+     * @private
+     */
+    get _viewportFlipped(){
+        return this.context.getTransform().a < 0;
+    }
+
     /**
      * Fires the tile-drawing event.
      * @private
@@ -310,13 +321,6 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
                     tiledImage.getClippedBounds(true))
                     .getIntegerBoundingBox();
 
-                if(this.viewer.viewport.getFlip()) {
-                    if (this.viewport.getRotation(true) % 360 !== 0 ||
-                        tiledImage.getRotation(true) % 360 !== 0) {
-                        bounds.x = this.viewer.container.clientWidth - (bounds.x + bounds.width);
-                    }
-                }
-
                 bounds = bounds.times($.pixelDensityRatio);
             }
             this._clear(true, bounds);
@@ -325,27 +329,7 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         // When scaling, we must rotate only when blending the sketch canvas to
         // avoid interpolation
         if (!sketchScale) {
-            if (this.viewport.getRotation(true) % 360 !== 0) {
-                this._offsetForRotation({
-                    degrees: this.viewport.getRotation(true),
-                    useSketch: useSketch
-                });
-            }
-            if (tiledImage.getRotation(true) % 360 !== 0) {
-                this._offsetForRotation({
-                    degrees: tiledImage.getRotation(true),
-                    point: this.viewport.pixelFromPointNoRotate(
-                        tiledImage._getRotationPoint(true), true),
-                    useSketch: useSketch
-                });
-            }
-
-            if (this.viewport.getRotation(true) % 360 === 0 &&
-                tiledImage.getRotation(true) % 360 === 0) {
-                if(this.viewer.viewport.getFlip()) {
-                    this._flip();
-                }
-            }
+            this._setRotations(tiledImage, useSketch);
         }
 
         let usedClip = false;
@@ -465,20 +449,7 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
 
         if (useSketch) {
             if (sketchScale) {
-                if (this.viewport.getRotation(true) % 360 !== 0) {
-                    this._offsetForRotation({
-                        degrees: this.viewport.getRotation(true),
-                        useSketch: false
-                    });
-                }
-                if (tiledImage.getRotation(true) % 360 !== 0) {
-                    this._offsetForRotation({
-                        degrees: tiledImage.getRotation(true),
-                        point: this.viewport.pixelFromPointNoRotate(
-                            tiledImage._getRotationPoint(true), true),
-                        useSketch: false
-                    });
-                }
+                this._setRotations(tiledImage);
             }
             this.blendSketch({
                 opacity: tiledImage.opacity,
@@ -497,15 +468,6 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
             }
         }
 
-        if (!sketchScale) {
-            if (this.viewport.getRotation(true) % 360 === 0 &&
-                tiledImage.getRotation(true) % 360 === 0) {
-                if(this.viewer.viewport.getFlip()) {
-                    this._flip();
-                }
-            }
-        }
-
         this._drawDebugInfo( tiledImage, lastDrawn );
 
         // Fire tiled-image-drawn event.
@@ -587,7 +549,6 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
             size     = tile.size.times($.pixelDensityRatio);
 
         context.save();
-        // context.globalAlpha = this.options.opacity; // this was deprecated previously and should not be applied as it is set per TiledImage
 
         if (typeof scale === 'number' && scale !== 1) {
             // draw tile at a different scale
@@ -835,21 +796,10 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         context.strokeStyle = this.debugGridColor[colorIndex];
         context.fillStyle = this.debugGridColor[colorIndex];
 
-        if (this.viewport.getRotation(true) % 360 !== 0 ) {
-            this._offsetForRotation({degrees: this.viewport.getRotation(true)});
-        }
-        if (tiledImage.getRotation(true) % 360 !== 0) {
-            this._offsetForRotation({
-                degrees: tiledImage.getRotation(true),
-                point: tiledImage.viewport.pixelFromPointNoRotate(
-                    tiledImage._getRotationPoint(true), true)
-            });
-        }
-        if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
-            tiledImage.getRotation(true) % 360 === 0) {
-            if(tiledImage._drawer.viewer.viewport.getFlip()) {
-                tiledImage._drawer._flip();
-            }
+        this._setRotations(tiledImage);
+
+        if(this._viewportFlipped){
+            this._flip({point: tile.position.plus(tile.size.divide(2))});
         }
 
         context.strokeRect(
@@ -864,7 +814,8 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
 
         // Rotate the text the right way around.
         context.translate( tileCenterX, tileCenterY );
-        context.rotate( Math.PI / 180 * -this.viewport.getRotation(true) );
+        const angleInDegrees = this.viewport.getRotation(true);
+        context.rotate( Math.PI / 180 * -angleInDegrees );
         context.translate( -tileCenterX, -tileCenterY );
 
         if( tile.x === 0 && tile.y === 0 ){
@@ -917,13 +868,6 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
             this._restoreRotationChanges();
         }
 
-        if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
-            tiledImage.getRotation(true) % 360 === 0) {
-            if(tiledImage._drawer.viewer.viewport.getFlip()) {
-                tiledImage._drawer._flip();
-            }
-        }
-
         context.restore();
     }
 
@@ -954,6 +898,33 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         return new $.Point(this.canvas.width / 2, this.canvas.height / 2);
     }
 
+    /**
+     * Set rotations for viewport & tiledImage
+     * @private
+     * @param {OpenSeadragon.TiledImage} tiledImage
+     * @param {Boolean} [useSketch=false]
+     */
+    _setRotations(tiledImage, useSketch = false) {
+        var saveContext = false;
+        if (this.viewport.getRotation(true) % 360 !== 0) {
+            this._offsetForRotation({
+                degrees: this.viewport.getRotation(true),
+                useSketch: useSketch,
+                saveContext: saveContext
+            });
+            saveContext = false;
+        }
+        if (tiledImage.getRotation(true) % 360 !== 0) {
+            this._offsetForRotation({
+                degrees: tiledImage.getRotation(true),
+                point: this.viewport.pixelFromPointNoRotate(
+                    tiledImage._getRotationPoint(true), true),
+                useSketch: useSketch,
+                saveContext: saveContext
+            });
+        }
+    }
+
     // private
     _offsetForRotation(options) {
         var point = options.point ?
@@ -964,26 +935,21 @@ class CanvasDrawer extends OpenSeadragon.DrawerBase{
         context.save();
 
         context.translate(point.x, point.y);
-        if(this.viewer.viewport.flipped){
-          context.rotate(Math.PI / 180 * -options.degrees);
-          context.scale(-1, 1);
-        } else{
-          context.rotate(Math.PI / 180 * options.degrees);
-        }
+        context.rotate(Math.PI / 180 * options.degrees);
         context.translate(-point.x, -point.y);
     }
 
     // private
     _flip(options) {
-      options = options || {};
-      var point = options.point ?
+        options = options || {};
+        var point = options.point ?
         options.point.times($.pixelDensityRatio) :
         this._getCanvasCenter();
-      var context = this._getContext(options.useSketch);
+        var context = this._getContext(options.useSketch);
 
-      context.translate(point.x, 0);
-      context.scale(-1, 1);
-      context.translate(-point.x, 0);
+        context.translate(point.x, 0);
+        context.scale(-1, 1);
+        context.translate(-point.x, 0);
     }
 
     // private

src/drawerbase.js

@@ -188,10 +188,11 @@ OpenSeadragon.DrawerBase = class DrawerBase{
     }
 
     /**
+     * @param {TiledImage} tiledImage the tiled image that is calling the function
      * @returns {Boolean} Whether this drawer requires enforcing minimum tile overlap to avoid showing seams.
      * @private
      */
-    minimumOverlapRequired() {
+    minimumOverlapRequired(tiledImage) {
         return false;
     }
 

src/htmldrawer.js

@@ -90,11 +90,13 @@ class HTMLDrawer extends OpenSeadragon.DrawerBase{
     }
 
     /**
+     * @param {TiledImage} tiledImage the tiled image that is calling the function
      * @returns {Boolean} Whether this drawer requires enforcing minimum tile overlap to avoid showing seams.
+     * @private
      */
-    minimumOverlapRequired() {
+    minimumOverlapRequired(tiledImage) {
         return true;
-     }
+    }
 
     /**
      * create the HTML element (e.g. canvas, div) that the image will be drawn into

src/navigator.js

@@ -309,6 +309,7 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
                 this.oldContainerSize = containerSize;
                 this.world.update();
                 this.world.draw();
+                this.update(this.viewer.viewport);
             }
         }
     },
@@ -355,7 +356,7 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
     /**
      * Used to update the navigator minimap's viewport rectangle when a change in the viewer's viewport occurs.
      * @function
-     * @param {OpenSeadragon.Viewport} The viewport this navigator is tracking.
+     * @param {OpenSeadragon.Viewport} [viewport] The viewport to display. Default: the viewport this navigator is tracking.
      */
     update: function( viewport ) {
 
@@ -366,6 +367,10 @@ $.extend( $.Navigator.prototype, $.EventSource.prototype, $.Viewer.prototype, /*
             topleft,
             bottomright;
 
+        if(!viewport){
+            viewport = this.viewer.viewport;
+        }
+
         viewerSize = $.getElementSize( this.viewer.element );
         if ( this._resizeWithViewer && viewerSize.x && viewerSize.y && !viewerSize.equals( this.oldViewerSize ) ) {
             this.oldViewerSize = viewerSize;

src/tiledimage.js

@@ -1741,7 +1741,7 @@ $.extend($.TiledImage.prototype, $.EventSource.prototype, /** @lends OpenSeadrag
             tileCenter = positionT.plus( sizeT.divide( 2 ) ),
             tileSquaredDistance = viewportCenter.squaredDistanceTo( tileCenter );
 
-        if(this.viewer.drawer.minimumOverlapRequired()){
+        if(this.viewer.drawer.minimumOverlapRequired(this)){
             if ( !overlap ) {
                 sizeC = sizeC.plus( new $.Point(1, 1));
             }

src/tilesource.js

@@ -585,13 +585,13 @@ $.TileSource.prototype = {
     },
 
     /**
-     * Responsible determining if a the particular TileSource supports the
+     * Responsible for determining if the particular TileSource supports the
      * data format ( and allowed to apply logic against the url the data was
      * loaded from, if any ). Overriding implementations are expected to do
      * something smart with data and / or url to determine support.  Also
-     * understand that iteration order of TileSources is not guarunteed so
+     * understand that iteration order of TileSources is not guaranteed so
      * please make sure your data or url is expressive enough to ensure a simple
-     * and sufficient mechanisim for clear determination.
+     * and sufficient mechanism for clear determination.
      * @function
      * @param {String|Object|Array|Document} data
      * @param {String} url - the url the data was loaded
@@ -828,7 +828,7 @@ $.TileSource.prototype = {
         };
 
         // Load the tile with an AJAX request if the loadWithAjax option is
-        // set. Otherwise load the image by setting the source proprety of the image object.
+        // set. Otherwise load the image by setting the source property of the image object.
         if (context.loadWithAjax) {
             dataStore.request = $.makeAjaxRequest({
                 url: context.src,

src/viewer.js

@@ -2206,7 +2206,7 @@ $.extend( $.Viewer.prototype, $.EventSource.prototype, $.ControlDock.prototype,
      *      viewport which the location coordinates will be treated as relative
      *      to.
      * @param {function} [onDraw] - If supplied the callback is called when the overlay
-     *      needs to be drawn. It it the responsibility of the callback to do any drawing/positioning.
+     *      needs to be drawn. It is the responsibility of the callback to do any drawing/positioning.
      *      It is passed position, size and element.
      * @returns {OpenSeadragon.Viewer} Chainable.
      * @fires OpenSeadragon.Viewer.event:add-overlay

src/viewport.js

@@ -1711,7 +1711,7 @@ $.Viewport.prototype = {
      * 1 means original image size, 0.5 half size...
      * Viewport zoom: ratio of the displayed image's width to viewport's width.
      * 1 means identical width, 2 means image's width is twice the viewport's width...
-     * Note: not accurate with multi-image.
+     * Note: not accurate with multi-image; use [TiledImage.imageToViewportZoom] for the specific image of interest.
      * @function
      * @param {Number} imageZoom The image zoom
      * target zoom.
@@ -1723,7 +1723,7 @@ $.Viewport.prototype = {
             if (count > 1) {
                 if (!this.silenceMultiImageWarnings) {
                     $.console.error('[Viewport.imageToViewportZoom] is not accurate ' +
-                        'with multi-image.');
+                        'with multi-image. Instead, use [TiledImage.imageToViewportZoom] for the specific image of interest');
                 }
             } else if (count === 1) {
                 // It is better to use TiledImage.imageToViewportZoom
@@ -1789,7 +1789,41 @@ $.Viewport.prototype = {
        */
       this.viewer.raiseEvent('flip', {flipped: state});
       return this;
-    }
+    },
+
+    /**
+     * Gets current max zoom pixel ratio
+     * @function
+     * @returns {Number} Max zoom pixel ratio
+     */
+    getMaxZoomPixelRatio: function() {
+        return this.maxZoomPixelRatio;
+    },
+
+    /**
+     * Sets max zoom pixel ratio
+     * @function
+     * @param {Number} ratio - Max zoom pixel ratio
+     * @param {Boolean} [applyConstraints=true] - Apply constraints after setting ratio;
+     * Takes effect only if current zoom is greater than set max zoom pixel ratio
+     * @param {Boolean} [immediately=false] - Whether to animate to new zoom
+     */
+    setMaxZoomPixelRatio: function(ratio, applyConstraints = true, immediately = false) {
+
+        $.console.assert(!isNaN(ratio), "[Viewport.setMaxZoomPixelRatio] ratio must be a number");
+
+        if (isNaN(ratio)) {
+            return;
+        }
+
+        this.maxZoomPixelRatio = ratio;
+
+        if (applyConstraints) {
+            if (this.getZoom() > this.getMaxZoom()) {
+                this.applyConstraints(immediately);
+            }
+        }
+    },
 
 };
 

src/webgldrawer.js

@@ -206,6 +206,16 @@
             return 'webgl';
         }
 
+        /**
+         * @param {TiledImage} tiledImage the tiled image that is calling the function
+         * @returns {Boolean} Whether this drawer requires enforcing minimum tile overlap to avoid showing seams.
+         * @private
+         */
+        minimumOverlapRequired(tiledImage) {
+            // return true if the tiled image is tainted, since the backup canvas drawer will be used.
+            return tiledImage.isTainted();
+        }
+
         /**
         * create the HTML element (canvas in this case) that the image will be drawn into
         * @private
@@ -347,7 +357,7 @@
                         // This can apparently happen on some systems if too many WebGL contexts have been created
                         // in which case maxTextures can be null, leading to out of bounds errors with the array.
                         // For example, when viewers were created and not destroyed in the test suite, this error
-                        // occured in the TravisCI tests, though it did not happen when testing locally either in
+                        // occurred in the TravisCI tests, though it did not happen when testing locally either in
                         // a browser or on the command line via grunt test.
 
                         throw(new Error(`WegGL error: bad value for gl parameter MAX_TEXTURE_IMAGE_UNITS (${maxTextures}). This could happen
@@ -513,10 +523,14 @@
             }
             this._outputContext.restore();
             if(tiledImage.debugMode){
-                let colorIndex = this.viewer.world.getIndexOfItem(tiledImage) % this.debugGridColor.length;
-                let strokeStyle = this.debugGridColor[colorIndex];
-                let fillStyle = this.debugGridColor[colorIndex];
-                this._drawDebugInfo(tilesToDraw, tiledImage, strokeStyle, fillStyle);
+                const flipped = this.viewer.viewport.getFlip();
+                if(flipped){
+                    this._flip();
+                }
+                this._drawDebugInfo(tilesToDraw, tiledImage, flipped);
+                if(flipped){
+                    this._flip();
+                }
             }
 
 
@@ -998,32 +1012,64 @@
             this._clippingContext.restore();
         }
 
+        /**
+         * Set rotations for viewport & tiledImage
+         * @private
+         * @param {OpenSeadragon.TiledImage} tiledImage
+         */
+        _setRotations(tiledImage) {
+            var saveContext = false;
+            if (this.viewport.getRotation(true) % 360 !== 0) {
+                this._offsetForRotation({
+                    degrees: this.viewport.getRotation(true),
+                    saveContext: saveContext
+                });
+                saveContext = false;
+            }
+            if (tiledImage.getRotation(true) % 360 !== 0) {
+                this._offsetForRotation({
+                    degrees: tiledImage.getRotation(true),
+                    point: this.viewport.pixelFromPointNoRotate(
+                        tiledImage._getRotationPoint(true), true),
+                    saveContext: saveContext
+                });
+            }
+        }
+
         // private
         _offsetForRotation(options) {
             var point = options.point ?
                 options.point.times($.pixelDensityRatio) :
-                new $.Point(this._outputCanvas.width / 2, this._outputCanvas.height / 2);
+                this._getCanvasCenter();
 
             var context = this._outputContext;
             context.save();
 
             context.translate(point.x, point.y);
-            if(this.viewport.flipped){
-                context.rotate(Math.PI / 180 * -options.degrees);
-                context.scale(-1, 1);
-            } else{
-                context.rotate(Math.PI / 180 * options.degrees);
-            }
+            context.rotate(Math.PI / 180 * options.degrees);
             context.translate(-point.x, -point.y);
         }
 
         // private
-        _drawDebugInfo( tilesToDraw, tiledImage, stroke, fill ) {
+        _flip(options) {
+            options = options || {};
+            var point = options.point ?
+            options.point.times($.pixelDensityRatio) :
+            this._getCanvasCenter();
+            var context = this._outputContext;
+
+            context.translate(point.x, 0);
+            context.scale(-1, 1);
+            context.translate(-point.x, 0);
+        }
+
+        // private
+        _drawDebugInfo( tilesToDraw, tiledImage, flipped ) {
 
             for ( var i = tilesToDraw.length - 1; i >= 0; i-- ) {
                 var tile = tilesToDraw[ i ].tile;
                 try {
-                    this._drawDebugInfoOnTile(tile, tilesToDraw.length, i, tiledImage, stroke, fill);
+                    this._drawDebugInfoOnTile(tile, tilesToDraw.length, i, tiledImage, flipped);
                 } catch(e) {
                     $.console.error(e);
                 }
@@ -1031,30 +1077,20 @@
         }
 
         // private
-        _drawDebugInfoOnTile(tile, count, i, tiledImage, stroke, fill) {
+        _drawDebugInfoOnTile(tile, count, i, tiledImage, flipped) {
 
-            var context = this._outputContext;
+            var colorIndex = this.viewer.world.getIndexOfItem(tiledImage) % this.debugGridColor.length;
+            var context = this.context;
             context.save();
             context.lineWidth = 2 * $.pixelDensityRatio;
             context.font = 'small-caps bold ' + (13 * $.pixelDensityRatio) + 'px arial';
-            context.strokeStyle = stroke;
-            context.fillStyle = fill;
+            context.strokeStyle = this.debugGridColor[colorIndex];
+            context.fillStyle = this.debugGridColor[colorIndex];
 
-            if (this.viewport.getRotation(true) % 360 !== 0 ) {
-                this._offsetForRotation({degrees: this.viewport.getRotation(true)});
-            }
-            if (tiledImage.getRotation(true) % 360 !== 0) {
-                this._offsetForRotation({
-                    degrees: tiledImage.getRotation(true),
-                    point: tiledImage.viewport.pixelFromPointNoRotate(
-                        tiledImage._getRotationPoint(true), true)
-                });
-            }
-            if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
-                tiledImage.getRotation(true) % 360 === 0) {
-                if(tiledImage._drawer.viewer.viewport.getFlip()) {
-                    tiledImage._drawer._flip();
-                }
+            this._setRotations(tiledImage);
+
+            if(flipped){
+                this._flip({point: tile.position.plus(tile.size.divide(2))});
             }
 
             context.strokeRect(
@@ -1069,7 +1105,8 @@
 
             // Rotate the text the right way around.
             context.translate( tileCenterX, tileCenterY );
-            context.rotate( Math.PI / 180 * -this.viewport.getRotation(true) );
+            const angleInDegrees = this.viewport.getRotation(true);
+            context.rotate( Math.PI / 180 * -angleInDegrees );
             context.translate( -tileCenterX, -tileCenterY );
 
             if( tile.x === 0 && tile.y === 0 ){
@@ -1122,13 +1159,6 @@
                 this._restoreRotationChanges();
             }
 
-            if (tiledImage.viewport.getRotation(true) % 360 === 0 &&
-                tiledImage.getRotation(true) % 360 === 0) {
-                if(tiledImage._drawer.viewer.viewport.getFlip()) {
-                    tiledImage._drawer._flip();
-                }
-            }
-
             context.restore();
         }
 
@@ -1156,6 +1186,15 @@
 
         }
 
+        /**
+         * Get the canvas center
+         * @private
+         * @returns {OpenSeadragon.Point} The center point of the canvas
+         */
+        _getCanvasCenter() {
+            return new $.Point(this.canvas.width / 2, this.canvas.height / 2);
+        }
+
         // private
         _restoreRotationChanges() {
             var context = this._outputContext;

src/world.js

@@ -277,11 +277,14 @@ $.extend( $.World.prototype, $.EventSource.prototype, /** @lends OpenSeadragon.W
      * Draws all items.
      */
     draw: function() {
-        this.viewer.drawer.draw(this._items);
-        this._needsDraw = false;
-        for (let item of this._items) {
-            this._needsDraw = item.setDrawn() || this._needsDraw;
-        }
+        return new $.Promise((resolve) => {
+            this.viewer.drawer.draw(this._items);
+            this._needsDraw = false;
+            for (let item of this._items) {
+                this._needsDraw = item.setDrawn() || this._needsDraw;
+            }
+            resolve();
+        });
     },
 
     /**

test/demo/basic2.html

@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <title>OpenSeadragon maxTilesPerFrame Demo</title>
+    <script type="text/javascript" src='../../build/openseadragon/openseadragon.js'></script>
+    <script type="text/javascript" src='../lib/jquery-1.9.1.min.js'></script>
+    <style type="text/css">
+
+        .openseadragon1 {
+            width: 100vw;
+            height: 100vh;
+        }
+
+    </style>
+</head>
+<body>
+<div>
+    Simple demo page to show an OpenSeadragon viewer with a higher maxTilesPerFrame.
+</div>
+<div id="contentDiv" class="openseadragon1"></div>
+<script type="text/javascript">
+
+    var viewer = OpenSeadragon({
+        debugMode: true,
+        id: "contentDiv",
+        prefixUrl: "../../build/openseadragon/images/",
+        tileSources:  "https://openseadragon.github.io/example-images/duomo/duomo.dzi",
+        showNavigator:true,
+        debugMode:true,
+        maxTilesPerFrame:3,
+    });
+
+</script>
+</body>
+</html>

test/modules/iiif.js

@@ -243,7 +243,7 @@
         /*
          * FIXME: following https://iiif.io/api/image/3.0/#47-canonical-uri-syntax and
          * https://iiif.io/api/image/2.1/#canonical-uri-syntax, I'd expect 'max' to be required to
-         * be served by a level 0 compliant service instead of 'w,h', 'full' instead of 'w,' respectivley.
+         * be served by a level 0 compliant service instead of 'w,h', 'full' instead of 'w,' respectively.
          */
         //assert.equal(levelsVersion3[1].url, 'http://example.com/identifier/full/max/0/default.jpg');
     });

test/modules/viewport.js

@@ -1407,4 +1407,25 @@
       viewer.open(DZI_PATH);
     });
 
+    QUnit.test('setMaxZoomPixelRatio', function(assert) {
+      var done = assert.async();
+      var openHandler = function(event) {
+          viewer.removeHandler('open', openHandler);
+          var viewport = viewer.viewport;
+
+          for (var i = 0; i < testZoomLevels.length; i++) {
+              viewport.setMaxZoomPixelRatio(testZoomLevels[i])
+              assert.equal(viewport.getMaxZoomPixelRatio(), testZoomLevels[i], "Max zoom pixel ratio is set correctly.");
+          }
+
+          viewport.zoomTo(viewport.getMaxZoom())
+          viewport.setMaxZoomPixelRatio(testZoomLevels[0], true)
+          assert.equal(viewport.getZoom(), viewport.getMaxZoom(), "Zoom should be adjusted to max zoom level.");
+
+          done();
+      };
+      viewer.addHandler('open', openHandler);
+      viewer.open(DZI_PATH);
+    });
+
 })();