Merge pull request #185 from robhobbes/master

Adding partial support for rotation.

src/drawer.js

@@ -407,6 +407,10 @@ $.Drawer.prototype = {
         }
 
         return loading;
+    },
+
+    canRotate: function() {
+        return USE_CANVAS;
     }
 };
 
@@ -509,6 +513,7 @@ function updateViewport( drawer ) {
                 Math.log( 2 )
             ))
         ),
+        degrees         = drawer.viewport.degrees,
         renderPixelRatioC,
         renderPixelRatioT,
         zeroRatioT,
@@ -533,7 +538,14 @@ function updateViewport( drawer ) {
         drawer.context.clearRect( 0, 0, viewportSize.x, viewportSize.y );
     }
 
-    //TODO
+    //Change bounds for rotation
+    if (degrees === 90 || degrees === 270) {
+        var rotatedBounds = viewportBounds.rotate( degrees );
+        viewportTL = rotatedBounds.getTopLeft();
+        viewportBR = rotatedBounds.getBottomRight();
+    }
+
+    //Don't draw if completely outside of the viewport
     if  ( !drawer.wrapHorizontal &&
         ( viewportBR.x < 0 || viewportTL.x > 1 ) ) {
         return;
@@ -575,6 +587,7 @@ function updateViewport( drawer ) {
             continue;
         }
 
+        //Perform calculations for draw if we haven't drawn this
         renderPixelRatioT = drawer.viewport.deltaPixelsFromPoints(
             drawer.source.getPixelRatio( level ),
             false
@@ -1117,7 +1130,7 @@ function drawOverlay( viewport, overlay, container ){
         overlay.bounds.getSize(),
         true
     );
-    overlay.drawHTML( container );
+    overlay.drawHTML( container, viewport );
 }
 
 function drawTiles( drawer, lastDrawn ){
@@ -1196,7 +1209,15 @@ function drawTiles( drawer, lastDrawn ){
         } else {
 
             if ( USE_CANVAS ) {
+                // TODO do this in a more performant way
+                // specifically, don't save,rotate,restore every time we draw a tile
+                if( drawer.viewport.degrees !== 0 ) {
+                    offsetForRotation( tile, drawer.canvas, drawer.context, drawer.viewport.degrees );
                     tile.drawCanvas( drawer.context );
+                    restoreRotationChanges( tile, drawer.canvas, drawer.context );
+                } else {
+                    tile.drawCanvas( drawer.context );
+                }
             } else {
                 tile.drawHTML( drawer.canvas );
             }
@@ -1222,6 +1243,32 @@ function drawTiles( drawer, lastDrawn ){
     }
 }
 
+function offsetForRotation( tile, canvas, context, degrees ){
+    var cx = canvas.width / 2,
+        cy = canvas.height / 2,
+        px = tile.position.x - cx,
+        py = tile.position.y - cy;
+
+    context.save();
+
+    context.translate(cx, cy);
+    context.rotate( Math.PI / 180 * degrees);
+    tile.position.x = px;
+    tile.position.y = py;
+}
+
+function restoreRotationChanges( tile, canvas, context ){
+    var cx = canvas.width / 2,
+        cy = canvas.height / 2,
+        px = tile.position.x + cx,
+        py = tile.position.y + cy;
+
+    tile.position.x = px;
+    tile.position.y = py;
+
+    context.restore();
+}
+
 
 function drawDebugInfo( drawer, tile, count, i ){
 

src/openseadragon.js

@@ -533,6 +533,9 @@ window.OpenSeadragon = window.OpenSeadragon || function( options ){
             navigatorPosition:      null,
             navigatorSizeRatio:     0.2,
 
+            // INITIAL ROTATION
+            degrees:                0,
+
             //REFERENCE STRIP SETTINGS
             showReferenceStrip:          false,
             referenceStripScroll:       'horizontal',

src/overlay.js

@@ -174,12 +174,18 @@
          * @function
          * @param {Element} container
          */
-        drawHTML: function( container ) {
+        drawHTML: function( container, viewport ) {
             var element = this.element,
                 style   = this.style,
                 scales  = this.scales,
+                drawerCenter = new $.Point(
+                    viewport.viewer.drawer.canvas.width / 2,
+                    viewport.viewer.drawer.canvas.height / 2
+                ),
+                degrees = viewport.degrees,
                 position,
-                size;
+                size,
+                overlayCenter;
 
             if ( element.parentNode != container ) {
                 //save the source parent for later if we need it
@@ -200,6 +206,23 @@
             position = position.apply( Math.floor );
             size     = size.apply( Math.ceil );
 
+            // rotate the position of the overlay
+            // TODO only rotate overlays if in canvas mode
+            // TODO replace the size rotation with CSS3 transforms
+            // TODO add an option to overlays to not rotate with the image
+            // Currently only rotates position and size
+            if( degrees !== 0 && this.scales ) {
+                overlayCenter = new $.Point( size.x / 2, size.y / 2 );
+
+                position = position.plus( overlayCenter ).rotate(
+                    degrees,
+                    drawerCenter
+                ).minus( overlayCenter );
+
+                size = size.rotate( degrees, new $.Point( 0, 0 ) );
+                size = new $.Point( Math.abs( size.x ), Math.abs( size.y ) );
+            }
+
             // call the onDraw callback if there is one to allow, this allows someone to overwrite
             // the drawing/positioning/sizing of the overlay
             if (this.onDraw) {

src/point.js

@@ -160,6 +160,21 @@ $.Point.prototype = {
         );
     },
 
+    /**
+     * Rotates the point around the specified pivot
+     * From http://stackoverflow.com/questions/4465931/rotate-rectangle-around-a-point
+     * @function
+     * @param {Number} degress to rotate around the pivot.
+     * @param {OpenSeadragon.Point} pivot Point about which to rotate.
+     * @returns {OpenSeadragon.Point}. A new point representing the point rotated around the specified pivot
+     */
+    rotate: function ( degrees, pivot ) {
+        var angle = degrees * Math.PI / 180.0,
+            x = Math.cos( angle ) * ( this.x - pivot.x ) - Math.sin( angle ) * ( this.y - pivot.y ) + pivot.x,
+            y = Math.sin( angle ) * ( this.x - pivot.x ) + Math.cos( angle ) * ( this.y - pivot.y ) + pivot.y;
+        return new $.Point( x, y );
+    },
+
     /**
      * Add another Point to this point and return a new Point.
      * @function

src/rectangle.js

@@ -69,14 +69,17 @@ $.Rect.prototype = {
     },
 
     /**
-     * Provides the coordinates of the upper-left corner of the rectanglea s a
+     * Provides the coordinates of the upper-left corner of the rectangle as a
      * point.
      * @function
      * @returns {OpenSeadragon.Point} The coordinate of the upper-left corner of
      *  the rectangle.
      */
     getTopLeft: function() {
-        return new $.Point( this.x, this.y );
+        return new $.Point(
+            this.x,
+            this.y
+        );
     },
 
     /**
@@ -93,10 +96,38 @@ $.Rect.prototype = {
         );
     },
 
+    /**
+     * Provides the coordinates of the top-right corner of the rectangle as a
+     * point.
+     * @function
+     * @returns {OpenSeadragon.Point} The coordinate of the top-right corner of
+     *  the rectangle.
+     */
+    getTopRight: function() {
+        return new $.Point(
+            this.x + this.width,
+            this.y
+        );
+    },
+
+    /**
+     * Provides the coordinates of the bottom-left corner of the rectangle as a
+     * point.
+     * @function
+     * @returns {OpenSeadragon.Point} The coordinate of the bottom-left corner of
+     *  the rectangle.
+     */
+    getBottomLeft: function() {
+        return new $.Point(
+            this.x,
+            this.y + this.height
+        );
+    },
+
     /**
      * Computes the center of the rectangle.
      * @function
-     * @returns {OpenSeadragon.Point} The center of the rectangle as represnted
+     * @returns {OpenSeadragon.Point} The center of the rectangle as represented
      *  as represented by a 2-dimensional vector (x,y)
      */
     getCenter: function() {
@@ -109,7 +140,7 @@ $.Rect.prototype = {
     /**
      * Returns the width and height component as a vector OpenSeadragon.Point
      * @function
-     * @returns {OpenSeadragon.Point} The 2 dimensional vector represnting the
+     * @returns {OpenSeadragon.Point} The 2 dimensional vector representing the
      *  the width and height of the rectangle.
      */
     getSize: function() {
@@ -117,7 +148,7 @@ $.Rect.prototype = {
     },
 
     /**
-     * Determines if two Rectanlges have equivalent components.
+     * Determines if two Rectangles have equivalent components.
      * @function
      * @param {OpenSeadragon.Rect} rectangle The Rectangle to compare to.
      * @return {Boolean} 'true' if all components are equal, otherwise 'false'.
@@ -131,7 +162,62 @@ $.Rect.prototype = {
     },
 
     /**
-     * Provides a string representation of the retangle which is useful for
+     * Rotates a rectangle around a point. Currently only 90, 180, and 270
+     * degrees are supported.
+     * @function
+     * @param {Number} degrees The angle in degrees to rotate.
+     * @param {OpenSeadragon.Point} pivot The point about which to rotate.
+     * Defaults to the center of the rectangle.
+     * @return {OpenSeadragon.Rect}
+     */
+    rotate: function( degrees, pivot ) {
+        // TODO support arbitrary rotation
+        var width = this.width,
+            height = this.height,
+            newTopLeft;
+
+        degrees = ( degrees + 360 ) % 360;
+        if( degrees % 90 !== 0 ) {
+            throw new Error('Currently only 0, 90, 180, and 270 degrees are supported.');
+        }
+
+        if( degrees === 0 ){
+            return new $.Rect(
+                this.x,
+                this.y,
+                this.width,
+                this.height
+            );
+        }
+
+        pivot = pivot || this.getCenter();
+
+        switch ( degrees ) {
+            case 90:
+                newTopLeft = this.getBottomLeft();
+                width = this.height;
+                height = this.width;
+                break;
+            case 180:
+                newTopLeft = this.getBottomRight();
+                break;
+            case 270:
+                newTopLeft = this.getTopRight();
+                width = this.height;
+                height = this.width;
+                break;
+            default:
+                newTopLeft = this.getTopLeft();
+                break;
+        }
+
+        newTopLeft = newTopLeft.rotate(degrees, pivot);
+
+        return new $.Rect(newTopLeft.x, newTopLeft.y, width, height);
+    },
+
+    /**
+     * Provides a string representation of the rectangle which is useful for
      * debugging.
      * @function
      * @returns {String} A string representation of the rectangle.

src/viewport.js

@@ -79,7 +79,8 @@ $.Viewport = function( options ) {
         wrapVertical:       $.DEFAULT_SETTINGS.wrapVertical,
         defaultZoomLevel:   $.DEFAULT_SETTINGS.defaultZoomLevel,
         minZoomLevel:       $.DEFAULT_SETTINGS.minZoomLevel,
-        maxZoomLevel:       $.DEFAULT_SETTINGS.maxZoomLevel
+        maxZoomLevel:       $.DEFAULT_SETTINGS.maxZoomLevel,
+        degrees:            $.DEFAULT_SETTINGS.degrees
 
     }, options );
 
@@ -500,6 +501,7 @@ $.Viewport.prototype = {
             this.centerSpringX.target.value,
             this.centerSpringY.target.value
         );
+        delta = delta.rotate( -this.degrees, new $.Point( 0, 0 ) );
         return this.panTo( center.plus( delta ), immediately );
     },
 
@@ -534,6 +536,12 @@ $.Viewport.prototype = {
      * @return {OpenSeadragon.Viewport} Chainable.
      */
     zoomBy: function( factor, refPoint, immediately ) {
+        if( refPoint ) {
+            refPoint = refPoint.rotate(
+                -this.degrees,
+                new $.Point( this.centerSpringX.target.value, this.centerSpringY.target.value )
+            );
+        }
         return this.zoomTo( this.zoomSpring.target.value * factor, refPoint, immediately );
     },
 
@@ -565,6 +573,40 @@ $.Viewport.prototype = {
         return this;
     },
 
+    /**
+     * Currently only 90 degree rotation is supported and it only works
+     * with the canvas. Additionally, the navigator does not rotate yet,
+     * debug mode doesn't rotate yet, and overlay rotation is only
+     * partially supported.
+     * @function
+     * @name OpenSeadragon.Viewport.prototype.setRotation
+     * @return {OpenSeadragon.Viewport} Chainable.
+     */
+    setRotation: function( degrees ) {
+        if( !( this.viewer && this.viewer.drawer.canRotate() ) ) {
+            return this;
+        }
+
+        degrees = ( degrees + 360 ) % 360;
+        if( degrees % 90 !== 0 ) {
+            throw new Error('Currently only 0, 90, 180, and 270 degrees are supported.');
+        }
+        this.degrees = degrees;
+        this.viewer.drawer.update();
+        
+        return this;
+    },
+
+    /**
+     * Gets the current rotation in degrees.
+     * @function
+     * @name OpenSeadragon.Viewport.prototype.setRotation
+     * @return {Number} The current rotation in degrees.
+     */
+    getRotation: function() {
+        return this.degrees;
+    },
+
     /**
      * @function
      * @return {OpenSeadragon.Viewport} Chainable.