/*
* OpenSeadragon - Drawer
*
* Copyright (C) 2009 CodePlex Foundation
* Copyright (C) 2010-2013 OpenSeadragon contributors
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* - Neither the name of CodePlex Foundation nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
(function( $ ){
var DEVICE_SCREEN = $.getWindowSize(),
BROWSER = $.Browser.vendor,
BROWSER_VERSION = $.Browser.version,
SUBPIXEL_RENDERING = (
( BROWSER == $.BROWSERS.FIREFOX ) ||
( BROWSER == $.BROWSERS.OPERA ) ||
( BROWSER == $.BROWSERS.SAFARI && BROWSER_VERSION >= 4 ) ||
( BROWSER == $.BROWSERS.CHROME && BROWSER_VERSION >= 2 ) ||
( BROWSER == $.BROWSERS.IE && BROWSER_VERSION >= 9 )
);
/**
* @class Drawer
* @classdesc Handles rendering of tiles for an {@link OpenSeadragon.Viewer}.
* A new instance is created for each TileSource opened (see {@link OpenSeadragon.Viewer#drawer}).
*
* @memberof OpenSeadragon
* @param {OpenSeadragon.TileSource} source - Reference to Viewer tile source.
* @param {OpenSeadragon.Viewport} viewport - Reference to Viewer viewport.
* @param {Element} element - Parent element.
*/
$.Drawer = function( options ) {
//backward compatibility for positional args while prefering more
//idiomatic javascript options object as the only argument
var args = arguments,
i;
if( !$.isPlainObject( options ) ){
options = {
source: args[ 0 ], // Reference to Viewer tile source.
viewport: args[ 1 ], // Reference to Viewer viewport.
element: args[ 2 ] // Parent element.
};
}
this._worldX = options.x || 0;
delete options.x;
this._worldY = options.y || 0;
delete options.y;
// Ratio of zoomable image height to width.
this.normHeight = options.source.dimensions.y / options.source.dimensions.x;
if ( options.width ) {
this._scale = options.width;
delete options.width;
if ( options.height ) {
$.console.error( "specifying both width and height to a drawer is not supported" );
delete options.height;
}
} else if ( options.height ) {
this._scale = options.height / this.normHeight;
delete options.height;
} else {
this._scale = 1;
}
this._worldWidth = this._scale;
this._worldHeight = this.normHeight * this._scale;
$.extend( true, this, {
//internal state properties
viewer: null,
imageLoader: new $.ImageLoader(),
tilesMatrix: {}, // A '3d' dictionary [level][x][y] --> Tile.
tilesLoaded: [], // An unordered list of Tiles with loaded images.
coverage: {}, // A '3d' dictionary [level][x][y] --> Boolean.
lastDrawn: [], // An unordered list of Tiles drawn last frame.
lastResetTime: 0, // Last time for which the drawer was reset.
midUpdate: false, // Is the drawer currently updating the viewport?
updateAgain: true, // Does the drawer need to update the viewport again?
//internal state / configurable settings
collectionOverlays: {}, // For collection mode. Here an overlay is actually a viewer.
//configurable settings
opacity: $.DEFAULT_SETTINGS.opacity,
maxImageCacheCount: $.DEFAULT_SETTINGS.maxImageCacheCount,
minZoomImageRatio: $.DEFAULT_SETTINGS.minZoomImageRatio,
wrapHorizontal: $.DEFAULT_SETTINGS.wrapHorizontal,
wrapVertical: $.DEFAULT_SETTINGS.wrapVertical,
immediateRender: $.DEFAULT_SETTINGS.immediateRender,
blendTime: $.DEFAULT_SETTINGS.blendTime,
alwaysBlend: $.DEFAULT_SETTINGS.alwaysBlend,
minPixelRatio: $.DEFAULT_SETTINGS.minPixelRatio,
debugMode: $.DEFAULT_SETTINGS.debugMode,
timeout: $.DEFAULT_SETTINGS.timeout,
crossOriginPolicy: $.DEFAULT_SETTINGS.crossOriginPolicy
}, options );
this.useCanvas = $.supportsCanvas && ( this.viewer ? this.viewer.useCanvas : true );
/**
* The parent element of this Drawer instance, passed in when the Drawer was created.
* The parent of {@link OpenSeadragon.Drawer#canvas}.
* @member {Element} container
* @memberof OpenSeadragon.Drawer#
*/
this.container = $.getElement( this.element );
/**
* A <canvas> element if the browser supports them, otherwise a <div> element.
* Child element of {@link OpenSeadragon.Drawer#container}.
* @member {Element} canvas
* @memberof OpenSeadragon.Drawer#
*/
this.canvas = $.makeNeutralElement( this.useCanvas ? "canvas" : "div" );
/**
* 2d drawing context for {@link OpenSeadragon.Drawer#canvas} if it's a <canvas> element, otherwise null.
* @member {Object} context
* @memberof OpenSeadragon.Drawer#
*/
this.context = this.useCanvas ? this.canvas.getContext( "2d" ) : null;
/**
* @member {Element} element
* @memberof OpenSeadragon.Drawer#
* @deprecated Alias for {@link OpenSeadragon.Drawer#container}.
*/
this.element = this.container;
// We force our container to ltr because our drawing math doesn't work in rtl.
// This issue only affects our canvas renderer, but we do it always for consistency.
// Note that this means overlays you want to be rtl need to be explicitly set to rtl.
this.container.dir = 'ltr';
this.canvas.style.width = "100%";
this.canvas.style.height = "100%";
this.canvas.style.position = "absolute";
$.setElementOpacity( this.canvas, this.opacity, true );
// explicit left-align
this.container.style.textAlign = "left";
this.container.appendChild( this.canvas );
//this.profiler = new $.Profiler();
};
$.Drawer.prototype = /** @lends OpenSeadragon.Drawer.prototype */{
/**
* Adds an html element as an overlay to the current viewport. Useful for
* highlighting words or areas of interest on an image or other zoomable
* interface.
* @method
* @param {Element|String|Object} element - A reference to an element or an id for
* the element which will overlayed. Or an Object specifying the configuration for the overlay
* @param {OpenSeadragon.Point|OpenSeadragon.Rect} location - The point or
* rectangle which will be overlayed.
* @param {OpenSeadragon.OverlayPlacement} placement - The position of the
* 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.
* It is passed position, size and element.
* @fires OpenSeadragon.Viewer.event:add-overlay
* @deprecated - use {@link OpenSeadragon.Viewer#addOverlay} instead.
*/
addOverlay: function( element, location, placement, onDraw ) {
$.console.error("drawer.addOverlay is deprecated. Use viewer.addOverlay instead.");
this.viewer.addOverlay( element, location, placement, onDraw );
return this;
},
/**
* Updates the overlay represented by the reference to the element or
* element id moving it to the new location, relative to the new placement.
* @method
* @param {OpenSeadragon.Point|OpenSeadragon.Rect} location - The point or
* rectangle which will be overlayed.
* @param {OpenSeadragon.OverlayPlacement} placement - The position of the
* viewport which the location coordinates will be treated as relative
* to.
* @return {OpenSeadragon.Drawer} Chainable.
* @fires OpenSeadragon.Viewer.event:update-overlay
* @deprecated - use {@link OpenSeadragon.Viewer#updateOverlay} instead.
*/
updateOverlay: function( element, location, placement ) {
$.console.error("drawer.updateOverlay is deprecated. Use viewer.updateOverlay instead.");
this.viewer.updateOverlay( element, location, placement );
return this;
},
/**
* Removes and overlay identified by the reference element or element id
* and schedules and update.
* @method
* @param {Element|String} element - A reference to the element or an
* element id which represent the ovelay content to be removed.
* @return {OpenSeadragon.Drawer} Chainable.
* @fires OpenSeadragon.Viewer.event:remove-overlay
* @deprecated - use {@link OpenSeadragon.Viewer#removeOverlay} instead.
*/
removeOverlay: function( element ) {
$.console.error("drawer.removeOverlay is deprecated. Use viewer.removeOverlay instead.");
this.viewer.removeOverlay( element );
return this;
},
/**
* Removes all currently configured Overlays from this Drawer and schedules
* and update.
* @method
* @return {OpenSeadragon.Drawer} Chainable.
* @fires OpenSeadragon.Viewer.event:clear-overlay
* @deprecated - use {@link OpenSeadragon.Viewer#clearOverlays} instead.
*/
clearOverlays: function() {
$.console.error("drawer.clearOverlays is deprecated. Use viewer.clearOverlays instead.");
this.viewer.clearOverlays();
return this;
},
/**
* Set the opacity of the drawer.
* @method
* @param {Number} opacity
* @return {OpenSeadragon.Drawer} Chainable.
*/
setOpacity: function( opacity ) {
this.opacity = opacity;
$.setElementOpacity( this.canvas, this.opacity, true );
return this;
},
/**
* Get the opacity of the drawer.
* @method
* @returns {Number}
*/
getOpacity: function() {
return this.opacity;
},
/**
* Returns whether the Drawer is scheduled for an update at the
* soonest possible opportunity.
* @method
* @returns {Boolean} - Whether the Drawer is scheduled for an update at the
* soonest possible opportunity.
*/
needsUpdate: function() {
return this.updateAgain;
},
/**
* Returns the total number of tiles that have been loaded by this Drawer.
* @method
* @returns {Number} - The total number of tiles that have been loaded by
* this Drawer.
*/
numTilesLoaded: function() {
return this.tilesLoaded.length;
},
/**
* Clears all tiles and triggers an update on the next call to
* Drawer.prototype.update().
* @method
* @return {OpenSeadragon.Drawer} Chainable.
*/
reset: function() {
clearTiles( this );
this.lastResetTime = $.now();
this.updateAgain = true;
return this;
},
/**
* Forces the Drawer to update.
* @method
* @return {OpenSeadragon.Drawer} Chainable.
*/
update: function() {
//this.profiler.beginUpdate();
this.midUpdate = true;
updateViewport( this );
this.midUpdate = false;
//this.profiler.endUpdate();
return this;
},
/**
* Returns whether rotation is supported or not.
* @method
* @return {Boolean} True if rotation is supported.
*/
canRotate: function() {
return this.useCanvas;
},
/**
* Destroy the drawer (unload current loaded tiles)
* @method
* @return null
*/
destroy: function() {
//unload current loaded tiles (=empty TILE_CACHE)
for ( var i = 0; i < this.tilesLoaded.length; ++i ) {
this.tilesLoaded[i].unload();
}
//force unloading of current canvas (1x1 will be gc later, trick not necessarily needed)
this.canvas.width = 1;
this.canvas.height = 1;
}
};
/**
* @private
* @inner
* Pretty much every other line in this needs to be documented so it's clear
* how each piece of this routine contributes to the drawing process. That's
* why there are so many TODO's inside this function.
*/
function updateViewport( drawer ) {
drawer.updateAgain = false;
if( drawer.viewer ){
/**
* - Needs documentation -
*
* @event update-viewport
* @memberof OpenSeadragon.Viewer
* @type {object}
* @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
* @property {?Object} userData - Arbitrary subscriber-defined object.
*/
drawer.viewer.raiseEvent( 'update-viewport', {} );
}
var tile,
level,
best = null,
haveDrawn = false,
currentTime = $.now(),
viewportSize = drawer.viewport.getContainerSize(),
viewportBounds = drawer.viewport.getBounds( true ),
viewportTL = viewportBounds.getTopLeft(),
viewportBR = viewportBounds.getBottomRight(),
zeroRatioC = drawer.viewport.deltaPixelsFromPoints(
drawer.source.getPixelRatio( 0 ),
true
).x * drawer._scale,
lowestLevel = Math.max(
drawer.source.minLevel,
Math.floor(
Math.log( drawer.minZoomImageRatio ) /
Math.log( 2 )
)
),
highestLevel = Math.min(
Math.abs(drawer.source.maxLevel),
Math.abs(Math.floor(
Math.log( zeroRatioC / drawer.minPixelRatio ) /
Math.log( 2 )
))
),
degrees = drawer.viewport.degrees,
renderPixelRatioC,
renderPixelRatioT,
zeroRatioT,
optimalRatio,
levelOpacity,
levelVisibility;
viewportTL.x -= drawer._worldX;
viewportTL.y -= drawer._worldY;
viewportBR.x -= drawer._worldX;
viewportBR.y -= drawer._worldY;
// Reset tile's internal drawn state
while ( drawer.lastDrawn.length > 0 ) {
tile = drawer.lastDrawn.pop();
tile.beingDrawn = false;
}
// Clear canvas
drawer.canvas.innerHTML = "";
if ( drawer.useCanvas ) {
if( drawer.canvas.width != viewportSize.x ||
drawer.canvas.height != viewportSize.y ){
drawer.canvas.width = viewportSize.x;
drawer.canvas.height = viewportSize.y;
}
drawer.context.clearRect( 0, 0, viewportSize.x, viewportSize.y );
}
//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 > drawer._worldWidth ) ) {
return;
} else if
( !drawer.wrapVertical &&
( viewportBR.y < 0 || viewportTL.y > drawer._worldHeight ) ) {
return;
}
// Calculate viewport rect / bounds
if ( !drawer.wrapHorizontal ) {
viewportTL.x = Math.max( viewportTL.x, 0 );
viewportBR.x = Math.min( viewportBR.x, drawer._worldWidth );
}
if ( !drawer.wrapVertical ) {
viewportTL.y = Math.max( viewportTL.y, 0 );
viewportBR.y = Math.min( viewportBR.y, drawer._worldHeight );
}
// Calculations for the interval of levels to draw
// (above in initial var statement)
// can return invalid intervals; fix that here if necessary
lowestLevel = Math.min( lowestLevel, highestLevel );
// Update any level that will be drawn
var drawLevel; // FIXME: drawLevel should have a more explanatory name
for ( level = highestLevel; level >= lowestLevel; level-- ) {
drawLevel = false;
//Avoid calculations for draw if we have already drawn this
renderPixelRatioC = drawer.viewport.deltaPixelsFromPoints(
drawer.source.getPixelRatio( level ),
true
).x * drawer._scale;
if ( ( !haveDrawn && renderPixelRatioC >= drawer.minPixelRatio ) ||
( level == lowestLevel ) ) {
drawLevel = true;
haveDrawn = true;
} else if ( !haveDrawn ) {
continue;
}
//Perform calculations for draw if we haven't drawn this
renderPixelRatioT = drawer.viewport.deltaPixelsFromPoints(
drawer.source.getPixelRatio( level ),
false
).x * drawer._scale;
zeroRatioT = drawer.viewport.deltaPixelsFromPoints(
drawer.source.getPixelRatio(
Math.max(
drawer.source.getClosestLevel( drawer.viewport.containerSize ) - 1,
0
)
),
false
).x * drawer._scale;
optimalRatio = drawer.immediateRender ?
1 :
zeroRatioT;
levelOpacity = Math.min( 1, ( renderPixelRatioC - 0.5 ) / 0.5 );
levelVisibility = optimalRatio / Math.abs(
optimalRatio - renderPixelRatioT
);
// Update the level and keep track of 'best' tile to load
best = updateLevel(
drawer,
haveDrawn,
drawLevel,
level,
levelOpacity,
levelVisibility,
viewportTL,
viewportBR,
currentTime,
best
);
// Stop the loop if lower-res tiles would all be covered by
// already drawn tiles
if ( providesCoverage( drawer.coverage, level ) ) {
break;
}
}
// Perform the actual drawing
drawTiles( drawer, drawer.lastDrawn );
// Load the new 'best' tile
if ( best ) {
loadTile( drawer, best, currentTime );
// because we haven't finished drawing, so
drawer.updateAgain = true;
}
}
function updateLevel( drawer, haveDrawn, drawLevel, level, levelOpacity, levelVisibility, viewportTL, viewportBR, currentTime, best ){
var x, y,
tileTL,
tileBR,
numberOfTiles,
viewportCenter = drawer.viewport.pixelFromPoint( drawer.viewport.getCenter() );
if( drawer.viewer ){
/**
* - Needs documentation -
*
* @event update-level
* @memberof OpenSeadragon.Viewer
* @type {object}
* @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
* @property {Object} havedrawn
* @property {Object} level
* @property {Object} opacity
* @property {Object} visibility
* @property {Object} topleft
* @property {Object} bottomright
* @property {Object} currenttime
* @property {Object} best
* @property {?Object} userData - Arbitrary subscriber-defined object.
*/
drawer.viewer.raiseEvent( 'update-level', {
havedrawn: haveDrawn,
level: level,
opacity: levelOpacity,
visibility: levelVisibility,
topleft: viewportTL,
bottomright: viewportBR,
currenttime: currentTime,
best: best
});
}
//OK, a new drawing so do your calculations
tileTL = drawer.source.getTileAtPoint( level, viewportTL.divide( drawer._scale ));
tileBR = drawer.source.getTileAtPoint( level, viewportBR.divide( drawer._scale ));
numberOfTiles = drawer.source.getNumTiles( level );
resetCoverage( drawer.coverage, level );
if ( !drawer.wrapHorizontal ) {
tileBR.x = Math.min( tileBR.x, numberOfTiles.x - 1 );
}
if ( !drawer.wrapVertical ) {
tileBR.y = Math.min( tileBR.y, numberOfTiles.y - 1 );
}
for ( x = tileTL.x; x <= tileBR.x; x++ ) {
for ( y = tileTL.y; y <= tileBR.y; y++ ) {
best = updateTile(
drawer,
drawLevel,
haveDrawn,
x, y,
level,
levelOpacity,
levelVisibility,
viewportCenter,
numberOfTiles,
currentTime,
best
);
}
}
return best;
}
function updateTile( drawer, drawLevel, haveDrawn, x, y, level, levelOpacity, levelVisibility, viewportCenter, numberOfTiles, currentTime, best){
var tile = getTile(
x, y,
level,
drawer.source,
drawer.tilesMatrix,
currentTime,
numberOfTiles,
drawer._worldWidth,
drawer._worldHeight
),
drawTile = drawLevel;
if( drawer.viewer ){
/**
* - Needs documentation -
*
* @event update-tile
* @memberof OpenSeadragon.Viewer
* @type {object}
* @property {OpenSeadragon.Viewer} eventSource - A reference to the Viewer which raised the event.
* @property {OpenSeadragon.Tile} tile
* @property {?Object} userData - Arbitrary subscriber-defined object.
*/
drawer.viewer.raiseEvent( 'update-tile', {
tile: tile
});
}
setCoverage( drawer.coverage, level, x, y, false );
if ( !tile.exists ) {
return best;
}
if ( haveDrawn && !drawTile ) {
if ( isCovered( drawer.coverage, level, x, y ) ) {
setCoverage( drawer.coverage, level, x, y, true );
} else {
drawTile = true;
}
}
if ( !drawTile ) {
return best;
}
positionTile(
tile,
drawer.source.tileOverlap,
drawer.viewport,
viewportCenter,
levelVisibility,
drawer
);
if ( tile.loaded ) {
var needsUpdate = blendTile(
drawer,
tile,
x, y,
level,
levelOpacity,
currentTime
);
if ( needsUpdate ) {
drawer.updateAgain = true;
}
} else if ( tile.loading ) {
// the tile is already in the download queue
// thanks josh1093 for finally translating this typo
} else {
best = compareTiles( best, tile );
}
return best;
}
function getTile( x, y, level, tileSource, tilesMatrix, time, numTiles, worldWidth, worldHeight ) {
var xMod,
yMod,
bounds,
exists,
url,
tile;
if ( !tilesMatrix[ level ] ) {
tilesMatrix[ level ] = {};
}
if ( !tilesMatrix[ level ][ x ] ) {
tilesMatrix[ level ][ x ] = {};
}
if ( !tilesMatrix[ level ][ x ][ y ] ) {
xMod = ( numTiles.x + ( x % numTiles.x ) ) % numTiles.x;
yMod = ( numTiles.y + ( y % numTiles.y ) ) % numTiles.y;
bounds = tileSource.getTileBounds( level, xMod, yMod );
exists = tileSource.tileExists( level, xMod, yMod );
url = tileSource.getTileUrl( level, xMod, yMod );
bounds.x += worldWidth * ( x - xMod ) / numTiles.x;
bounds.y += worldHeight * ( y - yMod ) / numTiles.y;
tilesMatrix[ level ][ x ][ y ] = new $.Tile(
level,
x,
y,
bounds,
exists,
url
);
}
tile = tilesMatrix[ level ][ x ][ y ];
tile.lastTouchTime = time;
return tile;
}
function loadTile( drawer, tile, time ) {
if( drawer.viewport.collectionMode ){
drawer.midUpdate = false;
onTileLoad( drawer, tile, time );
} else {
tile.loading = true;
drawer.imageLoader.addJob({
src: tile.url,
crossOriginPolicy: drawer.crossOriginPolicy,
callback: function( image ){
onTileLoad( drawer, tile, time, image );
}
});
}
}
function onTileLoad( drawer, tile, time, image ) {
var insertionIndex,
cutoff,
worstTile,
worstTime,
worstLevel,
worstTileIndex,
prevTile,
prevTime,
prevLevel,
i;
tile.loading = false;
if ( drawer.midUpdate ) {
$.console.warn( "Tile load callback in middle of drawing routine." );
return;
} else if ( !image && !drawer.viewport.collectionMode ) {
$.console.log( "Tile %s failed to load: %s", tile, tile.url );
if( !drawer.debugMode ){
tile.exists = false;
return;
}
} else if ( time < drawer.lastResetTime ) {
$.console.log( "Ignoring tile %s loaded before reset: %s", tile, tile.url );
return;
}
tile.loaded = true;
tile.image = image;
insertionIndex = drawer.tilesLoaded.length;
if ( drawer.tilesLoaded.length >= drawer.maxImageCacheCount ) {
cutoff = Math.ceil( Math.log( drawer.source.getTileSize(tile.level) ) / Math.log( 2 ) );
worstTile = null;
worstTileIndex = -1;
for ( i = drawer.tilesLoaded.length - 1; i >= 0; i-- ) {
prevTile = drawer.tilesLoaded[ i ];
if ( prevTile.level <= drawer.cutoff || prevTile.beingDrawn ) {
continue;
} else if ( !worstTile ) {
worstTile = prevTile;
worstTileIndex = i;
continue;
}
prevTime = prevTile.lastTouchTime;
worstTime = worstTile.lastTouchTime;
prevLevel = prevTile.level;
worstLevel = worstTile.level;
if ( prevTime < worstTime ||
( prevTime == worstTime && prevLevel > worstLevel ) ) {
worstTile = prevTile;
worstTileIndex = i;
}
}
if ( worstTile && worstTileIndex >= 0 ) {
worstTile.unload();
insertionIndex = worstTileIndex;
}
}
drawer.tilesLoaded[ insertionIndex ] = tile;
drawer.updateAgain = true;
}
function positionTile( tile, overlap, viewport, viewportCenter, levelVisibility, drawer ){
var boundsTL = tile.bounds.getTopLeft();
boundsTL.x *= drawer._scale;
boundsTL.y *= drawer._scale;
boundsTL.x += drawer._worldX;
boundsTL.y += drawer._worldY;
var boundsSize = tile.bounds.getSize();
boundsSize.x *= drawer._scale;
boundsSize.y *= drawer._scale;
var positionC = viewport.pixelFromPoint( boundsTL, true ),
positionT = viewport.pixelFromPoint( boundsTL, false ),
sizeC = viewport.deltaPixelsFromPoints( boundsSize, true ),
sizeT = viewport.deltaPixelsFromPoints( boundsSize, false ),
tileCenter = positionT.plus( sizeT.divide( 2 ) ),
tileDistance = viewportCenter.distanceTo( tileCenter );
if ( !overlap ) {
sizeC = sizeC.plus( new $.Point( 1, 1 ) );
}
tile.position = positionC;
tile.size = sizeC;
tile.distance = tileDistance;
tile.visibility = levelVisibility;
}
function blendTile( drawer, tile, x, y, level, levelOpacity, currentTime ){
var blendTimeMillis = 1000 * drawer.blendTime,
deltaTime,
opacity;
if ( !tile.blendStart ) {
tile.blendStart = currentTime;
}
deltaTime = currentTime - tile.blendStart;
opacity = blendTimeMillis ? Math.min( 1, deltaTime / ( blendTimeMillis ) ) : 1;
if ( drawer.alwaysBlend ) {
opacity *= levelOpacity;
}
tile.opacity = opacity;
drawer.lastDrawn.push( tile );
if ( opacity == 1 ) {
setCoverage( drawer.coverage, level, x, y, true );
} else if ( deltaTime < blendTimeMillis ) {
return true;
}
return false;
}
function clearTiles( drawer ) {
drawer.tilesMatrix = {};
drawer.tilesLoaded = [];
}
/**
* @private
* @inner
* Returns true if the given tile provides coverage to lower-level tiles of
* lower resolution representing the same content. If neither x nor y is
* given, returns true if the entire visible level provides coverage.
*
* Note that out-of-bounds tiles provide coverage in this sense, since
* there's no content that they would need to cover. Tiles at non-existent
* levels that are within the image bounds, however, do not.
*/
function providesCoverage( coverage, level, x, y ) {
var rows,
cols,
i, j;
if ( !coverage[ level ] ) {
return false;
}
if ( x === undefined || y === undefined ) {
rows = coverage[ level ];
for ( i in rows ) {
if ( rows.hasOwnProperty( i ) ) {
cols = rows[ i ];
for ( j in cols ) {
if ( cols.hasOwnProperty( j ) && !cols[ j ] ) {
return false;
}
}
}
}
return true;
}
return (
coverage[ level ][ x] === undefined ||
coverage[ level ][ x ][ y ] === undefined ||
coverage[ level ][ x ][ y ] === true
);
}
/**
* @private
* @inner
* Returns true if the given tile is completely covered by higher-level
* tiles of higher resolution representing the same content. If neither x
* nor y is given, returns true if the entire visible level is covered.
*/
function isCovered( coverage, level, x, y ) {
if ( x === undefined || y === undefined ) {
return providesCoverage( coverage, level + 1 );
} else {
return (
providesCoverage( coverage, level + 1, 2 * x, 2 * y ) &&
providesCoverage( coverage, level + 1, 2 * x, 2 * y + 1 ) &&
providesCoverage( coverage, level + 1, 2 * x + 1, 2 * y ) &&
providesCoverage( coverage, level + 1, 2 * x + 1, 2 * y + 1 )
);
}
}
/**
* @private
* @inner
* Sets whether the given tile provides coverage or not.
*/
function setCoverage( coverage, level, x, y, covers ) {
if ( !coverage[ level ] ) {
$.console.warn(
"Setting coverage for a tile before its level's coverage has been reset: %s",
level
);
return;
}
if ( !coverage[ level ][ x ] ) {
coverage[ level ][ x ] = {};
}
coverage[ level ][ x ][ y ] = covers;
}
/**
* @private
* @inner
* Resets coverage information for the given level. This should be called
* after every draw routine. Note that at the beginning of the next draw
* routine, coverage for every visible tile should be explicitly set.
*/
function resetCoverage( coverage, level ) {
coverage[ level ] = {};
}
/**
* @private
* @inner
* Determines whether the 'last best' tile for the area is better than the
* tile in question.
*/
function compareTiles( previousBest, tile ) {
if ( !previousBest ) {
return tile;
}
if ( tile.visibility > previousBest.visibility ) {
return tile;
} else if ( tile.visibility == previousBest.visibility ) {
if ( tile.distance < previousBest.distance ) {
return tile;
}
}
return previousBest;
}
function drawTiles( drawer, lastDrawn ){
var i,
tile,
tileKey,
viewer,
viewport,
position,
tileSource,
collectionTileSource;
// We need a callback to give image manipulation a chance to happen
var drawingHandler = function(args) {
if (drawer.viewer) {
/**
* This event is fired just before the tile is drawn giving the application a chance to alter the image.
*
* NOTE: This event is only fired when the drawer is using a