/*global define*/
define([
'../Core/Color',
'../Core/defaultValue',
'../Core/defined',
'../Core/defineProperties',
'../Core/Event',
'../Core/GeographicTilingScheme',
'../ThirdParty/when'
], function(
Color,
defaultValue,
defined,
defineProperties,
Event,
GeographicTilingScheme,
when) {
'use strict';
var defaultColor = new Color(1.0, 1.0, 1.0, 0.4);
var defaultGlowColor = new Color(0.0, 1.0, 0.0, 0.05);
var defaultBackgroundColor = new Color(0.0, 0.5, 0.0, 0.2);
/**
* An {@link ImageryProvider} that draws a wireframe grid on every tile with controllable background and glow.
* May be useful for custom rendering effects or debugging terrain.
*
* @alias GridImageryProvider
* @constructor
*
* @param {Object} [options] Object with the following properties:
* @param {TilingScheme} [options.tilingScheme=new GeographicTilingScheme()] The tiling scheme for which to draw tiles.
* @param {Ellipsoid} [options.ellipsoid] The ellipsoid. If the tilingScheme is specified,
* this parameter is ignored and the tiling scheme's ellipsoid is used instead. If neither
* parameter is specified, the WGS84 ellipsoid is used.
* @param {Number} [options.cells=8] The number of grids cells.
* @param {Color} [options.color=Color(1.0, 1.0, 1.0, 0.4)] The color to draw grid lines.
* @param {Color} [options.glowColor=Color(0.0, 1.0, 0.0, 0.05)] The color to draw glow for grid lines.
* @param {Number} [options.glowWidth=6] The width of lines used for rendering the line glow effect.
* @param {Color} [backgroundColor=Color(0.0, 0.5, 0.0, 0.2)] Background fill color.
* @param {Number} [options.tileWidth=256] The width of the tile for level-of-detail selection purposes.
* @param {Number} [options.tileHeight=256] The height of the tile for level-of-detail selection purposes.
* @param {Number} [options.canvasSize=256] The size of the canvas used for rendering.
*/
function GridImageryProvider(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
this._tilingScheme = defined(options.tilingScheme) ? options.tilingScheme : new GeographicTilingScheme({ ellipsoid : options.ellipsoid });
this._cells = defaultValue(options.cells, 8);
this._color = defaultValue(options.color, defaultColor);
this._glowColor = defaultValue(options.glowColor, defaultGlowColor);
this._glowWidth = defaultValue(options.glowWidth, 6);
this._backgroundColor = defaultValue(options.backgroundColor, defaultBackgroundColor);
this._errorEvent = new Event();
this._tileWidth = defaultValue(options.tileWidth, 256);
this._tileHeight = defaultValue(options.tileHeight, 256);
// A little larger than tile size so lines are sharper
// Note: can't be too much difference otherwise texture blowout
this._canvasSize = defaultValue(options.canvasSize, 256);
// We only need a single canvas since all tiles will be the same
this._canvas = this._createGridCanvas();
this._readyPromise = when.resolve(true);
}
defineProperties(GridImageryProvider.prototype, {
/**
* Gets the proxy used by this provider.
* @memberof GridImageryProvider.prototype
* @type {Proxy}
* @readonly
*/
proxy : {
get : function() {
return undefined;
}
},
/**
* Gets the width of each tile, in pixels. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Number}
* @readonly
*/
tileWidth : {
get : function() {
return this._tileWidth;
}
},
/**
* Gets the height of each tile, in pixels. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Number}
* @readonly
*/
tileHeight : {
get : function() {
return this._tileHeight;
}
},
/**
* Gets the maximum level-of-detail that can be requested. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Number}
* @readonly
*/
maximumLevel : {
get : function() {
return undefined;
}
},
/**
* Gets the minimum level-of-detail that can be requested. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Number}
* @readonly
*/
minimumLevel : {
get : function() {
return undefined;
}
},
/**
* Gets the tiling scheme used by this provider. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {TilingScheme}
* @readonly
*/
tilingScheme : {
get : function() {
return this._tilingScheme;
}
},
/**
* Gets the rectangle, in radians, of the imagery provided by this instance. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Rectangle}
* @readonly
*/
rectangle : {
get : function() {
return this._tilingScheme.rectangle;
}
},
/**
* Gets the tile discard policy. If not undefined, the discard policy is responsible
* for filtering out "missing" tiles via its shouldDiscardImage function. If this function
* returns undefined, no tiles are filtered. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {TileDiscardPolicy}
* @readonly
*/
tileDiscardPolicy : {
get : function() {
return undefined;
}
},
/**
* Gets an event that is raised when the imagery provider encounters an asynchronous error. By subscribing
* to the event, you will be notified of the error and can potentially recover from it. Event listeners
* are passed an instance of {@link TileProviderError}.
* @memberof GridImageryProvider.prototype
* @type {Event}
* @readonly
*/
errorEvent : {
get : function() {
return this._errorEvent;
}
},
/**
* Gets a value indicating whether or not the provider is ready for use.
* @memberof GridImageryProvider.prototype
* @type {Boolean}
* @readonly
*/
ready : {
get : function() {
return true;
}
},
/**
* Gets a promise that resolves to true when the provider is ready for use.
* @memberof GridImageryProvider.prototype
* @type {Promise.<Boolean>}
* @readonly
*/
readyPromise : {
get : function() {
return this._readyPromise;
}
},
/**
* Gets the credit to display when this imagery provider is active. Typically this is used to credit
* the source of the imagery. This function should not be called before {@link GridImageryProvider#ready} returns true.
* @memberof GridImageryProvider.prototype
* @type {Credit}
* @readonly
*/
credit : {
get : function() {
return undefined;
}
},
/**
* Gets a value indicating whether or not the images provided by this imagery provider
* include an alpha channel. If this property is false, an alpha channel, if present, will
* be ignored. If this property is true, any images without an alpha channel will be treated
* as if their alpha is 1.0 everywhere. When this property is false, memory usage
* and texture upload time are reduced.
* @memberof GridImageryProvider.prototype
* @type {Boolean}
* @readonly
*/
hasAlphaChannel : {
get : function() {
return true;
}
}
});
/**
* Draws a grid of lines into a canvas.
*/
GridImageryProvider.prototype._drawGrid = function(context) {
var minPixel = 0;
var maxPixel = this._canvasSize;
for (var x = 0; x <= this._cells; ++x) {
var nx = x / this._cells;
var val = 1 + nx * (maxPixel - 1);
context.moveTo(val, minPixel);
context.lineTo(val, maxPixel);
context.moveTo(minPixel, val);
context.lineTo(maxPixel, val);
}
context.stroke();
};
/**
* Render a grid into a canvas with background and glow
*/
GridImageryProvider.prototype._createGridCanvas = function() {
var canvas = document.createElement('canvas');
canvas.width = this._canvasSize;
canvas.height = this._canvasSize;
var minPixel = 0;
var maxPixel = this._canvasSize;
var context = canvas.getContext('2d');
// Fill the background
var cssBackgroundColor = this._backgroundColor.toCssColorString();
context.fillStyle = cssBackgroundColor;
context.fillRect(minPixel, minPixel, maxPixel, maxPixel);
// Glow for grid lines
var cssGlowColor = this._glowColor.toCssColorString();
context.strokeStyle = cssGlowColor;
// Wide
context.lineWidth = this._glowWidth;
context.strokeRect(minPixel, minPixel, maxPixel, maxPixel);
this._drawGrid(context);
// Narrow
context.lineWidth = this._glowWidth * 0.5;
context.strokeRect(minPixel, minPixel, maxPixel, maxPixel);
this._drawGrid(context);
// Grid lines
var cssColor = this._color.toCssColorString();
// Border
context.strokeStyle = cssColor;
context.lineWidth = 2;
context.strokeRect(minPixel, minPixel, maxPixel, maxPixel);
// Inner
context.lineWidth = 1;
this._drawGrid(context);
return canvas;
};
/**
* Gets the credits to be displayed when a given tile is displayed.
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level;
* @returns {Credit[]} The credits to be displayed when the tile is displayed.
*
* @exception {DeveloperError} <code>getTileCredits</code> must not be called before the imagery provider is ready.
*/
GridImageryProvider.prototype.getTileCredits = function(x, y, level) {
return undefined;
};
/**
* Requests the image for a given tile. This function should
* not be called before {@link GridImageryProvider#ready} returns true.
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level.
* @returns {Promise.<Image|Canvas>|undefined} A promise for the image that will resolve when the image is available, or
* undefined if there are too many active requests to the server, and the request
* should be retried later. The resolved image may be either an
* Image or a Canvas DOM object.
*/
GridImageryProvider.prototype.requestImage = function(x, y, level) {
return this._canvas;
};
/**
* Picking features is not currently supported by this imagery provider, so this function simply returns
* undefined.
*
* @param {Number} x The tile X coordinate.
* @param {Number} y The tile Y coordinate.
* @param {Number} level The tile level.
* @param {Number} longitude The longitude at which to pick features.
* @param {Number} latitude The latitude at which to pick features.
* @return {Promise.<ImageryLayerFeatureInfo[]>|undefined} A promise for the picked features that will resolve when the asynchronous
* picking completes. The resolved value is an array of {@link ImageryLayerFeatureInfo}
* instances. The array may be empty if no features are found at the given location.
* It may also be undefined if picking is not supported.
*/
GridImageryProvider.prototype.pickFeatures = function() {
return undefined;
};
return GridImageryProvider;
});