88 lines
2.0 KiB
JavaScript
88 lines
2.0 KiB
JavaScript
goog.provide('ol.source.ImageCanvas');
|
|
|
|
goog.require('ol');
|
|
goog.require('ol.ImageCanvas');
|
|
goog.require('ol.extent');
|
|
goog.require('ol.source.Image');
|
|
|
|
|
|
/**
|
|
* @classdesc
|
|
* Base class for image sources where a canvas element is the image.
|
|
*
|
|
* @constructor
|
|
* @extends {ol.source.Image}
|
|
* @param {olx.source.ImageCanvasOptions} options Constructor options.
|
|
* @api
|
|
*/
|
|
ol.source.ImageCanvas = function(options) {
|
|
|
|
ol.source.Image.call(this, {
|
|
attributions: options.attributions,
|
|
logo: options.logo,
|
|
projection: options.projection,
|
|
resolutions: options.resolutions,
|
|
state: options.state
|
|
});
|
|
|
|
/**
|
|
* @private
|
|
* @type {ol.CanvasFunctionType}
|
|
*/
|
|
this.canvasFunction_ = options.canvasFunction;
|
|
|
|
/**
|
|
* @private
|
|
* @type {ol.ImageCanvas}
|
|
*/
|
|
this.canvas_ = null;
|
|
|
|
/**
|
|
* @private
|
|
* @type {number}
|
|
*/
|
|
this.renderedRevision_ = 0;
|
|
|
|
/**
|
|
* @private
|
|
* @type {number}
|
|
*/
|
|
this.ratio_ = options.ratio !== undefined ?
|
|
options.ratio : 1.5;
|
|
|
|
};
|
|
ol.inherits(ol.source.ImageCanvas, ol.source.Image);
|
|
|
|
|
|
/**
|
|
* @inheritDoc
|
|
*/
|
|
ol.source.ImageCanvas.prototype.getImageInternal = function(extent, resolution, pixelRatio, projection) {
|
|
resolution = this.findNearestResolution(resolution);
|
|
|
|
var canvas = this.canvas_;
|
|
if (canvas &&
|
|
this.renderedRevision_ == this.getRevision() &&
|
|
canvas.getResolution() == resolution &&
|
|
canvas.getPixelRatio() == pixelRatio &&
|
|
ol.extent.containsExtent(canvas.getExtent(), extent)) {
|
|
return canvas;
|
|
}
|
|
|
|
extent = extent.slice();
|
|
ol.extent.scaleFromCenter(extent, this.ratio_);
|
|
var width = ol.extent.getWidth(extent) / resolution;
|
|
var height = ol.extent.getHeight(extent) / resolution;
|
|
var size = [width * pixelRatio, height * pixelRatio];
|
|
|
|
var canvasElement = this.canvasFunction_(
|
|
extent, resolution, pixelRatio, size, projection);
|
|
if (canvasElement) {
|
|
canvas = new ol.ImageCanvas(extent, resolution, pixelRatio, canvasElement);
|
|
}
|
|
this.canvas_ = canvas;
|
|
this.renderedRevision_ = this.getRevision();
|
|
|
|
return canvas;
|
|
};
|