Files
openlayers/src/ol/renderer/canvas/canvasvectorlayerrenderer.js
2013-02-06 16:26:24 +01:00

351 lines
10 KiB
JavaScript

goog.provide('ol.renderer.canvas.VectorLayer');
goog.require('goog.vec.Mat4');
goog.require('ol.Extent');
goog.require('ol.Size');
goog.require('ol.TileCoord');
goog.require('ol.filter.Geometry');
goog.require('ol.geom.GeometryType');
goog.require('ol.layer.Vector');
goog.require('ol.renderer.canvas');
goog.require('ol.renderer.canvas.Layer');
goog.require('ol.renderer.canvas.Renderer');
goog.require('ol.style.LiteralLine');
goog.require('ol.style.LiteralPolygon');
goog.require('ol.style.LiteralShape');
goog.require('ol.style.ShapeType');
/**
* @constructor
* @extends {ol.renderer.canvas.Layer}
* @param {ol.renderer.Map} mapRenderer Map renderer.
* @param {ol.layer.Vector} layer Vector layer.
*/
ol.renderer.canvas.VectorLayer = function(mapRenderer, layer) {
goog.base(this, mapRenderer, layer);
/**
* Final canvas made available to the map renderer.
* @private
* @type {HTMLCanvasElement}
*/
this.canvas_ = /** @type {HTMLCanvasElement} */
(goog.dom.createElement(goog.dom.TagName.CANVAS));
/**
* @private
* @type {CanvasRenderingContext2D}
*/
this.context_ = /** @type {CanvasRenderingContext2D} */
this.canvas_.getContext('2d');
/**
* @private
* @type {!goog.vec.Mat4.Number}
*/
this.transform_ = goog.vec.Mat4.createNumber();
/**
* Interim canvas for drawing newly visible features.
* @private
* @type {HTMLCanvasElement}
*/
this.sketchCanvas_ = /** @type {HTMLCanvasElement} */
(goog.dom.createElement(goog.dom.TagName.CANVAS));
/**
* @private
* @type {!goog.vec.Mat4.Number}
*/
this.sketchTransform_ = goog.vec.Mat4.createNumber();
/**
* @private
* @type {Object.<string, HTMLCanvasElement>}
*/
this.tileCache_ = {};
/**
* @private
* @type {Array.<string>}
*/
this.tileCacheIndex_ = [];
/**
* @private
* @type {HTMLCanvasElement}
*/
this.tileArchetype_ = null;
/**
* Geometry filters in rendering order.
* @private
* @type {Array.<ol.filter.Geometry>}
* TODO: deal with multis
*/
this.geometryFilters_ = [
new ol.filter.Geometry(ol.geom.GeometryType.POLYGON),
new ol.filter.Geometry(ol.geom.GeometryType.LINESTRING),
new ol.filter.Geometry(ol.geom.GeometryType.POINT)
];
/**
* @private
* @type {number}
*/
this.renderedResolution_;
/**
* @private
* @type {ol.Extent}
*/
this.renderedExtent_ = null;
/**
* Flag to be set internally when we know something has changed that suggests
* we need to re-render.
* TODO: discuss setting this for all layers when something changes before
* calling map.render().
* @private
* @type {boolean}
*/
this.dirty_ = false;
// TODO: implement layer.setStyle(style) where style is a set of rules
// and a rule has a filter and array of symbolizers
var symbolizers = {};
symbolizers[ol.geom.GeometryType.POINT] = new ol.style.LiteralShape({
type: ol.style.ShapeType.CIRCLE,
size: 10,
fillStyle: '#ffcc99',
strokeStyle: '#ff9933',
strokeWidth: 2,
opacity: 0.75
});
symbolizers[ol.geom.GeometryType.LINESTRING] = new ol.style.LiteralLine({
strokeStyle: '#ff9933',
strokeWidth: 2,
opacity: 1
});
symbolizers[ol.geom.GeometryType.POLYGON] = new ol.style.LiteralPolygon({
fillStyle: '#ffcc99',
strokeStyle: '#ff9933',
strokeWidth: 2,
opacity: 0.5
});
// TODO: remove this
this.symbolizers_ = symbolizers;
};
goog.inherits(ol.renderer.canvas.VectorLayer, ol.renderer.canvas.Layer);
/**
* @inheritDoc
*/
ol.renderer.canvas.VectorLayer.prototype.getImage = function() {
return this.canvas_;
};
/**
* @return {ol.layer.Vector} Vector layer.
*/
ol.renderer.canvas.VectorLayer.prototype.getVectorLayer = function() {
return /** @type {ol.layer.Vector} */ (this.getLayer());
};
/**
* @inheritDoc
*/
ol.renderer.canvas.VectorLayer.prototype.getTransform = function() {
return this.transform_;
};
/**
* @inheritDoc
*/
ol.renderer.canvas.VectorLayer.prototype.renderFrame =
function(frameState, layerState) {
// TODO: consider bailing out here if rendered center and resolution
// have not changed. Requires that other change listeners set a dirty flag.
var view2DState = frameState.view2DState,
resolution = view2DState.resolution,
extent = frameState.extent,
source = this.getVectorLayer().getVectorSource(),
tileGrid = source.getTileGrid();
if (goog.isNull(tileGrid)) {
// lazy tile source creation to match the view projection
tileGrid = ol.tilegrid.createForProjection(
view2DState.projection, /** TODO: get this elsewhere */ 22);
source.setTileGrid(tileGrid);
}
// set up transform for the layer canvas to be drawn to the map canvas
var tileSize = tileGrid.getTileSize(),
z = tileGrid.getZForResolution(resolution),
tileResolution = tileGrid.getResolution(z),
tileRange = tileGrid.getTileRangeForExtentAndResolution(
extent, tileResolution),
tileRangeExtent = tileGrid.getTileRangeExtent(z, tileRange),
sketchOrigin = tileRangeExtent.getTopLeft(),
transform = this.transform_;
goog.vec.Mat4.makeIdentity(transform);
goog.vec.Mat4.translate(transform,
frameState.size.width / 2,
frameState.size.height / 2,
0);
goog.vec.Mat4.scale(transform,
tileResolution / resolution, tileResolution / resolution, 1);
goog.vec.Mat4.rotateZ(transform, view2DState.rotation);
goog.vec.Mat4.translate(transform,
(sketchOrigin.x - view2DState.center.x) / tileResolution,
(view2DState.center.y - sketchOrigin.y) / tileResolution,
0);
/**
* Fastest path out of here. This method is called many many times while
* there is nothing to do (e.g. while waiting for tiles from every other
* layer to load.) Do not put anything above here that is more expensive than
* necessary. And look for ways to get here faster.
*/
if (!this.dirty_ && this.renderedResolution_ === tileResolution &&
// TODO: extent.equals()
this.renderedResolution_.toString() === tileRangeExtent.toString()) {
return;
}
if (goog.isNull(this.tileArchetype_)) {
this.tileArchetype_ = /** @type {HTMLCanvasElement} */
goog.dom.createElement(goog.dom.TagName.CANVAS);
this.tileArchetype_.width = tileSize.width;
this.tileArchetype_.height = tileSize.height;
}
/**
* Prepare the sketch canvas. This covers the currently visible tile range
* and will have rendered all newly visible features.
*/
var sketchCanvas = this.sketchCanvas_;
var sketchSize = new ol.Size(
tileSize.width * tileRange.getWidth(),
tileSize.height * tileRange.getHeight());
// transform for map coords to sketch canvas pixel coords
var sketchTransform = this.sketchTransform_;
var halfWidth = sketchSize.width / 2;
var halfHeight = sketchSize.height / 2;
goog.vec.Mat4.makeIdentity(sketchTransform);
goog.vec.Mat4.translate(sketchTransform,
halfWidth,
halfHeight,
0);
goog.vec.Mat4.scale(sketchTransform,
1 / tileResolution,
-1 / tileResolution,
1);
goog.vec.Mat4.translate(sketchTransform,
-(sketchOrigin.x + halfWidth * tileResolution),
-(sketchOrigin.y - halfHeight * tileResolution),
0);
// clear/resize sketch canvas
sketchCanvas.width = sketchSize.width;
sketchCanvas.height = sketchSize.height;
var sketchCanvasRenderer = new ol.renderer.canvas.Renderer(
sketchCanvas, sketchTransform);
// clear/resize final canvas
var finalCanvas = this.canvas_;
finalCanvas.width = sketchSize.width;
finalCanvas.height = sketchSize.height;
var finalContext = this.context_;
var renderedFeatures = {};
var tilesToRender = {};
var tile, tileCoord, key, tileExtent, tileState, x, y;
// render features by geometry type
var filters = this.geometryFilters_,
numFilters = filters.length,
i, filter, type, features, symbolizer;
for (x = tileRange.minX; x <= tileRange.maxX; ++x) {
for (y = tileRange.minY; y <= tileRange.maxY; ++y) {
tileCoord = new ol.TileCoord(z, x, y);
key = tileCoord.toString();
tile = this.tileCache_[key];
if (tile === undefined) {
tileExtent = tileGrid.getTileCoordExtent(tileCoord);
// TODO: instead of filtering here, do this on the source and maintain
// a spatial index
function filterFn(feature) {
var id = goog.getUid(feature);
var include = !(id in renderedFeatures) &&
feature.getGeometry().getBounds().intersects(tileExtent);
if (include === true) {
renderedFeatures[id] = true;
}
return include;
}
for (i = 0; i < numFilters; ++i) {
filter = filters[i];
type = filter.getType();
features = source.getFeatures(filter);
// TODO: spatial index of tiles - see filterFn above
features = goog.array.filter(features, filterFn);
if (features.length) {
// TODO: layer.getSymbolizerLiterals(features) or similar
symbolizer = this.symbolizers_[type];
sketchCanvasRenderer.renderFeaturesByGeometryType(
type, features, symbolizer);
}
}
}
tilesToRender[key] = tileCoord;
}
}
for (key in tilesToRender) {
tile = this.tileCache_[key];
tileCoord = tilesToRender[key];
// LRU - move tile key to the end of the index
goog.array.remove(this.tileCacheIndex_, key);
this.tileCacheIndex_.push(key);
if (tile === undefined) {
tile = /** @type {HTMLCanvasElement} */
this.tileArchetype_.cloneNode(false);
tile.getContext('2d').drawImage(sketchCanvas,
(tileRange.minX - tileCoord.x) * tileSize.width,
(tileCoord.y - tileRange.maxY) * tileSize.height);
this.tileCache_[key] = tile;
// manage cache
if (this.tileCacheIndex_.length >=
ol.renderer.canvas.VectorLayer.TILECACHE_SIZE) {
delete this.tileCache_[this.tileCacheIndex_.shift()];
}
}
finalContext.drawImage(tile,
tileSize.width * (tileCoord.x - tileRange.minX),
tileSize.height * (tileRange.maxY - tileCoord.y));
}
this.renderedResolution_ = tileResolution;
};
/**
* @type {number}
*/
ol.renderer.canvas.VectorLayer.TILECACHE_SIZE = 128;