Add ol.reproj

2015-05-25 10:55:14 +02:00
parent 44a64ba451
commit 1222287f22
4 changed files with 669 additions and 0 deletions
@@ -0,0 +1,181 @@
+goog.provide('ol.reproj.Image');
+
+goog.require('goog.asserts');
+goog.require('goog.events');
+goog.require('goog.events.EventType');
+goog.require('ol.ImageBase');
+goog.require('ol.ImageState');
+goog.require('ol.dom');
+goog.require('ol.extent');
+goog.require('ol.proj');
+goog.require('ol.reproj');
+goog.require('ol.reproj.triangulation');
+
+
+
+/**
+ * @constructor
+ * @extends {ol.ImageBase}
+ * @param {ol.proj.Projection} sourceProj
+ * @param {ol.proj.Projection} targetProj
+ * @param {ol.Extent} targetExtent
+ * @param {number} targetResolution
+ * @param {number} pixelRatio
+ * @param {function(ol.Extent, number, number, ol.proj.Projection) :
+ *             ol.ImageBase} getImageFunction
+ */
+ol.reproj.Image = function(sourceProj, targetProj,
+    targetExtent, targetResolution, pixelRatio, getImageFunction) {
+
+  var width = ol.extent.getWidth(targetExtent) / targetResolution;
+  var height = ol.extent.getHeight(targetExtent) / targetResolution;
+
+  /**
+   * @private
+   * @type {Canvas2DRenderingContext}
+   */
+  this.context_ = ol.dom.createCanvasContext2D(width, height);
+  this.context_.imageSmoothingEnabled = true;
+
+  if (goog.DEBUG) {
+    this.context_.fillStyle = 'rgba(255,0,0,0.1)';
+    this.context_.fillRect(0, 0, width, height);
+  }
+
+  /**
+   * @private
+   * @type {HTMLCanvasElement}
+   */
+  this.canvas_ = this.context_.canvas;
+
+  var transformInv = ol.proj.getTransform(targetProj, sourceProj);
+
+  /**
+   * @private
+   * @type {!ol.reproj.Triangulation}
+   */
+  this.triangles_ = ol.reproj.triangulation.createForExtent(
+                        targetExtent, transformInv);
+
+  /**
+   * @private
+   * @type {number}
+   */
+  this.targetResolution_ = targetResolution;
+
+  /**
+   * @private
+   * @type {!ol.Extent}
+   */
+  this.targetExtent_ = targetExtent;
+
+  var srcExtent = ol.reproj.triangulation.getSourceExtent(this.triangles_);
+
+  var idealSourceResolution =
+      targetProj.getPointResolution(targetResolution,
+                                    ol.extent.getCenter(targetExtent)) *
+      targetProj.getMetersPerUnit() / sourceProj.getMetersPerUnit();
+
+  /**
+   * @private
+   * @type {ol.ImageBase}
+   */
+  this.srcImage_ = getImageFunction(srcExtent, idealSourceResolution,
+                                    pixelRatio, sourceProj);
+
+  /**
+   * @private
+   * @type {goog.events.Key}
+   */
+  this.sourceListenerKey_ = null;
+
+
+  var state = ol.ImageState.LOADED;
+  var attributions = [];
+
+  if (!goog.isNull(this.srcImage_)) {
+    state = ol.ImageState.IDLE;
+    attributions = this.srcImage_.getAttributions();
+  }
+
+  goog.base(this, targetExtent, targetResolution, pixelRatio,
+            state, attributions);
+};
+goog.inherits(ol.reproj.Image, ol.ImageBase);
+
+
+/**
+ * @inheritDoc
+ */
+ol.reproj.Image.prototype.disposeInternal = function() {
+  if (this.state == ol.ImageState.LOADING) {
+    this.unlistenSource_();
+  }
+  goog.base(this, 'disposeInternal');
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.reproj.Image.prototype.getImage = function(opt_context) {
+  return this.canvas_;
+};
+
+
+/**
+ * @private
+ */
+ol.reproj.Image.prototype.reproject_ = function() {
+  var srcState = this.srcImage_.getState();
+  if (srcState == ol.ImageState.LOADED) {
+    // render the reprojected content
+    ol.reproj.renderTriangles(this.context_, this.srcImage_.getResolution(),
+                              this.targetResolution_, this.targetExtent_,
+                              this.triangles_, [{
+          extent: this.srcImage_.getExtent(),
+          image: this.srcImage_.getImage()
+        }]);
+  }
+  this.state = srcState;
+  this.changed();
+};
+
+
+/**
+ * @inheritDoc
+ */
+ol.reproj.Image.prototype.load = function() {
+  if (this.state == ol.ImageState.IDLE) {
+    this.state = ol.ImageState.LOADING;
+    this.changed();
+
+    var srcState = this.srcImage_.getState();
+    if (srcState == ol.ImageState.LOADED ||
+        srcState == ol.ImageState.ERROR) {
+      this.reproject_();
+    } else {
+      this.sourceListenerKey_ = this.srcImage_.listen(
+          goog.events.EventType.CHANGE, function(e) {
+            var srcState = this.srcImage_.getState();
+            if (srcState == ol.ImageState.LOADED ||
+                srcState == ol.ImageState.ERROR) {
+              this.unlistenSource_();
+              this.reproject_();
+            }
+          }, false, this);
+      this.srcImage_.load();
+    }
+  }
+};
+
+
+/**
+ * @private
+ */
+ol.reproj.Image.prototype.unlistenSource_ = function() {
+  goog.asserts.assert(!goog.isNull(this.sourceListenerKey_),
+      'this.sourceListenerKey_ should not be null');
+  goog.events.unlistenByKey(this.sourceListenerKey_);
+  this.sourceListenerKey_ = null;
+};