<!DOCTYPE html>
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<html lang="en">
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<head>
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<meta charset="utf-8" />
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<meta http-equiv="X-UA-Compatible" content="IE=edge" />
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<meta
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name="viewport"
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content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"
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/>
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<meta name="description" content="Star burst overlapping billboards." />
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<meta name="cesium-sandcastle-labels" content="Showcases" />
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<title>Cesium Demo</title>
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<script type="text/javascript" src="../Sandcastle-header.js"></script>
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<script
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type="text/javascript"
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src="../../../Build/CesiumUnminified/Cesium.js"
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nomodule
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></script>
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<script type="module" src="../load-cesium-es6.js"></script>
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</head>
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<body
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class="sandcastle-loading"
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data-sandcastle-bucket="bucket-requirejs.html"
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>
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<style>
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@import url(../templates/bucket.css);
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</style>
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<div id="cesiumContainer" class="fullSize"></div>
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<div id="loadingOverlay"><h1>Loading...</h1></div>
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<div id="toolbar">
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<div id="zoomButtons"></div>
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</div>
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<script id="cesium_sandcastle_script">
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function startup(Cesium) {
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"use strict";
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//Sandcastle_Begin
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var viewer = new Cesium.Viewer("cesiumContainer", {
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selectionIndicator: false,
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});
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// Add labels clustered at the same location
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var numBillboards = 30;
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for (var i = 0; i < numBillboards; ++i) {
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var position = Cesium.Cartesian3.fromDegrees(-75.59777, 40.03883);
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viewer.entities.add({
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position: position,
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billboard: {
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image: "../images/facility.gif",
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scale: 2.5,
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},
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label: {
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text: "Label" + i,
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show: false,
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},
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});
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}
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var scene = viewer.scene;
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var camera = scene.camera;
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var handler = new Cesium.ScreenSpaceEventHandler(scene.canvas);
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handler.setInputAction(function (movement) {
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// Star burst on left mouse click.
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starBurst(movement.position);
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}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
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handler.setInputAction(function (movement) {
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// Remove the star burst when the mouse exits the circle or show the label of the billboard the mouse is hovering over.
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updateStarBurst(movement.endPosition);
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}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
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camera.moveStart.addEventListener(function () {
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// Reset the star burst on camera move because the lines from the center
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// because the line end points rely on the screen space positions of the billboards.
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undoStarBurst();
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});
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// State saved across mouse click and move events
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var starBurstState = {
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enabled: false,
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pickedEntities: undefined,
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billboardEyeOffsets: undefined,
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labelEyeOffsets: undefined,
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linePrimitive: undefined,
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radius: undefined,
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center: undefined,
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pixelPadding: 10.0,
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angleStart: 0.0,
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angleEnd: Cesium.Math.PI,
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maxDimension: undefined,
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};
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function offsetBillboard(
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entity,
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entityPosition,
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angle,
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magnitude,
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lines,
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billboardEyeOffsets,
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labelEyeOffsets
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) {
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var x = magnitude * Math.cos(angle);
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var y = magnitude * Math.sin(angle);
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var offset = new Cesium.Cartesian2(x, y);
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var drawingBufferWidth = scene.drawingBufferWidth;
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var drawingBufferHeight = scene.drawingBufferHeight;
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var pixelRatio = scene.pixelRatio;
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var diff = Cesium.Cartesian3.subtract(
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entityPosition,
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camera.positionWC,
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new Cesium.Cartesian3()
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);
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var distance = Cesium.Cartesian3.dot(camera.directionWC, diff);
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var dimensions = camera.frustum.getPixelDimensions(
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drawingBufferWidth,
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drawingBufferHeight,
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distance,
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pixelRatio,
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new Cesium.Cartesian2()
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);
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Cesium.Cartesian2.multiplyByScalar(
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offset,
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Cesium.Cartesian2.maximumComponent(dimensions),
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offset
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);
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var labelOffset;
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var billboardOffset = entity.billboard.eyeOffset;
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var eyeOffset = new Cesium.Cartesian3(offset.x, offset.y, 0.0);
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entity.billboard.eyeOffset = eyeOffset;
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if (Cesium.defined(entity.label)) {
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labelOffset = entity.label.eyeOffset;
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entity.label.eyeOffset = new Cesium.Cartesian3(
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offset.x,
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offset.y,
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-10.0
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);
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}
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var endPoint = Cesium.Matrix4.multiplyByPoint(
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camera.viewMatrix,
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entityPosition,
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new Cesium.Cartesian3()
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);
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Cesium.Cartesian3.add(eyeOffset, endPoint, endPoint);
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Cesium.Matrix4.multiplyByPoint(
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camera.inverseViewMatrix,
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endPoint,
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endPoint
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);
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lines.push(endPoint);
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billboardEyeOffsets.push(billboardOffset);
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labelEyeOffsets.push(labelOffset);
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}
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function starBurst(mousePosition) {
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if (Cesium.defined(starBurstState.pickedEntities)) {
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return;
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}
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var pickedObjects = scene.drillPick(mousePosition);
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if (!Cesium.defined(pickedObjects) || pickedObjects.length < 2) {
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return;
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}
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var billboardEntities = [];
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var length = pickedObjects.length;
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var i;
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for (i = 0; i < length; ++i) {
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var pickedObject = pickedObjects[i];
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if (pickedObject.primitive instanceof Cesium.Billboard) {
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billboardEntities.push(pickedObject);
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}
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}
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if (billboardEntities.length === 0) {
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return;
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}
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var pickedEntities = (starBurstState.pickedEntities = []);
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var billboardEyeOffsets = (starBurstState.billboardEyeOffsets = []);
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var labelEyeOffsets = (starBurstState.labelEyeOffsets = []);
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var lines = [];
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starBurstState.maxDimension = Number.NEGATIVE_INFINITY;
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var angleStart = starBurstState.angleStart;
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var angleEnd = starBurstState.angleEnd;
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var angle = angleStart;
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var angleIncrease;
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var magnitude;
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var magIncrease;
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var maxDimension;
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// Drill pick gets all of the entities under the mouse pointer.
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// Find the billboards and set their pixel offsets in a circle pattern.
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length = billboardEntities.length;
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i = 0;
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while (i < length) {
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var object = billboardEntities[i];
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if (pickedEntities.length === 0) {
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starBurstState.center = Cesium.Cartesian3.clone(
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object.primitive.position
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);
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}
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if (!Cesium.defined(angleIncrease)) {
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var width = object.primitive.width;
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var height = object.primitive.height;
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maxDimension =
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Math.max(width, height) * object.primitive.scale +
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starBurstState.pixelPadding;
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magnitude = maxDimension + maxDimension * 0.5;
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magIncrease = magnitude;
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angleIncrease = maxDimension / magnitude;
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}
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offsetBillboard(
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object.id,
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object.primitive.position,
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angle,
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magnitude,
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lines,
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billboardEyeOffsets,
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labelEyeOffsets
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);
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pickedEntities.push(object);
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var reflectedAngle = angleEnd - angle;
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if (
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i + 1 < length &&
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reflectedAngle - angleIncrease * 0.5 > angle + angleIncrease * 0.5
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) {
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object = billboardEntities[++i];
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offsetBillboard(
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object.id,
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object.primitive.position,
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reflectedAngle,
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magnitude,
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lines,
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billboardEyeOffsets,
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labelEyeOffsets
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);
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pickedEntities.push(object);
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}
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angle += angleIncrease;
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if (
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reflectedAngle - angleIncrease * 0.5 <
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angle + angleIncrease * 0.5
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) {
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magnitude += magIncrease;
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angle = angleStart;
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angleIncrease = maxDimension / magnitude;
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}
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++i;
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}
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// Add lines from the pick center out to the translated billboard.
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var instances = [];
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length = lines.length;
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for (i = 0; i < length; ++i) {
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var pickedEntity = pickedEntities[i];
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starBurstState.maxDimension = Math.max(
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pickedEntity.primitive.width,
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pickedEntity.primitive.height,
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starBurstState.maxDimension
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);
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instances.push(
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new Cesium.GeometryInstance({
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geometry: new Cesium.SimplePolylineGeometry({
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positions: [starBurstState.center, lines[i]],
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arcType: Cesium.ArcType.NONE,
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granularity: Cesium.Math.PI_OVER_FOUR,
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}),
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attributes: {
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color: Cesium.ColorGeometryInstanceAttribute.fromColor(
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Cesium.Color.WHITE
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),
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},
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})
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);
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}
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starBurstState.linePrimitive = scene.primitives.add(
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new Cesium.Primitive({
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geometryInstances: instances,
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appearance: new Cesium.PerInstanceColorAppearance({
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flat: true,
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translucent: false,
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}),
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asynchronous: false,
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})
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);
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viewer.selectedEntity = undefined;
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starBurstState.radius = magnitude + magIncrease;
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}
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function updateStarBurst(mousePosition) {
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if (!Cesium.defined(starBurstState.pickedEntities)) {
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return;
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}
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if (!starBurstState.enabled) {
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// For some reason we get a mousemove event on click, so
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// do not show a label on the first event.
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starBurstState.enabled = true;
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return;
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}
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// Remove the star burst if the mouse exits the screen space circle.
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// If the mouse is inside the circle, show the label of the billboard the mouse is hovering over.
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var screenPosition = Cesium.SceneTransforms.wgs84ToWindowCoordinates(
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scene,
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starBurstState.center
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);
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var fromCenter = Cesium.Cartesian2.subtract(
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mousePosition,
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screenPosition,
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new Cesium.Cartesian2()
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);
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var radius = starBurstState.radius;
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if (
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Cesium.Cartesian2.magnitudeSquared(fromCenter) > radius * radius ||
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fromCenter.y >
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3.0 * (starBurstState.maxDimension + starBurstState.pixelPadding)
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) {
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undoStarBurst();
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} else {
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showLabels(mousePosition);
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}
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}
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function undoStarBurst() {
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var pickedEntities = starBurstState.pickedEntities;
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if (!Cesium.defined(pickedEntities)) {
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return;
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}
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var billboardEyeOffsets = starBurstState.billboardEyeOffsets;
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var labelEyeOffsets = starBurstState.labelEyeOffsets;
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// Reset billboard and label pixel offsets.
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// Hide overlapping labels.
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for (var i = 0; i < pickedEntities.length; ++i) {
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var entity = pickedEntities[i].id;
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entity.billboard.eyeOffset = billboardEyeOffsets[i];
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if (Cesium.defined(entity.label)) {
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entity.label.eyeOffset = labelEyeOffsets[i];
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entity.label.show = false;
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}
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}
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// Remove lines from the scene.
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// Free resources and reset state.
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scene.primitives.remove(starBurstState.linePrimitive);
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starBurstState.linePrimitive = undefined;
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starBurstState.pickedEntities = undefined;
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starBurstState.billboardEyeOffsets = undefined;
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starBurstState.labelEyeOffsets = undefined;
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starBurstState.radius = undefined;
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starBurstState.enabled = false;
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}
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var currentObject;
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function showLabels(mousePosition) {
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var pickedObjects = scene.drillPick(mousePosition);
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var pickedObject;
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if (Cesium.defined(pickedObjects)) {
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var length = pickedObjects.length;
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for (var i = 0; i < length; ++i) {
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if (pickedObjects[i].primitive instanceof Cesium.Billboard) {
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pickedObject = pickedObjects[i];
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break;
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}
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}
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}
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if (pickedObject !== currentObject) {
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if (
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Cesium.defined(pickedObject) &&
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Cesium.defined(pickedObject.id.label)
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) {
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if (Cesium.defined(currentObject)) {
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currentObject.id.label.show = false;
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}
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currentObject = pickedObject;
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pickedObject.id.label.show = true;
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} else if (Cesium.defined(currentObject)) {
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currentObject.id.label.show = false;
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currentObject = undefined;
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}
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}
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}
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//Sandcastle_End
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Sandcastle.finishedLoading();
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}
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if (typeof Cesium !== "undefined") {
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window.startupCalled = true;
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startup(Cesium);
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}
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</script>
|
</body>
|
</html>
|
