<html lang="en">
<head>
<meta charset="UTF-8"/>
<script src="Build/Cesium/Cesium.js"></script>
<link rel="stylesheet" href="Build/Cesium/Widgets/widgets.css">
<script src="initMap.js"></script>
<script>
var viewer=null;
function load() {
console.log("Cesium:",window.Cesium);
//初始化地图
initMap();
//定位
var obj = {lng:118.0850887298584, lat: 24.439001083374023,eyeHeight:5000,pitch:-65,heading:0.0,time:1};
viewerFlyToLonLat(obj);
//关闭地形检测（必须得设置该属性），否则扩散圈会移动
viewer.scene.globe.depthTestAgainstTerrain = true;
addCircleScan();
}
function addCircleScan(){
var cartographicCenter = new Cesium.Cartographic(Cesium.Math.toRadians(118.0850887298584), Cesium.Math.toRadians(24.439001083374023), 320);
var scanColor = new Cesium.Color(0.0, 1.0, 0.0, 1);
var lastStage = addCircleScanPostStage(viewer, cartographicCenter, 1000, scanColor, 4000);
}
/**
*
* @param viewer
* @param cartographicCenter 扩散圆中心点
* @param maxRadius 最大半径
* @param scanColor 扩散颜色
* @param duration 扩散完成时间
* @returns {Cesium.PostProcessStage}
*/
function addCircleScanPostStage(viewer, cartographicCenter, maxRadius, scanColor, duration) {
var _Cartesian3Center = Cesium.Cartographic.toCartesian(cartographicCenter);
var _Cartesian4Center = new Cesium.Cartesian4(_Cartesian3Center.x, _Cartesian3Center.y, _Cartesian3Center.z, 1);
var _CartograhpicCenter1 = new Cesium.Cartographic(cartographicCenter.longitude, cartographicCenter.latitude, cartographicCenter.height + 500);
var _Cartesian3Center1 = Cesium.Cartographic.toCartesian(_CartograhpicCenter1);
var _Cartesian4Center1 = new Cesium.Cartesian4(_Cartesian3Center1.x, _Cartesian3Center1.y, _Cartesian3Center1.z, 1);
var _time = (new Date()).getTime();
var _scratchCartesian4Center = new Cesium.Cartesian4();
var _scratchCartesian4Center1 = new Cesium.Cartesian4();
var _scratchCartesian3Normal = new Cesium.Cartesian3();
var ScanPostStage = new Cesium.PostProcessStage({
fragmentShader: getScanSegmentShader(),
uniforms: {
u_scanCenterEC: function () {
var temp = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
return temp;
},
u_scanPlaneNormalEC: function () {
var temp = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
var temp1 = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center1, _scratchCartesian4Center1);
_scratchCartesian3Normal.x = temp1.x - temp.x;
_scratchCartesian3Normal.y = temp1.y - temp.y;
_scratchCartesian3Normal.z = temp1.z - temp.z;
Cesium.Cartesian3.normalize(_scratchCartesian3Normal, _scratchCartesian3Normal);
return _scratchCartesian3Normal;
},
u_radius: function () {
return maxRadius * (((new Date()).getTime() - _time) % duration) / duration;
},
u_scanColor: scanColor
}
});
viewer.scene.postProcessStages.add(ScanPostStage);
return ScanPostStage;
}
//扩散效果Shader
function getScanSegmentShader() {
var scanSegmentShader = "\n\
uniform sampler2D colorTexture;\n\
uniform sampler2D depthTexture;\n\
varying vec2 v_textureCoordinates;\n\
uniform vec4 u_scanCenterEC;\n\
uniform vec3 u_scanPlaneNormalEC;\n\
uniform float u_radius;\n\
uniform vec4 u_scanColor;\n\
\n\
vec4 toEye(in vec2 uv,in float depth)\n\
{\n\
vec2 xy = vec2((uv.x * 2.0 - 1.0),(uv.y * 2.0 - 1.0));\n\
vec4 posIncamera = czm_inverseProjection * vec4(xy,depth,1.0);\n\
posIncamera = posIncamera/posIncamera.w;\n\
return posIncamera;\n\
}\n\
\n\
vec3 pointProjectOnPlane(in vec3 planeNormal,in vec3 planeOrigin,in vec3 point)\n\
{\n\
vec3 v01 = point - planeOrigin;\n\
float d = dot(planeNormal,v01);\n\
return (point-planeNormal * d);\n\
}\n\
float getDepth(in vec4 depth)\n\
{\n\
float z_window = czm_unpackDepth(depth);\n\
z_window = czm_reverseLogDepth(z_window);\n\
float n_range = czm_depthRange.near;\n\
float f_range = czm_depthRange.far;\n\
return (2.0 * z_window - n_range - f_range)/(f_range-n_range);\n\
} \n\
void main()\n\
{\n\
gl_FragColor = texture2D(colorTexture,v_textureCoordinates);\n\
float depth = getDepth(texture2D(depthTexture,v_textureCoordinates));\n\
vec4 viewPos = toEye(v_textureCoordinates,depth);\n\
vec3 prjOnPlane = pointProjectOnPlane(u_scanPlaneNormalEC.xyz,u_scanCenterEC.xyz,viewPos.xyz);\n\
float dis = length(prjOnPlane.xyz - u_scanCenterEC.xyz);\n\
if(dis<u_radius)\n\
{\n\
float f = 1.0-abs(u_radius - dis )/ u_radius;\n\
f = pow(f,4.0);\n\
gl_FragColor = mix(gl_FragColor,u_scanColor,f);\n\
}\n\
} \n\ ";
console.log("scanSegmentShader",scanSegmentShader);
return scanSegmentShader;
}
</script>
</head>
<body onload="load()" >
<div id="map" style='z-index:100;position: absolute;top: 0; bottom: 0;right: 0;left: 0;'></div>
</body>
</html>