cesium雷达扫描圈

import * as Cesium from "cesium";
let lastStage="";
// 圆扩散
export function showCircleScan(viewer,lon, lat,color,maxRadius,height) {
    var cartographicCenter = new Cesium.Cartographic(Cesium.Math.toRadians(lon), Cesium.Math.toRadians(lat), height?height:2);
    var scanColor = new Cesium.Color.fromCssColorString(color)
    lastStage = addCircleScanPostStage(viewer, cartographicCenter, maxRadius?maxRadius:100, scanColor, 1000);
}
// showRadarScan() // 雷达扫描
export function showRadarScan(lon, lat,color,height) {

    var cartographicCenter = new Cesium.Cartographic(Cesium.Math.toRadians(lon), Cesium.Math.toRadians(lat), height?height:32);
    var scanColor = new Cesium.Color(color);

    lastStage = addRadarScanPostStage(viewer, cartographicCenter, 1000, scanColor, 3000);
}

/*
  添加扩散效果扫描线
  viewer
  cartographicCenter 扫描中心
  radius  半径 米
  scanColor 扫描颜色
  duration 持续时间 毫秒
*/
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\ ";
    return scanSegmentShader;
}

/*
  添加雷达扫描线
  viewer
  cartographicCenter 扫描中心
  radius  半径 米
  scanColor 扫描颜色
  duration 持续时间 毫秒
*/
function addRadarScanPostStage(viewer, cartographicCenter, radius, scanColor, duration) {
    var _Cartesian3Center = Cesium.Cartographic.toCartesian(cartographicCenter);
    var _Cartesian4Center = new Cesium.Cartesian4(_Cartesian3Center.x, _Cartesian3Center.y, _Cartesian3Center.z, 1);

    var _CartographicCenter1 = new Cesium.Cartographic(cartographicCenter.longitude, cartographicCenter.latitude, cartographicCenter.height + 500);
    var _Cartesian3Center1 = Cesium.Cartographic.toCartesian(_CartographicCenter1);
    var _Cartesian4Center1 = new Cesium.Cartesian4(_Cartesian3Center1.x, _Cartesian3Center1.y, _Cartesian3Center1.z, 1);

    var _CartographicCenter2 = new Cesium.Cartographic(cartographicCenter.longitude + Cesium.Math.toRadians(0.001), cartographicCenter.latitude, cartographicCenter.height);
    var _Cartesian3Center2 = Cesium.Cartographic.toCartesian(_CartographicCenter2);
    var _Cartesian4Center2 = new Cesium.Cartesian4(_Cartesian3Center2.x, _Cartesian3Center2.y, _Cartesian3Center2.z, 1);
    var _RotateQ = new Cesium.Quaternion();
    var _RotateM = new Cesium.Matrix3();

    var _time = (new Date()).getTime();

    var _scratchCartesian4Center = new Cesium.Cartesian4();
    var _scratchCartesian4Center1 = new Cesium.Cartesian4();
    var _scratchCartesian4Center2 = new Cesium.Cartesian4();
    var _scratchCartesian3Normal = new Cesium.Cartesian3();
    var _scratchCartesian3Normal1 = new Cesium.Cartesian3();

    var ScanPostStage = new Cesium.PostProcessStage({
        fragmentShader: getRadarScanShader(),
        uniforms: {
            u_scanCenterEC: function () {
                return Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
            },
            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: radius,
            u_scanLineNormalEC: function () {
                var temp = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
                var temp1 = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center1, _scratchCartesian4Center1);
                var temp2 = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center2, _scratchCartesian4Center2);

                _scratchCartesian3Normal.x = temp1.x - temp.x;
                _scratchCartesian3Normal.y = temp1.y - temp.y;
                _scratchCartesian3Normal.z = temp1.z - temp.z;

                Cesium.Cartesian3.normalize(_scratchCartesian3Normal, _scratchCartesian3Normal);

                _scratchCartesian3Normal1.x = temp2.x - temp.x;
                _scratchCartesian3Normal1.y = temp2.y - temp.y;
                _scratchCartesian3Normal1.z = temp2.z - temp.z;

                var tempTime = (((new Date()).getTime() - _time) % duration) / duration;
                Cesium.Quaternion.fromAxisAngle(_scratchCartesian3Normal, tempTime * Cesium.Math.PI * 2, _RotateQ);
                Cesium.Matrix3.fromQuaternion(_RotateQ, _RotateM);
                Cesium.Matrix3.multiplyByVector(_RotateM, _scratchCartesian3Normal1, _scratchCartesian3Normal1);
                Cesium.Cartesian3.normalize(_scratchCartesian3Normal1, _scratchCartesian3Normal1);
                return _scratchCartesian3Normal1;
            },
            u_scanColor: scanColor
        }
    });
    viewer.scene.postProcessStages.add(ScanPostStage);

    return ScanPostStage;
}


//雷达扫描线效果Shader
function getRadarScanShader() {
    var scanSegmentShader =
        "uniform sampler2D colorTexture;\n" +
        "uniform sampler2D depthTexture;\n" +
        "varying vec2 v_textureCoordinates;\n" +
        "uniform vec4 u_scanCenterEC;\n" +
        "uniform vec3 u_scanPlaneNormalEC;\n" +
        "uniform vec3 u_scanLineNormalEC;\n" +
        "uniform float u_radius;\n" +
        "uniform vec4 u_scanColor;\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" +

        "bool isPointOnLineRight(in vec3 ptOnLine, in vec3 lineNormal, in vec3 testPt)\n" +
        "{\n" +
        "vec3 v01 = testPt - ptOnLine;\n" +
        "normalize(v01);\n" +
        "vec3 temp = cross(v01, lineNormal);\n" +
        "float d = dot(temp, u_scanPlaneNormalEC);\n" +
        "return d > 0.5;\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 distancePointToLine(in vec3 ptOnLine, in vec3 lineNormal, in vec3 testPt)\n" +
        "{\n" +
        "vec3 tempPt = pointProjectOnPlane(lineNormal, ptOnLine, testPt);\n" +
        "return length(tempPt - ptOnLine);\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" +
        "float twou_radius = u_radius * 2.0;\n" +
        "if(dis < u_radius)\n" +
        "{\n" +
        "float f0 = 1.0 -abs(u_radius - dis) / u_radius;\n" +
        "f0 = pow(f0, 64.0);\n" +
        "vec3 lineEndPt = vec3(u_scanCenterEC.xyz) + u_scanLineNormalEC * u_radius;\n" +
        "float f = 0.0;\n" +
        "if(isPointOnLineRight(u_scanCenterEC.xyz, u_scanLineNormalEC.xyz, prjOnPlane.xyz))\n" +
        "{\n" +
        "float dis1= length(prjOnPlane.xyz - lineEndPt);\n" +
        "f = abs(twou_radius -dis1) / twou_radius;\n" +
        "f = pow(f, 3.0);\n" +
        "}\n" +
        "gl_FragColor = mix(gl_FragColor, u_scanColor, f + f0);\n" +
        "}\n" +
        "}\n";
    return scanSegmentShader;
}