/*
 * Circle Scan from center
 */

(function (window) {
	'use strict';

	function define_CesiumCircleScan(){
		//Main object
		var CesiumCircleScan = {};
		
		/*
		 * 添加扫描线 depth关闭
		 * viewer
		 * cartographicCenter 扫描中心
		 * maxRadius 最大半径 米
		 * scanColor 扫描颜色
		 * duration 持续时间 毫秒
		 */
        function AddCircleScanPostStage(viewer, cartographicCenter, maxRadius, scanColor, duration) {
            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 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" +
                "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";
            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 _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: ScanSegmentShader,
                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: function () {
                        return maxRadius * (((new Date()).getTime() - _time) % duration) / duration;
                    },
                    u_scanColor: scanColor
                }
            });
            viewer.scene.postProcessStages.add(ScanPostStage);
            return ScanPostStage;
        }
        
        /*
         * options = {
         * 		viewer:viewer,
         * 		lon:124.3,
         * 		lat:42.2,
         * 		maxRadius:20,
         * 		scanColor:Cesium.Color.GREEN,
         * 		duration:5000
         * };
         * */
        CesiumCircleScan.add = function(options){
        	var CartographicCenter = new Cesium.Cartographic(Cesium.Math.toRadians(options.lon), Cesium.Math.toRadians(options.lat), 0);
        	var ScanPostStage = AddCircleScanPostStage(options.viewer, CartographicCenter, options.maxRadius, options.scanColor, options.duration);
        	return ScanPostStage;
        };
        
        CesiumCircleScan.remove = function(viewer,ScanPostStage){
        	viewer.scene.postProcessStages.remove(ScanPostStage);
        };
        
        CesiumCircleScan.removes = function(viewer,ScanPostStages){
        	for ( var i = 0; i < ScanPostStages.length; i++) {
        		viewer.scene.postProcessStages.remove(ScanPostStages[i]);
			}
        };
        
		return CesiumCircleScan;
	}
	
	if (typeof(CesiumCircleScan) === 'undefined') {
		window.CesiumCircleScan = define_CesiumCircleScan();
	} else {
		console.log("CesiumCircleScan already defined.");
	}
})(window);