export default `
 #define USE_CUBE_MAP_SHADOW true
 uniform sampler2D colorTexture;
 uniform sampler2D depthTexture;
 varying vec2 v_textureCoordinates;
 uniform mat4 camera_projection_matrix;
 uniform mat4 camera_view_matrix;
 uniform vec4 helsing_visibleAreaColor;
 uniform vec4 helsing_invisibleAreaColor;
 uniform sampler2D helsing_texture;

 vec4 getPositionEC(){
     return czm_windowToEyeCoordinates(gl_FragCoord);
 }

 vec3 getNormalEC(){
     return vec3(1.);
 }

 vec4 toEye(in vec2 uv,in float depth){
     vec2 xy=vec2((uv.x*2.-1.),(uv.y*2.-1.));
     vec4 posInCamera=czm_inverseProjection*vec4(xy,depth,1.);
     posInCamera=posInCamera/posInCamera.w;
     return posInCamera;
 }

 vec3 pointProjectOnPlane(in vec3 planeNormal,in vec3 planeOrigin,in vec3 point){
     vec3 v01=point-planeOrigin;
     float d=dot(planeNormal,v01);
     return(point-planeNormal*d);
 }

 float getDepth(in vec4 depth){
     float z_window=czm_unpackDepth(depth);
     z_window=czm_reverseLogDepth(z_window);
     float n_range=czm_depthRange.near;
     float f_range=czm_depthRange.far;
     return(2.*z_window-n_range-f_range)/(f_range-n_range);
 }

 bool visible(in vec4 result)
 {
     result.x/=result.w;
     result.y/=result.w;
     result.z/=result.w;
     return result.x>=-1.&&result.x<=1.
     &&result.y>=-1.&&result.y<=1.
     &&result.z>=-1.&&result.z<=1.;
 }

 void main(){
     // 釉色 = 结构二维(颜色纹理, 纹理坐标)
     gl_FragColor = texture2D(colorTexture, v_textureCoordinates);
     // 深度 = 获取深度(结构二维(深度纹理, 纹理坐标))
     float depth = getDepth(texture2D(depthTexture, v_textureCoordinates));
     // 视角 = (纹理坐标, 深度)
     vec4 positionEC = toEye(v_textureCoordinates, depth);
     // 世界坐标
     vec4 wordPos = czm_inverseView * positionEC;
     // 虚拟相机中坐标
     vec4 vcPos = camera_view_matrix * wordPos;
     vec4 videoColor = texture2D(helsing_texture, v_textureCoordinates);
     float dis = length(vcPos.xyz);
     vec4 posInEye = camera_projection_matrix * vcPos;
         // 可视区颜色
         // vec4 helsing_visibleAreaColor=vec4(0.,1.,0.,.5);
         // vec4 helsing_invisibleAreaColor=vec4(1.,0.,0.,.5);
         if(visible(posInEye)){
            vec4 out_FragColor = helsing_visibleAreaColor;
            gl_FragColor = mix(gl_FragColor,videoColor,1.0);
        }
 }`;