export default `
#define USE_CUBE_MAP_SHADOW true
uniform sampler2D colorTexture;
uniform sampler2D depthTexture;
in vec2 v_textureCoordinates;
uniform mat4 camera_projection_matrix;
uniform mat4 camera_view_matrix;
uniform samplerCube shadowMap_textureCube;
uniform mat4 shadowMap_matrix;
uniform vec4 shadowMap_lightPositionEC;
uniform vec4 shadowMap_normalOffsetScaleDistanceMaxDistanceAndDarkness;
uniform vec4 shadowMap_texelSizeDepthBiasAndNormalShadingSmooth;
uniform float helsing_viewDistance;
uniform vec4 helsing_visibleAreaColor;
uniform vec4 helsing_invisibleAreaColor;
struct zx_shadowParameters
{
    vec3 texCoords;
    float depthBias;
    float depth;
    float nDotL;
    vec2 texelStepSize;
    float normalShadingSmooth;
    float darkness;
};
float czm_shadowVisibility(samplerCube shadowMap,zx_shadowParameters shadowParameters)
{
    float depthBias = shadowParameters.depthBias;
    float depth = shadowParameters.depth;
    float nDotL = shadowParameters.nDotL;
    float normalShadingSmooth = shadowParameters.normalShadingSmooth;
    float darkness = shadowParameters.darkness;
    vec3 uvw = shadowParameters.texCoords;
    depth -= depthBias;
    float visibility = czm_shadowDepthCompare(shadowMap, uvw, depth);
    return czm_private_shadowVisibility(visibility, nDotL, normalShadingSmooth, darkness);
}
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;
}
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);
}
float shadow(in vec4 positionEC,in float depth){
    vec3 normalEC=getNormalEC();
    zx_shadowParameters shadowParameters;
    shadowParameters.texelStepSize=shadowMap_texelSizeDepthBiasAndNormalShadingSmooth.xy;
    shadowParameters.depthBias=shadowMap_texelSizeDepthBiasAndNormalShadingSmooth.z;
    shadowParameters.normalShadingSmooth=shadowMap_texelSizeDepthBiasAndNormalShadingSmooth.w;
    shadowParameters.darkness=shadowMap_normalOffsetScaleDistanceMaxDistanceAndDarkness.w;
    vec3 directionEC=positionEC.xyz-shadowMap_lightPositionEC.xyz;
    float distance=length(directionEC);
    directionEC=normalize(directionEC);
    float radius=shadowMap_lightPositionEC.w;
    if(distance>radius)
    {
        return 2.;
    }
    vec3 directionWC=czm_inverseViewRotation*directionEC;
    shadowParameters.depth=distance/radius-.0003;
    shadowParameters.nDotL=clamp(dot(normalEC,-directionEC),0.,1.);
    shadowParameters.texCoords=directionWC;
    float visibility=czm_shadowVisibility(shadowMap_textureCube,shadowParameters);
    return visibility;
}
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(){
    out_FragColor=texture(colorTexture,v_textureCoordinates);
    float depth=getDepth(texture(depthTexture,v_textureCoordinates));
    vec4 viewPos=toEye(v_textureCoordinates,depth);
    // 世界坐标
    vec4 wordPos=czm_inverseView*viewPos;
    // 虚拟相机中坐标
    vec4 vcPos=camera_view_matrix*wordPos;
    float near=.001*helsing_viewDistance;
    float dis=length(vcPos.xyz);
    if(dis>near&&dis<helsing_viewDistance){
        // 透视投影
        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)){
            float vis=shadow(viewPos,depth);
            if(vis>.3){
                out_FragColor=mix(out_FragColor,helsing_visibleAreaColor,.5);
            }else{
                out_FragColor=mix(out_FragColor,helsing_invisibleAreaColor,.5);
            }
        }
    }
}`;