import {
	ShaderLib,
	ShaderMaterial,
	UniformsLib,
	UniformsUtils,
	Vector2
} from '../build/three.module.js';

/**
 * parameters = {
 *  color: <hex>,
 *  lineWidth: <float>,
 *  dashed: <boolean>,
 *  dashScale: <float>,
 *  dashSize: <float>,
 *  dashOffset: <float>,
 *  gapSize: <float>,
 *  resolution: <Vector2>, // to be set by renderer
 * }
 */

UniformsLib.line = {
  
	lineWidth: { value: 1 },
	resolution: { value: new Vector2( 1, 1 ) },
    viewportOffset: { value: new Vector2(0, 0 ) }, //left, top    
	dashScale: { value: 1 },
	dashSize: { value: 1 },
	dashOffset: { value: 0 },
	gapSize: { value: 1 }, // todo FIX - maybe change to totalSize
	opacity: { value: 1 },
    
    depthTexture:{ value: null },
    nearPlane:{value: 0.1},
    farPlane:{value: 100000},
};

ShaderLib[ 'line' ] = {

	uniforms: UniformsUtils.merge( [
		UniformsLib.common,
		UniformsLib.fog,
		UniformsLib.line
	] ),

	vertexShader:
		`
		#include <common>
		#include <color_pars_vertex>
		#include <fog_pars_vertex>
		#include <logdepthbuf_pars_vertex>
		#include <clipping_planes_pars_vertex>

		uniform float lineWidth;
		uniform vec2 resolution;

		attribute vec3 instanceStart;
		attribute vec3 instanceEnd;

		attribute vec3 instanceColorStart;
		attribute vec3 instanceColorEnd;

		varying vec2 vUv;

		#ifdef USE_DASH

			uniform float dashScale;
			attribute float instanceDistanceStart;
			attribute float instanceDistanceEnd;
			varying float vLineDistance;

		#endif

		void trimSegment( const in vec4 start, inout vec4 end ) {

			// trim end segment so it terminates between the camera plane and the near plane

			// conservative estimate of the near plane
			float a = projectionMatrix[ 2 ][ 2 ]; // 3nd entry in 3th column
			float b = projectionMatrix[ 3 ][ 2 ]; // 3nd entry in 4th column
			float nearEstimate = - 0.5 * b / a;

			float alpha = ( nearEstimate - start.z ) / ( end.z - start.z );

			end.xyz = mix( start.xyz, end.xyz, alpha );

		}

		void main() {

			#ifdef USE_COLOR

				vColor.xyz = ( position.y < 0.5 ) ? instanceColorStart : instanceColorEnd;

			#endif

			#ifdef USE_DASH

				vLineDistance = ( position.y < 0.5 ) ? dashScale * instanceDistanceStart : dashScale * instanceDistanceEnd;

			#endif
            
             

			float aspect = resolution.x / resolution.y;

			vUv = uv;

			// camera space
			vec4 start = modelViewMatrix * vec4( instanceStart, 1.0 );
			vec4 end = modelViewMatrix * vec4( instanceEnd, 1.0 );

			// special case for perspective projection, and segments that terminate either in, or behind, the camera plane
			// clearly the gpu firmware has a way of addressing this issue when projecting into ndc space
			// but we need to perform ndc-space calculations in the shader, so we must address this issue directly
			// perhaps there is a more elegant solution -- WestLangley

			bool perspective = ( projectionMatrix[ 2 ][ 3 ] == - 1.0 ); // 4th entry in the 3rd column

			if ( perspective ) {

				if ( start.z < 0.0 && end.z >= 0.0 ) {

					trimSegment( start, end );

				} else if ( end.z < 0.0 && start.z >= 0.0 ) {

					trimSegment( end, start );

				}

			}

			// clip space
			vec4 clipStart = projectionMatrix * start;
			vec4 clipEnd = projectionMatrix * end;

			// ndc space
			vec2 ndcStart = clipStart.xy / clipStart.w;
			vec2 ndcEnd = clipEnd.xy / clipEnd.w;

			// direction
			vec2 dir = ndcEnd - ndcStart;

			// account for clip-space aspect ratio
			dir.x *= aspect;
			dir = normalize( dir );

			// perpendicular to dir
			vec2 offset = vec2( dir.y, - dir.x );

			// undo aspect ratio adjustment
			dir.x /= aspect;
			offset.x /= aspect;

			// sign flip
			if ( position.x < 0.0 ) offset *= - 1.0;

			// endcaps
			if ( position.y < 0.0 ) {

				offset += - dir;

			} else if ( position.y > 1.0 ) {

				offset += dir;

			}

			// adjust for lineWidth
			offset *= lineWidth;

			// adjust for clip-space to screen-space conversion // maybe resolution should be based on viewport ...
			offset /= resolution.y;

			// select end
			vec4 clip = ( position.y < 0.5 ) ? clipStart : clipEnd;

			// back to clip space
			offset *= clip.w;

			clip.xy += offset;

			gl_Position = clip;

			vec4 mvPosition = ( position.y < 0.5 ) ? start : end; // this is an approximation

			#include <logdepthbuf_vertex>
			#include <clipping_planes_vertex>
			#include <fog_vertex>

		}
		`,

	fragmentShader:
		`
		uniform vec3 diffuse;
		uniform float opacity;

		#ifdef USE_DASH

			uniform float dashSize;
			uniform float dashOffset;
			uniform float gapSize;

		#endif
        
        //加
        #if defined(GL_EXT_frag_depth) && defined(useDepth)    
            uniform sampler2D depthTexture;
            uniform float nearPlane;
            uniform float farPlane; 
            uniform vec2 resolution;
            uniform vec2 viewportOffset;
        #endif
        
        
		varying float vLineDistance;

		#include <common>
		#include <color_pars_fragment>
		#include <fog_pars_fragment>
		#include <logdepthbuf_pars_fragment>
		#include <clipping_planes_pars_fragment>

		varying vec2 vUv;



        #if defined(GL_EXT_frag_depth) && defined(useDepth)  
            float convertToLinear(float zValue)
            {
                float z = zValue * 2.0 - 1.0;
                return (2.0 * nearPlane * farPlane) / (farPlane + nearPlane - z * (farPlane - nearPlane));
            }
        #endif





		void main() {

			#include <clipping_planes_fragment>

			#ifdef USE_DASH

				if ( vUv.y < - 1.0 || vUv.y > 1.0 ) discard; // discard endcaps
                
                
                bool unvisible = mod( vLineDistance + dashOffset, dashSize + gapSize ) > dashSize;
                //加
                #ifdef DASH_with_depth
                    
                #else  
                    if (unvisible) discard; // todo - FIX
                #endif
			#endif

			if ( abs( vUv.y ) > 1.0 ) {

				float a = vUv.x;
				float b = ( vUv.y > 0.0 ) ? vUv.y - 1.0 : vUv.y + 1.0;
				float len2 = a * a + b * b;

				if ( len2 > 1.0 ) discard;

			}

            vec4 diffuseColor = vec4( diffuse, opacity );
            //加
            #if defined(GL_EXT_frag_depth) && defined(useDepth)    
               
                float mixFactor = 0.0;
                float clipFactor = 0.0;

                float fragDepth = convertToLinear(gl_FragCoord.z);

                vec2 depthTxtCoords = vec2(gl_FragCoord.x - viewportOffset.x,  gl_FragCoord.y) / resolution;

                float textureDepth = convertToLinear(texture2D(depthTexture, depthTxtCoords).r);

                float delta = textureDepth - fragDepth;

                if (delta < 0.0)
                {
                    float occlusionDistance = - 1.0;
                    float clipDistance = - 4.0;
                    mixFactor = clamp(delta / occlusionDistance, 0.0, 1.0);
                    clipFactor = clamp(delta / clipDistance, 0.0, 1.0);
                }
                 
                if (clipFactor == 1.0)
                {
                    discard;
                }
                
                vec4 backColor = vec4(0.8,0.8,0.8, 0.8*opacity);
                 
                #ifdef DASH_with_depth  
                    // 只在被遮住的部分显示虚线
                    if(unvisible) backColor.a = 0.0;
                #endif 
                
                //vec4 diffuseColor = vec4(mix(diffuse, backColor, mixFactor), opacity*(1.0 - clipFactor));
               
               
               
                diffuseColor = mix(diffuseColor, backColor , mixFactor);   
               
               
                diffuseColor.a *= (1.0 - clipFactor);  
                
            #endif
 

 

			#include <logdepthbuf_fragment>
			#include <color_fragment>

			gl_FragColor = vec4( diffuseColor.rgb, diffuseColor.a );

			#include <tonemapping_fragment>
			#include <encodings_fragment>
			#include <fog_fragment>
			#include <premultiplied_alpha_fragment>

		}
		`
};

var LineMaterial = function ( parameters ) {

	ShaderMaterial.call( this, {

		type: 'LineMaterial',

		uniforms: UniformsUtils.clone( ShaderLib[ 'line' ].uniforms ),

		vertexShader: ShaderLib[ 'line' ].vertexShader,
		fragmentShader: ShaderLib[ 'line' ].fragmentShader,

		clipping: true // required for clipping support

	} );

	this.dashed = false;
    this.lineWidth_ = 0
    


	Object.defineProperties( this, {
        dashed:{//add
            enumerable: true,

			get: function () {

				return 'USE_DASH' in this.defines 

			},

			set: function ( value ) {
                if(value){
                    this.defines.USE_DASH = ''
                }else{
                    delete this.defines.USE_DASH
                }
                this.needsUpdate = true
			}  
        },
        
        useDepth:{//add
            enumerable: true,

			get: function () {

				return 'useDepth' in this.defines 

			},

			set: function ( value ) {
                if(value != this.useDepth){ 
                    if(value){
                        this.defines.useDepth = ''
                        this.updateDepthParams()
                    }else{
                        delete this.defines.useDepth
                    }
                    this.needsUpdate = true
                }
			}  
        },
        
        dashWithDepth:{//add 
            enumerable: true,

			get: function () {

				return 'DASH_with_depth' in this.defines 

			},

			set: function ( value ) {
                if(value != this.dashWithDepth){ 
                    if(value){
                        this.defines.DASH_with_depth = '' 
                    }else{
                        delete this.defines.DASH_with_depth
                    }
                    this.needsUpdate = true
                }
			}  
        },
       
        
        
		color: {

			enumerable: true,

			get: function () {

				return this.uniforms.diffuse.value;

			},

			set: function ( value ) {

				this.uniforms.diffuse.value = value;

			}

		},

		lineWidth: {

			enumerable: true,

			get: function () {

				return this.lineWidth_;//this.uniforms.lineWidth.value;

			},

			set: function ( value ) {
 
				this.uniforms.lineWidth.value = value * window.devicePixelRatio;
                this.lineWidth_ = value
			}

		},

		dashScale: {

			enumerable: true,

			get: function () {

				return this.uniforms.dashScale.value;

			},

			set: function ( value ) {

				this.uniforms.dashScale.value = value;

			}

		},

		dashSize: {

			enumerable: true,

			get: function () {

				return this.uniforms.dashSize.value;

			},

			set: function ( value ) {

				this.uniforms.dashSize.value = value;

			}

		},

		dashOffset: {

			enumerable: true,

			get: function () {

				return this.uniforms.dashOffset.value;

			},

			set: function ( value ) {

				this.uniforms.dashOffset.value = value;

			}

		},

		gapSize: {

			enumerable: true,

			get: function () {

				return this.uniforms.gapSize.value;

			},

			set: function ( value ) {

				this.uniforms.gapSize.value = value;

			}

		},

		opacity: {

			enumerable: true,

			get: function () {

				return this.uniforms.opacity.value;

			},

			set: function ( value ) {

				this.uniforms.opacity.value = value;

			}

		},

		resolution: {

			enumerable: true,

			get: function () {

				return this.uniforms.resolution.value;

			},

			set: function ( value ) {

				this.uniforms.resolution.value.copy( value );

			}

		}

	} );

	this.setValues( parameters );
 

    //add
    this.updateDepthParams()
    
    viewer.addEventListener('camera_changed', (e)=>{
        if(e.viewport.name != 'mapViewport') this.updateDepthParams(e) 
    })   

    let setSize = (e)=>{ 
        let viewport = e.viewport
        let viewportOffset = viewport.offset || new Vector2() 
        this.uniforms.resolution.value.copy(viewport.resolution2) 
        this.uniforms.viewportOffset.value.copy(viewportOffset) 
        this.lineWidth = this.lineWidth_
    }
    
    let viewport = viewer.mainViewport;
     
    setSize({viewport})


    viewer.addEventListener('resize',(e)=>{
        if(!e.viewport || e.viewport.name != 'mapViewport'){
            setSize(e)
            //console.log(this.name +  viewportOffset.toArray())     
        } 
    })  
    
    
    /* viewer.addEventListener("render.begin", (e)=>{//before render  如果有大于两个viewport的话可能要
        if(e.viewport.name != 'mapViewport') this.updateDepthParams({camera:e.viewport.camera})
    }) */






};

LineMaterial.prototype = Object.create( ShaderMaterial.prototype );
LineMaterial.prototype.constructor = LineMaterial;

LineMaterial.prototype.isLineMaterial = true;
LineMaterial.prototype.updateDepthParams = function(e={}){   
    if(this.useDepth){
        var camera = e.camera || viewer.scene.getActiveCamera()
        this.uniforms.depthTexture.value = viewer.getPRenderer().rtEDL.depthTexture  
        this.uniforms.nearPlane.value = camera.near;
        this.uniforms.farPlane.value = camera.far; 
    }
}
export { LineMaterial };