File: //var/www/aspa/three/addons/lines/LineMaterial.js
/**
* parameters = {
* color: <hex>,
* linewidth: <float>,
* dashed: <boolean>,
* dashScale: <float>,
* dashSize: <float>,
* dashOffset: <float>,
* gapSize: <float>,
* resolution: <Vector2>, // to be set by renderer
* }
*/
import {
ShaderLib,
ShaderMaterial,
UniformsLib,
UniformsUtils,
Vector2
} from 'three';
UniformsLib.line = {
worldUnits: { value: 1 },
linewidth: { value: 1 },
resolution: { value: new Vector2( 1, 1 ) },
dashOffset: { value: 0 },
dashScale: { value: 1 },
dashSize: { value: 1 },
gapSize: { value: 1 } // todo FIX - maybe change to totalSize
};
ShaderLib[ 'line' ] = {
uniforms: UniformsUtils.merge( [
UniformsLib.common,
UniformsLib.fog,
UniformsLib.line
] ),
vertexShader:
/* glsl */`
#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;
#ifdef WORLD_UNITS
varying vec4 worldPos;
varying vec3 worldStart;
varying vec3 worldEnd;
#ifdef USE_DASH
varying vec2 vUv;
#endif
#else
varying vec2 vUv;
#endif
#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;
vUv = uv;
#endif
float aspect = resolution.x / resolution.y;
// camera space
vec4 start = modelViewMatrix * vec4( instanceStart, 1.0 );
vec4 end = modelViewMatrix * vec4( instanceEnd, 1.0 );
#ifdef WORLD_UNITS
worldStart = start.xyz;
worldEnd = end.xyz;
#else
vUv = uv;
#endif
// 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
vec3 ndcStart = clipStart.xyz / clipStart.w;
vec3 ndcEnd = clipEnd.xyz / clipEnd.w;
// direction
vec2 dir = ndcEnd.xy - ndcStart.xy;
// account for clip-space aspect ratio
dir.x *= aspect;
dir = normalize( dir );
#ifdef WORLD_UNITS
vec3 worldDir = normalize( end.xyz - start.xyz );
vec3 tmpFwd = normalize( mix( start.xyz, end.xyz, 0.5 ) );
vec3 worldUp = normalize( cross( worldDir, tmpFwd ) );
vec3 worldFwd = cross( worldDir, worldUp );
worldPos = position.y < 0.5 ? start: end;
// height offset
float hw = linewidth * 0.5;
worldPos.xyz += position.x < 0.0 ? hw * worldUp : - hw * worldUp;
// don't extend the line if we're rendering dashes because we
// won't be rendering the endcaps
#ifndef USE_DASH
// cap extension
worldPos.xyz += position.y < 0.5 ? - hw * worldDir : hw * worldDir;
// add width to the box
worldPos.xyz += worldFwd * hw;
// endcaps
if ( position.y > 1.0 || position.y < 0.0 ) {
worldPos.xyz -= worldFwd * 2.0 * hw;
}
#endif
// project the worldpos
vec4 clip = projectionMatrix * worldPos;
// shift the depth of the projected points so the line
// segments overlap neatly
vec3 clipPose = ( position.y < 0.5 ) ? ndcStart : ndcEnd;
clip.z = clipPose.z * clip.w;
#else
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;
#endif
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:
/* glsl */`
uniform vec3 diffuse;
uniform float opacity;
uniform float linewidth;
#ifdef USE_DASH
uniform float dashOffset;
uniform float dashSize;
uniform float gapSize;
#endif
varying float vLineDistance;
#ifdef WORLD_UNITS
varying vec4 worldPos;
varying vec3 worldStart;
varying vec3 worldEnd;
#ifdef USE_DASH
varying vec2 vUv;
#endif
#else
varying vec2 vUv;
#endif
#include <common>
#include <color_pars_fragment>
#include <fog_pars_fragment>
#include <logdepthbuf_pars_fragment>
#include <clipping_planes_pars_fragment>
vec2 closestLineToLine(vec3 p1, vec3 p2, vec3 p3, vec3 p4) {
float mua;
float mub;
vec3 p13 = p1 - p3;
vec3 p43 = p4 - p3;
vec3 p21 = p2 - p1;
float d1343 = dot( p13, p43 );
float d4321 = dot( p43, p21 );
float d1321 = dot( p13, p21 );
float d4343 = dot( p43, p43 );
float d2121 = dot( p21, p21 );
float denom = d2121 * d4343 - d4321 * d4321;
float numer = d1343 * d4321 - d1321 * d4343;
mua = numer / denom;
mua = clamp( mua, 0.0, 1.0 );
mub = ( d1343 + d4321 * ( mua ) ) / d4343;
mub = clamp( mub, 0.0, 1.0 );
return vec2( mua, mub );
}
void main() {
#include <clipping_planes_fragment>
#ifdef USE_DASH
if ( vUv.y < - 1.0 || vUv.y > 1.0 ) discard; // discard endcaps
if ( mod( vLineDistance + dashOffset, dashSize + gapSize ) > dashSize ) discard; // todo - FIX
#endif
float alpha = opacity;
#ifdef WORLD_UNITS
// Find the closest points on the view ray and the line segment
vec3 rayEnd = normalize( worldPos.xyz ) * 1e5;
vec3 lineDir = worldEnd - worldStart;
vec2 params = closestLineToLine( worldStart, worldEnd, vec3( 0.0, 0.0, 0.0 ), rayEnd );
vec3 p1 = worldStart + lineDir * params.x;
vec3 p2 = rayEnd * params.y;
vec3 delta = p1 - p2;
float len = length( delta );
float norm = len / linewidth;
#ifndef USE_DASH
#ifdef USE_ALPHA_TO_COVERAGE
float dnorm = fwidth( norm );
alpha = 1.0 - smoothstep( 0.5 - dnorm, 0.5 + dnorm, norm );
#else
if ( norm > 0.5 ) {
discard;
}
#endif
#endif
#else
#ifdef USE_ALPHA_TO_COVERAGE
// artifacts appear on some hardware if a derivative is taken within a conditional
float a = vUv.x;
float b = ( vUv.y > 0.0 ) ? vUv.y - 1.0 : vUv.y + 1.0;
float len2 = a * a + b * b;
float dlen = fwidth( len2 );
if ( abs( vUv.y ) > 1.0 ) {
alpha = 1.0 - smoothstep( 1.0 - dlen, 1.0 + dlen, len2 );
}
#else
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;
}
#endif
#endif
vec4 diffuseColor = vec4( diffuse, alpha );
#include <logdepthbuf_fragment>
#include <color_fragment>
gl_FragColor = vec4( diffuseColor.rgb, alpha );
#include <tonemapping_fragment>
#include <colorspace_fragment>
#include <fog_fragment>
#include <premultiplied_alpha_fragment>
}
`
};
class LineMaterial extends ShaderMaterial {
constructor( parameters ) {
super( {
type: 'LineMaterial',
uniforms: UniformsUtils.clone( ShaderLib[ 'line' ].uniforms ),
vertexShader: ShaderLib[ 'line' ].vertexShader,
fragmentShader: ShaderLib[ 'line' ].fragmentShader,
clipping: true // required for clipping support
} );
this.isLineMaterial = true;
this.setValues( parameters );
}
get color() {
return this.uniforms.diffuse.value;
}
set color( value ) {
this.uniforms.diffuse.value = value;
}
get worldUnits() {
return 'WORLD_UNITS' in this.defines;
}
set worldUnits( value ) {
if ( value === true ) {
this.defines.WORLD_UNITS = '';
} else {
delete this.defines.WORLD_UNITS;
}
}
get linewidth() {
return this.uniforms.linewidth.value;
}
set linewidth( value ) {
if ( ! this.uniforms.linewidth ) return;
this.uniforms.linewidth.value = value;
}
get dashed() {
return 'USE_DASH' in this.defines;
}
set dashed( value ) {
if ( ( value === true ) !== this.dashed ) {
this.needsUpdate = true;
}
if ( value === true ) {
this.defines.USE_DASH = '';
} else {
delete this.defines.USE_DASH;
}
}
get dashScale() {
return this.uniforms.dashScale.value;
}
set dashScale( value ) {
this.uniforms.dashScale.value = value;
}
get dashSize() {
return this.uniforms.dashSize.value;
}
set dashSize( value ) {
this.uniforms.dashSize.value = value;
}
get dashOffset() {
return this.uniforms.dashOffset.value;
}
set dashOffset( value ) {
this.uniforms.dashOffset.value = value;
}
get gapSize() {
return this.uniforms.gapSize.value;
}
set gapSize( value ) {
this.uniforms.gapSize.value = value;
}
get opacity() {
return this.uniforms.opacity.value;
}
set opacity( value ) {
if ( ! this.uniforms ) return;
this.uniforms.opacity.value = value;
}
get resolution() {
return this.uniforms.resolution.value;
}
set resolution( value ) {
this.uniforms.resolution.value.copy( value );
}
get alphaToCoverage() {
return 'USE_ALPHA_TO_COVERAGE' in this.defines;
}
set alphaToCoverage( value ) {
if ( ! this.defines ) return;
if ( ( value === true ) !== this.alphaToCoverage ) {
this.needsUpdate = true;
}
if ( value === true ) {
this.defines.USE_ALPHA_TO_COVERAGE = '';
this.extensions.derivatives = true;
} else {
delete this.defines.USE_ALPHA_TO_COVERAGE;
this.extensions.derivatives = false;
}
}
}
export { LineMaterial };