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[READ-ONLY] Mirror of https://github.com/flo-bit/shapecraft. flo-bit.dev/shapecraft
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4.3 kB · 89 lines
JavaScript
at commit da69385e
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990import { abs, cross, float, Fn, normalize, ivec2, sub, vec2, vec3, vec4 } from '../tsl/TSLBase.js';import { textureSize } from '../accessors/TextureSizeNode.js';import { textureLoad } from '../accessors/TextureNode.js';import { WebGPUCoordinateSystem } from '../../constants.js';
/*** Computes a position in view space based on a fragment's screen position expressed as uv coordinates, the fragments* depth value and the camera's inverse projection matrix.** @param {vec2} screenPosition - The fragment's screen position expressed as uv coordinates.* @param {float} depth - The fragment's depth value.* @param {mat4} projectionMatrixInverse - The camera's inverse projection matrix.* @return {vec3} The fragments position in view space.*/export const getViewPosition = /*@__PURE__*/ Fn( ( [ screenPosition, depth, projectionMatrixInverse ], builder ) => {
let clipSpacePosition;
if ( builder.renderer.coordinateSystem === WebGPUCoordinateSystem ) {
screenPosition = vec2( screenPosition.x, screenPosition.y.oneMinus() ).mul( 2.0 ).sub( 1.0 ); clipSpacePosition = vec4( vec3( screenPosition, depth ), 1.0 );
} else {
clipSpacePosition = vec4( vec3( screenPosition.x, screenPosition.y.oneMinus(), depth ).mul( 2.0 ).sub( 1.0 ), 1.0 );
}
const viewSpacePosition = vec4( projectionMatrixInverse.mul( clipSpacePosition ) );
return viewSpacePosition.xyz.div( viewSpacePosition.w );
} );
/*** Computes a screen position expressed as uv coordinates based on a fragment's position in view space* and the camera's projection matrix** @param {vec3} viewPosition - The fragments position in view space.* @param {mat4} projectionMatrix - The camera's projection matrix.* @return {vec2} The fragment's screen position expressed as uv coordinates.*/export const getScreenPosition = /*@__PURE__*/ Fn( ( [ viewPosition, projectionMatrix ] ) => {
const sampleClipPos = projectionMatrix.mul( vec4( viewPosition, 1.0 ) ); const sampleUv = sampleClipPos.xy.div( sampleClipPos.w ).mul( 0.5 ).add( 0.5 ).toVar(); return vec2( sampleUv.x, sampleUv.y.oneMinus() );
} );
/*** Computes a normal vector based on depth data. Can be used as a fallback when no normal render* target is available or if flat surface normals are required.** @param {vec2} uv - The texture coordinate.* @param {DepthTexture} depthTexture - The depth texture.* @param {mat4} projectionMatrixInverse - The camera's inverse projection matrix.* @return {vec3} The computed normal vector.*/export const getNormalFromDepth = /*@__PURE__*/ Fn( ( [ uv, depthTexture, projectionMatrixInverse ] ) => {
const size = textureSize( textureLoad( depthTexture ) ); const p = ivec2( uv.mul( size ) ).toVar();
const c0 = textureLoad( depthTexture, p ).toVar();
const l2 = textureLoad( depthTexture, p.sub( ivec2( 2, 0 ) ) ).toVar(); const l1 = textureLoad( depthTexture, p.sub( ivec2( 1, 0 ) ) ).toVar(); const r1 = textureLoad( depthTexture, p.add( ivec2( 1, 0 ) ) ).toVar(); const r2 = textureLoad( depthTexture, p.add( ivec2( 2, 0 ) ) ).toVar(); const b2 = textureLoad( depthTexture, p.add( ivec2( 0, 2 ) ) ).toVar(); const b1 = textureLoad( depthTexture, p.add( ivec2( 0, 1 ) ) ).toVar(); const t1 = textureLoad( depthTexture, p.sub( ivec2( 0, 1 ) ) ).toVar(); const t2 = textureLoad( depthTexture, p.sub( ivec2( 0, 2 ) ) ).toVar();
const dl = abs( sub( float( 2 ).mul( l1 ).sub( l2 ), c0 ) ).toVar(); const dr = abs( sub( float( 2 ).mul( r1 ).sub( r2 ), c0 ) ).toVar(); const db = abs( sub( float( 2 ).mul( b1 ).sub( b2 ), c0 ) ).toVar(); const dt = abs( sub( float( 2 ).mul( t1 ).sub( t2 ), c0 ) ).toVar();
const ce = getViewPosition( uv, c0, projectionMatrixInverse ).toVar();
const dpdx = dl.lessThan( dr ).select( ce.sub( getViewPosition( uv.sub( vec2( float( 1 ).div( size.x ), 0 ) ), l1, projectionMatrixInverse ) ), ce.negate().add( getViewPosition( uv.add( vec2( float( 1 ).div( size.x ), 0 ) ), r1, projectionMatrixInverse ) ) ); const dpdy = db.lessThan( dt ).select( ce.sub( getViewPosition( uv.add( vec2( 0, float( 1 ).div( size.y ) ) ), b1, projectionMatrixInverse ) ), ce.negate().add( getViewPosition( uv.sub( vec2( 0, float( 1 ).div( size.y ) ) ), t1, projectionMatrixInverse ) ) );
return normalize( cross( dpdx, dpdy ) );
} );