95 lines
2.9 KiB
JavaScript
95 lines
2.9 KiB
JavaScript
import TempNode from '../core/TempNode.js';
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import { addNodeClass } from '../core/Node.js';
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import { add, mul, div } from '../math/OperatorNode.js';
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import { floor, ceil, fract, pow } from '../math/MathNode.js';
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import { nodeProxy, addNodeElement, float, vec2, vec4, int } from '../shadernode/ShaderNode.js';
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// Mipped Bicubic Texture Filtering by N8
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// https://www.shadertoy.com/view/Dl2SDW
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const bC = 1.0 / 6.0;
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const w0 = ( a ) => mul( bC, mul( a, mul( a, a.negate().add( 3.0 ) ).sub( 3.0 ) ).add( 1.0 ) );
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const w1 = ( a ) => mul( bC, mul( a, mul( a, mul( 3.0, a ).sub( 6.0 ) ) ).add( 4.0 ) );
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const w2 = ( a ) => mul( bC, mul( a, mul( a, mul( - 3.0, a ).add( 3.0 ) ).add( 3.0 ) ).add( 1.0 ) );
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const w3 = ( a ) => mul( bC, pow( a, 3 ) );
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const g0 = ( a ) => w0( a ).add( w1( a ) );
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const g1 = ( a ) => w2( a ).add( w3( a ) );
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// h0 and h1 are the two offset functions
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const h0 = ( a ) => add( - 1.0, w1( a ).div( w0( a ).add( w1( a ) ) ) );
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const h1 = ( a ) => add( 1.0, w3( a ).div( w2( a ).add( w3( a ) ) ) );
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const bicubic = ( textureNode, texelSize, lod ) => {
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const uv = textureNode.uvNode;
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const uvScaled = mul( uv, texelSize.zw ).add( 0.5 );
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const iuv = floor( uvScaled );
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const fuv = fract( uvScaled );
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const g0x = g0( fuv.x );
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const g1x = g1( fuv.x );
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const h0x = h0( fuv.x );
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const h1x = h1( fuv.x );
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const h0y = h0( fuv.y );
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const h1y = h1( fuv.y );
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const p0 = vec2( iuv.x.add( h0x ), iuv.y.add( h0y ) ).sub( 0.5 ).mul( texelSize.xy );
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const p1 = vec2( iuv.x.add( h1x ), iuv.y.add( h0y ) ).sub( 0.5 ).mul( texelSize.xy );
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const p2 = vec2( iuv.x.add( h0x ), iuv.y.add( h1y ) ).sub( 0.5 ).mul( texelSize.xy );
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const p3 = vec2( iuv.x.add( h1x ), iuv.y.add( h1y ) ).sub( 0.5 ).mul( texelSize.xy );
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const a = g0( fuv.y ).mul( add( g0x.mul( textureNode.uv( p0 ).level( lod ) ), g1x.mul( textureNode.uv( p1 ).level( lod ) ) ) );
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const b = g1( fuv.y ).mul( add( g0x.mul( textureNode.uv( p2 ).level( lod ) ), g1x.mul( textureNode.uv( p3 ).level( lod ) ) ) );
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return a.add( b );
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};
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const textureBicubicMethod = ( textureNode, lodNode ) => {
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const fLodSize = vec2( textureNode.size( int( lodNode ) ) );
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const cLodSize = vec2( textureNode.size( int( lodNode.add( 1.0 ) ) ) );
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const fLodSizeInv = div( 1.0, fLodSize );
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const cLodSizeInv = div( 1.0, cLodSize );
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const fSample = bicubic( textureNode, vec4( fLodSizeInv, fLodSize ), floor( lodNode ) );
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const cSample = bicubic( textureNode, vec4( cLodSizeInv, cLodSize ), ceil( lodNode ) );
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return fract( lodNode ).mix( fSample, cSample );
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};
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class TextureBicubicNode extends TempNode {
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constructor( textureNode, blurNode = float( 3 ) ) {
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super( 'vec4' );
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this.textureNode = textureNode;
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this.blurNode = blurNode;
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}
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setup() {
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return textureBicubicMethod( this.textureNode, this.blurNode );
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}
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}
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export default TextureBicubicNode;
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export const textureBicubic = nodeProxy( TextureBicubicNode );
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addNodeElement( 'bicubic', textureBicubic );
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addNodeClass( 'TextureBicubicNode', TextureBicubicNode );
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