three
Version:
JavaScript 3D library
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JavaScript
import { dot, max, mix } from '../math/MathNode.js';
import { add } from '../math/OperatorNode.js';
import { Fn, If, float, vec3, vec4 } from '../tsl/TSLBase.js';
import { ColorManagement } from '../../math/ColorManagement.js';
import { Vector3 } from '../../math/Vector3.js';
import { LinearSRGBColorSpace } from '../../constants.js';
export const grayscale = /*@__PURE__*/ Fn( ( [ color ] ) => {
return luminance( color.rgb );
} );
export const saturation = /*@__PURE__*/ Fn( ( [ color, adjustment = float( 1 ) ] ) => {
return adjustment.mix( luminance( color.rgb ), color.rgb );
} );
export const vibrance = /*@__PURE__*/ Fn( ( [ color, adjustment = float( 1 ) ] ) => {
const average = add( color.r, color.g, color.b ).div( 3.0 );
const mx = color.r.max( color.g.max( color.b ) );
const amt = mx.sub( average ).mul( adjustment ).mul( - 3.0 );
return mix( color.rgb, mx, amt );
} );
export const hue = /*@__PURE__*/ Fn( ( [ color, adjustment = float( 1 ) ] ) => {
const k = vec3( 0.57735, 0.57735, 0.57735 );
const cosAngle = adjustment.cos();
return vec3( color.rgb.mul( cosAngle ).add( k.cross( color.rgb ).mul( adjustment.sin() ).add( k.mul( dot( k, color.rgb ).mul( cosAngle.oneMinus() ) ) ) ) );
} );
export const luminance = (
color,
luminanceCoefficients = vec3( ColorManagement.getLuminanceCoefficients( new Vector3() ) )
) => dot( color, luminanceCoefficients );
export const threshold = ( color, threshold ) => mix( vec3( 0.0 ), color, luminance( color ).sub( threshold ).max( 0 ) );
/**
* Color Decision List (CDL) v1.2
*
* Compact representation of color grading information, defined by slope, offset, power, and
* saturation. The CDL should be typically be given input in a log space (such as LogC, ACEScc,
* or AgX Log), and will return output in the same space. Output may require clamping >=0.
*
* @param {vec4} color Input (-Infinity < input < +Infinity)
* @param {number | vec3} slope Slope (0 ≤ slope < +Infinity)
* @param {number | vec3} offset Offset (-Infinity < offset < +Infinity; typically -1 < offset < 1)
* @param {number | vec3} power Power (0 < power < +Infinity)
* @param {number} saturation Saturation (0 ≤ saturation < +Infinity; typically 0 ≤ saturation < 4)
* @param {vec3} luminanceCoefficients Luminance coefficients for saturation term, typically Rec. 709
* @return Output, -Infinity < output < +Infinity
*
* References:
* - ASC CDL v1.2
* - https://blender.stackexchange.com/a/55239/43930
* - https://docs.acescentral.com/specifications/acescc/
*/
export const cdl = /*@__PURE__*/ Fn( ( [
color,
slope = vec3( 1 ),
offset = vec3( 0 ),
power = vec3( 1 ),
saturation = float( 1 ),
// ASC CDL v1.2 explicitly requires Rec. 709 luminance coefficients.
luminanceCoefficients = vec3( ColorManagement.getLuminanceCoefficients( new Vector3(), LinearSRGBColorSpace ) )
] ) => {
// NOTE: The ASC CDL v1.2 defines a [0, 1] clamp on the slope+offset term, and another on the
// saturation term. Per the ACEScc specification and Filament, limits may be omitted to support
// values outside [0, 1], requiring a workaround for negative values in the power expression.
const luma = color.rgb.dot( vec3( luminanceCoefficients ) );
const v = max( color.rgb.mul( slope ).add( offset ), 0.0 ).toVar();
const pv = v.pow( power ).toVar();
If( v.r.greaterThan( 0.0 ), () => { v.r.assign( pv.r ); } ); // eslint-disable-line
If( v.g.greaterThan( 0.0 ), () => { v.g.assign( pv.g ); } ); // eslint-disable-line
If( v.b.greaterThan( 0.0 ), () => { v.b.assign( pv.b ); } ); // eslint-disable-line
v.assign( luma.add( v.sub( luma ).mul( saturation ) ) );
return vec4( v.rgb, color.a );
} );