src/materials/LuminanceMaterial.js
import { NoBlending, REVISION, ShaderMaterial, Uniform } from "three";
import fragmentShader from "./glsl/luminance.frag";
import vertexShader from "./glsl/common.vert";
/**
* A luminance shader material.
*
* This shader produces a greyscale luminance map that describes the absolute amount of light emitted by a scene. It can
* also be configured to output colors that are scaled with their respective luminance value. Additionally, a range may
* be provided to mask out undesired texels.
*
* The alpha channel always contains the luminance value.
*
* On luminance coefficients:
* http://www.poynton.com/notes/colour_and_gamma/ColorFAQ.html#RTFToC9
*
* Coefficients for different color spaces:
* https://hsto.org/getpro/habr/post_images/2ab/69d/084/2ab69d084f9a597e032624bcd74d57a7.png
*
* Luminance range reference:
* https://cycling74.com/2007/05/23/your-first-shader/#.Vty9FfkrL4Z
*/
export class LuminanceMaterial extends ShaderMaterial {
/**
* Constructs a new luminance material.
*
* @param {Boolean} [colorOutput=false] - Defines whether the shader should output colors scaled with their luminance value.
* @param {Vector2} [luminanceRange] - If provided, the shader will mask out texels that aren't in the specified luminance range.
*/
constructor(colorOutput = false, luminanceRange = null) {
super({
name: "LuminanceMaterial",
defines: {
THREE_REVISION: REVISION.replace(/\D+/g, "")
},
uniforms: {
inputBuffer: new Uniform(null),
threshold: new Uniform(0.0),
smoothing: new Uniform(1.0),
range: new Uniform(null)
},
blending: NoBlending,
toneMapped: false,
depthWrite: false,
depthTest: false,
fragmentShader,
vertexShader
});
this.colorOutput = colorOutput;
this.luminanceRange = luminanceRange;
}
/**
* The input buffer.
*
* @type {Texture}
*/
set inputBuffer(value) {
this.uniforms.inputBuffer.value = value;
}
/**
* Sets the input buffer.
*
* @deprecated Use inputBuffer instead.
* @param {Texture} value - The input buffer.
*/
setInputBuffer(value) {
this.uniforms.inputBuffer.value = value;
}
/**
* The luminance threshold.
*
* @type {Number}
*/
get threshold() {
return this.uniforms.threshold.value;
}
set threshold(value) {
if(this.smoothing > 0 || value > 0) {
this.defines.THRESHOLD = "1";
} else {
delete this.defines.THRESHOLD;
}
this.uniforms.threshold.value = value;
}
/**
* Returns the luminance threshold.
*
* @deprecated Use threshold instead.
* @return {Number} The threshold.
*/
getThreshold() {
return this.threshold;
}
/**
* Sets the luminance threshold.
*
* @deprecated Use threshold instead.
* @param {Number} value - The threshold.
*/
setThreshold(value) {
this.threshold = value;
}
/**
* The luminance threshold smoothing.
*
* @type {Number}
*/
get smoothing() {
return this.uniforms.smoothing.value;
}
set smoothing(value) {
if(this.threshold > 0 || value > 0) {
this.defines.THRESHOLD = "1";
} else {
delete this.defines.THRESHOLD;
}
this.uniforms.smoothing.value = value;
}
/**
* Returns the luminance threshold smoothing factor.
*
* @deprecated Use smoothing instead.
* @return {Number} The smoothing factor.
*/
getSmoothingFactor() {
return this.smoothing;
}
/**
* Sets the luminance threshold smoothing factor.
*
* @deprecated Use smoothing instead.
* @param {Number} value - The smoothing factor.
*/
setSmoothingFactor(value) {
this.smoothing = value;
}
/**
* Indicates whether the luminance threshold is enabled.
*
* @type {Boolean}
* @deprecated Adjust the threshold or smoothing factor instead.
*/
get useThreshold() {
return (this.threshold > 0 || this.smoothing > 0);
}
set useThreshold(value) {}
/**
* Indicates whether color output is enabled.
*
* @type {Boolean}
*/
get colorOutput() {
return (this.defines.COLOR !== undefined);
}
set colorOutput(value) {
if(value) {
this.defines.COLOR = "1";
} else {
delete this.defines.COLOR;
}
this.needsUpdate = true;
}
/**
* Indicates whether color output is enabled.
*
* @deprecated Use colorOutput instead.
* @return {Boolean} Whether color output is enabled.
*/
isColorOutputEnabled(value) {
return this.colorOutput;
}
/**
* Enables or disables color output.
*
* @deprecated Use colorOutput instead.
* @param {Boolean} value - Whether color output should be enabled.
*/
setColorOutputEnabled(value) {
this.colorOutput = value;
}
/**
* Indicates whether luminance masking is enabled.
*
* @type {Boolean}
* @deprecated
*/
get useRange() {
return (this.luminanceRange !== null);
}
set useRange(value) {
this.luminanceRange = null;
}
/**
* The luminance range. Set to null to disable.
*
* @type {Boolean}
*/
get luminanceRange() {
return this.uniforms.range.value;
}
set luminanceRange(value) {
if(value !== null) {
this.defines.RANGE = "1";
} else {
delete this.defines.RANGE;
}
this.uniforms.range.value = value;
this.needsUpdate = true;
}
/**
* Returns the current luminance range.
*
* @deprecated Use luminanceRange instead.
* @return {Vector2} The luminance range.
*/
getLuminanceRange() {
return this.luminanceRange;
}
/**
* Sets a luminance range. Set to null to disable.
*
* @deprecated Use luminanceRange instead.
* @param {Vector2} value - The luminance range.
*/
setLuminanceRange(value) {
this.luminanceRange = value;
}
}
