fabric/dist/src/filters/Grayscale.mjs

Object model for HTML5 canvas, and SVG-to-canvas parser. Backed by jsdom and node-canvas.

import { _defineProperty } from "../../_virtual/_@oxc-project_runtime@0.122.0/helpers/defineProperty.mjs";
import { classRegistry } from "../ClassRegistry.mjs";
import { BaseFilter } from "./BaseFilter.mjs";
import { fragmentSource } from "./shaders/grayscale.mjs";
//#region src/filters/Grayscale.ts
const grayscaleDefaultValues = { mode: "average" };
/**
* Grayscale image filter class
* @example
* const filter = new Grayscale();
* object.filters.push(filter);
* object.applyFilters();
*/
var Grayscale = class extends BaseFilter {
	/**
	* Apply the Grayscale operation to a Uint8Array representing the pixels of an image.
	*
	* @param {Object} options
	* @param {ImageData} options.imageData The Uint8Array to be filtered.
	*/
	applyTo2d({ imageData: { data } }) {
		for (let i = 0, value; i < data.length; i += 4) {
			const r = data[i];
			const g = data[i + 1];
			const b = data[i + 2];
			switch (this.mode) {
				case "average":
					value = (r + g + b) / 3;
					break;
				case "lightness":
					value = (Math.min(r, g, b) + Math.max(r, g, b)) / 2;
					break;
				case "luminosity":
					value = .21 * r + .72 * g + .07 * b;
					break;
			}
			data[i + 2] = data[i + 1] = data[i] = value;
		}
	}
	getCacheKey() {
		return `${this.type}_${this.mode}`;
	}
	getFragmentSource() {
		return fragmentSource[this.mode];
	}
	/**
	* Send data from this filter to its shader program's uniforms.
	*
	* @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.
	* @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects
	*/
	sendUniformData(gl, uniformLocations) {
		gl.uniform1i(uniformLocations.uMode, 1);
	}
	/**
	* Grayscale filter isNeutralState implementation
	* The filter is never neutral
	* on the image
	**/
	isNeutralState() {
		return false;
	}
};
_defineProperty(Grayscale, "type", "Grayscale");
_defineProperty(Grayscale, "defaults", grayscaleDefaultValues);
_defineProperty(Grayscale, "uniformLocations", ["uMode"]);
classRegistry.setClass(Grayscale);
//#endregion
export { Grayscale };

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