{"version":3,"file":"Contrast.min.mjs","names":[],"sources":["../../../src/filters/Contrast.ts"],"sourcesContent":["import { BaseFilter } from './BaseFilter';\nimport type { T2DPipelineState, TWebGLUniformLocationMap } from './typedefs';\nimport { classRegistry } from '../ClassRegistry';\nimport { fragmentSource } from './shaders/constrast';\n\ntype ContrastOwnProps = {\n  contrast: number;\n};\n\nexport const contrastDefaultValues: ContrastOwnProps = {\n  contrast: 0,\n};\n\n/**\n * Contrast filter class\n * @example\n * const filter = new Contrast({\n *   contrast: 0.25\n * });\n * object.filters.push(filter);\n * object.applyFilters();\n */\nexport class Contrast extends BaseFilter<'Contrast', ContrastOwnProps> {\n  /**\n   * contrast value, range from -1 to 1.\n   * @param {Number} contrast\n   * @default 0\n   */\n  declare contrast: ContrastOwnProps['contrast'];\n\n  static type = 'Contrast';\n\n  static defaults = contrastDefaultValues;\n\n  static uniformLocations = ['uContrast'];\n\n  getFragmentSource() {\n    return fragmentSource;\n  }\n\n  isNeutralState() {\n    return this.contrast === 0;\n  }\n\n  /**\n   * Apply the Contrast operation to a Uint8Array representing the pixels of an image.\n   *\n   * @param {Object} options\n   * @param {ImageData} options.imageData The Uint8Array to be filtered.\n   */\n  applyTo2d({ imageData: { data } }: T2DPipelineState) {\n    const contrast = Math.floor(this.contrast * 255),\n      contrastF = (259 * (contrast + 255)) / (255 * (259 - contrast));\n\n    for (let i = 0; i < data.length; i += 4) {\n      data[i] = contrastF * (data[i] - 128) + 128;\n      data[i + 1] = contrastF * (data[i + 1] - 128) + 128;\n      data[i + 2] = contrastF * (data[i + 2] - 128) + 128;\n    }\n  }\n\n  /**\n   * Send data from this filter to its shader program's uniforms.\n   *\n   * @param {WebGLRenderingContext} gl The GL canvas context used to compile this filter's shader.\n   * @param {Object} uniformLocations A map of string uniform names to WebGLUniformLocation objects\n   */\n  sendUniformData(\n    gl: WebGLRenderingContext,\n    uniformLocations: TWebGLUniformLocationMap,\n  ) {\n    gl.uniform1f(uniformLocations.uContrast, this.contrast);\n  }\n}\n\nclassRegistry.setClass(Contrast);\n"],"mappings":"sRAsBA,IAAa,EAAb,cAA8B,CAAA,CAc5B,mBAAA,CACE,OAAO,EAGT,gBAAA,CACE,OAAO,KAAK,WAAa,EAS3B,UAAA,CAAY,UAAA,CAAW,KAAE,IAAA,CACvB,IAAM,EAAW,KAAK,MAAsB,IAAhB,KAAK,SAAA,CAC/B,EAAa,KAAO,EAAW,MAAS,KAAO,IAAM,IAEvD,IAAK,IAAI,EAAI,EAAG,EAAI,EAAK,OAAQ,GAAK,EACpC,EAAK,GAAK,GAAa,EAAK,GAAK,KAAO,IACxC,EAAK,EAAI,GAAK,GAAa,EAAK,EAAI,GAAK,KAAO,IAChD,EAAK,EAAI,GAAK,GAAa,EAAK,EAAI,GAAK,KAAO,IAUpD,gBACE,EACA,EAAA,CAEA,EAAG,UAAU,EAAiB,UAAW,KAAK,SAAA,GAAA,EAAA,EAzCzC,OAAO,WAAA,CAAA,EAAA,EAEP,WAvB8C,CACrD,SAAU,EAAA,CAAA,CAAA,EAAA,EAwBH,mBAAmB,CAAC,YAAA,CAAA,CAyC7B,EAAc,SAAS,EAAA,CAAA,OAAA,KAAA"}