{"version":3,"file":"Contrast.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":";;;;;AASA,MAAa,wBAA0C,EACrD,UAAU,GACX;;;;;;;;;;AAWD,IAAa,WAAb,cAA8B,WAAyC;CAcrE,oBAAoB;AAClB,SAAO;;CAGT,iBAAiB;AACf,SAAO,KAAK,aAAa;;;;;;;;CAS3B,UAAU,EAAE,WAAW,EAAE,UAA4B;EACnD,MAAM,WAAW,KAAK,MAAM,KAAK,WAAW,IAAI,EAC9C,YAAa,OAAO,WAAW,QAAS,OAAO,MAAM;AAEvD,OAAK,IAAI,IAAI,GAAG,IAAI,KAAK,QAAQ,KAAK,GAAG;AACvC,QAAK,KAAK,aAAa,KAAK,KAAK,OAAO;AACxC,QAAK,IAAI,KAAK,aAAa,KAAK,IAAI,KAAK,OAAO;AAChD,QAAK,IAAI,KAAK,aAAa,KAAK,IAAI,KAAK,OAAO;;;;;;;;;CAUpD,gBACE,IACA,kBACA;AACA,KAAG,UAAU,iBAAiB,WAAW,KAAK,SAAS;;;0BAzClD,QAAO,WAAW;0BAElB,YAAW,sBAAsB;0BAEjC,oBAAmB,CAAC,YAAY,CAAC;AAyC1C,cAAc,SAAS,SAAS"}