{"version":3,"file":"StrokeLineCapProjections.min.mjs","names":[],"sources":["../../../../../src/util/misc/projectStroke/StrokeLineCapProjections.ts"],"sourcesContent":["import type { XY } from '../../../Point';\nimport { Point } from '../../../Point';\nimport { getOrthonormalVector, getUnitVector } from '../vectors';\nimport { StrokeLineJoinProjections } from './StrokeLineJoinProjections';\nimport { StrokeProjectionsBase } from './StrokeProjectionsBase';\nimport type { TProjection, TProjectStrokeOnPointsOptions } from './types';\n\n/**\n * class in charge of finding projections for each type of line cap for start/end of an open path\n * @see {@link [Open path projections at #8344](https://github.com/fabricjs/fabric.js/pull/8344#1-open-path)}\n *\n * Reference:\n * - MDN:\n *   - https://developer.mozilla.org/en-US/docs/Web/API/CanvasRenderingContext2D/lineCap\n *   - https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/stroke-linecap\n * - Spec: https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-linecap-dev\n * - Playground to understand how the line joins works: https://hypertolosana.github.io/efficient-webgl-stroking/index.html\n * - View the calculated projections for each of the control points: https://codesandbox.io/s/project-stroke-points-with-context-to-trace-b8jc4j?file=/src/index.js\n */\nexport class StrokeLineCapProjections extends StrokeProjectionsBase {\n  /**\n   * edge point\n   */\n  declare A: Point;\n  /**\n   * point next to edge point\n   */\n  declare T: Point;\n\n  constructor(A: XY, T: XY, options: TProjectStrokeOnPointsOptions) {\n    super(options);\n    this.A = new Point(A);\n    this.T = new Point(T);\n  }\n\n  calcOrthogonalProjection(\n    from: Point,\n    to: Point,\n    magnitude: number = this.strokeProjectionMagnitude,\n  ) {\n    const vector = this.createSideVector(from, to);\n    return this.scaleUnitVector(getOrthonormalVector(vector), magnitude);\n  }\n\n  /**\n   * OPEN PATH START/END - Line cap: Butt\n   * Calculation: to find the projections, just find the points orthogonal to the stroke\n   *\n   * @see https://github.com/fabricjs/fabric.js/pull/8344#1-1-butt\n   */\n  projectButt() {\n    return [\n      this.projectOrthogonally(this.A, this.T, this.strokeProjectionMagnitude),\n      this.projectOrthogonally(this.A, this.T, -this.strokeProjectionMagnitude),\n    ];\n  }\n\n  /**\n   * OPEN PATH START/END - Line cap: Round\n   * Calculation: same as stroke line join `round`\n   *\n   * @see https://github.com/fabricjs/fabric.js/pull/8344#1-2-round\n   */\n  projectRound() {\n    const projections: Point[] = [];\n\n    if (!this.isSkewed() && this.A.eq(this.T)) {\n      /* 1 point case without `skew`\n        When `strokeUniform` is true, scaling has no effect.\n        So we divide by scale, to remove its effect.\n      */\n      const projection = new Point(1, 1)\n        .scalarMultiply(this.strokeProjectionMagnitude)\n        .multiply(this.strokeUniformScalar);\n      projections.push(\n        this.applySkew(this.A.add(projection)),\n        this.applySkew(this.A.subtract(projection)),\n      );\n    } else {\n      projections.push(\n        ...new StrokeLineJoinProjections(\n          this.A,\n          this.T,\n          this.T,\n          this.options,\n        ).projectRound(),\n      );\n    }\n\n    return projections;\n  }\n\n  /**\n   * OPEN PATH START/END - Line cap: Square\n   * Calculation: project a rectangle of points on the stroke in the opposite direction of the vector `AT`\n   *\n   * @see https://github.com/fabricjs/fabric.js/pull/8344#1-3-square\n   */\n  projectSquare() {\n    const projections: Point[] = [];\n\n    if (this.A.eq(this.T)) {\n      /* 1 point case without `skew`\n        When `strokeUniform` is true, scaling has no effect.\n        So we divide by scale, to remove its effect.\n      */\n      const projection = new Point(1, 1)\n        .scalarMultiply(this.strokeProjectionMagnitude)\n        .multiply(this.strokeUniformScalar);\n      projections.push(this.A.add(projection), this.A.subtract(projection));\n    } else {\n      const orthogonalProjection = this.calcOrthogonalProjection(\n        this.A,\n        this.T,\n        this.strokeProjectionMagnitude,\n      );\n      const strokePointingOut = this.scaleUnitVector(\n        getUnitVector(this.createSideVector(this.A, this.T)),\n        -this.strokeProjectionMagnitude,\n      );\n      const projectedA = this.A.add(strokePointingOut);\n      projections.push(\n        projectedA.add(orthogonalProjection),\n        projectedA.subtract(orthogonalProjection),\n      );\n    }\n\n    return projections.map((p) => this.applySkew(p));\n  }\n\n  protected projectPoints() {\n    switch (this.options.strokeLineCap) {\n      case 'round':\n        return this.projectRound();\n      case 'square':\n        return this.projectSquare();\n      default:\n        return this.projectButt();\n    }\n  }\n\n  public project(): TProjection[] {\n    return this.projectPoints().map((point) => ({\n      originPoint: this.A,\n      projectedPoint: point,\n    }));\n  }\n}\n"],"mappings":"oRAmBA,IAAa,EAAb,cAA8C,CAAA,CAU5C,YAAY,EAAO,EAAO,EAAA,CACxB,MAAM,EAAA,CACN,KAAK,EAAI,IAAI,EAAM,EAAA,CACnB,KAAK,EAAI,IAAI,EAAM,EAAA,CAGrB,yBACE,EACA,EACA,EAAoB,KAAK,0BAAA,CAEzB,IAAM,EAAS,KAAK,iBAAiB,EAAM,EAAA,CAC3C,OAAO,KAAK,gBAAgB,EAAqB,EAAA,CAAS,EAAA,CAS5D,aAAA,CACE,MAAO,CACL,KAAK,oBAAoB,KAAK,EAAG,KAAK,EAAG,KAAK,0BAAA,CAC9C,KAAK,oBAAoB,KAAK,EAAG,KAAK,EAAA,CAAI,KAAK,0BAAA,CAAA,CAUnD,cAAA,CACE,IAAM,EAAuB,EAAA,CAE7B,GAAA,CAAK,KAAK,UAAA,EAAc,KAAK,EAAE,GAAG,KAAK,EAAA,CAAI,CAKzC,IAAM,EAAa,IAAI,EAAM,EAAG,EAAA,CAC7B,eAAe,KAAK,0BAAA,CACpB,SAAS,KAAK,oBAAA,CACjB,EAAY,KACV,KAAK,UAAU,KAAK,EAAE,IAAI,EAAA,CAAA,CAC1B,KAAK,UAAU,KAAK,EAAE,SAAS,EAAA,CAAA,CAAA,MAGjC,EAAY,KAAA,GACP,IAAI,EACL,KAAK,EACL,KAAK,EACL,KAAK,EACL,KAAK,QAAA,CACL,cAAA,CAAA,CAIN,OAAO,EAST,eAAA,CACE,IAAM,EAAuB,EAAA,CAE7B,GAAI,KAAK,EAAE,GAAG,KAAK,EAAA,CAAI,CAKrB,IAAM,EAAa,IAAI,EAAM,EAAG,EAAA,CAC7B,eAAe,KAAK,0BAAA,CACpB,SAAS,KAAK,oBAAA,CACjB,EAAY,KAAK,KAAK,EAAE,IAAI,EAAA,CAAa,KAAK,EAAE,SAAS,EAAA,CAAA,KACpD,CACL,IAAM,EAAuB,KAAK,yBAChC,KAAK,EACL,KAAK,EACL,KAAK,0BAAA,CAED,EAAoB,KAAK,gBAC7B,EAAc,KAAK,iBAAiB,KAAK,EAAG,KAAK,EAAA,CAAA,CAAA,CAChD,KAAK,0BAAA,CAEF,EAAa,KAAK,EAAE,IAAI,EAAA,CAC9B,EAAY,KACV,EAAW,IAAI,EAAA,CACf,EAAW,SAAS,EAAA,CAAA,CAIxB,OAAO,EAAY,IAAK,GAAM,KAAK,UAAU,EAAA,CAAA,CAG/C,eAAA,CACE,OAAQ,KAAK,QAAQ,cAArB,CACE,IAAK,QACH,OAAO,KAAK,cAAA,CACd,IAAK,SACH,OAAO,KAAK,eAAA,CACd,QACE,OAAO,KAAK,aAAA,EAIlB,SAAA,CACE,OAAO,KAAK,eAAA,CAAgB,IAAK,IAAA,CAC/B,YAAa,KAAK,EAClB,eAAgB,EAAA,EAAA,GAAA,OAAA,KAAA"}