{"version":3,"file":"skew.mjs","names":[],"sources":["../../../src/controls/skew.ts"],"sourcesContent":["import type {\n  ControlCursorCallback,\n  TPointerEvent,\n  Transform,\n  TransformActionHandler,\n} from '../EventTypeDefs';\nimport { resolveOrigin } from '../util/misc/resolveOrigin';\nimport { Point } from '../Point';\nimport type { TAxis, TAxisKey } from '../typedefs';\nimport {\n  degreesToRadians,\n  radiansToDegrees,\n} from '../util/misc/radiansDegreesConversion';\nimport {\n  findCornerQuadrant,\n  getLocalPoint,\n  isLocked,\n  NOT_ALLOWED_CURSOR,\n} from './util';\nimport { wrapWithFireEvent } from './wrapWithFireEvent';\nimport { wrapWithFixedAnchor } from './wrapWithFixedAnchor';\nimport {\n  CENTER,\n  SCALE_X,\n  SCALE_Y,\n  SKEWING,\n  SKEW_X,\n  SKEW_Y,\n} from '../constants';\n\nexport type SkewTransform = Transform & { skewingSide: -1 | 1 };\n\nconst AXIS_KEYS: Record<\n  TAxis,\n  {\n    counterAxis: TAxis;\n    scale: TAxisKey<'scale'>;\n    skew: TAxisKey<'skew'>;\n    lockSkewing: TAxisKey<'lockSkewing'>;\n    origin: TAxisKey<'origin'>;\n    flip: TAxisKey<'flip'>;\n  }\n> = {\n  x: {\n    counterAxis: 'y',\n    scale: SCALE_X,\n    skew: SKEW_X,\n    lockSkewing: 'lockSkewingX',\n    origin: 'originX',\n    flip: 'flipX',\n  },\n  y: {\n    counterAxis: 'x',\n    scale: SCALE_Y,\n    skew: SKEW_Y,\n    lockSkewing: 'lockSkewingY',\n    origin: 'originY',\n    flip: 'flipY',\n  },\n};\n\nconst skewMap = ['ns', 'nesw', 'ew', 'nwse'];\n\n/**\n * return the correct cursor style for the skew action\n * @param {Event} eventData the javascript event that is causing the scale\n * @param {Control} control the control that is interested in the action\n * @param {FabricObject} fabricObject the fabric object that is interested in the action\n * @return {String} a valid css string for the cursor\n */\nexport const skewCursorStyleHandler: ControlCursorCallback = (\n  eventData,\n  control,\n  fabricObject,\n  coord,\n) => {\n  if (control.x !== 0 && isLocked(fabricObject, 'lockSkewingY')) {\n    return NOT_ALLOWED_CURSOR;\n  }\n  if (control.y !== 0 && isLocked(fabricObject, 'lockSkewingX')) {\n    return NOT_ALLOWED_CURSOR;\n  }\n  const n = findCornerQuadrant(fabricObject, control, coord) % 4;\n  return `${skewMap[n]}-resize`;\n};\n\n/**\n * Since skewing is applied before scaling, calculations are done in a scaleless plane\n * @see https://github.com/fabricjs/fabric.js/pull/8380\n */\nfunction skewObject(\n  axis: TAxis,\n  { target, ex, ey, skewingSide, ...transform }: SkewTransform,\n  pointer: Point,\n) {\n  const { skew: skewKey } = AXIS_KEYS[axis],\n    offset = pointer\n      .subtract(new Point(ex, ey))\n      .divide(new Point(target.scaleX, target.scaleY))[axis],\n    skewingBefore = target[skewKey],\n    skewingStart = transform[skewKey],\n    shearingStart = Math.tan(degreesToRadians(skewingStart)),\n    // let a, b be the size of target\n    // let a' be the value of a after applying skewing\n    // then:\n    // a' = a + b * skewA => skewA = (a' - a) / b\n    // the value b is tricky since skewY is applied before skewX\n    b =\n      axis === 'y'\n        ? target._getTransformedDimensions({\n            scaleX: 1,\n            scaleY: 1,\n            // since skewY is applied before skewX, b (=width) is not affected by skewX\n            skewX: 0,\n          }).x\n        : target._getTransformedDimensions({\n            scaleX: 1,\n            scaleY: 1,\n          }).y;\n\n  const shearing =\n    (2 * offset * skewingSide) /\n      // we max out fractions to safeguard from asymptotic behavior\n      Math.max(b, 1) +\n    // add starting state\n    shearingStart;\n\n  const skewing = radiansToDegrees(Math.atan(shearing));\n\n  target.set(skewKey, skewing);\n  const changed = skewingBefore !== target[skewKey];\n\n  if (changed && axis === 'y') {\n    // we don't want skewing to affect scaleX\n    // so we factor it by the inverse skewing diff to make it seem unchanged to the viewer\n    const { skewX, scaleX } = target,\n      dimBefore = target._getTransformedDimensions({ skewY: skewingBefore }),\n      dimAfter = target._getTransformedDimensions(),\n      compensationFactor = skewX !== 0 ? dimBefore.x / dimAfter.x : 1;\n    compensationFactor !== 1 &&\n      target.set(SCALE_X, compensationFactor * scaleX);\n  }\n\n  return changed;\n}\n\n/**\n * Wrapped Action handler for skewing on a given axis, takes care of the\n * skew direction and determines the correct transform origin for the anchor point\n * @param {Event} eventData javascript event that is doing the transform\n * @param {Object} transform javascript object containing a series of information around the current transform\n * @param {number} x current mouse x position, canvas normalized\n * @param {number} y current mouse y position, canvas normalized\n * @return {Boolean} true if some change happened\n */\nfunction skewHandler(\n  axis: TAxis,\n  eventData: TPointerEvent,\n  transform: Transform,\n  x: number,\n  y: number,\n) {\n  const { target } = transform,\n    {\n      counterAxis,\n      origin: originKey,\n      lockSkewing: lockSkewingKey,\n      skew: skewKey,\n      flip: flipKey,\n    } = AXIS_KEYS[axis];\n  if (isLocked(target, lockSkewingKey)) {\n    return false;\n  }\n\n  const { origin: counterOriginKey, flip: counterFlipKey } =\n      AXIS_KEYS[counterAxis],\n    counterOriginFactor =\n      resolveOrigin(transform[counterOriginKey]) *\n      (target[counterFlipKey] ? -1 : 1),\n    // if the counter origin is top/left (= -0.5) then we are skewing x/y values on the bottom/right side of target respectively.\n    // if the counter origin is bottom/right (= 0.5) then we are skewing x/y values on the top/left side of target respectively.\n    // skewing direction on the top/left side of target is OPPOSITE to the direction of the movement of the pointer,\n    // so we factor skewing direction by this value.\n    skewingSide = (-Math.sign(counterOriginFactor) *\n      (target[flipKey] ? -1 : 1)) as 1 | -1,\n    skewingDirection =\n      ((target[skewKey] === 0 &&\n        // in case skewing equals 0 we use the pointer offset from target center to determine the direction of skewing\n        getLocalPoint(transform, CENTER, CENTER, x, y)[axis] > 0) ||\n      // in case target has skewing we use that as the direction\n      target[skewKey] > 0\n        ? 1\n        : -1) * skewingSide,\n    // anchor to the opposite side of the skewing direction\n    // normalize value from [-1, 1] to origin value [0, 1]\n    origin = -skewingDirection * 0.5 + 0.5;\n\n  const finalHandler = wrapWithFireEvent<SkewTransform>(\n    SKEWING,\n    wrapWithFixedAnchor((eventData, transform, x, y) =>\n      skewObject(axis, transform, new Point(x, y)),\n    ),\n  );\n\n  return finalHandler(\n    eventData,\n    {\n      ...transform,\n      [originKey]: origin,\n      skewingSide,\n    },\n    x,\n    y,\n  );\n}\n\n/**\n * Wrapped Action handler for skewing on the X axis, takes care of the\n * skew direction and determines the correct transform origin for the anchor point\n * @param {Event} eventData javascript event that is doing the transform\n * @param {Object} transform javascript object containing a series of information around the current transform\n * @param {number} x current mouse x position, canvas normalized\n * @param {number} y current mouse y position, canvas normalized\n * @return {Boolean} true if some change happened\n */\nexport const skewHandlerX: TransformActionHandler = (\n  eventData,\n  transform,\n  x,\n  y,\n) => {\n  return skewHandler('x', eventData, transform, x, y);\n};\n\n/**\n * Wrapped Action handler for skewing on the Y axis, takes care of the\n * skew direction and determines the correct transform origin for the anchor point\n * @param {Event} eventData javascript event that is doing the transform\n * @param {Object} transform javascript object containing a series of information around the current transform\n * @param {number} x current mouse x position, canvas normalized\n * @param {number} y current mouse y position, canvas normalized\n * @return {Boolean} true if some change happened\n */\nexport const skewHandlerY: TransformActionHandler = (\n  eventData,\n  transform,\n  x,\n  y,\n) => {\n  return skewHandler('y', eventData, transform, x, y);\n};\n"],"mappings":";;;;;;;;AAgCA,MAAM,YAUF;CACF,GAAG;EACD,aAAa;EACb,OAAO;EACP,MAAM;EACN,aAAa;EACb,QAAQ;EACR,MAAM;EACP;CACD,GAAG;EACD,aAAa;EACb,OAAO;EACP,MAAM;EACN,aAAa;EACb,QAAQ;EACR,MAAM;EACP;CACF;AAED,MAAM,UAAU;CAAC;CAAM;CAAQ;CAAM;CAAO;;;;;;;;AAS5C,MAAa,0BACX,WACA,SACA,cACA,UACG;AACH,KAAI,QAAQ,MAAM,KAAK,SAAS,cAAc,eAAe,CAC3D,QAAO;AAET,KAAI,QAAQ,MAAM,KAAK,SAAS,cAAc,eAAe,CAC3D,QAAO;AAGT,QAAO,GAAG,QADA,mBAAmB,cAAc,SAAS,MAAM,GAAG,GACxC;;;;;;AAOvB,SAAS,WACP,MACA,EAAE,QAAQ,IAAI,IAAI,aAAa,GAAG,aAClC,SACA;CACA,MAAM,EAAE,MAAM,YAAY,UAAU,OAClC,SAAS,QACN,SAAS,IAAI,MAAM,IAAI,GAAG,CAAC,CAC3B,OAAO,IAAI,MAAM,OAAO,QAAQ,OAAO,OAAO,CAAC,CAAC,OACnD,gBAAgB,OAAO,UACvB,eAAe,UAAU,UACzB,gBAAgB,KAAK,IAAI,iBAAiB,aAAa,CAAC,EAMxD,IACE,SAAS,MACL,OAAO,0BAA0B;EAC/B,QAAQ;EACR,QAAQ;EAER,OAAO;EACR,CAAC,CAAC,IACH,OAAO,0BAA0B;EAC/B,QAAQ;EACR,QAAQ;EACT,CAAC,CAAC;CAEX,MAAM,WACH,IAAI,SAAS,cAEZ,KAAK,IAAI,GAAG,EAAE,GAEhB;CAEF,MAAM,UAAU,iBAAiB,KAAK,KAAK,SAAS,CAAC;AAErD,QAAO,IAAI,SAAS,QAAQ;CAC5B,MAAM,UAAU,kBAAkB,OAAO;AAEzC,KAAI,WAAW,SAAS,KAAK;EAG3B,MAAM,EAAE,OAAO,WAAW,QACxB,YAAY,OAAO,0BAA0B,EAAE,OAAO,eAAe,CAAC,EACtE,WAAW,OAAO,2BAA2B,EAC7C,qBAAqB,UAAU,IAAI,UAAU,IAAI,SAAS,IAAI;AAChE,yBAAuB,KACrB,OAAO,IAAA,UAAa,qBAAqB,OAAO;;AAGpD,QAAO;;;;;;;;;;;AAYT,SAAS,YACP,MACA,WACA,WACA,GACA,GACA;CACA,MAAM,EAAE,WAAW,WACjB,EACE,aACA,QAAQ,WACR,aAAa,gBACb,MAAM,SACN,MAAM,YACJ,UAAU;AAChB,KAAI,SAAS,QAAQ,eAAe,CAClC,QAAO;CAGT,MAAM,EAAE,QAAQ,kBAAkB,MAAM,mBACpC,UAAU,cACZ,sBACE,cAAc,UAAU,kBAAkB,IACzC,OAAO,kBAAkB,KAAK,IAKjC,cAAe,CAAC,KAAK,KAAK,oBAAoB,IAC3C,OAAO,WAAW,KAAK,IAW1B,SAAS,GATL,OAAO,aAAa,KAEpB,cAAc,WAAA,UAAA,UAA2B,GAAG,EAAE,CAAC,QAAQ,KAEzD,OAAO,WAAW,IACd,IACA,MAAM,eAGiB,KAAM;AASrC,QAPqB,kBACnB,SACA,qBAAqB,WAAW,WAAW,GAAG,MAC5C,WAAW,MAAM,WAAW,IAAI,MAAM,GAAG,EAAE,CAAC,CAC7C,CACF,CAGC,WACA;EACE,GAAG;GACF,YAAY;EACb;EACD,EACD,GACA,EACD;;;;;;;;;;;AAYH,MAAa,gBACX,WACA,WACA,GACA,MACG;AACH,QAAO,YAAY,KAAK,WAAW,WAAW,GAAG,EAAE;;;;;;;;;;;AAYrD,MAAa,gBACX,WACA,WACA,GACA,MACG;AACH,QAAO,YAAY,KAAK,WAAW,WAAW,GAAG,EAAE"}