Transformable.js

var matrix = require("../core/matrix");

var vector = require("../core/vector");

/**
 * 提供变换扩展
 * @module zrender/mixin/Transformable
 * @author pissang (https://www.github.com/pissang)
 */
var mIdentity = matrix.identity;
var EPSILON = 5e-5;

function isNotAroundZero(val) {
  return val > EPSILON || val < -EPSILON;
}
/**
 * @alias module:zrender/mixin/Transformable
 * @constructor
 */


var Transformable = function (opts) {
  opts = opts || {}; // If there are no given position, rotation, scale

  if (!opts.position) {
    /**
     * 平移
     * @type {Array.<number>}
     * @default [0, 0]
     */
    this.position = [0, 0];
  }

  if (opts.rotation == null) {
    /**
     * 旋转
     * @type {Array.<number>}
     * @default 0
     */
    this.rotation = 0;
  }

  if (!opts.scale) {
    /**
     * 缩放
     * @type {Array.<number>}
     * @default [1, 1]
     */
    this.scale = [1, 1];
  }
  /**
   * 旋转和缩放的原点
   * @type {Array.<number>}
   * @default null
   */


  this.origin = this.origin || null;
};

var transformableProto = Transformable.prototype;
transformableProto.transform = null;
/**
 * 判断是否需要有坐标变换
 * 如果有坐标变换, 则从position, rotation, scale以及父节点的transform计算出自身的transform矩阵
 */

transformableProto.needLocalTransform = function () {
  return isNotAroundZero(this.rotation) || isNotAroundZero(this.position[0]) || isNotAroundZero(this.position[1]) || isNotAroundZero(this.scale[0] - 1) || isNotAroundZero(this.scale[1] - 1);
};

var scaleTmp = [];

transformableProto.updateTransform = function () {
  var parent = this.parent;
  var parentHasTransform = parent && parent.transform;
  var needLocalTransform = this.needLocalTransform();
  var m = this.transform;

  if (!(needLocalTransform || parentHasTransform)) {
    m && mIdentity(m);
    return;
  }

  m = m || matrix.create();

  if (needLocalTransform) {
    this.getLocalTransform(m);
  } else {
    mIdentity(m);
  } // 应用父节点变换


  if (parentHasTransform) {
    if (needLocalTransform) {
      matrix.mul(m, parent.transform, m);
    } else {
      matrix.copy(m, parent.transform);
    }
  } // 保存这个变换矩阵


  this.transform = m;
  var globalScaleRatio = this.globalScaleRatio;

  if (globalScaleRatio != null && globalScaleRatio !== 1) {
    this.getGlobalScale(scaleTmp);
    var relX = scaleTmp[0] < 0 ? -1 : 1;
    var relY = scaleTmp[1] < 0 ? -1 : 1;
    var sx = ((scaleTmp[0] - relX) * globalScaleRatio + relX) / scaleTmp[0] || 0;
    var sy = ((scaleTmp[1] - relY) * globalScaleRatio + relY) / scaleTmp[1] || 0;
    m[0] *= sx;
    m[1] *= sx;
    m[2] *= sy;
    m[3] *= sy;
  }

  this.invTransform = this.invTransform || matrix.create();
  matrix.invert(this.invTransform, m);
};

transformableProto.getLocalTransform = function (m) {
  return Transformable.getLocalTransform(this, m);
};
/**
 * 将自己的transform应用到context上
 * @param {CanvasRenderingContext2D} ctx
 */


transformableProto.setTransform = function (ctx) {
  var m = this.transform;
  var dpr = ctx.dpr || 1;

  if (m) {
    ctx.setTransform(dpr * m[0], dpr * m[1], dpr * m[2], dpr * m[3], dpr * m[4], dpr * m[5]);
  } else {
    ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
  }
};

transformableProto.restoreTransform = function (ctx) {
  var dpr = ctx.dpr || 1;
  ctx.setTransform(dpr, 0, 0, dpr, 0, 0);
};

var tmpTransform = [];
var originTransform = matrix.create();

transformableProto.setLocalTransform = function (m) {
  if (!m) {
    // TODO return or set identity?
    return;
  }

  var sx = m[0] * m[0] + m[1] * m[1];
  var sy = m[2] * m[2] + m[3] * m[3];
  var position = this.position;
  var scale = this.scale;

  if (isNotAroundZero(sx - 1)) {
    sx = Math.sqrt(sx);
  }

  if (isNotAroundZero(sy - 1)) {
    sy = Math.sqrt(sy);
  }

  if (m[0] < 0) {
    sx = -sx;
  }

  if (m[3] < 0) {
    sy = -sy;
  }

  position[0] = m[4];
  position[1] = m[5];
  scale[0] = sx;
  scale[1] = sy;
  this.rotation = Math.atan2(-m[1] / sy, m[0] / sx);
};
/**
 * 分解`transform`矩阵到`position`, `rotation`, `scale`
 */


transformableProto.decomposeTransform = function () {
  if (!this.transform) {
    return;
  }

  var parent = this.parent;
  var m = this.transform;

  if (parent && parent.transform) {
    // Get local transform and decompose them to position, scale, rotation
    matrix.mul(tmpTransform, parent.invTransform, m);
    m = tmpTransform;
  }

  var origin = this.origin;

  if (origin && (origin[0] || origin[1])) {
    originTransform[4] = origin[0];
    originTransform[5] = origin[1];
    matrix.mul(tmpTransform, m, originTransform);
    tmpTransform[4] -= origin[0];
    tmpTransform[5] -= origin[1];
    m = tmpTransform;
  }

  this.setLocalTransform(m);
};
/**
 * Get global scale
 * @return {Array.<number>}
 */


transformableProto.getGlobalScale = function (out) {
  var m = this.transform;
  out = out || [];

  if (!m) {
    out[0] = 1;
    out[1] = 1;
    return out;
  }

  out[0] = Math.sqrt(m[0] * m[0] + m[1] * m[1]);
  out[1] = Math.sqrt(m[2] * m[2] + m[3] * m[3]);

  if (m[0] < 0) {
    out[0] = -out[0];
  }

  if (m[3] < 0) {
    out[1] = -out[1];
  }

  return out;
};
/**
 * 变换坐标位置到 shape 的局部坐标空间
 * @method
 * @param {number} x
 * @param {number} y
 * @return {Array.<number>}
 */


transformableProto.transformCoordToLocal = function (x, y) {
  var v2 = [x, y];
  var invTransform = this.invTransform;

  if (invTransform) {
    vector.applyTransform(v2, v2, invTransform);
  }

  return v2;
};
/**
 * 变换局部坐标位置到全局坐标空间
 * @method
 * @param {number} x
 * @param {number} y
 * @return {Array.<number>}
 */


transformableProto.transformCoordToGlobal = function (x, y) {
  var v2 = [x, y];
  var transform = this.transform;

  if (transform) {
    vector.applyTransform(v2, v2, transform);
  }

  return v2;
};
/**
 * @static
 * @param {Object} target
 * @param {Array.<number>} target.origin
 * @param {number} target.rotation
 * @param {Array.<number>} target.position
 * @param {Array.<number>} [m]
 */


Transformable.getLocalTransform = function (target, m) {
  m = m || [];
  mIdentity(m);
  var origin = target.origin;
  var scale = target.scale || [1, 1];
  var rotation = target.rotation || 0;
  var position = target.position || [0, 0];

  if (origin) {
    // Translate to origin
    m[4] -= origin[0];
    m[5] -= origin[1];
  }

  matrix.scale(m, m, scale);

  if (rotation) {
    matrix.rotate(m, m, rotation);
  }

  if (origin) {
    // Translate back from origin
    m[4] += origin[0];
    m[5] += origin[1];
  }

  m[4] += position[0];
  m[5] += position[1];
  return m;
};

var _default = Transformable;
module.exports = _default;