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/**
* 提供变换扩展
* @module zrender/mixin/Transformable
* @author pissang (https://www.github.com/pissang)
*/
define(function (require) {
'use strict';
var matrix = require('../tool/matrix');
var vector = require('../tool/vector');
var origin = [ 0, 0 ];
var EPSILON = 5e-5;
function isAroundZero(val) {
return val > -EPSILON && val < EPSILON;
}
function isNotAroundZero(val) {
return val > EPSILON || val < -EPSILON;
}
/**
* @alias module:zrender/mixin/Transformable
* @constructor
*/
var Transformable = function () {
if (!this.position) {
/**
* 平移
* @type {Array.<number>}
* @default [0, 0]
*/
this.position = [ 0, 0 ];
}
if (typeof(this.rotation) == 'undefined') {
/**
* 旋转，可以通过数组二三项指定旋转的原点
* @type {Array.<number>}
* @default [0, 0, 0]
*/
this.rotation = [ 0, 0, 0 ];
}
if (!this.scale) {
/**
* 缩放，可以通过数组三四项指定缩放的原点
* @type {Array.<number>}
* @default [1, 1, 0, 0]
*/
this.scale = [ 1, 1, 0, 0 ];
}
this.needLocalTransform = false;
/**
* 是否有坐标变换
* @type {boolean}
* @readOnly
*/
this.needTransform = false;
};
Transformable.prototype = {
constructor: Transformable,
updateNeedTransform: function () {
this.needLocalTransform = isNotAroundZero(this.rotation[0])
|| isNotAroundZero(this.position[0])
|| isNotAroundZero(this.position[1])
|| isNotAroundZero(this.scale[0] - 1)
|| isNotAroundZero(this.scale[1] - 1);
},
/**
* 判断是否需要有坐标变换，更新needTransform属性。
* 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
*/
updateTransform: function () {
this.updateNeedTransform();
if (this.parent) {
this.needTransform = this.needLocalTransform || this.parent.needTransform;
}
else {
this.needTransform = this.needLocalTransform;
}
if (!this.needTransform) {
return;
}
var m = this.transform || matrix.create();
matrix.identity(m);
if (this.needLocalTransform) {
if (
isNotAroundZero(this.scale[0])
|| isNotAroundZero(this.scale[1])
) {
origin[0] = -this.scale[2] || 0;
origin[1] = -this.scale[3] || 0;
var haveOrigin = isNotAroundZero(origin[0])
|| isNotAroundZero(origin[1]);
if (haveOrigin) {
matrix.translate(
m, m, origin
);
}
matrix.scale(m, m, this.scale);
if (haveOrigin) {
origin[0] = -origin[0];
origin[1] = -origin[1];
matrix.translate(
m, m, origin
);
}
}
if (this.rotation instanceof Array) {
if (this.rotation[0] !== 0) {
origin[0] = -this.rotation[1] || 0;
origin[1] = -this.rotation[2] || 0;
var haveOrigin = isNotAroundZero(origin[0])
|| isNotAroundZero(origin[1]);
if (haveOrigin) {
matrix.translate(
m, m, origin
);
}
matrix.rotate(m, m, this.rotation[0]);
if (haveOrigin) {
origin[0] = -origin[0];
origin[1] = -origin[1];
matrix.translate(
m, m, origin
);
}
}
}
else {
if (this.rotation !== 0) {
matrix.rotate(m, m, this.rotation);
}
}
if (
isNotAroundZero(this.position[0]) || isNotAroundZero(this.position[1])
) {
matrix.translate(m, m, this.position);
}
}
// 保存这个变换矩阵
this.transform = m;
// 应用父节点变换
if (this.parent && this.parent.needTransform) {
if (this.needLocalTransform) {
matrix.mul(this.transform, this.parent.transform, this.transform);
}
else {
matrix.copy(this.transform, this.parent.transform);
}
}
},
/**
* 将自己的transform应用到context上
* @param {Context2D} ctx
*/
setTransform: function (ctx) {
if (this.needTransform) {
var m = this.transform;
ctx.transform(
m[0], m[1],
m[2], m[3],
m[4], m[5]
);
}
},
/**
* 设置图形的朝向
* @param {Array.<number>|Float32Array} target
* @method
*/
lookAt: (function () {
var v = vector.create();
return function(target) {
if (!this.transform) {
this.transform = matrix.create();
}
var m = this.transform;
vector.sub(v, target, this.position);
if (isAroundZero(v[0]) && isAroundZero(v[1])) {
return;
}
vector.normalize(v, v);
// Y Axis
// TODO Scale origin ?
m[2] = v[0] * this.scale[1];
m[3] = v[1] * this.scale[1];
// X Axis
m[0] = v[1] * this.scale[0];
m[1] = -v[0] * this.scale[0];
// Position
m[4] = this.position[0];
m[5] = this.position[1];
this.decomposeTransform();
};
})(),
/**
* 分解`transform`矩阵到`position`, `rotation`, `scale`
*/
decomposeTransform: function () {
if (!this.transform) {
return;
}
var m = this.transform;
var sx = m[0] * m[0] + m[1] * m[1];
var position = this.position;
var scale = this.scale;
var rotation = this.rotation;
if (isNotAroundZero(sx - 1)) {
sx = Math.sqrt(sx);
}
var sy = m[2] * m[2] + m[3] * m[3];
if (isNotAroundZero(sy - 1)) {
sy = Math.sqrt(sy);
}
position[0] = m[4];
position[1] = m[5];
scale[0] = sx;
scale[1] = sy;
scale[2] = scale[3] = 0;
rotation[0] = Math.atan2(-m[1] / sy, m[0] / sx);
rotation[1] = rotation[2] = 0;
}
};
return Transformable;
});