libs/matrix/matrix.js
/**
* Snap.svg Matrix subclass
*/
var PI = Math.PI,
math = Math;
function rad(deg) {
return deg % 360 * PI / 180;
}
function deg(rad) {
return rad * 180 / PI % 360;
}
function Matrix(a, b, c, d, e, f) {
if (a != null && typeof a == 'object'){
this.a = +a.a;
this.b = +a.b;
this.c = +a.c;
this.d = +a.d;
this.e = +a.e;
this.f = +a.f;
} else
if (a != null) {
this.a = +a;
this.b = +b;
this.c = +c;
this.d = +d;
this.e = +e;
this.f = +f;
} else {
this.a = 1;
this.b = 0;
this.c = 0;
this.d = 1;
this.e = 0;
this.f = 0;
}
}
(function (matrixproto) {
/*\
* Matrix.add
[ method ]
**
* Adds the given matrix to existing one
- a (number)
- b (number)
- c (number)
- d (number)
- e (number)
- f (number)
* or
- matrix (object) @Matrix
\*/
matrixproto.add = function (a, b, c, d, e, f) {
var out = [[], [], []],
m = [[this.a, this.c, this.e], [this.b, this.d, this.f], [0, 0, 1]],
matrix = [[a, c, e], [b, d, f], [0, 0, 1]],
x, y, z, res;
if (a && a instanceof Matrix) {
matrix = [[a.a, a.c, a.e], [a.b, a.d, a.f], [0, 0, 1]];
}
for (x = 0; x < 3; x++) {
for (y = 0; y < 3; y++) {
res = 0;
for (z = 0; z < 3; z++) {
res += m[x][z] * matrix[z][y];
}
out[x][y] = res;
}
}
this.a = out[0][0];
this.b = out[1][0];
this.c = out[0][1];
this.d = out[1][1];
this.e = out[0][2];
this.f = out[1][2];
return this;
};
/*\
* Matrix.invert
[ method ]
**
* Returns an inverted version of the matrix
= (object) @Matrix
\*/
matrixproto.invert = function () {
var me = this,
x = me.a * me.d - me.b * me.c;
return new Matrix(me.d / x, -me.b / x, -me.c / x, me.a / x, (me.c * me.f - me.d * me.e) / x, (me.b * me.e - me.a * me.f) / x);
};
/*\
* Matrix.clone
[ method ]
**
* Returns a copy of the matrix
= (object) @Matrix
\*/
matrixproto.clone = function () {
return new Matrix(this.a, this.b, this.c, this.d, this.e, this.f);
};
/*\
* Matrix.translate
[ method ]
**
* Translate the matrix
- x (number) horizontal offset distance
- y (number) vertical offset distance
\*/
matrixproto.translate = function (x, y) {
return this.add(1, 0, 0, 1, x, y);
};
/*\
* Matrix.scale
[ method ]
**
* Scales the matrix
- x (number) amount to be scaled, with `1` resulting in no change
- y (number) #optional amount to scale along the vertical axis. (Otherwise `x` applies to both axes.)
- cx (number) #optional horizontal origin point from which to scale
- cy (number) #optional vertical origin point from which to scale
* Default cx, cy is the middle point of the element.
\*/
matrixproto.scale = function (x, y, cx, cy) {
y == null && (y = x);
(cx || cy) && this.add(1, 0, 0, 1, cx, cy);
this.add(x, 0, 0, y, 0, 0);
(cx || cy) && this.add(1, 0, 0, 1, -cx, -cy);
return this;
};
/*\
* Matrix.rotate
[ method ]
**
* Rotates the matrix
- a (number) angle of rotation, in degrees
- x (number) horizontal origin point from which to rotate
- y (number) vertical origin point from which to rotate
\*/
matrixproto.rotate = function (a, x, y) {
a = rad(a);
x = x || 0;
y = y || 0;
var cos = +math.cos(a).toFixed(9),
sin = +math.sin(a).toFixed(9);
this.add(cos, sin, -sin, cos, x, y);
return this.add(1, 0, 0, 1, -x, -y);
};
/*\
* Matrix.x
[ method ]
**
* Returns x coordinate for given point after transformation described by the matrix. See also @Matrix.y
- x (number)
- y (number)
= (number) x
\*/
matrixproto.x = function (x, y) {
return x * this.a + y * this.c + this.e;
};
/*\
* Matrix.y
[ method ]
**
* Returns y coordinate for given point after transformation described by the matrix. See also @Matrix.x
- x (number)
- y (number)
= (number) y
\*/
matrixproto.y = function (x, y) {
return x * this.b + y * this.d + this.f;
};
matrixproto.get = function (i) {
return +this[Str.fromCharCode(97 + i)].toFixed(4);
};
matrixproto.toString = function () {
return "matrix(" + [this.get(0), this.get(1), this.get(2), this.get(3), this.get(4), this.get(5)].join() + ")";
};
matrixproto.offset = function () {
return [this.e.toFixed(4), this.f.toFixed(4)];
};
function norm(a) {
return a[0] * a[0] + a[1] * a[1];
}
function normalize(a) {
var mag = math.sqrt(norm(a));
a[0] && (a[0] /= mag);
a[1] && (a[1] /= mag);
}
// SIERRA Matrix.split(): HTML formatting for the return value is scrambled. It should appear _Returns: {OBJECT} in format:..._
// SIERRA Matrix.split(): the _shear_ parameter needs to be detailed. Is it an angle? What does it affect?
// SIERRA Matrix.split(): The idea of _simple_ transforms needs to be detailed and contrasted with any alternatives.
/*\
* Matrix.split
[ method ]
**
* Splits matrix into primitive transformations
= (object) in format:
o dx (number) translation by x
o dy (number) translation by y
o scalex (number) scale by x
o scaley (number) scale by y
o shear (number) shear
o rotate (number) rotation in deg
o isSimple (boolean) could it be represented via simple transformations
\*/
matrixproto.split = function () {
var out = {};
// translation
out.dx = this.e;
out.dy = this.f;
// scale and shear
var row = [[this.a, this.c], [this.b, this.d]];
out.scalex = math.sqrt(norm(row[0]));
normalize(row[0]);
out.shear = row[0][0] * row[1][0] + row[0][1] * row[1][1];
row[1] = [row[1][0] - row[0][0] * out.shear, row[1][1] - row[0][1] * out.shear];
out.scaley = math.sqrt(norm(row[1]));
normalize(row[1]);
out.shear /= out.scaley;
// rotation
var sin = -row[0][1],
cos = row[1][1];
if (cos < 0) {
out.rotate = deg(math.acos(cos));
if (sin < 0) {
out.rotate = 360 - out.rotate;
}
} else {
out.rotate = deg(math.asin(sin));
}
out.isSimple = !+out.shear.toFixed(9) && (out.scalex.toFixed(9) == out.scaley.toFixed(9) || !out.rotate);
out.isSuperSimple = !+out.shear.toFixed(9) && out.scalex.toFixed(9) == out.scaley.toFixed(9) && !out.rotate;
out.noRotation = !+out.shear.toFixed(9) && !out.rotate;
return out;
};
// SIERRA Matrix.toTransformString(): The format of the string needs to be detailed.
/*\
* Matrix.toTransformString
[ method ]
**
* Returns transform string that represents given matrix
= (string) transform string
\*/
matrixproto.toTransformString = function (shorter) {
var s = shorter || this.split();
if (s.isSimple) {
s.scalex = +s.scalex.toFixed(4);
s.scaley = +s.scaley.toFixed(4);
s.rotate = +s.rotate.toFixed(4);
return (s.dx || s.dy ? "t" + [+s.dx.toFixed(4), +s.dy.toFixed(4)] : E) +
(s.scalex != 1 || s.scaley != 1 ? "s" + [s.scalex, s.scaley, 0, 0] : E) +
(s.rotate ? "r" + [+s.rotate.toFixed(4), 0, 0] : E);
} else {
return "m" + [this.get(0), this.get(1), this.get(2), this.get(3), this.get(4), this.get(5)];
}
};
})(Matrix.prototype);
module.exports = Matrix;