Current File : //proc/self/root/home/tjamichg/cursos.tjamich.gob.mx/main/inc/lib/javascript/svgedit/math.js
/*globals svgedit*/
/*jslint vars: true, eqeq: true */
/**
* Package: svedit.math
*
* Licensed under the MIT License
*
* Copyright(c) 2010 Alexis Deveria
* Copyright(c) 2010 Jeff Schiller
*/
// Dependencies:
// None.
/**
* @typedef AngleCoord45
* @type {object}
* @property {number} x - The angle-snapped x value
* @property {number} y - The angle-snapped y value
* @property {number} a - The angle at which to snap
*/
(function() {'use strict';
if (!svgedit.math) {
svgedit.math = {};
}
// Constants
var NEAR_ZERO = 1e-14;
// Throw away SVGSVGElement used for creating matrices/transforms.
var svg = document.createElementNS(svgedit.NS.SVG, 'svg');
/**
* A (hopefully) quicker function to transform a point by a matrix
* (this function avoids any DOM calls and just does the math)
* @param {number} x - Float representing the x coordinate
* @param {number} y - Float representing the y coordinate
* @param {SVGMatrix} m - Matrix object to transform the point with
* @returns {object} An x, y object representing the transformed point
*/
svgedit.math.transformPoint = function (x, y, m) {
return { x: m.a * x + m.c * y + m.e, y: m.b * x + m.d * y + m.f};
};
/**
* Helper function to check if the matrix performs no actual transform
* (i.e. exists for identity purposes)
* @param {SVGMatrix} m - The matrix object to check
* @returns {boolean} Indicates whether or not the matrix is 1,0,0,1,0,0
*/
svgedit.math.isIdentity = function (m) {
return (m.a === 1 && m.b === 0 && m.c === 0 && m.d === 1 && m.e === 0 && m.f === 0);
};
/**
* This function tries to return a SVGMatrix that is the multiplication m1*m2.
* We also round to zero when it's near zero
* @param {...SVGMatrix} matr - Two or more matrix objects to multiply
* @returns {SVGMatrix} The matrix object resulting from the calculation
*/
svgedit.math.matrixMultiply = function (matr) {
var args = arguments, i = args.length, m = args[i-1];
while (i-- > 1) {
var m1 = args[i-1];
m = m1.multiply(m);
}
if (Math.abs(m.a) < NEAR_ZERO) {m.a = 0;}
if (Math.abs(m.b) < NEAR_ZERO) {m.b = 0;}
if (Math.abs(m.c) < NEAR_ZERO) {m.c = 0;}
if (Math.abs(m.d) < NEAR_ZERO) {m.d = 0;}
if (Math.abs(m.e) < NEAR_ZERO) {m.e = 0;}
if (Math.abs(m.f) < NEAR_ZERO) {m.f = 0;}
return m;
};
/**
* See if the given transformlist includes a non-indentity matrix transform
* @param {object} [tlist] - The transformlist to check
* @returns {boolean} Whether or not a matrix transform was found
*/
svgedit.math.hasMatrixTransform = function (tlist) {
if (!tlist) {return false;}
var num = tlist.numberOfItems;
while (num--) {
var xform = tlist.getItem(num);
if (xform.type == 1 && !svgedit.math.isIdentity(xform.matrix)) {return true;}
}
return false;
};
/**
* Transforms a rectangle based on the given matrix
* @param {number} l - Float with the box's left coordinate
* @param {number} t - Float with the box's top coordinate
* @param {number} w - Float with the box width
* @param {number} h - Float with the box height
* @param {SVGMatrix} m - Matrix object to transform the box by
* @returns {object} An object with the following values:
* tl - The top left coordinate (x,y object)
* tr - The top right coordinate (x,y object)
* bl - The bottom left coordinate (x,y object)
* br - The bottom right coordinate (x,y object)
* aabox - Object with the following values:
* x - Float with the axis-aligned x coordinate
* y - Float with the axis-aligned y coordinate
* width - Float with the axis-aligned width coordinate
* height - Float with the axis-aligned height coordinate
*/
svgedit.math.transformBox = function (l, t, w, h, m) {
var transformPoint = svgedit.math.transformPoint,
tl = transformPoint(l, t, m),
tr = transformPoint((l + w), t, m),
bl = transformPoint(l, (t + h), m),
br = transformPoint((l + w), (t + h), m),
minx = Math.min(tl.x, tr.x, bl.x, br.x),
maxx = Math.max(tl.x, tr.x, bl.x, br.x),
miny = Math.min(tl.y, tr.y, bl.y, br.y),
maxy = Math.max(tl.y, tr.y, bl.y, br.y);
return {
tl: tl,
tr: tr,
bl: bl,
br: br,
aabox: {
x: minx,
y: miny,
width: (maxx - minx),
height: (maxy - miny)
}
};
};
/**
* This returns a single matrix Transform for a given Transform List
* (this is the equivalent of SVGTransformList.consolidate() but unlike
* that method, this one does not modify the actual SVGTransformList)
* This function is very liberal with its min, max arguments
* @param {object} tlist - The transformlist object
* @param {integer} [min=0] - Optional integer indicating start transform position
* @param {integer} [max] - Optional integer indicating end transform position;
* defaults to one less than the tlist's numberOfItems
* @returns {object} A single matrix transform object
*/
svgedit.math.transformListToTransform = function (tlist, min, max) {
if (tlist == null) {
// Or should tlist = null have been prevented before this?
return svg.createSVGTransformFromMatrix(svg.createSVGMatrix());
}
min = min || 0;
max = max || (tlist.numberOfItems - 1);
min = parseInt(min, 10);
max = parseInt(max, 10);
if (min > max) { var temp = max; max = min; min = temp; }
var m = svg.createSVGMatrix();
var i;
for (i = min; i <= max; ++i) {
// if our indices are out of range, just use a harmless identity matrix
var mtom = (i >= 0 && i < tlist.numberOfItems ?
tlist.getItem(i).matrix :
svg.createSVGMatrix());
m = svgedit.math.matrixMultiply(m, mtom);
}
return svg.createSVGTransformFromMatrix(m);
};
/**
* Get the matrix object for a given element
* @param {Element} elem - The DOM element to check
* @returns {SVGMatrix} The matrix object associated with the element's transformlist
*/
svgedit.math.getMatrix = function (elem) {
var tlist = svgedit.transformlist.getTransformList(elem);
return svgedit.math.transformListToTransform(tlist).matrix;
};
/**
* Returns a 45 degree angle coordinate associated with the two given
* coordinates
* @param {number} x1 - First coordinate's x value
* @param {number} x2 - Second coordinate's x value
* @param {number} y1 - First coordinate's y value
* @param {number} y2 - Second coordinate's y value
* @returns {AngleCoord45}
*/
svgedit.math.snapToAngle = function (x1, y1, x2, y2) {
var snap = Math.PI / 4; // 45 degrees
var dx = x2 - x1;
var dy = y2 - y1;
var angle = Math.atan2(dy, dx);
var dist = Math.sqrt(dx * dx + dy * dy);
var snapangle = Math.round(angle / snap) * snap;
return {
x: x1 + dist * Math.cos(snapangle),
y: y1 + dist * Math.sin(snapangle),
a: snapangle
};
};
/**
* Check if two rectangles (BBoxes objects) intersect each other
* @param {SVGRect} r1 - The first BBox-like object
* @param {SVGRect} r2 - The second BBox-like object
* @returns {boolean} True if rectangles intersect
*/
svgedit.math.rectsIntersect = function (r1, r2) {
return r2.x < (r1.x + r1.width) &&
(r2.x + r2.width) > r1.x &&
r2.y < (r1.y + r1.height) &&
(r2.y + r2.height) > r1.y;
};
}());
Mini Shell