123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246 |
- /**
- * Package: svedit.math
- *
- * Licensed under the Apache License, Version 2
- *
- * Copyright(c) 2010 Alexis Deveria
- * Copyright(c) 2010 Jeff Schiller
- */
- // Dependencies:
- // None.
- var svgedit = svgedit || {};
- (function() {
- if (!svgedit.math) {
- svgedit.math = {};
- }
- // Constants
- var NEAR_ZERO = 1e-14;
- // Throw away SVGSVGElement used for creating matrices/transforms.
- var svg = document.createElementNS('http://www.w3.org/2000/svg', 'svg');
- // Function: svgedit.math.transformPoint
- // A (hopefully) quicker function to transform a point by a matrix
- // (this function avoids any DOM calls and just does the math)
- //
- // Parameters:
- // x - Float representing the x coordinate
- // y - Float representing the y coordinate
- // m - Matrix object to transform the point with
- // Returns a 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};
- };
- // Function: svgedit.math.isIdentity
- // Helper function to check if the matrix performs no actual transform
- // (i.e. exists for identity purposes)
- //
- // Parameters:
- // m - The matrix object to check
- //
- // Returns:
- // Boolean indicating 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);
- };
- // Function: svgedit.math.matrixMultiply
- // This function tries to return a SVGMatrix that is the multiplication m1*m2.
- // We also round to zero when it's near zero
- //
- // Parameters:
- // >= 2 Matrix objects to multiply
- //
- // Returns:
- // The matrix object resulting from the calculation
- svgedit.math.matrixMultiply = function() {
- 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;
- };
- // Function: svgedit.math.hasMatrixTransform
- // See if the given transformlist includes a non-indentity matrix transform
- //
- // Parameters:
- // tlist - The transformlist to check
- //
- // Returns:
- // Boolean on 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;
- };
- // Function: svgedit.math.transformBox
- // Transforms a rectangle based on the given matrix
- //
- // Parameters:
- // l - Float with the box's left coordinate
- // t - Float with the box's top coordinate
- // w - Float with the box width
- // h - Float with the box height
- // m - Matrix object to transform the box by
- //
- // Returns:
- // 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:
- // * Float with the axis-aligned x coordinate
- // * Float with the axis-aligned y coordinate
- // * Float with the axis-aligned width coordinate
- // * Float with the axis-aligned height coordinate
- svgedit.math.transformBox = function(l, t, w, h, m) {
- var topleft = {x:l,y:t},
- topright = {x:(l+w),y:t},
- botright = {x:(l+w),y:(t+h)},
- botleft = {x:l,y:(t+h)};
- var transformPoint = svgedit.math.transformPoint;
- topleft = transformPoint( topleft.x, topleft.y, m );
- var minx = topleft.x,
- maxx = topleft.x,
- miny = topleft.y,
- maxy = topleft.y;
- topright = transformPoint( topright.x, topright.y, m );
- minx = Math.min(minx, topright.x);
- maxx = Math.max(maxx, topright.x);
- miny = Math.min(miny, topright.y);
- maxy = Math.max(maxy, topright.y);
- botleft = transformPoint( botleft.x, botleft.y, m);
- minx = Math.min(minx, botleft.x);
- maxx = Math.max(maxx, botleft.x);
- miny = Math.min(miny, botleft.y);
- maxy = Math.max(maxy, botleft.y);
- botright = transformPoint( botright.x, botright.y, m );
- minx = Math.min(minx, botright.x);
- maxx = Math.max(maxx, botright.x);
- miny = Math.min(miny, botright.y);
- maxy = Math.max(maxy, botright.y);
- return {tl:topleft, tr:topright, bl:botleft, br:botright,
- aabox: {x:minx, y:miny, width:(maxx-minx), height:(maxy-miny)} };
- };
- // Function: svgedit.math.transformListToTransform
- // 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
- //
- // Parameters:
- // tlist - The transformlist object
- // min - Optional integer indicating start transform position
- // max - Optional integer indicating end transform position
- //
- // Returns:
- // 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());
- }
- var min = min == undefined ? 0 : min;
- var max = max == undefined ? (tlist.numberOfItems-1) : max;
- min = parseInt(min);
- max = parseInt(max);
- if (min > max) { var temp = max; max = min; min = temp; }
- var m = svg.createSVGMatrix();
- for (var 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);
- };
- // Function: svgedit.math.getMatrix
- // Get the matrix object for a given element
- //
- // Parameters:
- // elem - The DOM element to check
- //
- // Returns:
- // 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;
- };
- // Function: svgedit.math.snapToAngle
- // Returns a 45 degree angle coordinate associated with the two given
- // coordinates
- //
- // Parameters:
- // x1 - First coordinate's x value
- // x2 - Second coordinate's x value
- // y1 - First coordinate's y value
- // y2 - Second coordinate's y value
- //
- // Returns:
- // Object with the following values:
- // x - The angle-snapped x value
- // y - The angle-snapped y value
- // snapangle - The angle at which to snap
- 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;
- var x = x1 + dist*Math.cos(snapangle);
- var y = y1 + dist*Math.sin(snapangle);
- //console.log(x1,y1,x2,y2,x,y,angle)
- return {x:x, y:y, a:snapangle};
- };
- // Function: rectsIntersect
- // Check if two rectangles (BBoxes objects) intersect each other
- //
- // Paramaters:
- // r1 - The first BBox-like object
- // r2 - The second BBox-like object
- //
- // Returns:
- // Boolean that's 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;
- };
- })();
|