/** * Package: svedit.math * * Licensed under the Apache License, Version 2 * * Copyright(c) 2010 Alexis Deveria * Copyright(c) 2010 Jeff Schiller */ // Dependencies: // None. (function() { if (!window.svgedit) { window.svgedit = {}; } 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.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; }; })();