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author | 2008-11-13 09:49:11 +0000 | |
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committer | 2008-11-13 09:49:11 +0000 | |
commit | e44a7e37b6c7b5961adaffc62b9042b8d442938e (patch) | |
tree | 95b67c356e93163467db2451f2b8cce84ed5d582 /includes/js/dojox/gfx/arc.js | |
parent | a62b9742ee5e28bcec6872d88f50f25b820914f6 (diff) | |
download | scuttle-e44a7e37b6c7b5961adaffc62b9042b8d442938e.tar.gz scuttle-e44a7e37b6c7b5961adaffc62b9042b8d442938e.zip |
New feature: basic Ajax suggestion for tags and implementation of Dojo toolkit
git-svn-id: https://semanticscuttle.svn.sourceforge.net/svnroot/semanticscuttle/trunk@151 b3834d28-1941-0410-a4f8-b48e95affb8f
Diffstat (limited to 'includes/js/dojox/gfx/arc.js')
-rw-r--r-- | includes/js/dojox/gfx/arc.js | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/includes/js/dojox/gfx/arc.js b/includes/js/dojox/gfx/arc.js new file mode 100644 index 0000000..4a0eade --- /dev/null +++ b/includes/js/dojox/gfx/arc.js @@ -0,0 +1,122 @@ +if(!dojo._hasResource["dojox.gfx.arc"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code. +dojo._hasResource["dojox.gfx.arc"] = true; +dojo.provide("dojox.gfx.arc"); + +dojo.require("dojox.gfx.matrix"); + +(function(){ + var m = dojox.gfx.matrix, + unitArcAsBezier = function(alpha){ + // summary: return a start point, 1st and 2nd control points, and an end point of + // a an arc, which is reflected on the x axis + // alpha: Number: angle in radians, the arc will be 2 * angle size + var cosa = Math.cos(alpha), sina = Math.sin(alpha), + p2 = {x: cosa + (4 / 3) * (1 - cosa), y: sina - (4 / 3) * cosa * (1 - cosa) / sina}; + return { // Object + s: {x: cosa, y: -sina}, + c1: {x: p2.x, y: -p2.y}, + c2: p2, + e: {x: cosa, y: sina} + }; + }, + twoPI = 2 * Math.PI, pi4 = Math.PI / 4, pi8 = Math.PI / 8, + pi48 = pi4 + pi8, curvePI4 = unitArcAsBezier(pi8); + + dojo.mixin(dojox.gfx.arc, { + unitArcAsBezier: unitArcAsBezier, + curvePI4: curvePI4, + arcAsBezier: function(last, rx, ry, xRotg, large, sweep, x, y){ + // summary: calculates an arc as a series of Bezier curves + // given the last point and a standard set of SVG arc parameters, + // it returns an array of arrays of parameters to form a series of + // absolute Bezier curves. + // last: Object: a point-like object as a start of the arc + // rx: Number: a horizontal radius for the virtual ellipse + // ry: Number: a vertical radius for the virtual ellipse + // xRotg: Number: a rotation of an x axis of the virtual ellipse in degrees + // large: Boolean: which part of the ellipse will be used (the larger arc if true) + // sweep: Boolean: direction of the arc (CW if true) + // x: Number: the x coordinate of the end point of the arc + // y: Number: the y coordinate of the end point of the arc + + // calculate parameters + large = Boolean(large); + sweep = Boolean(sweep); + var xRot = m._degToRad(xRotg), + rx2 = rx * rx, ry2 = ry * ry, + pa = m.multiplyPoint( + m.rotate(-xRot), + {x: (last.x - x) / 2, y: (last.y - y) / 2} + ), + pax2 = pa.x * pa.x, pay2 = pa.y * pa.y, + c1 = Math.sqrt((rx2 * ry2 - rx2 * pay2 - ry2 * pax2) / (rx2 * pay2 + ry2 * pax2)); + if(isNaN(c1)){ c1 = 0; } + var ca = { + x: c1 * rx * pa.y / ry, + y: -c1 * ry * pa.x / rx + }; + if(large == sweep){ + ca = {x: -ca.x, y: -ca.y}; + } + // the center + var c = m.multiplyPoint( + [ + m.translate( + (last.x + x) / 2, + (last.y + y) / 2 + ), + m.rotate(xRot) + ], + ca + ); + // calculate the elliptic transformation + var elliptic_transform = m.normalize([ + m.translate(c.x, c.y), + m.rotate(xRot), + m.scale(rx, ry) + ]); + // start, end, and size of our arc + var inversed = m.invert(elliptic_transform), + sp = m.multiplyPoint(inversed, last), + ep = m.multiplyPoint(inversed, x, y), + startAngle = Math.atan2(sp.y, sp.x), + endAngle = Math.atan2(ep.y, ep.x), + theta = startAngle - endAngle; // size of our arc in radians + if(sweep){ theta = -theta; } + if(theta < 0){ + theta += twoPI; + }else if(theta > twoPI){ + theta -= twoPI; + } + + // draw curve chunks + var alpha = pi8, curve = curvePI4, step = sweep ? alpha : -alpha, + result = []; + for(var angle = theta; angle > 0; angle -= pi4){ + if(angle < pi48){ + alpha = angle / 2; + curve = unitArcAsBezier(alpha); + step = sweep ? alpha : -alpha; + angle = 0; // stop the loop + } + var c1, c2, e, + M = m.normalize([elliptic_transform, m.rotate(startAngle + step)]); + if(sweep){ + c1 = m.multiplyPoint(M, curve.c1); + c2 = m.multiplyPoint(M, curve.c2); + e = m.multiplyPoint(M, curve.e ); + }else{ + c1 = m.multiplyPoint(M, curve.c2); + c2 = m.multiplyPoint(M, curve.c1); + e = m.multiplyPoint(M, curve.s ); + } + // draw the curve + result.push([c1.x, c1.y, c2.x, c2.y, e.x, e.y]); + startAngle += 2 * step; + } + return result; // Object + } + }); +})(); + +} |