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authormensonge <mensonge@b3834d28-1941-0410-a4f8-b48e95affb8f>2008-11-13 09:49:11 +0000
committermensonge <mensonge@b3834d28-1941-0410-a4f8-b48e95affb8f>2008-11-13 09:49:11 +0000
commite44a7e37b6c7b5961adaffc62b9042b8d442938e (patch)
tree95b67c356e93163467db2451f2b8cce84ed5d582 /includes/js/dojox/gfx/decompose.js
parenta62b9742ee5e28bcec6872d88f50f25b820914f6 (diff)
downloadsemanticscuttle-e44a7e37b6c7b5961adaffc62b9042b8d442938e.tar.gz
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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
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+if(!dojo._hasResource["dojox.gfx.decompose"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojox.gfx.decompose"] = true;
+dojo.provide("dojox.gfx.decompose");
+
+dojo.require("dojox.gfx.matrix");
+
+(function(){
+ var m = dojox.gfx.matrix;
+
+ var eq = function(/* Number */ a, /* Number */ b){
+ // summary: compare two FP numbers for equality
+ return Math.abs(a - b) <= 1e-6 * (Math.abs(a) + Math.abs(b)); // Boolean
+ };
+
+ var calcFromValues = function(/* Number */ r1, /* Number */ m1, /* Number */ r2, /* Number */ m2){
+ // summary: uses two close FP ration and their original magnitudes to approximate the result
+ if(!isFinite(r1)){
+ return r2; // Number
+ }else if(!isFinite(r2)){
+ return r1; // Number
+ }
+ m1 = Math.abs(m1), m2 = Math.abs(m2);
+ return (m1 * r1 + m2 * r2) / (m1 + m2); // Number
+ };
+
+ var transpose = function(/* dojox.gfx.matrix.Matrix2D */ matrix){
+ // matrix: dojox.gfx.matrix.Matrix2D: a 2D matrix-like object
+ var M = new m.Matrix2D(matrix);
+ return dojo.mixin(M, {dx: 0, dy: 0, xy: M.yx, yx: M.xy}); // dojox.gfx.matrix.Matrix2D
+ };
+
+ var scaleSign = function(/* dojox.gfx.matrix.Matrix2D */ matrix){
+ return (matrix.xx * matrix.yy < 0 || matrix.xy * matrix.yx > 0) ? -1 : 1; // Number
+ };
+
+ var eigenvalueDecomposition = function(/* dojox.gfx.matrix.Matrix2D */ matrix){
+ // matrix: dojox.gfx.matrix.Matrix2D: a 2D matrix-like object
+ var M = m.normalize(matrix),
+ b = -M.xx - M.yy,
+ c = M.xx * M.yy - M.xy * M.yx,
+ d = Math.sqrt(b * b - 4 * c),
+ l1 = -(b + (b < 0 ? -d : d)) / 2,
+ l2 = c / l1,
+ vx1 = M.xy / (l1 - M.xx), vy1 = 1,
+ vx2 = M.xy / (l2 - M.xx), vy2 = 1;
+ if(eq(l1, l2)){
+ vx1 = 1, vy1 = 0, vx2 = 0, vy2 = 1;
+ }
+ if(!isFinite(vx1)){
+ vx1 = 1, vy1 = (l1 - M.xx) / M.xy;
+ if(!isFinite(vy1)){
+ vx1 = (l1 - M.yy) / M.yx, vy1 = 1;
+ if(!isFinite(vx1)){
+ vx1 = 1, vy1 = M.yx / (l1 - M.yy);
+ }
+ }
+ }
+ if(!isFinite(vx2)){
+ vx2 = 1, vy2 = (l2 - M.xx) / M.xy;
+ if(!isFinite(vy2)){
+ vx2 = (l2 - M.yy) / M.yx, vy2 = 1;
+ if(!isFinite(vx2)){
+ vx2 = 1, vy2 = M.yx / (l2 - M.yy);
+ }
+ }
+ }
+ var d1 = Math.sqrt(vx1 * vx1 + vy1 * vy1),
+ d2 = Math.sqrt(vx2 * vx2 + vy2 * vy2);
+ if(!isFinite(vx1 /= d1)){ vx1 = 0; }
+ if(!isFinite(vy1 /= d1)){ vy1 = 0; }
+ if(!isFinite(vx2 /= d2)){ vx2 = 0; }
+ if(!isFinite(vy2 /= d2)){ vy2 = 0; }
+ return { // Object
+ value1: l1,
+ value2: l2,
+ vector1: {x: vx1, y: vy1},
+ vector2: {x: vx2, y: vy2}
+ };
+ };
+
+ var decomposeSR = function(/* dojox.gfx.matrix.Matrix2D */ M, /* Object */ result){
+ // summary: decomposes a matrix into [scale, rotate]; no checks are done.
+ var sign = scaleSign(M),
+ a = result.angle1 = (Math.atan2(M.yx, M.yy) + Math.atan2(-sign * M.xy, sign * M.xx)) / 2,
+ cos = Math.cos(a), sin = Math.sin(a);
+ result.sx = calcFromValues(M.xx / cos, cos, -M.xy / sin, sin);
+ result.sy = calcFromValues(M.yy / cos, cos, M.yx / sin, sin);
+ return result; // Object
+ };
+
+ var decomposeRS = function(/* dojox.gfx.matrix.Matrix2D */ M, /* Object */ result){
+ // summary: decomposes a matrix into [rotate, scale]; no checks are done
+ var sign = scaleSign(M),
+ a = result.angle2 = (Math.atan2(sign * M.yx, sign * M.xx) + Math.atan2(-M.xy, M.yy)) / 2,
+ cos = Math.cos(a), sin = Math.sin(a);
+ result.sx = calcFromValues(M.xx / cos, cos, M.yx / sin, sin);
+ result.sy = calcFromValues(M.yy / cos, cos, -M.xy / sin, sin);
+ return result; // Object
+ };
+
+ dojox.gfx.decompose = function(matrix){
+ // summary: decompose a 2D matrix into translation, scaling, and rotation components
+ // description: this function decompose a matrix into four logical components:
+ // translation, rotation, scaling, and one more rotation using SVD.
+ // The components should be applied in following order:
+ // | [translate, rotate(angle2), scale, rotate(angle1)]
+ // matrix: dojox.gfx.matrix.Matrix2D: a 2D matrix-like object
+ var M = m.normalize(matrix),
+ result = {dx: M.dx, dy: M.dy, sx: 1, sy: 1, angle1: 0, angle2: 0};
+ // detect case: [scale]
+ if(eq(M.xy, 0) && eq(M.yx, 0)){
+ return dojo.mixin(result, {sx: M.xx, sy: M.yy}); // Object
+ }
+ // detect case: [scale, rotate]
+ if(eq(M.xx * M.yx, -M.xy * M.yy)){
+ return decomposeSR(M, result); // Object
+ }
+ // detect case: [rotate, scale]
+ if(eq(M.xx * M.xy, -M.yx * M.yy)){
+ return decomposeRS(M, result); // Object
+ }
+ // do SVD
+ var MT = transpose(M),
+ u = eigenvalueDecomposition([M, MT]),
+ v = eigenvalueDecomposition([MT, M]),
+ U = new m.Matrix2D({xx: u.vector1.x, xy: u.vector2.x, yx: u.vector1.y, yy: u.vector2.y}),
+ VT = new m.Matrix2D({xx: v.vector1.x, xy: v.vector1.y, yx: v.vector2.x, yy: v.vector2.y}),
+ S = new m.Matrix2D([m.invert(U), M, m.invert(VT)]);
+ decomposeSR(VT, result);
+ S.xx *= result.sx;
+ S.yy *= result.sy;
+ decomposeRS(U, result);
+ S.xx *= result.sx;
+ S.yy *= result.sy;
+ return dojo.mixin(result, {sx: S.xx, sy: S.yy}); // Object
+ };
+})();
+
+}