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Diffstat (limited to 'includes/js/dojox/gfx/decompose.js')
-rw-r--r-- | includes/js/dojox/gfx/decompose.js | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/includes/js/dojox/gfx/decompose.js b/includes/js/dojox/gfx/decompose.js new file mode 100644 index 0000000..4e34ee6 --- /dev/null +++ b/includes/js/dojox/gfx/decompose.js @@ -0,0 +1,139 @@ +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 + }; +})(); + +} |