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Merge pull request #2091 from asturur/multiplyMatrice

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Shorter version of multiply transform matrix
This commit is contained in:
Juriy Zaytsev 2015-04-07 18:55:17 +02:00
commit 8dfaaab514
1 changed files with 10 additions and 36 deletions
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46
src/util/misc.js
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@ -459,45 +459,19 @@
* Multiply matrix A by matrix B to nest transformations
* @static
* @memberOf fabric.util
* @param {Array} matrixA First transformMatrix
* @param {Array} matrixB Second transformMatrix
* @param {Array} a First transformMatrix
* @param {Array} b Second transformMatrix
* @return {Array} The product of the two transform matrices
*/
multiplyTransformMatrices: function(matrixA, matrixB) {
// Matrix multiply matrixA * matrixB
var a = [
[matrixA[0], matrixA[2], matrixA[4]],
[matrixA[1], matrixA[3], matrixA[5]],
[0, 0, 1 ]
],
b = [
[matrixB[0], matrixB[2], matrixB[4]],
[matrixB[1], matrixB[3], matrixB[5]],
[0, 0, 1 ]
],
result = [];
for (var r = 0; r < 3; r++) {
result[r] = [];
for (var c = 0; c < 3; c++) {
var sum = 0;
for (var k = 0; k < 3; k++) {
sum += a[r][k] * b[k][c];
}
result[r][c] = sum;
}
}
multiplyTransformMatrices: function(a, b) {
// Matrix multiply a * b
return [
result[0][0],
result[1][0],
result[0][1],
result[1][1],
result[0][2],
result[1][2]
a[0] * b[0] + a[2] * b[1],
a[1] * b[0] + a[3] * b[1],
a[0] * b[2] + a[2] * b[3],
a[1] * b[2] + a[3] * b[3],
a[0] * b[4] + a[2] * b[5] + a[4],
a[1] * b[4] + a[3] * b[5] + a[5]
];
},