define([], function () {
"use strict";
/**
* Mat2 - 2x3 Matrix
* A mat2d contains six elements defined as:
* <pre>
* [a, b,
* c, d,
* tx,ty]
* </pre>
* This is a short form for the 3x3 matrix:
* <pre>
* [a, b, 0
* c, d, 0
* tx,ty,1]
* </pre>
* The last column is ignored so the array is shorter and operations are faster.
* @class Mat2d
* @namespace kick.math
*/
return {
/**
* Creates a new identity mat2d
*
* @method create
* @return {kick.math.Mat2d} New mat2d
* @static
*/
create: function () {
var out = new Float32Array(6);
out[0] = 1;
out[3] = 1;
return out;
},
/**
* Creates a new mat2d initialized with values from an existing matrix
* @method clone
* @param {kick.math.Mat2d} a matrix to clone
* @return {kick.math.Mat2d} a new 2x3 matrix
* @static
*/
clone: function (a) {
var out = new Float32Array(6);
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
out[4] = a[4];
out[5] = a[5];
return out;
},
/**
* Copy the values from one mat2d to another
* @method copy
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the source matrix
* @return {kick.math.Mat2d} out
* @static
*/
copy: function (out, a) {
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
out[4] = a[4];
out[5] = a[5];
return out;
},
/**
* Sets a Mat2d to the identity matrix
* @method identity
* @param {kick.math.Mat2d} out the receiving matrix
* @return {kick.math.Mat2d} out
* @static
*/
identity: function (out) {
out[0] = 1;
out[1] = 0;
out[2] = 0;
out[3] = 1;
out[4] = 0;
out[5] = 0;
return out;
},
/**
* Inverts a Mat2d
* @method invert
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the source matrix
* @return {kick.math.Mat2d} out
* @static
*/
invert: function (out, a) {
var aa = a[0], ab = a[1], ac = a[2], ad = a[3],
atx = a[4], aty = a[5];
var det = aa * ad - ab * ac;
if(!det){
return null;
}
det = 1.0 / det;
out[0] = ad * det;
out[1] = -ab * det;
out[2] = -ac * det;
out[3] = aa * det;
out[4] = (ac * aty - ad * atx) * det;
out[5] = (ab * atx - aa * aty) * det;
return out;
},
/**
* Calculates the determinant of a Mat2d
* @method determinant
* @param {kick.math.Mat2d} a the source matrix
* @return {Number} determinant of a
* @static
*/
determinant: function (a) {
return a[0] * a[3] - a[1] * a[2];
},
/**
* Multiplies two Mat2d's
* @method multiply
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the first operand
* @param {kick.math.Mat2d} b the second operand
* @return {kick.math.Mat2d} out
* @static
*/
multiply: function (out, a, b) {
var aa = a[0], ab = a[1], ac = a[2], ad = a[3],
atx = a[4], aty = a[5],
ba = b[0], bb = b[1], bc = b[2], bd = b[3],
btx = b[4], bty = b[5];
out[0] = aa*ba + ab*bc;
out[1] = aa*bb + ab*bd;
out[2] = ac*ba + ad*bc;
out[3] = ac*bb + ad*bd;
out[4] = ba*atx + bc*aty + btx;
out[5] = bb*atx + bd*aty + bty;
return out;
},
/**
* Rotates a mat2d by the given angle
* @method rotate
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the matrix to rotate
* @param {Number} rad the angle to rotate the matrix by
* @return {kick.math.Mat2d} out
* @static
*/
rotate: function (out, a, rad) {
var aa = a[0],
ab = a[1],
ac = a[2],
ad = a[3],
atx = a[4],
aty = a[5],
st = Math.sin(rad),
ct = Math.cos(rad);
out[0] = aa*ct + ab*st;
out[1] = -aa*st + ab*ct;
out[2] = ac*ct + ad*st;
out[3] = -ac*st + ct*ad;
out[4] = ct*atx + st*aty;
out[5] = ct*aty - st*atx;
return out;
},
/**
* Scales the mat2d by the dimensions in the given vec2
* @method scale
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the matrix to rotate
* @param {kick.math.Vec2} v the vec2 to scale the matrix by
* @return {kick.math.Mat2d} out
* @static
**/
scale: function (out, a, v) {
var vx = v[0], vy = v[1];
out[0] = a[0] * vx;
out[1] = a[1] * vy;
out[2] = a[2] * vx;
out[3] = a[3] * vy;
out[4] = a[4] * vx;
out[5] = a[5] * vy;
return out;
},
/**
* Translates the mat2d by the dimensions in the given vec2
*
* @method translate
* @param {kick.math.Mat2d} out the receiving matrix
* @param {kick.math.Mat2d} a the matrix to translate
* @param {kick.math.Vec2} v the vec2 to translate the matrix by
* @return {kick.math.Mat2d} out
* @static
*/
translate: function (out, a, v){
out[0] = a[0];
out[1] = a[1];
out[2] = a[2];
out[3] = a[3];
out[4] = a[4] + v[0];
out[5] = a[5] + v[1];
return out;
},
/**
* Returns a string representation of a Mat2d
* @method str
* @param {kick.math.Mat2d} a matrix to represent as a string
* @return {String} string representation of the matrix
* @static
*/
str: function (a) {
return '[' + a[0] + ', ' + a[1] + ', ' + a[2] + ', ' +
a[3] + ', ' + a[4] + ', ' + a[5] + ']';
},
/**
* Returns a string representation of a Mat2d printed as a 3x3 matrix (on 3 lines)
* @method strPretty
* @param {kick.math.Mat2d} mat mat2d to represent as a string
* @return {String} string representation of mat
* @static
*/
strPretty: function (mat) {
return '[' + mat[0] + ', ' + mat[1] + ', 0\n' +
', ' + mat[2] + ', ' + mat[3] + ', 0\n'+
', ' + mat[4] + ', ' + mat[5] + ', 1]';
}
};
});
