/*
* Copyright (C) 2009 Apple Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/* modified by wakufactory */
/*
CanvasMatrix4 class
This class implements a 4x4 matrix. It has functions which
duplicate the functionality of the OpenGL matrix stack and
glut functions.
IDL:
[
Constructor(in CanvasMatrix4 matrix), // copy passed matrix into new CanvasMatrix4
Constructor(in sequence<float> array) // create new CanvasMatrix4 with 16 floats (row major)
Constructor() // create new CanvasMatrix4 with identity matrix
]
interface CanvasMatrix4 {
attribute float buf[16]
void load(in CanvasMatrix4 matrix); // copy the values from the passed matrix
void load(in sequence<float> array); // copy 16 floats into the matrix
sequence<float> getAsArray(); // return the matrix as an array of 16 floats
WebGLFloatArray getAsWebGLFloatArray(); // return the matrix as a WebGLFloatArray with 16 values
void makeIdentity(); // replace the matrix with identity
void transpose(); // replace the matrix with its transpose
void invert(); // replace the matrix with its inverse
void translate(in float x, in float y, in float z); // multiply the matrix by passed translation values on the right
void scale(in float x, in float y, in float z); // multiply the matrix by passed scale values on the right
void rotate(in float angle, // multiply the matrix by passed rotation values on the right
in float x, in float y, in float z); // (angle is in degrees)
void multRight(in CanvasMatrix matrix); // multiply the matrix by the passed matrix on the right
void multLeft(in CanvasMatrix matrix); // multiply the matrix by the passed matrix on the left
void ortho(in float left, in float right, // multiply the matrix by the passed ortho values on the right
in float bottom, in float top,
in float near, in float far);
void frustum(in float left, in float right, // multiply the matrix by the passed frustum values on the right
in float bottom, in float top,
in float near, in float far);
void perspective(in float fovy, in float aspect, // multiply the matrix by the passed perspective values on the right
in float zNear, in float zFar);
void lookat(in float eyex, in float eyey, in float eyez, // multiply the matrix by the passed lookat
in float ctrx, in float ctry, in float ctrz, // values on the right
in float upx, in float upy, in float upz);
}
*/
CanvasMatrix4 = function(m)
{
this.buf = new Float32Array(16)
this.matrix = null
if (typeof m == 'object') {
if ("length" in m && m.length >= 16) {
this.load(m);
return this;
}
else if (m instanceof CanvasMatrix4) {
this.load(m);
return this;
}
}
this.makeIdentity();
return this ;
}
CanvasMatrix4.prototype.load = function()
{
if (arguments.length == 1 && typeof arguments[0] == 'object') {
var matrix = arguments[0];
if ("length" in matrix && matrix.length == 16) {
this.buf[0] = matrix[0];
this.buf[1] = matrix[1];
this.buf[2] = matrix[2];
this.buf[3] = matrix[3];
this.buf[4] = matrix[4];
this.buf[5] = matrix[5];
this.buf[6] = matrix[6];
this.buf[7] = matrix[7];
this.buf[8] = matrix[8];
this.buf[9] = matrix[9];
this.buf[10] = matrix[10];
this.buf[11] = matrix[11];
this.buf[12] = matrix[12];
this.buf[13] = matrix[13];
this.buf[14] = matrix[14];
this.buf[15] = matrix[15];
return this ;
}
if (arguments[0] instanceof CanvasMatrix4) {
this.buf[0] = matrix.buf[0];
this.buf[1] = matrix.buf[1];
this.buf[2] = matrix.buf[2];
this.buf[3] = matrix.buf[3];
this.buf[4] = matrix.buf[4];
this.buf[5] = matrix.buf[5];
this.buf[6] = matrix.buf[6];
this.buf[7] = matrix.buf[7];
this.buf[8] = matrix.buf[8];
this.buf[9] = matrix.buf[9];
this.buf[10] = matrix.buf[10];
this.buf[11] = matrix.buf[11];
this.buf[12] = matrix.buf[12];
this.buf[13] = matrix.buf[13];
this.buf[14] = matrix.buf[14];
this.buf[15] = matrix.buf[15];
return this ;
}
}
this.makeIdentity();
return this ;
}
CanvasMatrix4.prototype.getAsArray = function()
{
return [
this.buf[0], this.buf[1], this.buf[2], this.buf[3],
this.buf[4], this.buf[5], this.buf[6], this.buf[7],
this.buf[8], this.buf[9], this.buf[10], this.buf[11],
this.buf[12], this.buf[13], this.buf[14], this.buf[15]
];
}
CanvasMatrix4.prototype.getAsWebGLFloatArray = function()
{
return this.buf
}
CanvasMatrix4.prototype.initmatrix = function() {
if(!this.matrix) this.matrix = new CanvasMatrix4
this.matrix.makeIdentity()
return this ;
}
CanvasMatrix4.prototype.makeIdentity = function()
{
this.buf[0] = 1;
this.buf[1] = 0;
this.buf[2] = 0;
this.buf[3] = 0;
this.buf[4] = 0;
this.buf[5] = 1;
this.buf[6] = 0;
this.buf[7] = 0;
this.buf[8] = 0;
this.buf[9] = 0;
this.buf[10] = 1;
this.buf[11] = 0;
this.buf[12] = 0;
this.buf[13] = 0;
this.buf[14] = 0;
this.buf[15] = 1;
return this ;
}
CanvasMatrix4.prototype.transpose = function()
{
var tmp = this.buf[1];
this.buf[1] = this.buf[4];
this.buf[4] = tmp;
tmp = this.buf[2];
this.buf[2] = this.buf[8];
this.buf[8] = tmp;
tmp = this.buf[3];
this.buf[3] = this.buf[12];
this.buf[12] = tmp;
tmp = this.buf[6];
this.buf[6] = this.buf[9];
this.buf[9] = tmp;
tmp = this.buf[7];
this.buf[7] = this.buf[13];
this.buf[13] = tmp;
tmp = this.buf[11];
this.buf[11] = this.buf[14];
this.buf[14] = tmp;
return this ;
}
CanvasMatrix4.prototype.invert = function()
{
// Calculate the 4x4 determinant
// If the determinant is zero,
// then the inverse matrix is not unique.
var det = this._determinant4x4();
if (Math.abs(det) < 1e-8)
return null;
this._makeAdjoint();
// Scale the adjoint matrix to get the inverse
this.buf[0] /= det;
this.buf[1] /= det;
this.buf[2] /= det;
this.buf[3] /= det;
this.buf[4] /= det;
this.buf[5] /= det;
this.buf[6] /= det;
this.buf[7] /= det;
this.buf[8] /= det;
this.buf[9] /= det;
this.buf[10] /= det;
this.buf[11] /= det;
this.buf[12] /= det;
this.buf[13] /= det;
this.buf[14] /= det;
this.buf[15] /= det;
return this ;
}
CanvasMatrix4.prototype.translate = function(x,y,z)
{
if (x == undefined)
x = 0;
if (y == undefined)
y = 0;
if (z == undefined)
z = 0;
// this.initmatrix()
// this.matrix.buf[12] = x;
// this.matrix.buf[13] = y;
// this.matrix.buf[14] = z;
// this.multRight(this.matrix);
this.buf[12] += x;
this.buf[13] += y;
this.buf[14] += z;
return this ;
}
CanvasMatrix4.prototype.scale = function(x,y,z)
{
if (x == undefined)
x = 1;
if (z == undefined) {
if (y == undefined) {
y = x;
z = x;
}
else
z = 1;
}
else if (y == undefined)
y = x;
this.initmatrix()
this.matrix.buf[0] = x;
this.matrix.buf[5] = y;
this.matrix.buf[10] = z;
this.multRight(this.matrix);
return this ;
}
CanvasMatrix4.prototype.rotate = function(angle,x,y,z)
{
if(angle==0) return this
// angles are in degrees. Switch to radians
angle = angle / 180 * Math.PI;
angle /= 2;
var sinA = Math.sin(angle);
var cosA = Math.cos(angle);
var sinA2 = sinA * sinA;
// normalize
var length = Math.sqrt(x * x + y * y + z * z);
if (length == 0) {
// bad vector, just use something reasonable
x = 0;
y = 0;
z = 1;
} else if (length != 1) {
x /= length;
y /= length;
z /= length;
}
this.initmatrix()
// optimize case where axis is along major axis
if (x == 1 && y == 0 && z == 0) {
this.matrix.buf[5] = 1 - 2 * sinA2;
this.matrix.buf[6] = 2 * sinA * cosA;
this.matrix.buf[9] = -2 * sinA * cosA;
this.matrix.buf[10] = 1 - 2 * sinA2;
} else if (x == 0 && y == 1 && z == 0) {
this.matrix.buf[0] = 1 - 2 * sinA2;
this.matrix.buf[2] = -2 * sinA * cosA;
this.matrix.buf[8] = 2 * sinA * cosA;
this.matrix.buf[10] = 1 - 2 * sinA2;
} else if (x == 0 && y == 0 && z == 1) {
this.matrix.buf[0] = 1 - 2 * sinA2;
this.matrix.buf[1] = 2 * sinA * cosA;
this.matrix.buf[4] = -2 * sinA * cosA;
this.matrix.buf[5] = 1 - 2 * sinA2;
} else {
var x2 = x*x;
var y2 = y*y;
var z2 = z*z;
this.matrix.buf[0] = 1 - 2 * (y2 + z2) * sinA2;
this.matrix.buf[1] = 2 * (x * y * sinA2 + z * sinA * cosA);
this.matrix.buf[2] = 2 * (x * z * sinA2 - y * sinA * cosA);
this.matrix.buf[4] = 2 * (y * x * sinA2 - z * sinA * cosA);
this.matrix.buf[5] = 1 - 2 * (z2 + x2) * sinA2;
this.matrix.buf[6] = 2 * (y * z * sinA2 + x * sinA * cosA);
this.matrix.buf[8] = 2 * (z * x * sinA2 + y * sinA * cosA);
this.matrix.buf[9] = 2 * (z * y * sinA2 - x * sinA * cosA);
this.matrix.buf[10] = 1 - 2 * (x2 + y2) * sinA2;
}
this.multRight(this.matrix);
return this ;
}
CanvasMatrix4.prototype.multRight = function(matrix)
{
var m11 = (this.buf[0] * matrix.buf[0] + this.buf[1] * matrix.buf[4]
+ this.buf[2] * matrix.buf[8] + this.buf[3] * matrix.buf[12]);
var m12 = (this.buf[0] * matrix.buf[1] + this.buf[1] * matrix.buf[5]
+ this.buf[2] * matrix.buf[9] + this.buf[3] * matrix.buf[13]);
var m13 = (this.buf[0] * matrix.buf[2] + this.buf[1] * matrix.buf[6]
+ this.buf[2] * matrix.buf[10] + this.buf[3] * matrix.buf[14]);
var m14 = (this.buf[0] * matrix.buf[3] + this.buf[1] * matrix.buf[7]
+ this.buf[2] * matrix.buf[11] + this.buf[3] * matrix.buf[15]);
var m21 = (this.buf[4] * matrix.buf[0] + this.buf[5] * matrix.buf[4]
+ this.buf[6] * matrix.buf[8] + this.buf[7] * matrix.buf[12]);
var m22 = (this.buf[4] * matrix.buf[1] + this.buf[5] * matrix.buf[5]
+ this.buf[6] * matrix.buf[9] + this.buf[7] * matrix.buf[13]);
var m23 = (this.buf[4] * matrix.buf[2] + this.buf[5] * matrix.buf[6]
+ this.buf[6] * matrix.buf[10] + this.buf[7] * matrix.buf[14]);
var m24 = (this.buf[4] * matrix.buf[3] + this.buf[5] * matrix.buf[7]
+ this.buf[6] * matrix.buf[11] + this.buf[7] * matrix.buf[15]);
var m31 = (this.buf[8] * matrix.buf[0] + this.buf[9] * matrix.buf[4]
+ this.buf[10] * matrix.buf[8] + this.buf[11] * matrix.buf[12]);
var m32 = (this.buf[8] * matrix.buf[1] + this.buf[9] * matrix.buf[5]
+ this.buf[10] * matrix.buf[9] + this.buf[11] * matrix.buf[13]);
var m33 = (this.buf[8] * matrix.buf[2] + this.buf[9] * matrix.buf[6]
+ this.buf[10] * matrix.buf[10] + this.buf[11] * matrix.buf[14]);
var m34 = (this.buf[8] * matrix.buf[3] + this.buf[9] * matrix.buf[7]
+ this.buf[10] * matrix.buf[11] + this.buf[11] * matrix.buf[15]);
var m41 = (this.buf[12] * matrix.buf[0] + this.buf[13] * matrix.buf[4]
+ this.buf[14] * matrix.buf[8] + this.buf[15] * matrix.buf[12]);
var m42 = (this.buf[12] * matrix.buf[1] + this.buf[13] * matrix.buf[5]
+ this.buf[14] * matrix.buf[9] + this.buf[15] * matrix.buf[13]);
var m43 = (this.buf[12] * matrix.buf[2] + this.buf[13] * matrix.buf[6]
+ this.buf[14] * matrix.buf[10] + this.buf[15] * matrix.buf[14]);
var m44 = (this.buf[12] * matrix.buf[3] + this.buf[13] * matrix.buf[7]
+ this.buf[14] * matrix.buf[11] + this.buf[15] * matrix.buf[15]);
this.buf[0] = m11;
this.buf[1] = m12;
this.buf[2] = m13;
this.buf[3] = m14;
this.buf[4] = m21;
this.buf[5] = m22;
this.buf[6] = m23;
this.buf[7] = m24;
this.buf[8] = m31;
this.buf[9] = m32;
this.buf[10] = m33;
this.buf[11] = m34;
this.buf[12] = m41;
this.buf[13] = m42;
this.buf[14] = m43;
this.buf[15] = m44;
return this ;
}
CanvasMatrix4.prototype.multLeft = function(matrix)
{
var m11 = (matrix.buf[0] * this.buf[0] + matrix.buf[1] * this.buf[4]
+ matrix.buf[2] * this.buf[8] + matrix.buf[3] * this.buf[12]);
var m12 = (matrix.buf[0] * this.buf[1] + matrix.buf[1] * this.buf[5]
+ matrix.buf[2] * this.buf[9] + matrix.buf[3] * this.buf[13]);
var m13 = (matrix.buf[0] * this.buf[2] + matrix.buf[1] * this.buf[6]
+ matrix.buf[2] * this.buf[10] + matrix.buf[3] * this.buf[14]);
var m14 = (matrix.buf[0] * this.buf[3] + matrix.buf[1] * this.buf[7]
+ matrix.buf[2] * this.buf[11] + matrix.buf[3] * this.buf[15]);
var m21 = (matrix.buf[4] * this.buf[0] + matrix.buf[5] * this.buf[4]
+ matrix.buf[6] * this.buf[8] + matrix.buf[7] * this.buf[12]);
var m22 = (matrix.buf[4] * this.buf[1] + matrix.buf[5] * this.buf[5]
+ matrix.buf[6] * this.buf[9] + matrix.buf[7] * this.buf[13]);
var m23 = (matrix.buf[4] * this.buf[2] + matrix.buf[5] * this.buf[6]
+ matrix.buf[6] * this.buf[10] + matrix.buf[7] * this.buf[14]);
var m24 = (matrix.buf[4] * this.buf[3] + matrix.buf[5] * this.buf[7]
+ matrix.buf[6] * this.buf[11] + matrix.buf[7] * this.buf[15]);
var m31 = (matrix.buf[8] * this.buf[0] + matrix.buf[9] * this.buf[4]
+ matrix.buf[10] * this.buf[8] + matrix.buf[11] * this.buf[12]);
var m32 = (matrix.buf[8] * this.buf[1] + matrix.buf[9] * this.buf[5]
+ matrix.buf[10] * this.buf[9] + matrix.buf[11] * this.buf[13]);
var m33 = (matrix.buf[8] * this.buf[2] + matrix.buf[9] * this.buf[6]
+ matrix.buf[10] * this.buf[10] + matrix.buf[11] * this.buf[14]);
var m34 = (matrix.buf[8] * this.buf[3] + matrix.buf[9] * this.buf[7]
+ matrix.buf[10] * this.buf[11] + matrix.buf[11] * this.buf[15]);
var m41 = (matrix.buf[12] * this.buf[0] + matrix.buf[13] * this.buf[4]
+ matrix.buf[14] * this.buf[8] + matrix.buf[15] * this.buf[12]);
var m42 = (matrix.buf[12] * this.buf[1] + matrix.buf[13] * this.buf[5]
+ matrix.buf[14] * this.buf[9] + matrix.buf[15] * this.buf[13]);
var m43 = (matrix.buf[12] * this.buf[2] + matrix.buf[13] * this.buf[6]
+ matrix.buf[14] * this.buf[10] + matrix.buf[15] * this.buf[14]);
var m44 = (matrix.buf[12] * this.buf[3] + matrix.buf[13] * this.buf[7]
+ matrix.buf[14] * this.buf[11] + matrix.buf[15] * this.buf[15]);
this.buf[0] = m11;
this.buf[1] = m12;
this.buf[2] = m13;
this.buf[3] = m14;
this.buf[4] = m21;
this.buf[5] = m22;
this.buf[6] = m23;
this.buf[7] = m24;
this.buf[8] = m31;
this.buf[9] = m32;
this.buf[10] = m33;
this.buf[11] = m34;
this.buf[12] = m41;
this.buf[13] = m42;
this.buf[14] = m43;
this.buf[15] = m44;
return this ;
}
CanvasMatrix4.prototype.ortho = function(left, right, bottom, top, near, far)
{
var tx = (left + right) / (right - left);
var ty = (top + bottom) / (top - bottom);
var tz = (far + near) / (far - near);
this.initmatrix()
this.matrix.buf[0] = 2 / (right - left);
this.matrix.buf[5] = 2 / (top - bottom);
this.matrix.buf[10] = -2 / (far - near);
this.matrix.buf[12] = tx;
this.matrix.buf[13] = ty;
this.matrix.buf[14] = -tz;
this.multRight(this.matrix);
return this ;
}
CanvasMatrix4.prototype.frustum = function(left, right, bottom, top, near, far)
{
this.initmatrix()
var A = (right + left) / (right - left);
var B = (top + bottom) / (top - bottom);
var C = -(far + near) / (far - near);
var D = -(2 * far * near) / (far - near);
this.matrix.buf[0] = (2 * near) / (right - left);
this.matrix.buf[5] = 2 * near / (top - bottom);
this.matrix.buf[8] = A;
this.matrix.buf[9] = B;
this.matrix.buf[10] = C;
this.matrix.buf[11] = -1;
this.matrix.buf[14] = D;
this.matrix.buf[15] = 0;
this.multRight(this.matrix);
return this ;
}
CanvasMatrix4.prototype.perspective = function(fovy, aspect, zNear, zFar)
{
var top = Math.tan(fovy * Math.PI / 360) * zNear;
var bottom = -top;
var left = aspect * bottom;
var right = aspect * top;
this.frustum(left, right, bottom, top, zNear, zFar);
return this ;
}
CanvasMatrix4.prototype.pallarel = function(width, aspect, zNear, zFar)
{
var right = width/2;
var left = -right;
var top = right / aspect ;
var bottom = -top ;
this.ortho(left, right, bottom, top, zNear, zFar);
return this ;
}
CanvasMatrix4.prototype.lookat = function(eyex, eyey, eyez, centerx, centery, centerz, upx, upy, upz)
{
this.initmatrix()
// Make rotation matrix
// Z vector
var zx = eyex - centerx;
var zy = eyey - centery;
var zz = eyez - centerz;
var mag = Math.sqrt(zx * zx + zy * zy + zz * zz);
if (mag) {
zx /= mag;
zy /= mag;
zz /= mag;
}
// X vector = Y cross Z
xx = upy * zz - upz * zy;
xy = -upx * zz + upz * zx;
xz = upx * zy - upy * zx;
// Recompute Y = Z cross X
yx = zy * xz - zz * xy;
yy = -zx * xz + zz * xx;
yz = zx * xy - zy * xx;
// cross product gives area of parallelogram, which is < 1.0 for
// non-perpendicular unit-length vectors; so normalize x, y here
mag = Math.sqrt(xx * xx + xy * xy + xz * xz);
if (mag) {
xx /= mag;
xy /= mag;
xz /= mag;
}
mag = Math.sqrt(yx * yx + yy * yy + yz * yz);
if (mag) {
yx /= mag;
yy /= mag;
yz /= mag;
}
this.matrix.buf[0] = xx;
this.matrix.buf[1] = yx;
this.matrix.buf[2] = zx;
this.matrix.buf[4] = xy;
this.matrix.buf[5] = yy;
this.matrix.buf[6] = zy;
this.matrix.buf[8] = xz;
this.matrix.buf[9] = yz;
this.matrix.buf[10] = zz;
this.matrix.buf[12] = -(xx * eyex + xy * eyey + xz * eyez);
this.matrix.buf[13] = -(yx * eyex + yy * eyey + yz * eyez);
this.matrix.buf[14] = -(zx * eyex + zy * eyey + zz * eyez);
// matrix.translate(-eyex, -eyey, -eyez);
this.multRight(this.matrix);
return this ;
}
// Support functions
CanvasMatrix4.prototype._determinant2x2 = function(a, b, c, d)
{
return a * d - b * c;
}
CanvasMatrix4.prototype._determinant3x3 = function(a1, a2, a3, b1, b2, b3, c1, c2, c3)
{
return a1 * this._determinant2x2(b2, b3, c2, c3)
- b1 * this._determinant2x2(a2, a3, c2, c3)
+ c1 * this._determinant2x2(a2, a3, b2, b3);
}
CanvasMatrix4.prototype._determinant4x4 = function()
{
var a1 = this.buf[0];
var b1 = this.buf[1];
var c1 = this.buf[2];
var d1 = this.buf[3];
var a2 = this.buf[4];
var b2 = this.buf[5];
var c2 = this.buf[6];
var d2 = this.buf[7];
var a3 = this.buf[8];
var b3 = this.buf[9];
var c3 = this.buf[10];
var d3 = this.buf[11];
var a4 = this.buf[12];
var b4 = this.buf[13];
var c4 = this.buf[14];
var d4 = this.buf[15];
return a1 * this._determinant3x3(b2, b3, b4, c2, c3, c4, d2, d3, d4)
- b1 * this._determinant3x3(a2, a3, a4, c2, c3, c4, d2, d3, d4)
+ c1 * this._determinant3x3(a2, a3, a4, b2, b3, b4, d2, d3, d4)
- d1 * this._determinant3x3(a2, a3, a4, b2, b3, b4, c2, c3, c4);
}
CanvasMatrix4.prototype._makeAdjoint = function()
{
var a1 = this.buf[0];
var b1 = this.buf[1];
var c1 = this.buf[2];
var d1 = this.buf[3];
var a2 = this.buf[4];
var b2 = this.buf[5];
var c2 = this.buf[6];
var d2 = this.buf[7];
var a3 = this.buf[8];
var b3 = this.buf[9];
var c3 = this.buf[10];
var d3 = this.buf[11];
var a4 = this.buf[12];
var b4 = this.buf[13];
var c4 = this.buf[14];
var d4 = this.buf[15];
// Row column labeling reversed since we transpose rows & columns
this.buf[0] = this._determinant3x3(b2, b3, b4, c2, c3, c4, d2, d3, d4);
this.buf[4] = - this._determinant3x3(a2, a3, a4, c2, c3, c4, d2, d3, d4);
this.buf[8] = this._determinant3x3(a2, a3, a4, b2, b3, b4, d2, d3, d4);
this.buf[12] = - this._determinant3x3(a2, a3, a4, b2, b3, b4, c2, c3, c4);
this.buf[1] = - this._determinant3x3(b1, b3, b4, c1, c3, c4, d1, d3, d4);
this.buf[5] = this._determinant3x3(a1, a3, a4, c1, c3, c4, d1, d3, d4);
this.buf[9] = - this._determinant3x3(a1, a3, a4, b1, b3, b4, d1, d3, d4);
this.buf[13] = this._determinant3x3(a1, a3, a4, b1, b3, b4, c1, c3, c4);
this.buf[2] = this._determinant3x3(b1, b2, b4, c1, c2, c4, d1, d2, d4);
this.buf[6] = - this._determinant3x3(a1, a2, a4, c1, c2, c4, d1, d2, d4);
this.buf[10] = this._determinant3x3(a1, a2, a4, b1, b2, b4, d1, d2, d4);
this.buf[14] = - this._determinant3x3(a1, a2, a4, b1, b2, b4, c1, c2, c4);
this.buf[3] = - this._determinant3x3(b1, b2, b3, c1, c2, c3, d1, d2, d3);
this.buf[7] = this._determinant3x3(a1, a2, a3, c1, c2, c3, d1, d2, d3);
this.buf[11] = - this._determinant3x3(a1, a2, a3, b1, b2, b3, d1, d2, d3);
this.buf[15] = this._determinant3x3(a1, a2, a3, b1, b2, b3, c1, c2, c3);
}
CanvasMatrix4.prototype.multVec4 = function(x,y,z,w) {
var xx = this.buf[0]*x + this.buf[4]*y + this.buf[8]*z + this.buf[12]*w ;
var yy = this.buf[1]*x + this.buf[5]*y + this.buf[9]*z + this.buf[13]*w ;
var zz = this.buf[2]*x + this.buf[6]*y + this.buf[10]*z + this.buf[14]*w ;
var ww = this.buf[3]*x + this.buf[7]*y + this.buf[11]*z + this.buf[15]*w ;
return [xx,yy,zz,ww] ;
}