// augment Sylvester some
Matrix.Translation = function (v)
{
if (v.elements.length == 2) {
var r = Matrix.I(3);
r.elements[2][0] = v.elements[0];
r.elements[2][1] = v.elements[1];
return r;
}
if (v.elements.length == 3) {
var r = Matrix.I(4);
r.elements[0][3] = v.elements[0];
r.elements[1][3] = v.elements[1];
r.elements[2][3] = v.elements[2];
return r;
}
throw "Invalid length for Translation";
}
Matrix.prototype.flatten = function ()
{
var result = [];
if (this.elements.length == 0)
return [];
for (var j = 0; j < this.elements[0].length; j++)
for (var i = 0; i < this.elements.length; i++)
result.push(this.elements[i][j]);
return result;
}
Matrix.prototype.ensure4x4 = function()
{
if (this.elements.length == 4 &&
this.elements[0].length == 4)
return this;
if (this.elements.length > 4 ||
this.elements[0].length > 4)
return null;
for (var i = 0; i < this.elements.length; i++) {
for (var j = this.elements[i].length; j < 4; j++) {
if (i == j)
this.elements[i].push(1);
else
this.elements[i].push(0);
}
}
for (var i = this.elements.length; i < 4; i++) {
if (i == 0)
this.elements.push([1, 0, 0, 0]);
else if (i == 1)
this.elements.push([0, 1, 0, 0]);
else if (i == 2)
this.elements.push([0, 0, 1, 0]);
else if (i == 3)
this.elements.push([0, 0, 0, 1]);
}
return this;
};
Matrix.prototype.make3x3 = function()
{
if (this.elements.length != 4 ||
this.elements[0].length != 4)
return null;
return Matrix.create([[this.elements[0][0], this.elements[0][1], this.elements[0][2]],
[this.elements[1][0], this.elements[1][1], this.elements[1][2]],
[this.elements[2][0], this.elements[2][1], this.elements[2][2]]]);
};
Vector.prototype.flatten = function ()
{
return this.elements;
};
function mht(m) {
var s = "";
if (m.length == 16) {
for (var i = 0; i < 4; i++) {
s += "[" + m[i*4+0].toFixed(4) + "," + m[i*4+1].toFixed(4) + "," + m[i*4+2].toFixed(4) + "," + m[i*4+3].toFixed(4) + "]
";
}
} else if (m.length == 9) {
for (var i = 0; i < 3; i++) {
s += "[" + m[i*3+0].toFixed(4) + "," + m[i*3+1].toFixed(4) + "," + m[i*3+2].toFixed(4) + "]
";
}
} else {
return m.toString();
}
return s;
}
//
// gluLookAt
//
function makeLookAt(ex, ey, ez,
cx, cy, cz,
ux, uy, uz)
{
var eye = $V([ex, ey, ez]);
var center = $V([cx, cy, cz]);
var up = $V([ux, uy, uz]);
var mag;
var z = eye.subtract(center).toUnitVector();
var x = up.cross(z).toUnitVector();
var y = z.cross(x).toUnitVector();
var m = $M([[x.e(1), x.e(2), x.e(3), 0],
[y.e(1), y.e(2), y.e(3), 0],
[z.e(1), z.e(2), z.e(3), 0],
[0, 0, 0, 1]]);
var t = $M([[1, 0, 0, -ex],
[0, 1, 0, -ey],
[0, 0, 1, -ez],
[0, 0, 0, 1]]);
return m.x(t);
}
//
// gluPerspective
//
function makePerspective(fovy, aspect, znear, zfar)
{
var ymax = znear * Math.tan(fovy * Math.PI / 360.0);
var ymin = -ymax;
var xmin = ymin * aspect;
var xmax = ymax * aspect;
return makeFrustum(xmin, xmax, ymin, ymax, znear, zfar);
}
//
// glFrustum
//
function makeFrustum(left, right,
bottom, top,
znear, zfar)
{
var X = 2*znear/(right-left);
var Y = 2*znear/(top-bottom);
var A = (right+left)/(right-left);
var B = (top+bottom)/(top-bottom);
var C = -(zfar+znear)/(zfar-znear);
var D = -2*zfar*znear/(zfar-znear);
return $M([[X, 0, A, 0],
[0, Y, B, 0],
[0, 0, C, D],
[0, 0, -1, 0]]);
}
//
// glOrtho
//
function makeOrtho(left, right, bottom, top, znear, zfar)
{
var tx = - (right + left) / (right - left);
var ty = - (top + bottom) / (top - bottom);
var tz = - (zfar + znear) / (zfar - znear);
return $M([[2 / (right - left), 0, 0, tx],
[0, 2 / (top - bottom), 0, ty],
[0, 0, -2 / (zfar - znear), tz],
[0, 0, 0, 1]]);
}