nalgebra/src/mat_spec.rs

147 lines
3.6 KiB
Rust

use std::num::{Zero, One};
use vec::Vec3;
use mat::{Mat1, Mat2, Mat3};
use traits::inv::Inv;
use traits::row::Row;
// some specializations:
impl<N: Num + Clone>
Inv for Mat1<N> {
#[inline]
fn inverse(&self) -> Option<Mat1<N>> {
let mut res : Mat1<N> = self.clone();
if res.inplace_inverse() {
Some(res)
}
else {
None
}
}
#[inline]
fn inplace_inverse(&mut self) -> bool {
if self.m11.is_zero() {
false
}
else {
let _1: N = One::one();
self.m11 = _1 / self.m11;
true
}
}
}
impl<N: Num + Clone>
Inv for Mat2<N> {
#[inline]
fn inverse(&self) -> Option<Mat2<N>> {
let mut res : Mat2<N> = self.clone();
if res.inplace_inverse() {
Some(res)
}
else {
None
}
}
#[inline]
fn inplace_inverse(&mut self) -> bool {
let det = self.m11 * self.m22 - self.m21 * self.m12;
if det.is_zero() {
false
}
else {
*self = Mat2::new(
self.m22 / det , -self.m12 / det,
-self.m21 / det, self.m11 / det);
true
}
}
}
impl<N: Num + Clone>
Inv for Mat3<N> {
#[inline]
fn inverse(&self) -> Option<Mat3<N>> {
let mut res = self.clone();
if res.inplace_inverse() {
Some(res)
}
else {
None
}
}
#[inline]
fn inplace_inverse(&mut self) -> bool {
let minor_m12_m23 = self.m22 * self.m33 - self.m32 * self.m23;
let minor_m11_m23 = self.m21 * self.m33 - self.m31 * self.m23;
let minor_m11_m22 = self.m21 * self.m32 - self.m31 * self.m22;
let det = self.m11 * minor_m12_m23
- self.m12 * minor_m11_m23
+ self.m13 * minor_m11_m22;
if det.is_zero() {
false
}
else {
*self = Mat3::new(
(minor_m12_m23 / det),
((self.m13 * self.m32 - self.m33 * self.m12) / det),
((self.m12 * self.m23 - self.m22 * self.m13) / det),
(-minor_m11_m23 / det),
((self.m11 * self.m33 - self.m31 * self.m13) / det),
((self.m13 * self.m21 - self.m23 * self.m11) / det),
(minor_m11_m22 / det),
((self.m12 * self.m31 - self.m32 * self.m11) / det),
((self.m11 * self.m22 - self.m21 * self.m12) / det)
);
true
}
}
}
impl<N: Clone> Row<Vec3<N>> for Mat3<N> {
#[inline]
fn row(&self, i: uint) -> Vec3<N> {
match i {
0 => Vec3::new(self.m11.clone(), self.m12.clone(), self.m13.clone()),
1 => Vec3::new(self.m21.clone(), self.m22.clone(), self.m23.clone()),
2 => Vec3::new(self.m31.clone(), self.m32.clone(), self.m33.clone()),
_ => fail!("Index out of range: 3d matrices do not have " + i.to_str() + " rows.")
}
}
#[inline]
fn set_row(&mut self, i: uint, r: Vec3<N>) {
match i {
0 => {
self.m11 = r.x.clone();
self.m12 = r.y.clone();
self.m13 = r.z;
},
1 => {
self.m21 = r.x.clone();
self.m22 = r.y.clone();
self.m23 = r.z;
},
2 => {
self.m31 = r.x.clone();
self.m32 = r.y.clone();
self.m33 = r.z;
},
_ => fail!("Index out of range: 3d matrices do not have " + i.to_str() + " rows.")
}
}
}