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Merge pull request #414 from brendanzab/fix-matrix-inversions

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Fix matrix inversions for small determinants
This commit is contained in:
Brendan Zabarauskas 2017-05-13 19:11:57 +10:00 committed by GitHub
commit b87401be28
1 changed files with 15 additions and 6 deletions
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21
src/matrix.rs
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@ -443,11 +443,13 @@ impl<S: BaseFloat> SquareMatrix for Matrix2<S> {
#[inline]
fn invert(&self) -> Option<Matrix2<S>> {
let det = self.determinant();
if ulps_eq!(det, &S::zero()) {
if det == S::zero() {
None
} else {
Some(Matrix2::new( self[1][1] / det, -self[0][1] / det,
-self[1][0] / det, self[0][0] / det))
Some(Matrix2::new(self[1][1] / det,
-self[0][1] / det,
-self[1][0] / det,
self[0][0] / det))
}
}
@ -542,7 +544,9 @@ impl<S: BaseFloat> SquareMatrix for Matrix3<S> {
fn invert(&self) -> Option<Matrix3<S>> {
let det = self.determinant();
if ulps_eq!(det, &S::zero()) { None } else {
if det == S::zero() {
None
} else {
Some(Matrix3::from_cols(self[1].cross(self[2]) / det,
self[2].cross(self[0]) / det,
self[0].cross(self[1]) / det).transpose())
@ -665,7 +669,9 @@ impl<S: BaseFloat> SquareMatrix for Matrix4<S> {
#[cfg(not(feature = "use_simd"))]
fn invert(&self) -> Option<Matrix4<S>> {
let det = self.determinant();
if ulps_eq!(det, &S::zero()) { None } else {
if det == S::zero() {
None
} else {
let inv_det = S::one() / det;
let t = self.transpose();
let cf = |i, j| {
@ -692,7 +698,10 @@ impl<S: BaseFloat> SquareMatrix for Matrix4<S> {
det_sub_proc_unsafe(self, 1, 2, 3)
};
let det = tmp0.dot(Vector4::new(self[0][0], self[1][0], self[2][0], self[3][0]));
if ulps_eq!(det, &S::zero()) { None } else {
if det == S::zero() {
None
} else {
let inv_det = S::one() / det;
let tmp0 = tmp0 * inv_det;
let tmp1 = unsafe {