On Mon, Jul 30, 2012 at 7:39 AM, Patrick Baggett <baggett.patr...@gmail.com> wrote: > > > On Mon, Jul 30, 2012 at 4:31 AM, Pekka Paalanen <ppaala...@gmail.com> wrote: >> >> On Tue, 24 Jul 2012 11:31:59 -0600 >> Brian Paul <bri...@vmware.com> wrote: >> >> > When computing a matrix inverse, if the determinant is too small we >> > could hit >> > a divide by zero. There's a check to prevent this (we basically give up >> > on >> > computing the inverse and return the identity matrix.) This patches >> > loosens >> > this test to fix a lighting bug reported by Lars Henning Wendt. >> > >> > NOTE: This is a candidate for the 8.0 branch. >> > --- >> > src/mesa/math/m_matrix.c | 2 +- >> > 1 files changed, 1 insertions(+), 1 deletions(-) >> > >> > diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c >> > index 02aedba..ef377ee 100644 >> > --- a/src/mesa/math/m_matrix.c >> > +++ b/src/mesa/math/m_matrix.c >> > @@ -513,7 +513,7 @@ static GLboolean invert_matrix_3d_general( GLmatrix >> > *mat ) >> > >> > det = pos + neg; >> > >> > - if (det*det < 1e-25) >> > + if (det < 1e-25) >> > return GL_FALSE; >> > >> > det = 1.0F / det; >> >> Hi, >> >> just a fly-by question; doesn't that break if determinant is negative? >> I.e. reflection transformations. >> > Yeah, I think you need a fabsf() there.
v2 of the patch used abs() and was pushed a while ago. -Brian _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
