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 patch loosens
this test to fix a lighting bug reported by Lars Henning Wendt.
v2: use abs(det) to handle negative values
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..ffbdcdb 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 (FABSF(det) < 1e-25)
return GL_FALSE;
det = 1.0F / det;
--
1.7.3.4
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