From 50db8129152f3d5ea8db13d55f82673d53bf1b8f Mon Sep 17 00:00:00 2001 From: Brian Paul Date: Tue, 24 Jul 2012 11:11:45 -0600 Subject: [PATCH] mesa: loosen small matrix determinant check 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. Tested-by: Lars Henning Wendt --- src/mesa/math/m_matrix.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/mesa/math/m_matrix.c b/src/mesa/math/m_matrix.c index 02aedbad856..ffbdcdb4c96 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; -- 2.30.2