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 <lars.henning.wendt@gris.tu-darmstadt.de>
If _math_matrix_analyse() got called before we allocated the inverse
matrix array we could lose the flag indicating that we needed to compute
the inverse. This could happen with certain vertex shader cases.
1. Remove all.h and PC_HEADER junk.
2. Rolled mem.c and mem.h into imports.c and imports.h
3. Include imports.h instead of mem.h
Restore _mesa_create/initialize_context() to be like they were in 4.0.4
New wrappers for a few std C functions: _mesa_atoi(), _mesa_strstr(), etc.
Moved vertex program hash table into shared context state.
Implemented reference counting for vertex programs.
Replaced tnl "ProjectedClip" with "Ndc" (normalized device coordinates).
math: Provides basic matrix and vector functionality that
might be useful to multiple software t&l
implementations, and is used by core mesa to
manage the Model, Project, etc matrices.
tnl: The real transform & lighting code from core mesa,
including everything from glVertex3f through vertex
buffer handling, transformation, clipping, lighting
and handoff to a driver for rasterization.
The interfaces of these can be further tightened up, but the basic
splitting up of state and code move is done.