In AVR the labs() function takes a 32-bit signed int parameter. On
the PC it's at least 64-bits and maybe more. When we have a 32-bit
unsigned value we're taking the labs() of, coercing it to 32-bits
first turns our high-bit into a sign, but coercing it to 64-bits
does not. This causes all our negative values to appear to be
really big positive ones.
Create a new function abs32() which always coerces its argument to
a int32_t first before return the abs value. Use that function
whereved needed in dda.c.
This fixes a problem on the simulator which caused negative
direction movements to "never" end.
##############################################################################
# #
# Teacup - lean and efficient firmware for RepRap printers #
# #
# by Triffid Hunter, Traumflug, jakepoz, Markus Hitter, many others #
# #
##############################################################################
For installation instructions, see
http://reprap.org/wiki/Teacup_Firmware#Simple_Installation and/or
http://reprap.org/wiki/Teacup_Firmware#Developer_Installation
For documentation, see
http://reprap.org/wiki/Teacup_Firmware
##############################################################################
# #
# This firmware is Copyright (c) ... #
# 2009 - 2010 Michael Moon aka Triffid_Hunter #
# 2010 - 2013 Markus "Traumflug" Hitter <mah@jump-ing.de> #
# #
# This program is free software; you can redistribute it and/or modify #
# it under the terms of the GNU General Public License as published by #
# the Free Software Foundation; either version 2 of the License, or #
# (at your option) any later version. #
# #
# This program is distributed in the hope that it will be useful, #
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
# GNU General Public License for more details. #
# #
# You should have received a copy of the GNU General Public License #
# along with this program; if not, write to the Free Software #
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA #
# #
##############################################################################