(this is provisional)
Links:
to Project page at Sourceforge.net where the you can download the tarball.
to Discussion forum where I post answers to most common questions.
4bpp is a collection of graphical functions intended for speed on 4 bits-per-pixel screen buffers. I use it currently on a uCdimm microcontroller board. The CPU is a Motorola Dragonball VZ (MC68VZ328), and the LCD graphics are mapped directly in memory.
Since light CPU time has been priorized, many functions only use even X coordinates/sizes in order to operate with full bytes.
This should be easy to adapt to any 4bpp display system that can be mapped to memory.
I have not yet tried it on a 4bpp framebuffer, but it should go fine. I would like to implement this in order to emulate the software on workstations.
Source code is commented in Spanish (at the moment), anyway the function names are almost all in english. Here are some files to get started:
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., 675 Mass Ave, Cambridge, MA 02139, USA.