From 112ae49145da644f0e6a682d5e45be23cfd3d44b Mon Sep 17 00:00:00 2001 From: Ian C Date: Mon, 28 Nov 2016 16:00:48 +0000 Subject: Initial seemingly working version. --- doc/README.txt | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 51 insertions(+) create mode 100755 doc/README.txt (limited to 'doc') diff --git a/doc/README.txt b/doc/README.txt new file mode 100755 index 0000000..0de321f --- /dev/null +++ b/doc/README.txt @@ -0,0 +1,51 @@ + PNG8 + ==== + +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 (Version 3) for more details. + +Usage: +------ + +png8 -- convert a file + + +Options +------- + +General switches: +-h - Help text. + +One of these switches must be provided: +-1 - Produce a monochrome sprite data set (e.g. Spectrum). +-4 - Produce a 4-colour sprite data set (e.g. Commodore 64). + +Optional switches: +-b - Don't treat black the same as a transparent pixel. +-p - Use in place of 'byte' for output. +-s - For monochrome data, produce pre-shifted values. +-w - Set the sprite width to . This must be a multiple of 8. +-d - Don't use double-width pixels in 4 colour mode. +-c0 - Set colour 0 to RGB value RRGGBB, expressed as a hex number. +-c1 - Set colour 1 to RGB value RRGGBB, expressed as a hex number. +-c2 - Set colour 2 to RGB value RRGGBB, expressed as a hex number. +-c3 - Set colour 3 to RGB value RRGGBB, expressed as a hex number. + +Instructions +------------ + +PNG8 processes a sprite image strip and produces output that should be +compatible with most 8-bit assemblers. + +For monochrome images it produces 1-bit per pixel output, where any pixel that +is transparent or black (by default; this can be disabled with the -b switch) +is treated as a clear bit in the generated output. Other pixels are treated as +a set bit. + +For 4-colour images it generates bit patterns "00" for colour 0 (default black), +"01" for colour 1 (default red), "10" for colour 2 (default green) and "11" for +colour 3 (default blue). + +The colours used can be controlled by the switches -c0 to -c3. -- cgit v1.2.3