This patch "upgrades" the EGA DOS port of Planet of Lust to VGA.
Compare EGA vs VGA (yes, that is a real screenshot):
- Install dependencies: nasm, netpbm (a recent version, not the older debian one!), xdftool (from amitools), python3
- Populate the
inputsdirectory with files that matchMD5SUM. You might find these on sites like archive.org or myabandonware. - Run
make.sh(or alternatively,scripts/docker-build.sh)
The original DOS port of Planet of Lust created RLE-encoded EGA images using the default EGA palette. This was not ideal for representing the... ahem... skin tones that were common in the game. In some cases the screens look fine, but others look very far from ideal.
The Amiga version of the game contains full-color images, conveniently in 320x200 (which is the exact same resolution as VGA's linear mode 13h). The palette for each image (plus the standard 16-color EGA palette) are combined into a new VGA palette. The code for drawing images is replaced with a PCX decoder, but we also add code for things like palette initialization.
For some unknown reason, the game hard-codes the expected sizes for each of the images it loads. We have to patch all those out with our larger images. In addition, some of the new images would overflow the available buffer size so that needs to be patched as well.
The patch attempts to reproduce what a VGA port would have looked like. Because the VGA decoding is actually faster than EGA decoding, the patch adds a short sleep after the title screen pops up so the screen is visible.
This has currently been tested on DOSBox, but not real hardware. We're not doing anything too crazy with VGA, so it's likely to work.
Don't expect pretty code. This code is good enough to get things patched, but that's it. It's a hack after all!
The "backup buffer" the game allocates should be larger than any file we might have to load from disk, but at this time we haven't increased its size. This might result in random memory overwrites, especially on systems with lower amounts of RAM.
Use the PCX encoder from the Sex Vixens from Space project.