Making data

A program's pictures, sounds, music and models are files on its disc in the console's own formats. The converters here make each of them from the files a modern editor saves, and every one is tested against what Sony's own tools made of the same input:

A pipeline that remakes itself#

The converters run from go:generate lines in the program's main.go, so that go generate makes the files under assets/ from the sources beside them, and then declares them for the disc with discgen, last, which leaves the sources off the disc: pictures, models, sounds and scores by their extension, and whatever a line reads:

//go:generate mkdir -p assets
//go:generate go run go.chrisrx.dev/psx/tools/png2tim --at 640,0 --clut 0,481 -o assets/SHIP.TIM assets/ship.png
//go:generate go run go.chrisrx.dev/psx/tools/png2tim --at 704,0 --clut 0,483 -o assets/STONE.TIM assets/stone.png
//go:generate go run go.chrisrx.dev/psx/tools/obj2tmd --scale 64 -o assets/CUBE.TMD assets/cube.obj
//go:generate go run go.chrisrx.dev/psx/tools/wav2vag assets/tone.wav assets/blip.wav
//go:generate go run go.chrisrx.dev/psx/tools/mkvab -f assets/sounds.def -o assets/SOUNDS.VAB --split assets/tone.VAG assets/blip.VAG
//go:generate go run go.chrisrx.dev/psx/tools/smf2seq -o assets/TUNE.SEQ assets/tune.mid
//go:generate go run go.chrisrx.dev/psx/tools/discgen assets

The examples commit the generated files under assets/ as well, beside their sources, so that a build needs no generating.

Video memory#

Every image goes to a place in video memory that its TIM records, given to png2tim with --at for the pixels and --clut for the palette, and planning those places is the one part of the work no tool does. Video memory is 1024 by 512 units:

x:   0          320        640                     1023
y:0  +----------+----------+------------------------+
     | display  | free     | textures, in pages     |
     | buffer 0 |          | 64 units wide: 640,    |
240  +----------+          | 704, 768 ...           |
     | display  |          |                        |
     | buffer 1 |          |                        |
480  +----------+----------+------------------------+
     | palettes, a row each, x a multiple of 16      |
511  +-----------------------------------------------+

That is the default Screen, 320 by 240 with its two buffers one above the other. SideBySide puts them both at the top, which frees the rows below for images. A texture lies inside one texture page, 64 units wide and 256 lines tall, which is 256 pixels of a 4-bit image, 128 of an 8-bit one and 64 of a 16-bit one, and several small images can share a page. Screen.Font puts the font at the corner it is given, with its palette 128 lines below. Two images must not overlap, and png2tim and tim2png print where each one goes.

A model's TMD names its textures by where they are, so the TIM a model's material names is converted first, and the program loads that same TIM before it draws the model.

Sound memory#

A bank's samples go to the SPU's 512 KB. A second of sound at 22050 Hz is about 12.6 KB of samples, and a bank's definition says which sample each program plays at which notes. The boot disc's General MIDI bank, STD0, plays any General MIDI score but takes about 450 KB, so a game with sound effects of its own makes a bank of the instruments its music uses as well, with the programs numbered as the MIDI file numbers them. mkvab gives a definition to start from, and mkvab -r prints the definition of any bank, a 1998 game's included.

Older data#

tim2png turns any TIM into a PNG, mkvab -r reads any bank and rsdlink links any of Sony's RSD models, so the art and sound of the Net Yaroze samples, and of games whose files are on their discs, can be looked at, changed and put back.