Rooba
/
ReC98
mirror of https://github.com/nmlgc/ReC98.git
1
1
Fork 0
Code Issues Packages Projects Releases Wiki Activity
ReC98/th01/hardware/vram_planes_set.asm

13 lines
252 B
NASM
Raw Normal View History

[Reverse-engineering] 32-bit VRAM plane pointers I've looked at every openly available piece of PC-98 documentation, and there don't seem to be any official names for the individual planes. The closest thing I could find was the description at http://island.geocities.jp/cklouch/column/pc98bas/pc98disphw2.htm explaining that they represent the blue, red, green, and brightness component when using the default PC-98 palette. However, these planes correspond to nothing else but the 4 individual bits of the final index into the color palette, and you can assign any color to every single palette slot. Therefore, it's merely a convention that your own palettes don't have to follow (and in Touhou, they don't). Nevertheless, there doesn't seem to be an alternative, and the Neko Project II source code uses the same B/R/G/E convention, so I'll go with that as well.
2015-02-10 22:43:34 +00:00
; void vram_planes_set(void)
[C decompilation] [th02] Code segment #2 of all three executables Only one code segment left in both OP and FUUIN! its-happening.gif Yeah, that commit is way larger than I'm comfortable with, but none of these functions is particularly large or difficult to decompile (with the exception of graph_putsa_fx(), which I actually did weeks ago), and OP and MAIN have their own unique functions in between the shared ones, so…
2015-03-14 22:25:50 +00:00
public VRAM_PLANES_SET
[Reverse-engineering] 32-bit VRAM plane pointers I've looked at every openly available piece of PC-98 documentation, and there don't seem to be any official names for the individual planes. The closest thing I could find was the description at http://island.geocities.jp/cklouch/column/pc98bas/pc98disphw2.htm explaining that they represent the blue, red, green, and brightness component when using the default PC-98 palette. However, these planes correspond to nothing else but the 4 individual bits of the final index into the color palette, and you can assign any color to every single palette slot. Therefore, it's merely a convention that your own palettes don't have to follow (and in Touhou, they don't). Nevertheless, there doesn't seem to be an alternative, and the Neko Project II source code uses the same B/R/G/E convention, so I'll go with that as well.
2015-02-10 22:43:34 +00:00
vram_planes_set proc
push bp
mov bp, sp
Make the VRAM plane constants available to C
2015-02-24 15:17:50 +00:00
mov _VRAM_PLANE_B, 0A8000000h
mov _VRAM_PLANE_R, 0B0000000h
mov _VRAM_PLANE_G, 0B8000000h
mov _VRAM_PLANE_E, 0E0000000h
[Reverse-engineering] 32-bit VRAM plane pointers I've looked at every openly available piece of PC-98 documentation, and there don't seem to be any official names for the individual planes. The closest thing I could find was the description at http://island.geocities.jp/cklouch/column/pc98bas/pc98disphw2.htm explaining that they represent the blue, red, green, and brightness component when using the default PC-98 palette. However, these planes correspond to nothing else but the 4 individual bits of the final index into the color palette, and you can assign any color to every single palette slot. Therefore, it's merely a convention that your own palettes don't have to follow (and in Touhou, they don't). Nevertheless, there doesn't seem to be an alternative, and the Neko Project II source code uses the same B/R/G/E convention, so I'll go with that as well.
2015-02-10 22:43:34 +00:00
pop bp
ret
vram_planes_set endp