61 Colors in Tile

[tiberiyltim]

My BEX demo "61 colors in 1 tile - 4 Palettes" for Sega Mega Drive / Genesis - 2 tiles in A/B ScrollPlane and 2 Sprites = visual 61 colors in 1 tile. Music: Viktor Tsoy.

ROM - romhacking.ru/load/0-0-0-289-20

Screenshot: romhacking.ru/_ld/2/93220621.png

[Deleted]

Definitely makes the Genesis look closer to a Super Nintendo. Awesome demo tiberiyltim!

Does anybody know if there are existing graphic tools and BEX code to do this? Seems like we're all re-inventing the wheel.

[Deleted]

My graphic program will support things like this, but keep in mind this would be difficult to pull off in a larger project. You have to really plan out your graphics once you start veering off the standard usage.

[tiberiyltim]

Source code - romhacking.ru/GamesSMD/61demo.7z
It's not awesome. It's normal.

For Sega MD max colors - 1536 on screen. Demo - romhacking.ru/GamesSMD/md1536src.7z

And special VDP mode "Shadow/Highlight" - md.squee.co/VDP#Shadow.2FHighlight

"Toy Story" the best color game in Sega MD / Genesis - youtu.be/Z9rjwECf2wQ

[Deleted]

And all of those are mainly done on single screens - you have to carefully plan to make it a viable solution in your program. I can use 6 palettes at once before using shadow mode, but it comes with restrictions.

[tiberiyltim]

Mar 9, 2017 8:51:21 GMT -5 @elusive said:

I can use 6 palettes

In BEX or ASM? How, if it not secret?

[Deleted]

Here's an example:


hBlank 111
On InterruptHBlank GoSub MyHBlank
Enable InterruptHBlank

On InterruptVBlank GoSub MyVBlank
Enable InterruptVBlank

While 1
Valt ' Sleep cannot be used while hblank is enabled
Wend

MyVBlank:
Palettes MyPal1,0,0,16
Return

MyHBlank:
Palettes MyPal2,0,0,16
Return

MyPal1:
DataInt $0888,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000

MyPal2:
DataInt $0EEE,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000


Restrictions:
- You can't use the palette you replace below the scanline
- You can't use SLEEP commands while the HBLANK is on
- Decreases VBLANK time

You should be able to figure out how to add more palettes from that. Also, this may leave little dots on the screen on the real hardware - I don't think there's any way of avoiding that.

[tiberiyltim]

BEX error. Only SecondBASIC?

[Deleted]

It should work. You probably need to change the enable vblank and hblank keywords to whatever BEX uses (I think it's: interrupt hblank and interrupt vblank, with spaces).

It does work fine in SecondBASIC, though, which if you have no plans for Sega CD or 32x games, I would recommend switching over as I've added some stuff to make things easier.

[Deleted]

Here's an updated example that works in BEX (and SecondBASIC):



hBlank 111
On HBlank GoSub MyHBlank
Enable Interrupt HBlank

On VBlank GoSub MyVBlank
Enable Interrupt VBlank
hb_val = 111
While 1
j = joypad(0)
hb_val+=j.1-j.0
if hb_val = 0 then hb_val++
if hb_val = 224 then hb_val--
hblank hb_val
Valt ' Sleep cannot be used while hblank is enabled
Wend

MyVBlank:
Palettes MyPal1,0,0,16
Return

MyHBlank:
Palettes MyPal2,0,0,16
Return

MyPal1:
DataInt $0888,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000

MyPal2:
DataInt $0EEE,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000


I added in a joypad routine to adjust the hblank interval.

Things to remember:

- where the white color is is where the first palette ends and the replacement palette begins, so you can't use the replaced palette below that scan line (at least on the same palette index)

- Sleep commands (sleep, sleep2) can't be used when the hblank is enabled. You can use Valt, WaitRaster, or Halt

- HBlank time eats into the VBlank time, so your vblank time will be reduced slightly

- HBlank 0 will disable the vblank entirely, and doesn't leave a lot of time for other code execution outside of the vblank and hblank. For example:



a = addsprite(1,1)
propsprite a,1,0
movesprite a,200,200

hBlank 0
On HBlank GoSub MyHBlank
Enable Interrupt HBlank

On VBlank GoSub MyVBlank
Enable Interrupt VBlank
x = 200
y = 200
While 1
j = joypad(0)
x+=j.3-j.2
y+=j.1-j.0
movesprite a,x,y
Wend

MyVBlank:
Palettes MyPal1,0,0,16
Return

MyHBlank:
Palettes MyPal2,0,0,16
Return

MyPal1:
DataInt $0888,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000

MyPal2:
DataInt $0EEE,$0000,$0000,$0000,$0000,$0000,$0000,$0000
DataInt $0000,$0000,$0000,$0000,$0000,$0000,$0000,$0000


Since the hblank is set to 0, it triggers once every scanline. WaitRaster doesn't work at hblank 0 it seems (only a quick test was done), and if you move the sprite, it moves incredibly slow. Change the hblank to 5 or 25, and you'll need to use the Valt command in your program loop to make your sprite move at a normal speed, rather than way too fast.

Some things you can do with hblank effects:
- Stretch/distort background layers (Adventures of Batman & Robin and Rocket Knight Adventures do some excellent background raster tricks, unsure of Batman & Robin uses the horizontal interrupt, but Rocket Knight Adventures uses "hblank 0" when going through the castle where the fire shoots at you and the screen becomes wavy)

- Add more palettes/colors

-

Those are the only 2 things I know that can be done using the hblank, but only one of which I know how to do.

[tiberiyltim]

Cool! You have example 6 pal 64+ colors? For me does not work 6 pal.

[Deleted]

I don't think you'll be able to load 2 palettes during the hblank period, at least I couldn't.

Here's an example of using 6 palettes and shadow mode, getting ~186 colors on screen at once. This won't work in BEX, though, only SecondBASIC. The reason for this is because you can't load palettes from a variable in BEX, as well as the use of the ShadowMode command. This eliminates an If..End If block during the blanking period, and turns on Shadow Mode easily instead of using an ASM code block



Disable Screen

Palettes pal4,1,0,16
Palettes pal5,2,0,16
Palettes pal6,3,0,16


LoadTiles Tiles,20,100
x2 = 0
x3 = 10
For x = 100 To 109
x3 = x2+10
For y = 0 To 3
For y2 = 0 To 63 Step 8
DrawTile x+Priority(0),x2,y+y2
DrawTile x+Priority(1),x2,y+4+y2
Next
Next
x2++
Next
x2 = 0
n = 1
For x = 110 To 119
x3 = x2+10
For y = 0 To 3
If y > 1 Then n++
For y2 = 0 To 63 Step 8
DrawTile x+Priority(0)+Palette(1),x3,y+y2
DrawTile x+Priority(1)+Palette(1),x3,y+4+y2
DrawTile x+Priority(0)+Palette(2),x3+10,y+y2
DrawTile x+Priority(1)+Palette(2),x3+10,y+4+y2
DrawTile x+Priority(0)+Palette(3),x3+20,y+y2
DrawTile x+Priority(1)+Palette(3),x3+20,y+4+y2
Next
Next

x2++
Next
' 93 colors before shadow mode
ShadowMode @On
' 186 colors with shadow mode
Enable Screen

hBlank 75
pal& = LblPtr&(pal2)
On hBlank GoSub effect
On VBlank GoSub main
WaitRaster 0
Enable hBlank
Enable VBlank


End

main:
vcounter++
If vcounter = 100 Then
ShadowMode @Off
ElseIf vcounter = 200 Then
ShadowMode @On
vcounter = 0
End If
Palettes pal1,0,0,16
Scroll Up, 1
Return

effect:
Palettes pal&,0,0,16
pal_counter = pal_counter + 1 And 1
pal& = LblPtr&(pal3)
If pal_counter Then pal& = LblPtr&(pal2)
Return

pal1:
DataInt $0000,$0002,$0004,$0006,$0008,$000A,$000C,$000E
DataInt $020E,$020C,$020A,$0208,$0206,$0204,$0202,$0200
pal2:
DataInt $0E00,$0E02,$0E04,$0E06,$0E08,$0E0A,$0E0C,$0E0E
DataInt $0C2E,$0C2C,$0C0A,$0C08,$0C06,$0C04,$0C02,$0C00
pal3:
DataInt $00E0,$00E2,$00E4,$00E6,$00E8,$00EA,$00EC,$00EE
DataInt $02EE,$02EC,$02EA,$02E8,$02E6,$02E4,$02E2,$02E0

pal4:
DataInt $0EEE,$0EEC,$0EEA,$0EE8,$0EE6,$0EE4,$0EE2,$0EE0
DataInt $0CE0,$0CE2,$0CE4,$0CE6,$0CE8,$0CEA,$0CEC,$0CEE
pal5:
DataInt $0420,$0422,$0424,$0426,$0428,$042A,$042C,$042E
DataInt $064E,$064C,$064A,$0648,$0646,$0644,$0642,$0640
pal6:
DataInt $06E0,$06E2,$06E4,$06E6,$06E8,$06EA,$06EC,$06EE
DataInt $08CE,$08CC,$08CA,$08C8,$08C6,$08C4,$08C2,$08C0


Tiles:
DataFile hblanktiles.bnx, Bin


Here's a screenshot:


Here's the source code + files: www.second-dimension.com/downloads/hblank_example.zip