gbadev.org forum archive

This is a read-only mirror of the content originally found on forum.gbadev.org (now offline), salvaged from Wayback machine copies. A new forum can be found here.

DS development > scrolling a large bitmap?

#88010 - spinal_cord - Fri Jun 16, 2006 11:45 pm

can anyone do me a small example of scrolling a large bitmap (I assume mode 5?) im looking to scroll a large image (approx 1024x192) on a game and need it to be bitmapped rather than tiled, so i can remove bits. but i have little to no knowlage of nds.
_________________
I'm not a boring person, it's just that boring things keep happening to me.
Homepage

#88024 - silent_code - Sat Jun 17, 2006 1:46 am

hi!
what do you mean by removing bits?

#88045 - tepples - Sat Jun 17, 2006 6:34 am

For a clone of Lemmings or Worms, the playfield needs to be deformable, such that parts of the bitmap can be overwritten in real time. The Super NES and Mega Drive/Genesis ports of those games actually used a tile mode, but they edited the tiles within VRAM.
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.

#88061 - spinal_cord - Sat Jun 17, 2006 9:52 am

Using tiled mode, wouldn't I need to have LOTS of unique tiles? plus II wouldnt have a clue how to go about doing something like that in lited mode.
_________________
I'm not a boring person, it's just that boring things keep happening to me.
Homepage

#88091 - LiraNuna - Sat Jun 17, 2006 3:22 pm

mode 6 has large bitmap on BG3 (1024x512)

#88095 - tepples - Sat Jun 17, 2006 3:41 pm

spinal_cord wrote:
Using tiled mode, wouldn't I need to have LOTS of unique tiles?

This would require 33*24=792 unique tiles. You read a row of pixels in a tile, change one or more pixels, and write the row back out to memory.

Quote:
plus II wouldnt have a clue how to go about doing something like that in lited mode.

On a DS Lite, you just need to use a NoPass.

LiraNuna wrote:
mode 6 has large bitmap on BG3 (1024x512)

But does it allow any VRAM for use by the other screen?
_________________
-- Where is he?
-- Who?
-- You know, the human.
-- I think he moved to Tilwick.

#88112 - LiraNuna - Sat Jun 17, 2006 4:10 pm

tepples wrote:

LiraNuna wrote:
mode 6 has large bitmap on BG3 (1024x512)

But does it allow any VRAM for use by the other screen?


You still got VRAMs E - I for use for sub BG. Don't think he needs anything but stats display. Smart organization and 16col usge will be helpful

VRAM I is 16Kbytes. Exactly one tile base. i can do a lot with 16Kbytes on 16col mode.

#88138 - spinal_cord - Sat Jun 17, 2006 7:37 pm

REading this it appears I need to READ MORE into codeing the DS before I start.

would mode 6 allow me to have the large bitmap, plus about 32 pixel high stats display on a top layer (I assume this would need to be tiled?)

are there any GOOD doc describing the gfx modes and their capabilities?
_________________
I'm not a boring person, it's just that boring things keep happening to me.
Homepage

#88157 - LiraNuna - Sat Jun 17, 2006 9:42 pm

Quote:
would mode 6 allow me to have the large bitmap, plus about 32 pixel high stats display on a top layer (I assume this would need to be tiled?)

are there any GOOD doc describing the gfx modes and their capabilities?

http://dualis.1emulation.com/files/gfxnotes.txt and http://dualis.1emulation.com/dsti.html will guide you well, my son.
modes 0-2 are exactly the same as GBA. (http://www.work.de/nocash/gbatek.htm)

But in my oppinion, you shouldn't waste that much of VRAM... use a virtual plane stored in RAM, and buffer a part of it (visable on screen) to the screen.
that way you will able to use MODE5 with more VRAM space needed for other stuff (sprites and BGs, i guess)

#88174 - HyperHacker - Sat Jun 17, 2006 10:40 pm

tepples wrote:
Quote:
plus II wouldnt have a clue how to go about doing something like that in lited mode.

On a DS Lite, you just need to use a NoPass.

He probably meant tiled mode.
_________________
I'm a PSP hacker now, but I still <3 DS.

#88205 - silent_code - Sun Jun 18, 2006 1:39 am

check that page out:

http://user.chem.tue.nl/jakvijn/tonc/index.htm

hope it helps you!