The useful basiegaxorz sub topic

[sega16]

I think it would be useful for everyone to have a topic full of useful subs/function anyway
Here is something that works the same as drawtilesinc but does a hflip anyway here it is
Usage:
drawtilesinc_hflip vram offset, x, y, w,h

declare sub drawtilesinc_hflip(tiles as integer, x as integer, y as integer, w as integer, h as integer)
x--
xloop=0
for y_loop = 0 to h
for x_loop = w to 1 step -1
drawtile tiles+xloop+y_loop+hfliptile(1),x+x_loop,y+y_loop
xloop++
next x_loop
xloop--
next y_loop
end sub


[Deleted]

I've already asked for help in regards to this but I think an example of coordinate based collision detection would be nice.

Whoever wrote the workaround for the broken save support on real hardware could post his work here too..

[Deleted]

Since you asked nicely Theloon

Here is a way to get SRAM working in BEX.


option EXTERNALSRAM, &h200000, 8192, ODD

asm "move #$2700,sr"
a = peek(&h200001) ' Read from SRAM at address &h200001
asm "move #$2000,sr"

locate 1,1: print "SRAM Data: "; a

while 1

j = joypad()
sleep 1
if j > 0 then
randomize
a = rnd(99) + 1
locate 3,1: print "New SRAM Data: "; a
gosub SaveData
end if
wend

SaveData:
asm "move #$2700,sr"
poke &hA130F1, &h01
poke &h200001, a
asm "move #$2000,sr"
return


Apr 12, 2011 13:12:23 GMT -5 @theloon said:

I've already asked for help in regards to this but I think an example of coordinate based collision detection would be nice.

The problem with doing a collision detection is that everyone's map routines are going to be different. In an RPG setting there are several ways, but in a plaformer, such as finding out if a projectile has hit you or not, you could do something like this:

x = SpritePosX
y = SpritePosY

x1 = ProjectileX
y1 = ProjectileY

if (x + sprite.width) >= (x1 + projectile.width) & x <= x1 & (same stuff for the y positions) then collision = true

If you have any specific questions, feel free to PM me.

[Deleted]

moon provided a great example of tile based scrolling in this topic:
devster.proboards.com/index.cgi?action=display&board=basiegaxorz&thread=603&page=1

The file is Soleil.bex

I didn't copy and paste the code as it isn't mine and he may have optimized further in the months past..

[Deleted]

that example is highly unoptimized, thought it's great for learning. Moon is a very smart man when it comes to that sorta thing

[Tiido]

you write 1 to A130xx prior to doing any writes to 20xxxx area and when done then a 0 to A130xx. This would only matter if the game is bigger than 2MBytes.

[Deleted]

When performing collision detection between for example a character and a bullet, I recommend a "rectangle vs point" test that uses the "early-out" principle. That way you're only using one or two conditions per bullet most of the time. Attached is a basic example.

Obviously, in most cases you want to add a "layer" of spatial indexing on top to further improve performance.

Attachments:

[jlf65]

Apr 19, 2011 3:47:51 GMT -5 Tiido said:

you write 1 to A130xx prior to doing any writes to 20xxxx area and when done then a 0 to A130xx. This would only matter if the game is bigger than 2MBytes.

Even if the rom is 2MB or less, you're still supposed to write 1 to A130F1; you just do it in the game's hardware init and then don't worry about writing the reg before and after writing/reading the sram.

You should also always use the official address (A130F1) even if you know it's mirrored or responds to any address.

[Deleted]

Hey! Thanks for shaing the collision code moon. Actually, I could see using this logic in my PC and 2600 projects too.

Is there some general hardware collision flag that could be accessed from Basiegaxorz? Something that would tell me if ANY collisions have happened and then resort to the software collision check?

[Deleted]

Apr 20, 2011 8:04:42 GMT -5 @theloon said:

Is there some general hardware collision flag that could be accessed from Basiegaxorz?

There is actually ( for sprite vs sprite ), but you don't want to use it. See this post by oompa.

[Deleted]

Hey! I think music playback is a must have. Let's not forget Shiru left us with .BEX source to his TFM playback engine
devster.proboards.com/index.cgi?board=basiegaxorz&action=display&thread=261

Hopefully the TFM Music Maker 1.4 still makes compatible TFM files..
shiru.untergrund.net/software.shtml

Apparently Kramlib can play back certain music files?
devster.proboards.com/index.cgi?board=basiegaxorz&action=display&thread=487

I cannot recommend MVS Tracker as the .BEX example on Devster site is without comments and unintelligible to the beginner (me).

[Deleted]

TFM doesn't work on the real hardware without some rewrites, or borrow the z80 init code from kramlib.

Kramlib uses SMPS music files, and there isn't a single tracker for that format (that I'm aware of). There are tools out there to help convert to SMPS, though I've had no luck with getting any of them to work properly, or not crash on my OS's (Windows 7, XP, and Server 2003).

[Deleted]

I think I actually saw a post with the rewrites to TFM here. When I get 'round tuit I see if I can find them and test on an Everdrive. If anyone stashed away a working copy please repost! heck, a working music engine of any sort would be a great contribution!

UPDATE: The code and suggested fixes in this post resulted in a binary that played back no sound in Kega Fusion.
devster.proboards.com/index.cgi?board=basiegaxorz&action=display&thread=511

The TFM Music Maker from Shirus website also produced no sound. Yes, I did rename the included music to music.tfd
shiru.untergrund.net/software.shtml

UPDATE: Arrg, it appears the modules included with TFM Music Maker are NOT useable in BasiEgaXorz unless you export them as "TFD for the SMD" . I'll just assume that the other TFM examples have the same deal going on..

That being said has anyone played around with the LAKABJO example? Devster made it to interface with real hardware thus I'm sure he made sure the music works on a real Genesis..

[Deleted]

@theloon: the TFM engine in (I forget the example's name) worked on the Everdrive, worked in the model 3 genesis as a cart, but froze in the model 1, model 2, and sega cdx after it was made into a cart. It worked perfectly after adding in kramlib's initialization routines.

[Mairtrus]

Hai guys. Sorry for bump this not-so-old thread, but I have a few subroutines that I believe someone will find usefull:
This one allows you to change the Link property of a sprite:
Declare Asm Sub LinkSprite(d0.w,d1.w)
move #$2700,sr
lsl.w #3,d0
addi.w #$2C02,d0
swap d0
move.w #2,d0
move.l d0,4(a4)
nop
nop
move.w (a4),d2
nop
nop
move.b d1,d2
addi.l #$40000000,d0
nop
nop
move.l d0,4(a4)
move.w d2,(a4)
move #$2000,sr
End Sub
and use like this:
LinkSprite SpriteHandler,LinkNumber
The next one is used to change the form of a sprite:
Declare Asm Sub ResizeSprite(d0.w,d1.w,d2.w) move #$2700,sr
lsl.w #3,d0
addi.w #$2C02,d0
swap d0
move.w #2,d0
move.l d0,4(a4)
sub.b #1,d1
andi.w #3,d1
lsl.b #2,d1
move.w (a4),d3
sub.b #1,d2
andi.b #3,d2
or.b d2,d1
addi.l #$40000000,d0
lsl.w #8,d1
move.b d3,d1
move.l d0,4(a4)
move.w d1,(a4)
move #$2000,sr
End Sub

and use like this
ResizeSprite SpriteHandler,NewHeight,NewWidth (NewWidth and NewHeight take values from 1 to 4)
This last one is my latest achievement, and probably the only thing on the MD I hadn't learned how to use...yet:
Declare Asm Sub DmaCopy(d0.l,d1.w,d2.l)
move #$2700,sr
move.w #$9300,d3
lsr.w #1,d1
move.b d1,d3
move.w d3,4(a4)
lsr.w #8,d1
addi.w #$100,d3
move.b d1,d3
move.w d3,4(a4)
lsr.w #1,d0
addi.w #$100,d3
move.b d0,d3
move.w d3,4(a4)
lsr.w #8,d0
addi.w #$100,d3
move.b d0,d3
move.w d3,4(a4)
lsr.w #8,d0
andi.b #$7F,d0
addi.w #$100,d3
move.b d0,d3
move.w d3,4(a4)
lsl.l #2,d2
lsr.w #2,d2
addi.l #$804000,d2
swap d2
move.l d2,4(a4)
move #$2000,sr
End Sub
and use like this:
DmaCopy lblptr&(YourData)+SomethingIfYouWant,NumberOfBytesToCopy,StartPosition
If someone doesn't catch it yet, the DMA allows you to load data into the VRAM at a higher speed than normal, since it's the VDP who process the data, and not the M68K, freeing it for doing whatever else(Tiido has done some wonderful demos using this technique).