2010-03-05, 05:07 PM
I was updating fourspriter to use SUBs as opposed to gotos. Probably slower, but a little cleaner on the interface to the user.
Anyway, as it stands the main program:
Calls initialize for the first sprite
which calls a dummy "data" routine (which is really just for asm. The first line is return. It only calls it to make sure it's not peephole optimized out)
Comes back to main
calls coords for the first sprite
comes back to main
calls initialize for the second sprite
which calls the dummy data routine again......
and then it goes wrong. It never comes back from this data routine this second time, even though it should return immediately. In fact, it restarts the main program again. Over and over - and then after a few cycles, crashes.
I confirmed the code does the same thing with 1.23 and 1.22; and I didn't think they had the stack bugs, so it could be something I'm doing wrong, I suppose. I can't really see what could go wrong with "return" being the only statement, though.
The code is a bit complex, and is unfinished; but hopefully you can see where I'm going. It has testing PRINTs in it. Just copy and paste and see if it behaves the same way for you.
Anyway, as it stands the main program:
Calls initialize for the first sprite
which calls a dummy "data" routine (which is really just for asm. The first line is return. It only calls it to make sure it's not peephole optimized out)
Comes back to main
calls coords for the first sprite
comes back to main
calls initialize for the second sprite
which calls the dummy data routine again......
and then it goes wrong. It never comes back from this data routine this second time, even though it should return immediately. In fact, it restarts the main program again. Over and over - and then after a few cycles, crashes.
I confirmed the code does the same thing with 1.23 and 1.22; and I didn't think they had the stack bugs, so it could be something I'm doing wrong, I suppose. I can't really see what could go wrong with "return" being the only statement, though.
The code is a bit complex, and is unfinished; but hopefully you can see where I'm going. It has testing PRINTs in it. Just copy and paste and see if it behaves the same way for you.
Code:
SUB fspInitialize (n as uByte, a as uByte, b as uByte, c as uByte, d as uByte) 'Initialize Sprite: n (sprite number 0-3);a,b,c,d (UDG number 0-20,99 means the sprite won't be printed)
PRINT AT 0,0;"Initialize" : PAUSE 1: PAUSE 0
fspData() : REM call the data sub to make sure it isn't optimized out of the compile. That call just returns.
PRINT AT 2,0;"FSPData came back to Initialize" : PAUSE 1: PAUSE 0
IF n>3 OR a>20 or b>20 or c>20 or d>20 then return : END IF : REM Bounds checking - so a bad function call doesn't poke all over memory.
DIM targetAddr as uInteger
targetAddr=@fspDataStart+(48*n)
POKE targetAddr,a
targetAddr=targetAddr+1
POKE targetAddr,b
targetAddr=targetAddr+1
POKE targetAddr,c
targetAddr=targetAddr+1
POKE targetAddr,d
PRINT AT 3,0;"We're at the end of Initialize"
PAUSE 1:PAUSE 0
END SUB
SUB fspDisable (n as UByte)
IF n>3 then return : END IF
POKE @fspDataStart+48*n,99
end SUB
SUB fspCoord (n as uByte, x as uByte, y as uByte) 'Set sprite coords: n (sprite number);x,y (vertical,horizontal coords)
IF n>3 then return : END IF
DIM targetAddr as uInteger
targetAddr=@fspDataStart+4+48*n
POKE targetAddr,x
targetAddr=targetAddr+1
POKE targetAddr,y
rem targetAddr=targetAddr+1
rem POKE targetAddr,x
rem targetAddr=targetAddr+1
rem POKE targetAddr,y
END SUB
SUB fspAttrs (n as uByte, attra as uByte, attrb as uByte, attrc as uByte, attrd as uByte) 'Set sprite attrs: n (sprite number);a,b,c,d (UDG attrs)
IF n>3 then return : END IF
DIM targetAddr as uInteger
targetAddr=@fspDataStart+40+48*n
POKE targetAddr,attra
targetAddr=targetAddr+1
POKE targetAddr,attrb
targetAddr=targetAddr+1
POKE targetAddr,attrc
targetAddr=targetAddr+1
POKE targetAddr,attrd
END SUB
FUNCTION fspAttrByte(fspInk as uByte,fspPaper as uByte,fspBright as uByte, fspFlash as uByte) as uByte
if fspInk > 7 OR fspPaper > 7 OR fspBright > 1 or fspFlash >1 then return 0: END IF: Rem bounds check
return (fspFlash shl 7) + (fspBright shl 6) + (fspPaper shl 3) + fspInk
END FUNCTION
SUB fspAttr(n as uByte,fspInk as uByte,fspPaper as uByte,fspBright as uByte, fspFlash as uByte)
if fspInk > 7 OR fspPaper > 7 OR fspBright > 1 or fspFlash >1 then return : END IF: Rem bounds check
DIM attrByte as uByte
attrByte=fspAttrByte(fspInk,fspPaper,fspBright,fspFlash)
fspAttrs(n,fspAttrByte,fspAttrByte,fspAttrByte,fspAttrByte)
END SUB
SUB fspData()
fspDataStart:
RETURN : REM if called we should return immediately. This sub is for data and ASM only.
REM This routine contains Fourspriter data and code that is called by other routines. In effect, it's a dummy subroutine.
REM It is called by fspInitialize in order to ensure it is included in the build.
ASM
;; 16x16 Sprites moving a character each frame
;; Copyleft 2009 The Mojon Twins.
;; Pergreñado por na_th_an
;; Uses UDGs (it reads the address from the system variables).
;; It moves up to 4 sprites, preserving the backgrounds.
datap: ; each block is 48 bytes long. [This comment originally said 40 bytes, and it's clearly 48]
;; Sprite 1
udgs1: defb 0,0,0,0 ; Four UDGs of the first sprite.
x_pos1: defb 0 ; X position in chars.
y_pos1: defb 0 ; Y position in chars.
cx_pos1: defb 0 ; Previous X position in chars.
cy_pos1: defb 0 ; Previous Y position in chars.
buffer1: defb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0 ; Background Gfx buffer.
attrs1: defb 7,7,7,7 ; Sprite ATTRs
buffatrs1: defb 0,0,0,0 ; Background Attr's buffer
;; Sprite 2
udgs2: defb 0,0,0,0
x_pos2: defb 0
y_pos2: defb 0
cx_pos2: defb 0
cy_pos2: defb 0
buffer2: defb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
attrs2: defb 7,7,7,7
buffatrs2: defb 0,0,0,0
;; Sprite 3
udgs3: defb 0,0,0,0
x_pos3: defb 0
y_pos3: defb 0
cx_pos3: defb 0
cy_pos3: defb 0
buffer3: defb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
attrs3: defb 7,7,7,7
buffatrs3: defb 0,0,0,0
;; Sprite 4
udgs4: defb 0,0,0,0
x_pos4: defb 0
y_pos4: defb 0
cx_pos4: defb 0
cy_pos4: defb 0
buffer4: defb 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
attrs4: defb 7,7,7,7
buffatrs4: defb 0,0,0,0
;; General use coordinates
xpos: defb 0
ypos: defb 0
cxpos: defb 0
cypos: defb 0
;; Sprite control is done writing a certain number
;; in the Sprite's first UDG
;; If the first UDG is 99, it won't be printed
docopy:
call get_scr_address ; Dirección (xpos, ypos) en BC
ld l, c
ld h, b ; Dirección (xpos, ypos) en HL
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ret
;; Esta función devuelve en bc la dirección de memoria
;; de la posición (xpos, ypos) en carácteres. Extraído de código
;; por BloodBaz.
get_scr_address:
push de
ld a, (xpos)
and 31
ld c, a
ld a, (ypos)
ld d, a
and 24
add a, 64
ld b, a
ld a, d
and 7
rrca
rrca
rrca
or c
ld c, a
pop de
ret
;; Esta función devuelve en bc la dirección de memoria
;; de la posición (xpos, ypos) dentro del archivo de atributos.
;; Adaptado de código por Jonathan Cauldwell.
;; 010110YY YYYXXXXX
get_attr_address:
ld a, (ypos) ; Cogemos y
rrca
rrca
rrca ; La multiplicamos por 32
ld c, a ; nos lo guardamos en c
and 3 ; ponemos una mascarita 00000011
add a, 88 ; 88 * 256 = 22528, aquí empieza el tema
ld b, a ; Hecho el bite superior.
ld a, c ; Nos volvemos a traer y * 32
and 224 ; Mascarita 11100000
ld c, a ; Lo volvemos a poner en c
ld a, (xpos) ; Cogemos x
add a, c ; Le sumamos lo que teníamos antes.
ld c, a ; Listo. Ya tenemos en BC la dirección.
ret
spare: defb 85,85,85,85,85,85,85, 85
END ASM
END SUB
SUB fspErase()
asm
;; Routine to save the background to the buffer
;borra_sprites:
; pointer = datap
; for (i = 0; i < 4; i ++) {
; CX = *(pointer + 6)
; CY = *(pointer + 7)
; scr_address = get_scr_address (CX, CY);
; for (j = 0; j < 8; j ++) {
; *scr_address = *(pointer + 8 + j);
; scr_address += 256;
; }
; scr_address = get_scr_address (CX+1, CY);
; for (j = 0; j < 8; j ++) {
; *scr_address = *(pointer + 16 + j);
; scr_address += 256;
; }
; scr_address = get_scr_address (CX, CY+1);
; for (j = 0; j < 8; j ++) {
; *scr_address = *(pointer + 24 + j);
; scr_address += 256;
; }
; scr_address = get_scr_address (CX+1, CY+1);
; for (j = 0; j < 8; j ++) {
; *scr_address = *(pointer + 32 + j);
; scr_address += 256;
; }
; pointer += 40;
; }
ld de, datap ;
ld b, 4 ;
i4chars2: push bc
;;
ld a, (de)
cp 99
jr z, nxt2
;; A
inc de
inc de
inc de
inc de
inc de
inc de
; Obtenemos xpos = CX
ld a, (de)
ld hl, xpos
ld (hl), a
inc de
; Obtenemos ypos = CY
ld a, (de)
ld hl, ypos
ld (hl), a
inc de
;; B
; Pintamos el primer char
call borra_char
; xpos++
ld hl, xpos
inc (hl)
;; C
; Pintamos el segundo char
call borra_char
; xpos --
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos ++
ld hl, ypos
inc (hl)
;; D
; Pintamos el tercer char
call borra_char
; xpos++
ld hl, xpos
inc (hl)
;; E
; Pintamos el cuarto char
call borra_char
;; attr
inc de
inc de
inc de
inc de
;;
; xpos --
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos --
ld hl, ypos
ld a, (hl)
dec a
ld (hl), a
;
call get_attr_address
;
call copyattrs
;
nxt2: pop bc
djnz i4chars2
jp fspErase_end
borra_char:
call get_scr_address ;
ld l, c
ld h, b ;
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ld a, (de)
ld (hl), a
inc h
inc de
ret
fspErase_end:
end asm
END SUB
SUB fspBufferBackground()
asm
init_sprites:
; pointer = datap
; for (i = 0; i < 4; i ++) {
; X = *(pointer + 4); // A
; Y = *(pointer + 5);
; scr_address = get_scr_address (X, Y); // B
; for (j = 0; j < 8; j ++) {
; *(pointer + 8 + j) = *scraddress;
; scraddress += 256;
; }
; scr_address = get_scr_address (X+1, Y); // C
; for (j = 0; j < 8; j ++) {
; *(pointer + 16 + j) = *scraddress;
; scraddress += 256;
; }
; scr_address = get_scr_address (X, Y+1); // D
; for (j = 0; j < 8; j ++) {
; *(pointer + 24 + j) = *scraddress;
; scraddress += 256;
; }
; scr_address = get_scr_address (X+1, Y+1); // E
; for (j = 0; j < 8; j ++) {
; *(pointer + 32 + j) = *scraddress;
; scraddress += 256;
; }
; pointer = pointer + 40;
; }
ld de, datap ;
ld b, 4 ;
i4chars: push bc
;;
ld a, (de)
cp 99
jr z, nxt1
;; A
inc de
inc de
inc de
inc de
;
ld a, (de)
ld hl, xpos
ld (hl), a
inc de
;
ld a, (de)
ld hl, ypos
ld (hl), a
inc de
inc de
inc de
;; B
;
call copia_char
; xpos++
ld hl, xpos
inc (hl)
;; C
;
call copia_char
; xpos --
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos ++
ld hl, ypos
inc (hl)
;; D
;
call copia_char
; xpos++
ld hl, xpos
inc (hl)
;; E
;
call copia_char
;; Now we point to the ATTR buffer,adding 4:
inc de
inc de
inc de
inc de
;;
; xpos --
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos --
ld hl, ypos
ld a, (hl)
dec a
ld (hl), a
;
call get_attr_address
;
ld l, c
ld h, b
ld bc, 31
ld a, (hl)
ld (de), a ; Primer carácter
inc hl
inc de
ld a, (hl)
ld (de), a ; Segundo carácter
add hl, bc
inc de
ld a, (hl)
ld (de), a ; Tercer carácter
inc hl
inc de
ld a, (hl)
ld (de), a ; Cuarto carácter
inc de
; Fin del bucle
nxt1: pop bc
djnz i4chars
;ret
jp fspBufferBackground_end
copia_char:
call get_scr_address ;
ld l, c
ld h, b ;
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ld a, (hl)
ld (de), a
inc h
inc de
ret ; Subroutines don't need to return themselves.
fspBufferBackground_end:
;; Routine to move the sprites:
end asm
END SUB
SUB fspRedraw()
asm
halt
end asm
';call borra_sprites ; Erase the sprites
fspErase()
';call init_sprites ; Save background
fspBufferBackground()
';call draw_sprites ; print sprites
fspDraw()
';call update_coordinates ; update coordinates :)
fspUpdate()
';ret
END SUB
SUB fspDraw()
asm
;; Print sprites routine
;; UDGs are labeled from 0 to 21. The addres of the UDG is:
;; *(23675) + 256 * *(23676) + 8 * N
draw_sprites:
ld de, datap ;
ld b, 4 ;
i4chars3: push bc
ld a, (de)
cp 99
jr z, nxt3
;; copiar aquí "de" a un buffer
call charsabuff
; Obtenemos xpos
ld a, (de)
ld hl, xpos
ld (hl), a
inc de
; Obtenemos ypos
ld a, (de)
ld hl, ypos
ld (hl), a
inc de
inc de
inc de
push de
ld hl, bufchars
call getde
call docopy
; xpos++
ld hl, xpos
inc (hl)
; Dirección del gráfico
ld hl, bufchars
inc hl
call getde
; Pintamos el segundo char
call docopy
; xpos--
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos ++
ld hl, ypos
inc (hl)
; Dirección del gráfico
ld hl, bufchars
inc hl
inc hl
call getde
; Pintamos el tercer char
call docopy
; xpos ++
ld hl, xpos
inc (hl)
; Dirección del gráfico
ld hl, bufchars
inc hl
inc hl
inc hl
call getde
; Pintamos el cuarto char
call docopy
pop de
; de = de + 32
ld bc, 32
ld h, d
ld l, e
add hl, bc
ld d, h
ld e, l
;; attr
; xpos --
ld hl, xpos
ld a, (hl)
dec a
ld (hl), a
; ypos --
ld hl, ypos
ld a, (hl)
dec a
ld (hl), a
;
call get_attr_address
;
call copyattrs
inc de
inc de
inc de
inc de ;
nxt3: pop bc
djnz i4chars3
;ret
jp fspDraw_end
;; Esta función calcula la posición en memoria del UDG apuntado por
;; el número que está en la dirección hl.
getde: ld a, (hl)
ld d, a
ld hl, 23676
ld a, (hl)
ld e, a
ld hl, 23675
ld a, (hl)
ld l, a
ld a, e
ld h, a
;; HL = *(23675) + 256 * *(23676)
ld a, d
rlca
rlca
rlca ; a = N * 8
ld d, 0
ld e, a
add hl, de
ld d, h
ld e, l
ret
bufchars: defb 0,0,0, 0 ;
charsabuff: ld hl, bufchars
ld a, (de)
ld (hl), a
inc de
inc hl
ld a, (de)
ld (hl), a
inc de
inc hl
ld a, (de)
ld (hl), a
inc de
inc hl
ld a, (de)
ld (hl), a
inc de
inc hl
ret
copyattrs: ld l, c
ld h, b
ld bc, 31
ld a, (de)
ld (hl), a ; Primer carácter
inc hl
inc de
ld a, (de)
ld (hl), a ; Segundo carácter
add hl, bc
inc de
ld a, (de)
ld (hl), a ; Tercer carácter
inc hl
inc de
ld a, (de)
ld (hl), a ; Cuarto carácter
inc de ; Ahora de apunta a datap+48, o sea, al siguiente sprite.
ret
fspDraw_end:
END ASM
END SUB
SUB fspUpdate()
asm
update_coordinates:
ld de, datap ; Apuntamos a la zona de datos
ld hl, datap ; idem
ld b, 4 ; 4 iteraciones
i4chars4: push bc
;; Para cada sprite hay que hacer:
;; *(datap + 6) = *(datap + 4)
;; *(datap + 7) = *(datap + 5)
inc de
inc de
inc de
inc de
ld a, (de) ; a = X
inc hl
inc hl
inc hl
inc hl
inc hl
inc hl
ld (hl), a ; CX = a
inc de
ld a, (de) ; a = Y
inc hl
ld (hl), a ; CY = a
inc hl
;; hl = hl + 40
ld bc, 40
add hl, bc
;; de = hl
ld d, h
ld e, l
pop bc
djnz i4chars4
;ret
END ASM
END SUB
#include <sinclair.bas>
#include <memcopy.bas>
#include <keys.bas>
100 DIM gentle (0 to 3,0 to 7) AS uByte => { { 15, 15, 15, 15, 15, 15, 13, 15} , _
{ 240, 144, 208, 208, 240, 240, 176, 240} , _
{ 15, 14, 63, 0, 0, 12, 26, 30} , _
{ 176, 112, 252, 0, 0, 48, 104, 120}}
110 POKE Uinteger 23675, @gentle(0,0)
memcopy (0,16384,4092)
LET gx=10:LET gy=10:let dx=3:let dy=3:let tx=6:let ty=6:let cx=18:let cy=18
let dmx=1:let dmy=1:let tmx=-1:let tmy=-1:let cmx=1:let cmy=-1
fspInitialize (0,0,1,2,3)
PRINT AT 5,0;"We came back from Initialize the first time" : PAUSE 1: PAUSE 0
fspCoord (0,gy,gx)
PRINT AT 6,0;"We came back from fspCoord the first time": PAUSE 1: PAUSE 0
CLS
fspInitialize (1,0,1,2,3)
PRINT AT 7,0;"We came back from Initialize the second time" : PAUSE 1: PAUSE 0
fspCoord (1,dy,dx)
fspInitialize (2,0,1,2,3)
fspCoord (2,ty,tx)
fspInitialize (3,0,1,2,3)
fspCoord (3,cy,cx)
fspAttrs (0,31,31,31,31)
fspAttrs (1,12,12,12,12)
fspAttrs (2,26,26,26,26)
fspAttrs (3,6,6,6,6)
DO
IF MULTIKEYS(KEYO)<>0 and gx>0 THEN LET gx=gx-1: END IF
IF MULTIKEYS(KEYP)<>0 and gx<30 THEN LET gx=gx+1:END IF
IF MULTIKEYS(KEYQ)<>0 and gy>0 THEN LET gy=gy-1 :END IF
IF MULTIKEYS(KEYA)<>0 and gy<22 THEN LET gy=gy+1: END IF
let dx=dx+dmx:if dx=0 or dx=30 then let dmx=-dmx : END IF
let dy=dy+dmy:if dy=0 or dy=22 then let dmy=-dmy: END IF
let tx=tx+tmx:if tx=0 or tx=30 then let tmx=-tmx: END IF
let ty=ty+tmy:if ty=0 or ty=22 then let tmy=-tmy: END IF
let cx=cx+cmx:if cx=0 or cx=30 then let cmx=-cmx: END IF
let cy=cy+cmy:if cy=0 or cy=22 then let cmy=-cmy: END IF
pause 2
fspCoord (0,gx,gy)
fspCoord (1,dx,dy)
fspCoord (2,tx,ty)
fspCoord (3,cx,cy)
fspRedraw()
loop