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cc65/libsrc/atari/graphics.s
cuz d0599a24fe Move include files into /asminc, changed include file paths
git-svn-id: svn://svn.cc65.org/cc65/trunk@1249 b7a2c559-68d2-44c3-8de9-860c34a00d81
2002-04-21 14:19:16 +00:00

187 lines
3.3 KiB
ArmAsm

;
; Christian Groessler, October 2001
;
; this file provides an equivalent to the BASIC GRAPHICS function
;
; int __fastcall__ graphics(unsigned char mode);
;
;
.export _graphics
.constructor initscrmem,28
.import findfreeiocb
.import __seterrno,__do_oserror,__oserror
.import fddecusage
.import clriocb
.import fdtoiocb
.import newfd
.import __graphmode_used
.importzp tmp1,tmp2,tmp3
.include "atari.inc"
.include "errno.inc"
.code
; set new grapics mode
; gets new mode in A
; returns handle or -1 on error
; uses tmp1, tmp2, tmp3, tmp4 (in subroutines)
.proc _graphics
; tax
; and #15 ; get required graphics mode
; cmp #12
; bcs invmode ; invalid mode
; txa
; and #$c0 ; invalid bits set?
; bne invmode
; stx tmp1
sta tmp1 ; remember graphics mode
parmok: jsr findfreeiocb
beq iocbok ; we found one
lda #<EMFILE ; "too many open files"
ldx #>EMFILE
seterr: jsr __seterrno
lda #$FF
tax
rts ; return -1
;invmode:ldx #>EINVAL
; lda #<EINVAL
; bne seterr
iocbok: txa
tay ; move iocb # into Y
lda #3
sta tmp3 ; name length + 1
lda #<scrdev
ldx #>scrdev
jsr newfd
tya
tax
bcs doopen ; C set: open needed
ldx #0
lda tmp2 ; get fd used
jsr fdtoiocb
tax
doopen: txa
;brk
pha
jsr clriocb
pla
tax
lda #<scrdev
sta ICBAL,x
lda #>scrdev
sta ICBAH,x
lda #OPEN
sta ICCOM,x
lda tmp1 ; get requested graphics mode
and #15
sta ICAX2,x
lda tmp1
and #$30
eor #$10
ora #12
sta ICAX1,x
jsr CIOV
bmi cioerr
lda tmp2 ; get fd
ldx #0
stx __oserror
rts
cioerr: jsr fddecusage ; decrement usage counter of fd as open failed
jmp __do_oserror
.endproc ; _graphics
; calc. upper memory limit to use
.proc initscrmem
lda __graphmode_used
beq ignore ; mode 0 doesn't need adjustment
cmp #32
bcs ignore ; invalid value
asl a
tay
lda APPMHI
sec
sbc grmemusage,y
sta APPMHI
lda APPMHI+1
sbc grmemusage+1,y
sta APPMHI+1
ignore: rts
.endproc ; initscrmem
.rodata
scrdev: .byte "S:", 0
; memory usage of the different graphics modes (0-31)
; values < 0 of "bytes needed" are mappped to 0
; bytes needed ; mode ; val. of MEMTOP
grmemusage:
.word 0 ; 0 ; 39967
.word 0 ;-318 ; 1 ; 40285
.word 0 ;-568 ; 2 ; 40535
.word 0 ;-558 ; 3 ; 40525
.word 0 ;-298 ; 4 ; 40265
.word 182 ; 5 ; 39785
.word 1182 ; 6 ; 38785
.word 3198 ; 7 ; 36769
.word 7120 ; 8 ; 32847
.word 7146 ; 9 ; 32821
.word 7146 ; 10 ; 32821
.word 7146 ; 11 ; 32821
.word 162 ; 12 ; 39805
.word 0 ;-328 ; 13 ; 40295
.word 3278 ; 14 ; 36689
.word 7120 ; 15 ; 32847
.word 0 ; 16 ; 39967
.word 0 ;-320 ; 17 ; 40287
.word 0 ;-572 ; 18 ; 40539
.word 0 ;-560 ; 19 ; 40527
.word 0 ;-296 ; 20 ; 40263
.word 184 ; 21 ; 39783
.word 1192 ; 22 ; 38775
.word 3208 ; 23 ; 36759
.word 7146 ; 24 ; 32821
.word 7146 ; 25 ; 32821
.word 7146 ; 26 ; 32821
.word 7146 ; 27 ; 32821
.word 160 ; 28 ; 39807
.word 0 ;-332 ; 29 ; 40299
.word 3304 ; 30 ; 36663
.word 7146 ; 31 ; 32821
; the program used to get these values (Atari BASIC):
; 100 FILE=0
; 110 IF FILE=1 THEN OPEN #1,8,0,"D:FREEMEM.OUT"
; 120 IF FILE<>1 THEN OPEN #1,8,0,"E:"
; 200 DIM G(32)
; 210 FOR I=0 TO 32:GRAPHICS I:GOSUB 1000:G(I)=VAL:NEXT I
; 220 GRAPHICS 0
; 230 FOR I=0 TO 31:PRINT #1;I;":",G(I);" - ";G(0)-G(I):NEXT I
; 240 CLOSE #1
; 999 END
; 1000 VAL=PEEK(741)+256*PEEK(742)
; 1010 RETURN