implemented graphics() function

git-svn-id: svn://svn.cc65.org/cc65/trunk@1013 b7a2c559-68d2-44c3-8de9-860c34a00d81

diff --git a/libsrc/atari/graphics.s b/libsrc/atari/graphics.s
index 94dea3bd6140eacee0d0c8063c91ed71e4e8b3c3..57ef2b07ad36fac2dcea1b67c843ec3f7dd5b42b 100644 (file)
--- a/libsrc/atari/graphics.s
+++ b/libsrc/atari/graphics.s
@@ -1,25 +1,109 @@
 ;
-; Christian Groessler, December 2000
+; Christian Groessler, October 2001
 ;
 ; this file provides an equivalent to the BASIC GRAPHICS function
 ;
-; void __fastcall__ graphics(unsigned char mode);
+; 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        "../common/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
 
-       rts             ; not implemented yet!
-
-.endproc
+;      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
+
+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
@@ -42,10 +126,13 @@
        sta     APPMHI+1
 ignore:        rts
 
-.endproc
+.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