AppleIIAsm-Collection/source/disk1_stdio/T.SUB.THLINE
nathanriggs c8cac53c5e Rev 0.4 updates
Massive updates that changes the way most subroutines are handled. Major bugfixes, various utilities added, started higher-level libraries.
2019-04-26 18:49:10 -04:00

143 lines
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*
*``````````````````````````````*
* THLINE :: TEXT HORIZ LINE *
*- -*
* CREATES A HORIZONTAL LINE OF *
* TEXT COMPOSED OF THE FILL *
* CHARACTER SPECIFIED AT Y. *
*- -*
* CLOBBERS: *
* *
* FLAGS: ????---- REG: AXYM *
*- -*
* CYCLES: ??? *
* SIZE: *
*- -*
* USAGE: *
* LDA (X-START) *
* PHA *
* LDA (X-END) *
* PHA *
* LDA (Y-POS) *
* PHA *
* LDA (FILL CHAR) *
* PHA *
* JSR THLINE *
*- -*
* ENTRY *
* *
* TOP OF STACK *
* *
* LOW BYTE OF RETURN ADDRESS *
* HI BYTE OF RETURN ADDRESS *
* XPOS START OF LINE (:X1) *
* XPOS END OF LINE (:X2) *
* YPOS OF LINE (:Y) *
* FILL CHARACTER (:F) *
*- -*
* EXIT *
* *
* TOP OF STACK *
* *
* LOW BYTE OF RETURN ADDRESS *
* HI BYTE OF RETURN ADDRESS *
* *
* Y = START,END OF LINE *
* X = ??? *
* A = LOW BYTE OF RET ADDR *
*,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,*
*
THLINE
*
** SAVE RETURN ADDRESS
*
PLA
STA RETADR
PLA
STA RETADR+1
*
** GET PARAMETERS
*
PLA
STA :F
PLA
STA :Y
PLA
STA :X2
PLA
STA :X1
*
********************************
*
** ERROR CONTROL
*
********************************
*
LDA ERRCTRL
CMP #1
BEQ :CHKERR
JMP :ERREND
:CHKERR
LDA :X1
CMP :X2
BCS :ERRTOOHI ; X1 => X2
LDA :X1
CMP #39
BCS :ERRXOVF ; X VALUE OVERFLOW
LDA :X2
CMP #40 ; MAX COLS + 1
BCS :ERRXOVF
LDA :Y
CMP #24 ; MAX ROWS + 1
BCS :ERRYOVF
JMP :ERREND
:ERRTOOHI
_ERR #:E_SID;#:E_XHI;#:E_DMP1;#:X1;#4
JMP :ERREND
:ERRXOVF
_ERR #:E_SID;#:E_XOF;#:E_DMP1;#:X1;#4
JMP :ERREND
:ERRYOVF
_ERR #:E_SID;#:E_YOF;#:E_DMP1;#:X1;#4
JMP :ERREND
*
********************************
*
:ERREND
*
********************************
*
LDA :Y ; LOAD ROW
LDY :X1 ; LOAD X START POS
:LOOP
JSR $F847 ; GBASCALC ROUTINE
LDA :F
STA ($26),Y ; PUSH TO SCREEN MEMORY
LDA :Y
INY ; INCREASE X POS
CPY :X2 ; IF LESS THAN X END POS
BNE :LOOP ; REPEAT UNTIL DONE
:EXIT
*
** RESTORE RETURN ADDRESS
*
LDA RETADR+1
PHA
LDA RETADR
PHA
RTS
*
** DATA
*
:X1 DS 1
:X2 DS 1
:Y DS 1
:F DS 1 ; FILL CHAR
*
:E_SID ASC "THLINE (THLIN MACRO)",00
:E_DMP1 ASC "DUMPING X1(1) X1(1) Y(1) F(1)",00
:E_XHI ASC "X1 MUST BE LOWER THAN X2.",00
:E_XOF ASC "X > # OF AVAILABLE COLUMNS.",00
:E_YOF ASC "Y > # OF AVAILABLE ROWS",00
*