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cc65/libsrc/osic1p/osiscreen.inc
2017-03-10 11:21:14 +01:00

183 lines
4.7 KiB
PHP

;
; Macro definitions for screen layout modules
;
.include "extzp.inc"
.linecont +
;
; Internal function for screensize()
;
.macro osi_screensize ScrWidth, ScrHeight
; Macro implementation of internal screensize
; function for given width and height in
; characters
.export screensize
.proc screensize
ldx #ScrWidth
ldy #ScrHeight
rts
.endproc
.endmacro
;
; void clrscr (void);
;
.macro osi_clrscr ScrBase, ScrRamSize
.export _clrscr
.proc _clrscr
lda #<ScrBase ; Fill whole video RAM with blanks by calling
ldx #>ScrBase ; memset appropriately
jsr pushax
lda #' '
ldx #$00
jsr pushax
lda #<ScrRamSize
ldx #>ScrRamSize
jsr _memset
lda #$00 ; Cursor in upper left corner
sta CURS_X
sta CURS_Y
jmp plot ; Set the cursor position
.endproc
.endmacro
;
; cputc/cputcxy for Challenger 1P
; Based on PET/CBM implementation
;
.macro osi_cputfuncs ScrBase, ScrFirstChar, ScrWidth, ScrHeight, \
ScrollDist, ScrLo, ScrHi
; Number of characters to move for scrolling
; by one line
ScrollLength = (ScrHeight - 1) * ScrollDist
;
; void cputcxy (unsigned char x, unsigned char y, char c);
; void cputc (char c);
;
.export _cputcxy, _cputc, cputdirect, putchar
.export newline, plot
_cputcxy:
pha ; Save C
jsr gotoxy ; Set cursor, drop x and y
pla ; Restore C
; Plot a character - also used as internal function
_cputc: cmp #$0A ; CR?
bne L1
lda #0
sta CURS_X
beq plot ; Recalculate pointers
L1: cmp #$0D ; LF?
beq newline ; Recalculate pointers
cputdirect:
jsr putchar ; Write the character to the screen
; Advance cursor position, register Y contains horizontal position after
; putchar
cpy #(ScrWidth - 1) ; Check whether line is full
bne L3
jsr newline ; New line
ldy #$FF ; + cr
L3: iny
sty CURS_X
rts
newline:
inc CURS_Y
lda CURS_Y
cmp #ScrHeight ; Screen height
bne plot
dec CURS_Y ; Bottom of screen reached, scroll
; Scroll destination address
lda #<(ScrBase + ScrFirstChar)
ldx #>(ScrBase + ScrFirstChar)
jsr pushax
; Scroll source address
lda #<(ScrBase + ScrFirstChar + ScrollDist)
ldx #>(ScrBase + ScrFirstChar + ScrollDist)
jsr pushax
; Number of characters to move
lda #<ScrollLength
ldx #>ScrollLength
jsr _memmove
; Address of first character in last line
; of screen
lda #<(ScrBase + ScrFirstChar + ScrollLength)
sta ptr1
lda #>(ScrBase + ScrFirstChar + ScrollLength)
sta ptr1+1
ldy #ScrWidth ; Fill last line with blanks
lda #' '
clrln: sta (ptr1),y
dey
bpl clrln
plot: ldy CURS_Y
lda ScrLo,y
sta SCREEN_PTR
lda ScrHi,y
sta SCREEN_PTR+1
rts
; Write one character to the screen without doing anything else, return X
; position in register Y
putchar:
ldy CURS_X
sta (SCREEN_PTR),y ; Set char
rts
.endmacro
.macro osi_screen_funcs ScrBase, ScrRamSize, ScrFirstChar, \
ScrWidth, ScrHeight, ScrollDist
.import gotoxy
.import _memmove, _memset, pushax
.importzp ptr1
.rodata
; Screen address tables - offset to real screen
ScrTabLo:
.repeat ScrHeight, I
.byte <(ScrBase + ScrFirstChar + I * ScrollDist)
.endrep
ScrTabHi:
.repeat ScrHeight, I
.byte >(ScrBase + ScrFirstChar + I * ScrollDist)
.endrep
.code
osi_cputfuncs ScrBase, ScrFirstChar, ScrWidth, ScrHeight, \
ScrollDist, ScrTabLo, ScrTabHi
osi_screensize ScrWidth, ScrHeight
osi_clrscr ScrBase, ScrRamSize
.endmacro