6502/cc65
1
0
Fork 0
mirror of https://github.com/cc65/cc65.git synced 2024-06-28 03:29:39 +00:00
Code Issues Projects Releases Wiki Activity

Fixed problems with the Atari Lynx's TGI driver.

Browse Source 
* The sprite-types for black and transparent backgrounds were swapped.
* A filler-byte for text output isn't printed.  (A hardware bug might not need that work-around in most cases.)
This commit is contained in:
Greg King 2019-10-12 04:01:03 -04:00
parent 39b10f9599
commit f3f15cfd25
1 changed files with 28 additions and 24 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

52
libsrc/lynx/tgi/lynx-160-102-16.s
View File

@ -1,10 +1,10 @@
;
; Graphics driver for the 160x102x16 mode on the Lynx.
;
; All the drawing functions are simply done by sprites as the sprite
; All the drawing functions simply are done by sprites, as the sprite
; engine is the only way to do fast graphics on a Lynx.
;
; This code is written by Karri Kaksonen, 2004 for the cc65 compiler.
; This code was written by Karri Kaksonen, 2004 for the cc65 compiler.
;
.include "zeropage.inc"
@ -104,8 +104,10 @@ BGINDEX: .res 1 ; Pen to use for text background
DRAWPAGE: .res 1
SWAPREQUEST: .res 1
; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte.
; (As an experiment, the fill-byte isn't being generated.
; It might not be needed to work around a Suzy bug.)
text_bitmap: .res 8*(1+20+1)+1
; 8 rows with (one offset-byte plus 20 character bytes plus one fill-byte) plus one 0-offset-byte
; Constants and tables
@ -830,7 +832,7 @@ TEXTSTYLE:
; ------------------------------------------------------------------------
; OUTTEXT: Output text at X/Y = ptr1/ptr2 using the current color and the
; current text style. The text to output is given as a zero terminated
; current text style. The text to output is given as a zero-terminated
; string with address in ptr3.
;
; Must set an error code: NO
@ -842,12 +844,11 @@ OUTTEXT:
lda TEXTMAGY
sta text_sy+1
stz text_sprite ; Set normal sprite
lda BGINDEX
bne @L1
lda #4
sta text_sprite ; Set opaque sprite
beq @L1 ; Choose opaque black sprite?
lda #$04 ; No, choose normal sprite
@L1:
sta text_sprite
lda DRAWINDEX ; Set color
asl
asl
@ -875,15 +876,18 @@ OUTTEXT:
ldy #20
@L3:
sty STRLEN
tya
bne @L4
rts ; Zero length string
rts ; Zero-length string
@L4:
iny ; Prepare text_bitmap
iny
; The next instruction is commented because the code won't include a fill-byte.
; iny
sty STROFF
ldy #8-1 ; 8 pixel lines per character
ldx #0
ldx #$00
clc
@L5:
lda STROFF
@ -891,45 +895,45 @@ OUTTEXT:
txa
adc STROFF
tax
lda #$ff
sta text_bitmap-1,x
; This was the fill-byte.
; lda #$FF
; sta text_bitmap-1,x
dey
bpl @L5
stz text_bitmap,x
stz tmp2
iny
iny ;(ldy #$00)
@L6:
lda (STRPTR),y
sty tmp1
sec ; (ch-' ') * 8
sbc #32
stz FONTOFF
sub #' ' ; (ch - ' ') * 8
stz FONTOFF+1
asl
asl
rol FONTOFF+1
asl
rol FONTOFF+1
clc ; Choose font
adc #<font
;clc ; (cleared by rol)
adc #<font ; Choose font
sta FONTOFF
lda FONTOFF+1
adc #>font
sta FONTOFF+1
; and now copy the 8 bytes of that char
; And now, copy the 8 bytes of that glyph.
ldx tmp2
inx
stx tmp2
; draw char from top to bottom, reading char-data from offset 8-1 to offset 0
; Draw char. from top to bottom, reading char-data from offset 8-1 to offset 0.
ldy #8-1
@L7:
lda (FONTOFF),y ; *chptr
sta text_bitmap,x ;textbuf[y*(1+len+1)+1+x]
lda (FONTOFF),y ; *chptr
sta text_bitmap,x ; textbuf[y*(1+len+1)+1+x]
txa
adc STROFF
@ -938,7 +942,7 @@ OUTTEXT:
dey
bpl @L7
; goto next char
; Goto next char.
ldy tmp1
iny
dec STRLEN