Apple-2-SW/Applecorn
1
0
Fork 0
mirror of https://github.com/bobbimanners/Applecorn.git synced 2025-02-11 18:30:29 +00:00
Code Issues Projects Releases Wiki Activity

Cleaned up font explode. Added 320 mode explode.

Browse Source
This commit is contained in:
Bobbi Webber-Manners 2022-12-27 01:50:10 -05:00
parent 8a76beec21
commit f5203735de
2 changed files with 35 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

BIN
applecorn.po
View File

Binary file not shown.

63
auxmem.shr.s
View File

@ -191,25 +191,42 @@ SHRXPLDCHAR PHA
* Draw one pixel row of font in 320 mode
* 4 bytes per char, 4 bits per pixel
* TODO: Implement this
SHRCHAR320 PHY
LDA #$FF
LDY #$00
* On entry: A contains row of font data
SHRCHAR320 PHY ; Preserve Y
LDY #$00 ; Dest byte index
:L0 STZ ZP2
LDX #$00 ; Source bit index
:L1 ASL ; MS bit -> C
PHP ; Preserve C
ROL ZP2 ; C -> LS bit
PLP ; Recover C
PHP
ROL ZP2 ; C -> LS bit
PLP ; Recover C
PHP
ROL ZP2 ; C -> LS bit
PLP ; Recover C
ROL ZP2 ; C -> LS bit
INX
CPX #$02 ; Processed two bits of font?
BNE :L1
PHA ; Preserve partially shifted font
LDA ZP2
STA [VDUADDR],Y
PLA ; Recover partially shifted font
INY
STA [VDUADDR],Y
INY
STA [VDUADDR],Y
INY
STA [VDUADDR],Y
PLY
CPY #$04 ; Done 4 bytes?
BNE :L0
PLY ; Recover Y
RTS
* Draw one pixel row of font in 640 mode
* 2 bytes per char, 2 bits per pixel
SHRCHAR640 PHY
STZ ZP2
* On entry: A contains row of font data
SHRCHAR640 PHY ; Preserve Y
LDY #$00 ; Dest byte index
:L0 STZ ZP2
LDX #$00 ; Source bit index
:L1 ASL ; MS bit -> C
PHP ; Preserve C
@ -219,24 +236,14 @@ SHRCHAR640 PHY
INX
CPX #$04
BNE :L1
PHA
PHA ; Preserve partially shifted font
LDA ZP2
STA [VDUADDR]
PLA
STZ ZP2
LDX #$00
:L2 ASL ; MS bit -> C
PHP ; Preserve C
ROL ZP2 ; C -> LS bit
PLP ; Recover C
ROL ZP2 ; C -> LS bit
INX
CPX #$04
BNE :L2
LDA ZP2
LDY #$01
STA [VDUADDR],Y
PLY
PLA ; Recover partially shifted font
INY
CPY #$02 ; Done 2 bytes?
BNE :L0
PLY ; Recover Y
RTS