Apple-2-SW/asmgen
1
0
Fork 0
mirror of https://github.com/robmcmullen/asmgen.git synced 2025-01-03 13:30:19 +00:00
Code Issues Projects Releases Wiki Activity

Added direction flag instead of using signed bytes. This gets us to 255 horizontal positions for bw sprites

Browse Source
This commit is contained in:
Rob McMullen 2017-06-29 12:39:29 -07:00
parent b2842a1c39
commit 6c794b855e
2 changed files with 51 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

BIN
multitest.dsk
View File

Binary file not shown.

78
multitest.s
View File

@ -27,8 +27,8 @@ bgstore = $80
bgline = $82 bgline = $82
; constants ; constants
MAXPOSX = 127 ; This demo doesn't wanna do 16 bit math MAXPOSX = 250
MAXPOSY = 127 MAXPOSY = 192 - 16
*= $6000 *= $6000
@ -92,26 +92,60 @@ moveloop
movex movex
; Apply X velocity to X coordinate ; Apply X velocity to X coordinate
lda sprite_dirx,y
bpl move_right
sec
lda sprite_x,y
sbc sprite_dx,y
cmp #MAXPOSX
bcc movex_end
lda #1
sta sprite_dirx,y
lda #0
sta sprite_x,y
bpl movey
move_right
clc clc
lda sprite_x,y lda sprite_x,y
adc sprite_dx,y adc sprite_dx,y
bmi flipX
cmp #MAXPOSX cmp #MAXPOSX
bpl flipX bcc movex_end
lda #-1
sta sprite_dirx,y
lda #MAXPOSX
movex_end
; Store the new X ; Store the new X
sta sprite_x,y sta sprite_x,y
movey movey
; Apply Y velocity to Y coordinate ; Apply Y velocity to Y coordinate
lda sprite_diry,y
bpl move_down
sec
lda sprite_y,y
sbc sprite_dy,y
cmp #MAXPOSY ; checking wraparound
bcc movey_end ; less than => not wrapped
lda #1
sta sprite_diry,y
lda #0
sta sprite_y,y
bpl movenext
move_down
clc clc
lda sprite_y,y lda sprite_y,y
adc sprite_dy,y adc sprite_dy,y
bmi flipY
cmp #MAXPOSY cmp #MAXPOSY
bpl flipY bcc movey_end
lda #-1
sta sprite_diry,y
lda #MAXPOSY
; Store the new Y movey_end
; Store the new X
sta sprite_y,y sta sprite_y,y
movenext movenext
@ -122,23 +156,6 @@ moveend
rts rts
flipX
lda sprite_dx,y
eor #$ff
clc
adc #1
sta sprite_dx,y
jmp movey
flipY
lda sprite_dy,y
eor #$ff
clc
adc #1
sta sprite_dy,y
jmp movenext
wait wait
ldy #$06 ; Loop a bit ldy #$06 ; Loop a bit
@ -193,16 +210,23 @@ sprite_h
.byte >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE .byte >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE, >BWSPRITE
sprite_x sprite_x
.byte 80, 64, 33, 83, 4, 9, 55, 18 .byte 80, 164, 33, 245, 4, 9, 255, 18
sprite_y sprite_y
.byte 116, 126, 40, 60, 80, 100, 120, 140 .byte 116, 126, 40, 60, 80, 100, 120, 140
sprite_dx sprite_dx
.byte -1, -2, -3, -4, 1, 2, 3, 4 .byte 1, 2, 3, 4, 1, 2, 3, 4
sprite_dirx
.byte -1, -1, -1, -1, 1, 1, 1, 1
sprite_dy sprite_dy
.byte -4, -3, -2, -1, 4, 3, 2, 1 .byte 4, 3, 2, 1, 4, 3, 2, 1
sprite_diry
.byte 1, 1, 1, 1, -1, -1, -1, -1
.include colorsprite.s .include colorsprite.s