113 lines
2.3 KiB
ArmAsm
113 lines
2.3 KiB
ArmAsm
;=============================================
|
|
; put_sprite_raw
|
|
;=============================================
|
|
; Sprite to display in INH,INL
|
|
; Location is XPOS,YPOS
|
|
; Note, only works if YPOS is multiple of two
|
|
|
|
; no transparency, no cropping
|
|
|
|
; FIXME: force YPOS to be even?
|
|
|
|
put_sprite_raw:
|
|
|
|
ldy #0 ; byte 0 is xsize ; 2
|
|
lda (INL),Y ; 5
|
|
sta CH ; xsize is in CH ; 3
|
|
iny ; 2
|
|
clc
|
|
adc XPOS
|
|
sta XMAX
|
|
|
|
lda (INL),Y ; byte 1 is ysize ; 5
|
|
sta CV ; ysize is in CV ; 3
|
|
iny ; 2
|
|
|
|
lda YPOS ; make a copy of ypos ; 3
|
|
sta TEMPY ; as we modify it ; 3
|
|
;===========
|
|
; 28
|
|
put_sprite_raw_loop:
|
|
sty TEMP ; save sprite pointer ; 3
|
|
ldy TEMPY ; 3
|
|
|
|
bpl put_sprite_raw_pos ; if < 0, skip to next
|
|
|
|
clc ; skip line in sprite too
|
|
lda TEMP
|
|
adc CH
|
|
tay
|
|
|
|
bne raw_increment_y
|
|
|
|
put_sprite_raw_pos:
|
|
|
|
psr_smc1:
|
|
cpy #48 ; bge if >= 48, done sprite
|
|
bcs raw_sprite_done
|
|
|
|
|
|
lda gr_offsets,Y ; lookup low-res memory address ; 4
|
|
clc ; 2
|
|
adc XPOS ; add in xpos ; 3
|
|
sta OUTL ; store out low byte of addy ; 3
|
|
clc ; never wraps, handle negative
|
|
lda gr_offsets+1,Y ; look up high byte ; 4
|
|
adc DRAW_PAGE ; ; 3
|
|
sta OUTH ; and store it out ; 3
|
|
ldy TEMP ; restore sprite pointer ; 3
|
|
|
|
; OUTH:OUTL now points at right place
|
|
|
|
ldx XPOS ; load xposition into x ; 3
|
|
;===========
|
|
; 34
|
|
raw_put_sprite_pixel:
|
|
lda (INL),Y ; get sprite colors ; 5
|
|
iny ; increment sprite pointer ; 2
|
|
sty TEMP ; save sprite pointer ; 3
|
|
|
|
|
|
cpx #0 ; if off-screen left, skip draw
|
|
bmi skip_drawing
|
|
cpx #40
|
|
bcs skip_drawing ; if off-screen right, skip draw
|
|
|
|
ldy #$0 ; 2
|
|
|
|
|
|
sta COLOR ; save color for later ; 3
|
|
|
|
; check if top pixel transparent
|
|
|
|
|
|
raw_put_sprite_all:
|
|
lda COLOR ; load color ; 3
|
|
sta (OUTL),Y ; and write it out ; 6
|
|
;============
|
|
; 9
|
|
raw_put_sprite_done_draw:
|
|
skip_drawing:
|
|
|
|
ldy TEMP ; restore sprite pointer ; 3
|
|
|
|
inc OUTL ; increment output pointer ; 5
|
|
inx ; increment x counter ; 2
|
|
cpx XMAX
|
|
bne raw_put_sprite_pixel ; if not done, keep looping ; 2nt/3
|
|
;==============
|
|
; 12/13
|
|
raw_increment_y:
|
|
|
|
inc TEMPY ; each line has two y vars ; 5
|
|
inc TEMPY ; 5
|
|
dec CV ; decemenet total y count ; 5
|
|
bne put_sprite_raw_loop ; loop if not done ; 2nt/3
|
|
;==============
|
|
; 17/18
|
|
raw_sprite_done:
|
|
rts ; return ; 6
|
|
|
|
|
|
|