mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-11-04 20:06:09 +00:00
138 lines
3.2 KiB
ArmAsm
138 lines
3.2 KiB
ArmAsm
|
|
;=============================================
|
|
; put_sprite
|
|
;=============================================
|
|
; Sprite to display in INH,INL
|
|
; Location is XPOS,YPOS
|
|
; Note, only works if YPOS is multiple of two
|
|
|
|
|
|
; time= 28 setup
|
|
; Y*outerloop
|
|
; outerloop = 34 setup
|
|
; X*innerloop
|
|
; innerloop = 30 if $00 17+13(done)
|
|
; 64 if $0X 16+7+8+20(put_sprite_mask)+13(done)
|
|
; 69 if $X0 16+8+7+5+20(put_sprite_mask)+13(done)
|
|
; 54 if if $XX 16+8+8+9(put_all)+13(done)
|
|
|
|
|
|
; -1 for last iteration
|
|
; 18 (-1 for last)
|
|
; 6 return
|
|
|
|
; so cost = 28 + Y*(34+18)+ (INNER-Y) -1 + 6
|
|
; = 33 + Y*(52)+(INNER-Y)
|
|
; = 33 + Y*(52)+ [30A + 64B + 69C + 54D]-Y
|
|
|
|
put_sprite:
|
|
|
|
ldy #0 ; byte 0 is xsize ; 2
|
|
lda (INL),Y ; 5
|
|
sta CH ; xsize is in CH ; 3
|
|
iny ; 2
|
|
|
|
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_loop:
|
|
sty TEMP ; save sprite pointer ; 3
|
|
ldy TEMPY ; 3
|
|
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
|
|
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 CH ; load xsize into x ; 3
|
|
;===========
|
|
; 34
|
|
put_sprite_pixel:
|
|
lda (INL),Y ; get sprite colors ; 5
|
|
iny ; increment sprite pointer ; 2
|
|
|
|
sty TEMP ; save sprite pointer ; 3
|
|
ldy #$0 ; 2
|
|
|
|
; check if completely transparent
|
|
; if so, skip
|
|
|
|
cmp #$0 ; if all zero, transparent ; 2
|
|
beq put_sprite_done_draw ; don't draw it ; 2nt/3
|
|
;==============
|
|
; 16/17
|
|
|
|
sta COLOR ; save color for later ; 3
|
|
|
|
; check if top pixel transparent
|
|
|
|
and #$f0 ; check if top nibble zero ; 2
|
|
bne put_sprite_bottom ; if not skip ahead ; 2nt/3
|
|
;==============
|
|
; 7/8
|
|
|
|
lda #$f0 ; setup mask ; 2
|
|
sta MASK ; 3
|
|
bmi put_sprite_mask ; always? ; 3
|
|
;=============
|
|
; 8
|
|
|
|
put_sprite_bottom:
|
|
lda COLOR ; re-load color ; 3
|
|
and #$0f ; check if bottom nibble zero ; 2
|
|
bne put_sprite_all ; if not, skip ahead ; 2nt/3
|
|
;=============
|
|
; 7/8
|
|
|
|
lda #$0f ; 2
|
|
sta MASK ; setup mask ; 3
|
|
;===========
|
|
; 5
|
|
|
|
put_sprite_mask:
|
|
lda (OUTL),Y ; get color at output ; 5
|
|
and MASK ; mask off unneeded part ; 3
|
|
ora COLOR ; or the color in ; 3
|
|
sta (OUTL),Y ; store it back ; 6
|
|
|
|
jmp put_sprite_done_draw ; we are done ; 3
|
|
;===========
|
|
; 20
|
|
|
|
put_sprite_all:
|
|
lda COLOR ; load color ; 3
|
|
sta (OUTL),Y ; and write it out ; 6
|
|
;============
|
|
; 9
|
|
|
|
put_sprite_done_draw:
|
|
|
|
ldy TEMP ; restore sprite pointer ; 3
|
|
|
|
inc OUTL ; increment output pointer ; 5
|
|
dex ; decrement x counter ; 2
|
|
bne put_sprite_pixel ; if not done, keep looping ; 2nt/3
|
|
;==============
|
|
; 12/13
|
|
|
|
inc TEMPY ; each line has two y vars ; 5
|
|
inc TEMPY ; 5
|
|
dec CV ; decemenet total y count ; 5
|
|
bne put_sprite_loop ; loop if not done ; 2nt/3
|
|
;==============
|
|
; 17/18
|
|
|
|
rts ; return ; 6
|
|
|
|
|