dos33fsprogs/games/tfv/gr_putsprite_crop.s
2021-01-11 15:20:43 -05:00

360 lines
7.4 KiB
ArmAsm

;=============================================
; put_sprite_crop
;=============================================
; Sprite to display in INH,INL
; Location is XPOS,YPOS
; Note, only works if YPOS is multiple of two
; transparent color is $A (grey #2)
; this means we can have black ($0) in a sprite
; FIXME: force YPOS to be even?
put_sprite_crop:
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_crop_loop:
sty TEMP ; save sprite pointer ; 3
ldy TEMPY ; 3
bpl put_sprite_crop_pos ; if < 0, skip to next
clc ; skip line in sprite too
lda TEMP
adc CH
tay
bne crop_increment_y
put_sprite_crop_pos:
psc_smc1:
cpy #48 ; bge if >= 48, done sprite
bcs crop_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
crop_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 #$0 ; 2
; check if completely transparent
; if so, skip
cmp #$aa ; if all zero, transparent ; 2
beq crop_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 #$f0 ; check if top nibble zero ; 2
cmp #$a0
bne crop_put_sprite_bottom ; if not skip ahead ; 2nt/3
;==============
; 7/8
lda COLOR
and #$0f
sta COLOR
lda #$f0 ; setup mask ; 2
sta MASK ; 3
bmi crop_put_sprite_mask ; always? ; 3
;=============
; 8
crop_put_sprite_bottom:
lda COLOR ; re-load color ; 3
and #$0f ; check if bottom nibble zero ; 2
cmp #$0a
bne crop_put_sprite_all ; if not, skip ahead ; 2nt/3
;=============
; 7/8
lda COLOR
and #$f0
sta COLOR
lda #$0f ; 2
sta MASK ; setup mask ; 3
;===========
; 5
crop_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 crop_put_sprite_done_draw ; we are done ; 3
;===========
; 20
crop_put_sprite_all:
lda COLOR ; load color ; 3
sta (OUTL),Y ; and write it out ; 6
;============
; 9
crop_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 crop_put_sprite_pixel ; if not done, keep looping ; 2nt/3
;==============
; 12/13
crop_increment_y:
inc TEMPY ; each line has two y vars ; 5
inc TEMPY ; 5
dec CV ; decemenet total y count ; 5
bne put_sprite_crop_loop ; loop if not done ; 2nt/3
;==============
; 17/18
crop_sprite_done:
rts ; return ; 6
; 0,0 = 400+0
; -1,0 = 400+ff=4ff, inc=400
; sprite: 5x4
;
; -2,0 Xstart=0, sprite_offset=2, xsize=3
; -1,0, Xstart=0, sprite_offset=1, xsize=4
; 0,0, Xstrat=0, sprite_offset=0, xsize=5
; 1,0, Xstart=1, sprite_offset=0, xsize=5
;
; 39,0 Xstart=39, sprite_offset=0, xsize=1
;
;
;
;
.if 0
;=============================================
; put_sprite_flipped_crop
;=============================================
; Sprite to display in INH,INL
; Location is XPOS,YPOS
; Note, only works if YPOS is multiple of two
; transparent color is $A (grey #2)
; this means we can have black ($0) in a sprite
put_sprite_flipped_crop:
ldy #0 ; byte 0 is xsize ; 2
lda (INL),Y ; 5
sta CH ; xsize is in CH ; 3
iny ; 2
lda (INL),Y ; byte 1 is ysize ; 5
sta CV ; ysize is in CV ; 3
dey ; make Y zero again ; 2
lda INH ; ???
sta ppfc_smc+2
clc
lda INL
adc #1 ; add one (not two) because X counts
; from CH to 1 (not CH-1 to 0)
sta ppfc_smc+1
bcc psfc16
inc ppfc_smc+2
psfc16:
lda YPOS ; make a copy of ypos ; 3
sta TEMPY ; as we modify it ; 3
;===========
; 28
put_spritefc_loop:
; sty TEMP ; save sprite pointer ; 3
ldy TEMPY ; 3
bmi fcrop_increment_y ; if < 0, skip to next
psc_smc2:
cpy #48 ; bge if >= 48, done sprite
bcs fcrop_sprite_done
lda gr_offsets,Y ; lookup low-res memory address ; 4
clc ; 2
adc XPOS ; add in xpos ; 3
sta OUTL ; store out low byte of addy ; 3
lda gr_offsets+1,Y ; look up high byte ; 4
clc
adc DRAW_PAGE ; ; 3
sta OUTH ; and store it out ; 3
; ldy TEMP ; restore sprite pointer ; 3
; OUTH:OUTL now points at right place
ldx CH ; load xsize into x ; 3
;===========
; 34
put_spritefc_pixel:
clc
txa ; want (CH-X-1)+XPOS
eor #$ff
adc CH
adc XPOS
bmi cskip_drawing
cmp #40
bcs cskip_drawing ; if off-screen right, skip draw
ppfc_smc:
lda $C000,X ; get sprite colors ; 5
; iny ; increment sprite pointer ; 2
; sty TEMP ; save sprite pointer ; 3
ldy #$0 ; 2
; check if completely transparent
; if so, skip
cmp #$aa ; if all zero, transparent ; 2
beq put_spritefc_done_draw ; don't draw it ; 2nt/3
;==============
; 16/17
sta COLOR ; save color for later ; 3
; check if top pixel transparent
and #$f0 ; check if top nibble zero ; 2
cmp #$a0
bne put_spritefc_bottom ; if not skip ahead ; 2nt/3
;==============
; 7/8
lda COLOR
and #$0f
sta COLOR
lda #$f0 ; setup mask ; 2
sta MASK ; 3
bmi put_spritefc_mask ; always? ; 3
;=============
; 8
put_spritefc_bottom:
lda COLOR ; re-load color ; 3
and #$0f ; check if bottom nibble zero ; 2
cmp #$0a
bne put_spritefc_all ; if not, skip ahead ; 2nt/3
;=============
; 7/8
lda COLOR
and #$f0
sta COLOR
lda #$0f ; 2
sta MASK ; setup mask ; 3
;===========
; 5
put_spritefc_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_spritefc_done_draw ; we are done ; 3
;===========
; 20
put_spritefc_all:
lda COLOR ; load color ; 3
sta (OUTL),Y ; and write it out ; 6
;============
; 9
put_spritefc_done_draw:
cskip_drawing:
; ldy TEMP ; restore sprite pointer ; 3
inc OUTL ; increment output pointer ; 5
dex ; decrement x counter ; 2
bne put_spritefc_pixel ; if not done, keep looping ; 2nt/3
;==============
; 12/13
fcrop_increment_y:
inc TEMPY ; each line has two y vars ; 5
inc TEMPY ; 5
lda CH
clc
adc ppfc_smc+1
sta ppfc_smc+1
bcc psfco
inc ppfc_smc+2
psfco:
dec CV ; decemenet total y count ; 5
beq fcrop_sprite_done ; loop if not done ; 2nt/3
jmp put_spritefc_loop
;==============
; 17/18
fcrop_sprite_done:
rts ; return ; 6
.endif