dos33fsprogs/graphics/both/gears/dsr_bot.s
2022-10-11 03:47:24 -04:00

193 lines
3.5 KiB
ArmAsm

; dsr rotate lores
; by deater (Vince Weaver) <vince@deater.net>
; 147 bytes -- original attempt
; 145 bytes -- hires address tables in zero page
; 143 bytes -- optimize table init some more
; 138 bytes -- swap X and Y in lores code
; 136 bytes -- remove unnecessary compare
; 135 bytes -- realize with shift, hclr is unneccesary
; 134 bytes -- optimize Y usage in inner loop
; 132 bytes -- don't need to init rotate?
; 135 bytes -- bot jump
; Zero Page
GBASL = $26
GBASH = $27
COLOR = $30
HGR_X = $E0
HGR_Y = $E2
HGR_COLOR = $E4
HGR_HORIZ = $E5
HGR_PAGE = $E6
HGR_SCALE = $E7
ROTATION = $FA
COUNT = $FC
YY = $FD
BB = $FE
XX = $FF
; Soft Switches
SET_GR = $C050
SET_TEXT = $C051
FULLGR = $C052
TEXTGR = $C053
PAGE1 = $C054 ; Page1
PAGE2 = $C055 ; Page2
LORES = $C056 ; Enable LORES graphics
HIRES = $C057 ; Enable HIRES graphics
; ROM routines
HGR = $F3E2
HGR2 = $F3D8
HCLR = $F3F2
HPLOT0 = $F457 ; plot at (Y,X), (A)
WAIT = $FCA8 ; delay 1/2(26+27A+5A^2) us
HPOSN = $F411 ; (Y,X),(A) (valued stores in HGRX,XH,Y)
PLOT = $F800 ;; PLOT AT Y,A
SETCOL = $F864 ;; COLOR=A
XDRAW0 = $F65D
hgr_lookup_h = $40 ; $40-$70
hgr_lookup_l = $70 ; $70-$A0
;hgr_lookup_h = $1000
;hgr_lookup_l = $1100
dsr_rotate:
;===================
; init screen
jsr HGR ; clear PAGE1
; A,Y are 0?
bit FULLGR
;===================
; init vars
; sta ROTATION ; start at 0
; not needed if don't care start?
ldx #4
stx HGR_SCALE
;===================
; int tables
ldx #47
init_loop:
txa
jsr HPOSN ; important part is A=ycoord
ldx HGR_Y ; A value stored in HGR_Y
lda GBASL
sta hgr_lookup_l,X
lda GBASH
sta hgr_lookup_h,X
dex
bpl init_loop
bit LORES
big_loop:
;=====================================
; draw dsr
draw_dsr:
ldy #0 ; Y 0 here from HCLR
ldx #15
lda #20
jsr HPOSN ; set screen position to X= (y,x) Y=(a)
; saves X,Y,A to zero page
; after Y= orig X/7
; A and X are ??
ldx #<shape_dsr ; point to bottom byte of shape address
ldy #>shape_dsr ; point to top byte of shape address
; ROT in A
lda ROTATION ; ROT=0
jsr XDRAW0 ; XDRAW 1 AT X,Y
; Both A and X are 0 at exit
; Z flag set on exit
;===============================
; copy to lores
; X654 3210 X654 3210
ldy #47
sty YY ; set y-coord to 47
lsier_outer:
ldx YY ; a bit of a wash
lda hgr_lookup_l,X
sta hgr_scrn_smc+1
lda hgr_lookup_h,X
sta hgr_scrn_smc+2
ldx #0
ldy #0 ; COUNT
lsier_inner:
lda #6
sta BB
lsier_inner_inner:
hgr_scrn_smc:
lsr $2000,X ; note this also clears screen
lda #0
bcs no_color
lda YY ; get Y-coord into A
no_color:
jsr SETCOL
lda YY ; y-coord in A
; x-coord already in Y
jsr PLOT ; plot at Y,A
iny ; increment count
cpy #40 ; if hit 40, done
beq done_line
dec BB ; decrement byte count
bpl lsier_inner_inner ; if <7 then keep shifting
inx ; increment hires-x value
bne lsier_inner ; bra
done_line:
dec YY ; decrement y-coord
bpl lsier_outer ; until less than 0
end:
inc ROTATION
inc ROTATION
jmp big_loop
shape_dsr:
.byte $2d,$36,$ff,$3f
.byte $24,$ad,$22,$24,$94,$21,$2c,$4d
.byte $91,$3f,$36,$00
; $3F5 - 130 = $373
for_bot:
jmp dsr_rotate