orb: optimizing, still not enough

This commit is contained in:
Vince Weaver 2022-02-02 12:30:14 -05:00
parent dbd4351b0e
commit 37828ba154
3 changed files with 61 additions and 31 deletions

View File

@ -56,9 +56,10 @@ rectangle_loop:
lda XRUN ; XRUN into A
and #$3f
ldx #0 ; always 0
ldy #0 ; relative Y is 0
jsr HLINRL ; (X,A),(Y)
; ldx #0 ; always 0
; ldy #0 ; relative Y is 0
; jsr HLINRL ; (X,A),(Y)
jsr combo_hlinrl
blah:
inc Y1

View File

@ -2,6 +2,9 @@
; 280 bytes -- initial combo
; 276 bytes -- shave some bytes
; 275 bytes -- common HLINRL function (thought it would save more)
; 271 bytes -- optimize circle draw code
; 268 bytes -- circle code now <128 so use bne instead of jmp
; zero page
@ -19,6 +22,7 @@ YY = $F9
MINUSYY = $FA
D = $FB
R = $FC
DADD = $FD
FRAME = $FF
; soft-switches
@ -57,6 +61,14 @@ combo:
.include "staggered.s"
.include "boxes.s"
; sadly this only saves a byte
combo_hlinrl:
ldy #0
ldx #0
jmp HLINRL ; plot relative (X,A), (Y)
even_lookup:
.byte $D7,$DD,$F5,$D5, $D5,$D5,$D5,$D5
odd_lookup:

View File

@ -4,8 +4,6 @@
; it's doing Bresenham circle algo I think, which does weird
; things when radius=0
; FIXME: assume hcolor is 3 somehow?
orb:
; a=0, y=0 here
@ -23,17 +21,12 @@ draw_next:
; draw circle at (CX,CY) of radius R
; signed 8-bit math so problems if R > 64?
; XX=0 YY=R
; D=3-2*R
; GOTO6
lda #0
sta XX
sta XX ; XX = 0
; lda R
stx YY
stx YY ; YY =R (X is R here)
lda #3
lda #3 ; D=3-2*R
sec
sbc R
sbc R
@ -41,20 +34,26 @@ draw_next:
; always odd, never zero
bne do_plots ; bra
bne do_plots ; bra skip ahead first time through
circle_loop:
; X=X+1
inc XX ; XX=XX+1
inc XX
lda XX ; XX is common both paths
ldy #6 ; default path add 6
; IF D>0 THEN Y=Y-1:D=D+4*(X-Y)+10
lda D
bmi else
bit D ; check if negative w/o changing A
bmi d_negative
dec YY
dec YY ; YY=YY-1
lda XX
.if 0
d_positive:
; D=D+4*(XX-YY)+10
; XX is already in A
sec
sbc YY
asl
@ -63,9 +62,9 @@ circle_loop:
adc #10
jmp store_D
else:
d_negative:
; ELSE D=D+4*X+6
lda XX
; lda XX
asl
asl
clc
@ -73,6 +72,25 @@ else:
store_D:
adc D
sta D
.endif
d_positive:
; D=D+4*(XX-YY)+10
; XX is already in A
sec
sbc YY
ldy #10
d_negative:
; ELSE D=D+4*(XX)+6
common_D:
sty DADD
asl
asl
clc
adc DADD
adc D
sta D
do_plots:
; setup constants
@ -109,6 +127,8 @@ pos_loop:
eor #$2
tay
; lda CX
lda #128
clc
adc XX,Y
@ -135,14 +155,14 @@ pos_loop:
lda XX,Y
asl
ldy #0
ldx #0
; ldy #0
; ldx #0
jsr HLINRL ; plot relative (X,A), (Y)
; jsr HLINRL ; plot relative (X,A), (Y)
jsr combo_hlinrl
; so in our case (0,XX*2),0
dec COUNT
bpl pos_loop
@ -157,10 +177,7 @@ done:
inx ; increment radius
jsr HCOLOR1 ; use as color
cpx #48 ; loop
beq rdone
; GOTO1
jmp draw_next
cpx #48 ; run until R=48
bne draw_next ; loop (GOTO 1)
rdone: