hgr: more work on hgr starfield

including accidental cool effect
This commit is contained in:
Vince Weaver 2021-06-13 01:10:36 -04:00
parent 4c6ea54f22
commit c9ce996ad4
6 changed files with 390 additions and 33 deletions

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@ -16,7 +16,8 @@ appleiibot.dsk: E2.BAS FLAME.BAS FLAME2.BAS HELLO \
C64.BAS SIERPINSKI.BAS FAKES.BAS SIER.BAS DROPS.BAS RR.BAS RR_HGR.BAS \
COMBO.BAS WIRES.BAS PATTERN.BAS BALL.BAS LINES.BAS MOD9.BAS \
XOR_ZOOM.BAS MOD9_HGR.BAS SIER_HGR.BAS MOVE.BAS SINE.BAS XDRAW128.BAS \
GATOR.BAS CURSOR.BAS STARGATE.BAS TUNNEL.BAS STARFIELD.BAS
GATOR.BAS CURSOR.BAS STARGATE.BAS TUNNEL.BAS STARFIELD.BAS \
STAROOPS.BAS
# cp $(EMPTY_DISK)/empty.dsk appleiibot.dsk
cp empty.dsk appleiibot.dsk
@ -86,6 +87,7 @@ appleiibot.dsk: E2.BAS FLAME.BAS FLAME2.BAS HELLO \
$(DOS33) -y appleiibot.dsk SAVE A STARGATE.BAS
$(DOS33) -y appleiibot.dsk SAVE A TUNNEL.BAS
$(DOS33) -y appleiibot.dsk SAVE A STARFIELD.BAS
$(DOS33) -y appleiibot.dsk SAVE A STAROOPS.BAS
####
@ -274,6 +276,11 @@ TUNNEL.BAS: tunnel.bas
STARFIELD.BAS: starfield.bas
$(TOKENIZE) < starfield.bas > STARFIELD.BAS
####
STAROOPS.BAS: staroops.bas
$(TOKENIZE) < staroops.bas > STAROOPS.BAS
####

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@ -0,0 +1,2 @@
1FORI=0TO131:POKE884+I,4*PEEK(2125+I)-192+(PEEK(2257+I/3)-35)/4^(I-INT(I/3)*3):NEXT
2&",clU68V.b*lX.V7,fnV/Qh]\+d0FGb`\:b0T0OoQK]P7g/JPZUDe0l2aiQnVQWoX08=kYnC`,7a.b4X:^Rn^,kUS^0kU\\0l3N2/U0foH.31?o6I0Xob>m04nV:./Bo6H7J0S1PKFS4'W4#$G43*#%-%I#F#6.F?3'(,@(130(&$%;&S

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@ -7,12 +7,14 @@ EMPTY_DISK = ../../../empty_disk
all: starfield.dsk
starfield.dsk: HELLO STARS FASTAR STARBOT
starfield.dsk: HELLO STARS FASTAR STARBOT STARTINY STAROOPS
cp $(EMPTY_DISK)/empty.dsk starfield.dsk
$(DOS33) -y starfield.dsk SAVE A HELLO
$(DOS33) -y starfield.dsk BSAVE -a 0x0300 STARS
$(DOS33) -y starfield.dsk BSAVE -a 0x0C00 FASTAR
$(DOS33) -y starfield.dsk BSAVE -a 0x0C00 STARBOT
$(DOS33) -y starfield.dsk BSAVE -a 0x0C00 STARTINY
$(DOS33) -y starfield.dsk BSAVE -a 0x0374 STAROOPS
###
@ -44,6 +46,23 @@ STARBOT: starbot.o
starbot.o: starbot.s
ca65 -o starbot.o starbot.s -l starbot.lst
###
STARTINY: startiny.o
ld65 -o STARTINY startiny.o -C $(LINKER_SCRIPTS)/apple2_c00.inc
startiny.o: startiny.s
ca65 -o startiny.o startiny.s -l startiny.lst
###
STAROOPS: staroops.o
ld65 -o STAROOPS staroops.o -C $(LINKER_SCRIPTS)/apple2_374.inc
staroops.o: staroops.s
ca65 -o staroops.o staroops.s -l staroops.lst
###

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@ -3,17 +3,27 @@
; by Vince `deater` Weaver
; 139 bytes -- lores version
; 157 bytes -- initial hires
; 155 bytes -- scale to more of full screen
; 153 bytes -- blue/orange instead of purple/green
; 149 bytes -- optimize 2nd plot arg shuffling
NUMSTARS = 27 ; 27 good, 28+ not work ($1C)
; zero page locations
COLOR = $30
star_z = $00
star_z = $60
oldx = $70
oldy = $80
HGR_BITS = $1C
; 1C-40 has some things used by hires
oldx = $50
oldy = $70
star_x = $90
star_y = $A0
star_y = $B0
; D0+ used by HGR routines
HGR_COLOR = $E4
HGR_PAGE = $E6
@ -39,13 +49,14 @@ PLOT = $F800 ; PLOT AT Y,A (A colors output, Y preserved)
NEXTCOL = $F85F ; COLOR=COLOR+3
SETCOL = $F864 ; COLOR=A
SETGR = $FB40 ; set graphics and clear LO-RES screen
BELL2 = $FBE4
WAIT = $FCA8 ; delay 1/2(26+27A+5A^2) us
small_starfield:
;0GR:DIMV(64,48):FORZ=1TO48:FORX=0TO64:V(X,Z)=(X*4-128)/Z+20:NEXTX,Z
jsr HGR ; A is ? after
jsr HGR2 ; A is ? after
;===================================
; draw the stars
@ -54,7 +65,7 @@ small_starfield:
; there are ways to skip this, but on real hardware there's
; no guarantee star_z will be in a valid state, so waste the bytes
ldx #15
ldx #NUMSTARS
make_orig_stars:
jsr make_new_star
dex
@ -66,14 +77,16 @@ make_orig_stars:
;2FORP=0TO15
big_loop:
ldx #15
ldx #NUMSTARS
; really tried hard not to have to set this value
; hard to judge best value for this
lda #80
jsr WAIT
; jsr $FBE4 ; BEEP delays too
; lda #100
; jsr WAIT
ldy #30
jsr BELL2 ; BEEP delays too
; A now 0
@ -87,11 +100,13 @@ star_loop:
lda #$00 ; color to black
sta HGR_COLOR ; set HGR_COLOR to value in X
;PLOT O(P),Q(P)
;HPLOT O(P),Q(P)
stx SAVEX
ldy oldx,X
ldy oldx,X ; get X valu into Y
; tya
; tax
sty TEMP
lda oldy,X
ldx TEMP
@ -120,14 +135,19 @@ star_loop:
lda star_y,X ; get Y of star
jsr do_divide
adc #96
; if off-screen then need new star
bmi new_star ; if <0
cmp #40
cmp #192
bcs new_star ; bge >39
cmp #0
bcc new_star ; if <0
sta YY ; YY
sta oldy,X ; ;save for next time to erase
;==============================
; get X/Z
@ -138,14 +158,16 @@ star_loop:
lda star_x,X ; get X of start
jsr do_divide
adc #128
tay ; put XX in Y
sty oldx,X ; save for next time to erase
; if offscreen then draw new star
bmi new_star ; if <0
cpy #40
bcs new_star ; bge >40
; bmi new_star ; if <0
; cpy #40
; bcs new_star ; bge >40
;========================
; adjust Z
@ -158,8 +180,11 @@ star_loop:
draw_star:
lda #$7f ; white (with green/purple highlights)
sta HGR_COLOR ; set HGR_COLOR to value in X
; lda #$7f ; white (with green/purple highlights)
; sta HGR_COLOR ; set HGR_COLOR to value in X
dec HGR_COLOR ; smaller, but blue/orange highlights
;===========================
; actually plot the star
@ -169,16 +194,10 @@ draw_star:
stx SAVEX
tya ; XX in Y
tax ; XX now in X
lda YY ; YY
sta oldy,X ; ;save for next time to erase
; ldy XX ; XX already in Y
sty oldx,X ; save for next time to erase
sty TEMP
ldx TEMP
lda YY
ldy #0
@ -220,7 +239,7 @@ color_lookup:
sta star_y,X ; random YY
lda $F002,Y
and #$3f ; random ZZ 0..63
and #$7f ; random ZZ 0..127 (can't go negative or stars move backward)
ora #$1 ; avoid 0
sta star_z,X
@ -266,7 +285,7 @@ div_loop:
pos_add:
clc
do_add:
adc #20 ; pre-adjust to have star origin mid screen
early_out:
rts

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@ -0,0 +1,298 @@
; starfield tiny -- Apple II Hires
; by Vince `deater` Weaver
; 139 bytes -- lores version
; 157 bytes -- initial hires
; 155 bytes -- scale to more of full screen
; 153 bytes -- blue/orange instead of purple/green
; 149 bytes -- optimize 2nd plot arg shuffling
NUMSTARS = 27 ; 27 good, 28+ not work ($1C)
; zero page locations
star_z = $00
HGR_BITS = $1C
; 1C-40 has some things used by hires
oldx = $50
oldy = $70
star_x = $90
star_y = $B0
; D0+ used by HGR routines
HGR_COLOR = $E4
HGR_PAGE = $E6
SAVEX = $F8
TEMP = $F9
QUOTIENT = $FA
DIVISOR = $FB
DIVIDEND = $FC
XX = $FD
YY = $FE
FRAME = $FF
; soft-switches
; ROM routines
HGR2 = $F3D8 ; set hires page2 and clear $4000-$5fff
HGR = $F3E2 ; set hires page1 and clear $2000-$3fff
HPLOT0 = $F457 ; plot at (Y,X), (A)
HCOLOR1 = $F6F0 ; set HGR_COLOR to value in X
PLOT = $F800 ; PLOT AT Y,A (A colors output, Y preserved)
NEXTCOL = $F85F ; COLOR=COLOR+3
SETCOL = $F864 ; COLOR=A
SETGR = $FB40 ; set graphics and clear LO-RES screen
BELL2 = $FBE4
WAIT = $FCA8 ; delay 1/2(26+27A+5A^2) us
small_starfield:
;0GR:DIMV(64,48):FORZ=1TO48:FORX=0TO64:V(X,Z)=(X*4-128)/Z+20:NEXTX,Z
jsr HGR2 ; A is ? after
;===================================
; draw the stars
;===================================
; there are ways to skip this, but on real hardware there's
; no guarantee star_z will be in a valid state, so waste the bytes
ldx #NUMSTARS
make_orig_stars:
jsr make_new_star
dex
bpl make_orig_stars
;===================================
; starloop
;2FORP=0TO15
big_loop:
ldx #NUMSTARS
; really tried hard not to have to set this value
; hard to judge best value for this
; lda #100
; jsr WAIT
ldy #30
jsr BELL2 ; BEEP delays too
; A now 0
star_loop:
; X=FF
;===================
; erase old star
;4 COLOR=0
lda #$00 ; color to black
sta HGR_COLOR ; set HGR_COLOR to value in X
;HPLOT O(P),Q(P)
; stx SAVEX
; ldy oldx,X ; get X valu into Y
; tya
; tax
; sty TEMP
; lda oldy,X
; ldx TEMP
; ldy #0
; jsr HPLOT0 ; plot at (Y,X), (A)
; ldx SAVEX
;===========================
; position Z
; lda star_z,X
; beq new_star ; should never happen
; sta DIVISOR
; DIVISOR always star_z,X so can hard code this in divide routine
;==============================
; get Y/Z
; Y=V(B(P),Z(P))
; get YY
lda star_y,X ; get Y of star
jsr do_divide
adc #96
; if off-screen then need new star
cmp #192
bcs new_star ; bge >39
cmp #0
bcc new_star ; if <0
sta YY ; YY
sta oldy,X ; ;save for next time to erase
;==============================
; get X/Z
; X=V(A(P),Z(P))
; get XX
lda star_x,X ; get X of start
jsr do_divide
adc #128
tay ; put XX in Y
sty oldx,X ; save for next time to erase
; if offscreen then draw new star
; bmi new_star ; if <0
; cpy #40
; bcs new_star ; bge >40
;========================
; adjust Z
;Z(P)=Z(P)-1
dec star_z,X
beq new_star ; if Z=0 new star
; draw the star
draw_star:
; lda #$7f ; white (with green/purple highlights)
; sta HGR_COLOR ; set HGR_COLOR to value in X
dec HGR_COLOR ; smaller, but blue/orange highlights
;===========================
; actually plot the star
;HPLOT X,Y
; O(P)=X:Q(P)=Y
stx SAVEX
tya ; XX in Y
tax ; XX now in X
lda YY ; YY
ldy #0
jsr HPLOT0 ; plot at (Y,X), (A)
ldx SAVEX
jmp done_star ; bra
new_star:
jsr make_new_star ;
done_star:
;7NEXT
dex
bpl star_loop
; GOTO2
bmi big_loop ; bra
;===========================
; NEW STAR
;===========================
make_new_star:
;IFX<0ORX>39ORY<0ORY>39ORZ(P)<1THEN
; A(P)=RND(1)*64
; B(P)=RND(1)*64
; Z(P)=RND(1)*48+1:GOTO7
ldy FRAME
lda $F000,Y
sta star_x,X ; random XX
color_lookup:
lda $F100,Y
sta star_y,X ; random YY
lda $F002,Y
and #$7f ; random ZZ 0..127 (can't go negative or stars move backward)
ora #$1 ; avoid 0
sta star_z,X
inc FRAME
rts
;=============================
; do signed divide
; the signed part is the pain
;=============================
; Z is in divisor
; x/y is in A
do_divide:
; A was just loaded so flags still valid
php
bpl not_negative
eor #$ff ; make positive for division
clc ; is this necessary?
adc #1
not_negative:
ldy #$ff ; QUOTIENT
div_loop:
iny ; inc QUOTIENT
sec
sbc star_z,X ; DIVIDEND=DIVIDEND-DIVISOR
bpl div_loop
; write out quotient
tya ; lda QUOTIENT
plp
bpl pos_add
eor #$ff
; sec ; FIXME: made math inaccurate to save room
; bcs do_add
pos_add:
clc
do_add:
early_out:
rts
; for BASIC bot load
; need this to be at $3F5
; it's at 81, so 74
jmp small_starfield

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@ -0,0 +1,12 @@
MEMORY {
ZP: start = $00, size = $1A, type = rw;
RAM: start = $374, size = $8E00, file = %O;
}
SEGMENTS {
CODE: load = RAM, type = ro;
RODATA: load = RAM, type = ro;
DATA: load = RAM, type = rw;
BSS: load = RAM, type = bss, define = yes;
ZEROPAGE: load = ZP, type = zp;
}