mirror of
https://github.com/deater/dos33fsprogs.git
synced 2024-09-10 08:54:51 +00:00
264 lines
4.5 KiB
ArmAsm
264 lines
4.5 KiB
ArmAsm
; ANGLE in our case it's 0..15?
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CAL = $B0
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CAH = $B1
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SAL = $B2
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SAH = $B3
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YPL = $B4
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YPH = $B5
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XPL = $B6
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XPH = $B7
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;YY
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;XX
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CCAL = $B8
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CCAH = $B9
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CSAL = $BA
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CSAH = $BB
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YCAL = $BC
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YCAH = $BD
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YSAL = $BE
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YSAH = $BF
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rotozoom:
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; ca = cos(theta)*scale;
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; ca=fixed_sin[(theta+4)&0xf]
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lda ANGLE ; 3
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clc ; 2
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adc #4 ; 2
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and #$f ; 2
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asl ; 2
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tay ; 2
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lda fixed_sin,Y ; load integer half ; 4
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sta CAH ; 3
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lda fixed_sin+1,Y ; load integer half ; 4
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sta CAL ; 3
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;===========
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; 27
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; sa = sin(theta)*scale;
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lda ANGLE ; 3
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asl ; 2
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tay ; 2
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lda fixed_sin,Y ; load integer half ; 4
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sta SAH ; 3
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lda fixed_sin+1,Y ; load integer half ; 4
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sta SAL ; 3
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;==========
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; 21
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; cca = -20*ca;
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; csa = -20*sa;
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lda #0 ; 2
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sta CCAL ; 3
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sta CCAH ; 3
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sta CSAL ; 3
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sta CSAH ; 3
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;===========
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; 14
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ldx #20 ; 2
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mul20_loop:
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sec ; 2
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lda CCAL ; 3
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sbc CAL ; 3
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sta CCAL ; 3
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lda CCAH ; 3
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sbc CAH ; 3
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sta CCAH ; 3
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;===========
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; 20
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sec ; 2
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lda CSAL ; 3
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sbc SAL ; 3
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sta CSAL ; 3
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lda CSAH ; 3
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sbc SAH ; 3
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sta CSAH ; 3
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;===========
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; 20
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dex ; 2
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bne mul20_loop ;2nt/3
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;===================
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; total=2+(45*20)-1
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; 901 cycles
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; yca=cca+ycenter;
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lda CCAL ; 3
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sta YCAL ; 3
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clc ; 2
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lda CCAH ; 3
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adc #20 ; 2
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sta YCAH ; 3
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;===========
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; 16
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; ysa=csa+xcenter;
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lda CSAL ; 3
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sta YSAL ; 3
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clc ; 2
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lda CSAH ; 3
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adc #20 ; 2
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sta YSAH ; 3
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;===========
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; 16
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; for(yy=0;yy<40;yy++) {
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lda #0 ; 2
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sta YY ; 3
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rotozoom_yloop:
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; xp=cca+ysa;
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clc ; 2
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lda YSAL ; 3
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adc CCAL ; 3
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sta XPL ; 3
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lda YSAH ; 3
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adc CCAH ; 3
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sta XPH ; 3
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;==========
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; 20
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; yp=yca-csa;
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sec ; 2
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lda YCAL ; 3
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sbc CSAL ; 3
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sta YPL ; 3
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lda YCAH ; 3
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sbc CSAH ; 3
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sta YPH ; 3
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;===========
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; 20
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; for(xx=0;xx<40;xx++) {
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lda #0 ; 2
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sta XX ; 3
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rotozoom_xloop:
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; if ((xp<0) || (xp>39)) color=0;
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; else if ((yp<0) || (yp>39)) color=0;
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; else color=scrn_page(xp,yp,PAGE2);
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lda #0 ; 2
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ldx XPH ; 3
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bmi rotozoom_set_color ; 2nt/3
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cpx #40 ; 2
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bcs rotozoom_set_color ; 2nt/3
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ldx YPH ; 3
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bmi rotozoom_set_color ; 2nt/3
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cpx #40 ; 2
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bcs rotozoom_set_color ; 2nt/3
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; scrn(xp,yp)
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lda XPH ; 3
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sta XPOS ; 3
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lda YPH ; 3
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sta YPOS ; 3
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jsr scrn ; 6+??
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rotozoom_set_color:
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; color_equals(color);
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jsr SETCOL ; 6+??
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; plot(xx,yy);
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lda XX ; 3
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sta XPOS ; 3
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lda YY ; 3
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sta YPOS ; 3
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jsr plot ; 6+??
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; xp=xp+ca;
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clc ; 2
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lda CAL ; 3
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adc XPL ; 3
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sta XPL ; 3
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lda CAH ; 3
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adc XPH ; 3
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sta XPH ; 3
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; yp=yp-sa;
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sec ; 2
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lda YPL ; 3
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sbc SAL ; 3
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sta YPL ; 3
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lda YPH ; 3
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sbc SAH ; 3
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sta YPH ; 3
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rotozoom_end_xloop:
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inc XX ; 5
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lda XX ; 3
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cmp #40 ; 2
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bne rotozoom_xloop ; 2nt/3
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; yca+=ca;
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clc ; 2
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lda YCAL ; 3
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adc CAL ; 3
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sta YCAL ; 3
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lda YCAH ; 3
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adc CAH ; 3
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sta YCAH ; 3
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;===========
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; 20
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; ysa+=sa;
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clc ; 2
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lda YSAL ; 3
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adc SAL ; 3
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sta YSAL ; 3
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lda YSAH ; 3
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adc SAH ; 3
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sta YSAH ; 3
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;==========
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; 20
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rotozoom_end_yloop:
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inc YY ; 5
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lda YY ; 3
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cmp #40 ; 2
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beq done_rotozoom ; 2nt/3
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jmp rotozoom_yloop ; too far ; 3
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done_rotozoom:
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rts ; 6
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fixed_sin:
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.byte $00,$00 ; 0.000000=00.00
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.byte $00,$61 ; 0.382683=00.61
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.byte $00,$b5 ; 0.707107=00.b5
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.byte $00,$ec ; 0.923880=00.ec
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.byte $01,$00 ; 1.000000=01.00
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.byte $00,$ec ; 0.923880=00.ec
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.byte $00,$b5 ; 0.707107=00.b5
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.byte $00,$61 ; 0.382683=00.61
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.byte $00,$00 ; 0.000000=00.00
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.byte $ff,$9f ; -0.382683=ff.9f
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.byte $ff,$4b ; -0.707107=ff.4b
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.byte $ff,$14 ; -0.923880=ff.14
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.byte $ff,$00 ; -1.000000=ff.00
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.byte $ff,$14 ; -0.923880=ff.14
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.byte $ff,$4b ; -0.707107=ff.4b
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.byte $ff,$9f ; -0.382683=ff.9f
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