100 REM  'HIRES'  CIRCLE - POLYGON
110 REM  SOURCE FILE BY ANTHONY BRYANT
120 SYS 700
130 .OPT N
140 ;
150 ;
160 ;"HIRES" VARIABLES BY G.KIZIAK
170 X1   = $C027 ;CURRENT POSITION
180 Y1   = $C029
190 X2   = $C02B ;NEW POSITION
200 Y2   = $C02D
210 XC   = $C02F ;CIRC CENTRE (ALSO BOX)
220 YC   = $C031
230 HM   = $C035 ;HIRES/MULTI FLAG
240 ;
250 ;
260 ;"HIRES" INTERNAL SUBROUTINES
270 IGETI =$C17C ;INTERNAL GET INTEGER
280 IEGET =$C187 ;INTERNAL EAT & GET X,Y
290 MOVE  =$C26E ;'MOVE' RTN
300 IMOV  =$C271 ;INTERNAL MOVETO X1,Y1
310 IPLT  =$C375 ;INTERNAL PLOT
320 IDRW  =$C42B ;INTERNAL DRAWTO
330 ;
340 ;ZERO PAGE LABELS
350 THETA = $57  ;THE ANGLE (0-90DEG)
360 YSIGN = $58  ;DEPENDENT ON QUADRANT
370 XSIGN = $59  ;    "          "
380 ;
390 *=$8000      ;423 BYTES
400 ;
410 XR     .WOR 0  ;X RADIUS
420 YR     .WOR 0  ;Y RADIUS
430 ARCST  .WOR 0  ;ARC START (DEG)
440 ARCEND .WOR 360;ARC END ANGL (DEG)
450 DELTA  .BYT 5  ;POLY(null)N INCR (DEG)
460 ;
470 ;SUBROUTINE GET ANGLE (DEG) INTEGER
480 ;ACCURACY TO 1 DEG   (HEX 5A=90DEG)
490 GETAN PHA  ;SAVE ACC
500 JSR $0079
510 BEQ NOMORE
520 JSR $AEFD  ;EAT ","
530 CMP #","
540 BEQ NOMORE ;ANOTHER "," !
550 PLA        ;THROW AWAY ACC
560 JMP IGETI  ;GET INTEGER TO .A & .X
570 NOMORE PLA
580 RTS ;RESULT IN .A & .X
590 ;
600 ;SUBROUTINE MOVETO XC,YC
610 MOVC LDX #3
620 LDA X2,X
630 STA XC,X
640 DEX
650 BPL MOVC+2
660 RTS
670 ;
680 ;SUBROUTINE MOVETO XR,YR
690 MOVR LDX #3
700 LDA X2,X
710 STA XR,X
720 DEX
730 BPL MOVR+2
740 RTS
750 ;
760 ;SYS CIRCLE,XC,YC,XR,YR[,SA,EA,INC]
770 CIRCLE = *
780 JSR IEGET
790 JSR MOVC   ;MOVETO XC,YC
800 JSR IEGET
810 JSR MOVR   ;MOVETO XR,YR
820 LDA #0
830 LDX #0     ;DEFAULT ARCST
840 JSR GETAN  ;GET SA (DEGREES)
850 STA ARCST
860 STX ARCST+1
870 LDA #<360
880 LDX #>360;DEFAULT ARCEND
890 JSR GETAN  ;GET EA (DEGREES)
900 STA ARCEND
910 STX ARCEND+1
920 LDA #5             ;DEFAULT DELTA
930 JSR GETAN  ;GET INC (DEGREES)
940 TAX
950 BNE CRC1
960 LDA #1    ;MINIMUM
970 CRC1 STA DELTA
980 LDA #0
990 STA $5B
1000 STA $5C
1010 LOOP LDA ARCST
1020 LDX ARCST+1
1030 LDY #$FF
1040 ;FIND QUADRANT AND ANGLE THETA
1050 LP2 INY
1060 SEC
1070 SBC #$5A
1080 BCS LP2
1090 DEX
1100 BPL LP2  ;.Y=QUADN (0-3)
1110 ADC #$5A
1120 STA THETA  ;(0-90DEG)
1130 TYA
1140 LSR
1150 BCC LP3
1160 LDA #$5A
1170 SEC
1180 SBC THETA
1190 STA THETA
1200 LP3 TYA
1210 LSR
1220 LSR
1230 ROR
1240 STA YSIGN
1250 TYA
1260 AND #3
1270 BEQ LP4
1280 SEC
1290 SBC #3
1300 LP4 STA XSIGN
1310 ;DO YR*SIN(THETA)
1320 LDA YR
1330 LDX YR+1
1340 JSR CALCSIN
1350 LDY YSIGN
1360 JSR ABSV ;CHECK Y SIGN
1370 CLC
1380 ADC YC
1390 STA Y2
1400 TXA
1410 ADC YC+1
1420 STA Y2+1
1430 ;DO XR*COS(THETA)
1440 LDA XR
1450 LDX XR+1
1460 JSR CALCCOS
1470 LDY XSIGN
1480 JSR ABSV ;CHECK X SIGN
1490 CLC
1500 ADC XC
1510 STA X2
1520 TXA
1530 ADC XC+1
1540 STA X2+1
1550 LDX $5B
1560 BEQ LP5    ;FLAG A MOVETO
1570 JSR IDRW   ;DRAWTO
1580 LDX $5C
1590 BEQ LP6
1600 RTS
1610 LP5 DEC $5B  ;CANCEL FLAG
1620 JSR IMOV     ;MOVETO
1630 LP6 LDA DELTA
1640 CLC
1650 ADC ARCST
1660 STA ARCST
1670 BCC LP7
1680 INC ARCST+1
1690 LP7 LDA ARCST
1700 CMP ARCEND
1710 LDA ARCST+1
1720 SBC ARCEND+1
1730 BCC LP8
1740 DEC $5C  ;CANCEL FLAG
1750 LP8 JMP LOOP
1760 ;
1770 ;SUBROUTINE ABSOLUTE VALUE
1780 ABSV BPL ABOK
1790 CLC
1800 EOR #$FF
1810 ADC #1
1820 PHA
1830 TXA
1840 EOR #$FF
1850 ADC #0
1860 TAX
1870 PLA
1880 ABOK RTS ;RESULT IN .A & .X
1890 ;
1900 ;SUBROUTINE CALCULATE SINE FUNC
1910 CALCCOS PHA
1920 LDA #$5A
1930 SEC
1940 SBC THETA ;(90-THETA)
1950 TAY
1960 PLA
1970 .BYT $2C
1980 CALCSIN LDY THETA
1990 STX $15 ;HIBYT
2000 LDX SINE,Y
2010 CALC STX $22
2020 STA $14 ;LOBYT
2030 LDA #0
2040 STA $23
2050 LDX #8 ;16BIT*FRACT
2060 CAL2 LSR $22
2070 BCC CAL3
2080 CLC
2090 ADC $14
2100 PHA
2110 LDA $23
2120 ADC $15
2130 STA $23
2140 PLA
2150 CAL3 LSR $23
2160 ROR
2170 DEX
2180 BNE CAL2
2190 STA $22 ;RESLO IN .A
2200 LDX $23
2210 RTS ;RESHI IN .X
2220 ;
2230 SINE = * ;TABLE OF SINES (0-90 DEG)
2240 .BYT $00,$04,$09,$0D,$12,$16,$1B,$1F
2250 .BYT $24,$28,$2C,$31,$35,$3A,$3E,$42
2260 .BYT $47,$4B,$4F,$53,$58,$5C,$60,$64
2270 .BYT $68,$6C,$70,$74,$78,$7C,$80,$84
2280 .BYT $88,$8B,$8F,$93,$96,$9A,$9E,$A1
2290 .BYT $A5,$A8,$AB,$AF,$B2,$B5,$B8,$BB
2300 .BYT $BE,$C1,$C4,$C7,$CA,$CC,$CF,$D2
2310 .BYT $D4,$D7,$D9,$DB,$DE,$E0,$E2,$E4
2320 .BYT $E6,$E8,$EA,$EC,$ED,$EF,$F1,$F2
2330 .BYT $F3,$F5,$F6,$F7,$F8,$F9,$FA,$FB
2340 .BYT $FC,$FD,$FE,$FE,$FF,$FF,$FF,$FF
2350 .BYT $FF,$FF,$FF
2360 ;
2370 .END