10 ' MSX2 BASIC ray tracer. Found on https://www.msx.org/nl/downloads/diskmagazines/sunrise-magazine/sunrise-magazine-03. 20 ' Slightly improved speed. Made SCREEN 8 default. 1000 ' screen init 1010 SCREEN 8,0:SET PAGE 1,1 1020 'SCREEN 12:SET PAGE 1,1 1030 CLS 1040 _TURBO ON 1050 ' initialize 1060 DIM T(9),V(15),O(19,7),S(19,7),RI(3),GI(3),BI(3),I(3),Z(3),Y(3) 1070 FOR I%=0 TO 9:READ T(I%):NEXT I% 1080 V(0)=T(0):V(1)=T(1):V(2)=T(2) 1090 V(9)=T(0)-T(3):V(10)=T(1)-T(4):V(11)=T(2)-T(5) 1100 V=SQR(V(9)*V(9)+V(10)*V(10)+V(11)*V(11)) 1110 V(9)=V(9)/V:V(10)=V(10)/V:V(11)=V(11)/V 1120 V(6)=-V(9)*V(10):V(7)=1-V(10)*V(10):V(8)=-V(11)*V(10) 1130 V(3)=-(V(10)*V(8)-V(11)*V(7)):V(4)=-(V(11)*V(6)-V(9)*V(8)) 1140 V(5)=-(V(9)*V(7)-V(10)*V(6)):V(15)=T(9) 1150 V(12)=T(6):V(13)=T(7):V(14)=T(8) 1160 READ MO%:FOR I%=0 TO MO%-1:FOR J%=0 TO 7:READ O(I%,J%):NEXT J%,I% 1170 READ MS%:FOR I%=0 TO MS%-1:FOR J%=0 TO 7:READ S(I%,J%):NEXT J%,I% 1180 MA=1000:MI=1E-03:MD=0 1190 FOR I%=1 TO 4 1200 V=SQR(V(I%*3+0)*V(I%*3+0)+V(I%*3+1)*V(I%*3+1)+V(I%*3+2)*V(I%*3+2)) 1210 V(I%*3+0)=V(I%*3+0)/V:V(I%*3+1)=V(I%*3+1)/V:V(I%*3+2)=V(I%*3+2)/V 1220 NEXT I% 1230 ' trace 1240 FOR SY%=0 TO 211 STEP 4:FOR SX%=0 TO 255 STEP 4:FOR YD%=0 TO 3:FOR XD%=0 TO 3 1250 CX=V(0):CY=V(1):CZ=V(2) 1255 XC = (SX%+XD%-128)/99: YC = (106-SY%-YD%)/99 'XCenter, YCenter 1260 VX=V(3)*XC+V(6)*YC-V(9)*V(15) 1270 VY=V(4)*XC+V(7)*YC-V(10)*V(15) 1280 VZ=V(5)*XC+V(8)*YC-V(11)*V(15) 1290 V=SQR(VX*VX+VY*VY+VZ*VZ) 1300 VX=VX/V:VY=VY/V:VZ=VZ/V 1310 CR=0:CG=0:CB=0:RN%=0:RF=1 1320 GOSUB 1760 1330 IF CR>=1 THEN CR=.99 1340 IF CG>=1 THEN CG=.99 1350 IF CB>=1 THEN CB=.99 1360 IF MD THEN 1420 1370 RI(XD%)=CR:GI(XD%)=CG:BI(XD%)=CB 1380 NEXT XD% 1390 GOSUB 1470 1400 NEXT YD% 1410 GOTO 1440 1420 FOR XD%=0 TO 3:RI(XD%)=CR:GI(XD%)=CG:BI(XD%)=CB:NEXT XD% 1430 FOR YD%=0 TO 3:GOSUB 1470:NEXT YD% 1440 IF STRIG(0) THEN END 1450 NEXT SX%,SY% 1460 IF NOT STRIG(0) THEN 1460 ELSE END 1470 ' draw 1480 'GOTO 1560:'IF YOU WONT TO SEE SCREEN8 PICTUER THEN DELETE THIS LINE 1490 'MAKE RGB DATA FOR SCREEN8 AND WRITE IT ON THE SCREEN 1500 FOR XD%=0 TO 3 1520 PSET(SX%+XD%,SY%+YD%),INT(GI(XD%)*8)*32+INT(RI(XD%)*8)*4+INT(BI(XD%)*4) 1530 NEXT XD% 1540 RETURN 1550 'MAKE YJK DATA FOR SCREEN12 AND WRITE IT ON THE SCREEN 1560 FOR XD%=0 TO 3 1570 RI(XD%)=RI(XD%)*32:GI(XD%)=GI(XD%)*32:BI(XD%)=BI(XD%)*32 1590 I(XD%)=RI(XD%)/2+GI(XD%)+BI(XD%)/4 1600 Z(XD%)=RI(XD%)/4+GI(XD%)/8+BI(XD%)/2 1605 NEXT XD% 1610 J%=(RI(0)+RI(1)+RI(2)+RI(3)-Z(0)-Z(1)-Z(2)-Z(3))\4 1620 IF J%<-32 THEN J%=-32 ELSE IF J%> 31 THEN J%= 31 1640 K%=(GI(0)+GI(1)+GI(2)+GI(3)-Z(0)-Z(1)-Z(2)-Z(3))\4 1650 IF K%<-32 THEN K%=-32 ELSE IF K%> 31 THEN K%= 31 1670 JK%=6*J%+15*K%:FOR XD%=0 TO 3:Y(XD%)=(16*I(XD%)-JK%)\29 1680 IF Y(XD%)>31 THEN Y(XD%)=31 ELSE IF Y(XD%)<0 THEN Y(XD%)=0 1700 NEXT XD% 1710 PSET(SX%+0,SY%+YD%),Y(0)*8+(K% AND 7) 1720 PSET(SX%+1,SY%+YD%),Y(1)*8+(K% AND 56)\8 1730 PSET(SX%+2,SY%+YD%),Y(2)*8+(J% AND 7) 1740 PSET(SX%+3,SY%+YD%),Y(3)*8+(J% AND 56)\8 1750 RETURN 1760 ' pixsel 1770 TT=MA 1780 FOR N%=0 TO MO%-1 1790 GOSUB 1870 1800 IF TT>T AND T>MI THEN TT=T:TN%=N%:LX=NX:LY=NY:LZ=NZ 1810 NEXT N% 1820 IF TT=MA THEN 1860 1830 CX=CX+TT*VX:CY=CY+TT*VY:CZ=CZ+TT*VZ:N%=TN% 1840 GOSUB 2150 1850 IF F%=1 THEN 1760 1860 RETURN 1870 ' cross 1880 RX=CX-O(N%,0):RY=CY-O(N%,1):RZ=CZ-O(N%,2) 1890 A=O(N%,3):B=O(N%,4):C=O(N%,5) 1900 IF O(N%,6) = 1 THEN 2030 1920 ' box 1930 IF VX=0 THEN T1=MA ELSE IF RX<0 THEN T1=-(RX+A)/VX ELSE T1=-(RX-A)/VX 1940 IF VY=0 THEN T2=MA ELSE IF RY<0 THEN T2=-(RY+B)/VY ELSE T2=-(RY-B)/VY 1950 IF VZ=0 THEN T3=MA ELSE IF RZ<0 THEN T3=-(RZ+C)/VZ ELSE T3=-(RZ-C)/VZ 1960 IF ABS(RY+T1*VY)>B OR ABS(RZ+T1*VZ)>C THEN T1=MA 1970 IF ABS(RZ+T2*VZ)>C OR ABS(RX+T2*VX)>A THEN T2=MA 1980 IF ABS(RX+T3*VX)>A OR ABS(RY+T3*VY)>B THEN T3=MA 1990 IF T1=-1 THEN 2230 2180 PX%=ABS(CX+100)\4-(CX+100<0) 2190 PY%=ABS(CY+100)\4-(CY+100<0) 2200 PZ%=ABS(CZ+100)\4-(CZ+100<0) 2210 SH%=(PX%+PY%+PZ%) MOD 2 2230 SF=S(SH%,5) 2240 SE%=S(SH%,7) 2250 JX=V(12)-VX:JY=V(13)-VY:JZ=V(14)-VZ 2270 SM=(LX*JX+LY*JY+LZ*JZ)/SQR(JX*JX+JY*JY+JZ*JZ) 2280 IF SM<0 THEN SM=0 2290 FOR P%=1 TO SE%:SM=SM*SM:NEXT P% 2300 VN=-2*(LX*VX+LY*VY+LZ*VZ) 2310 WX=VX+VN*LX:WY=VY+VN*LY:WZ=VZ+VN*LZ 2320 VX=V(12):VY=V(13):VZ=V(14) 2330 SN=LX*VX+LY*VY+LZ*VZ 2340 IF SN<0 THEN SN=0 2350 FOR N%=0 TO MO%-1 2360 GOSUB 1870 2370 IF MA>T AND T>MI THEN SN=0:SM=0 2380 NEXT N% 2385 ST=S(SH%,3)+S(SH%,4)*SN:SP=S(SH%,6)*SM 2390 CR=CR+(S(SH%,0)*ST+SP)*RF 2400 CG=CG+(S(SH%,1)*ST+SP)*RF 2410 CB=CB+(S(SH%,2)*ST+SP)*RF 2420 IF SF=0 AND RN%<4 THEN F%=0:return 2430 F%=1:RF=RF*SF:RN%=RN%+1 2440 VX=WX:VY=WY:VZ=WZ 2450 RETURN 1060 DIM T(9),V(15),O(5,7),S(5,7),RI(3),GI(3),BI(3),I(3),Z(3),Y(3) 5000 ' Camera 5010 DATA 8, 4, 15 5020 DATA -1, 0, 1 5030 ' Light 5040 DATA 0.439, 0.868, -0.233 5050 ' Focal length 5060 DATA 3.571 5070 ' #objects 5080 DATA 5 5090 ' Sphere.009 5100 DATA -2.9, -1.2, 4.9 5110 DATA 0.444, 4, 0.444 5120 DATA 1, 2 5130 ' Sphere.010 5140 DATA 3, 2, -1 5150 DATA 0.25, 0.25, 0.25 5160 DATA 1, 3 5170 ' Sphere.011 5180 DATA 2, 0, 4 5190 DATA 0.346, 0.346, 0.346 5200 DATA 1, 4 5210 ' Cube 5220 DATA -3, 1, 1 5230 DATA 0.15, 3.3, 5.25 5240 DATA 0, 3 5250 ' Cube.003 5260 DATA 0, -3, 0 5270 DATA 10, 0.5, 10 5280 DATA 0, -1 5290 ' #shaders 5300 DATA 5 5310 ' Material 5320 DATA 0.416, 0.417, 0.423 5330 DATA 0.486, 1, 0.909 5340 DATA 0, 0 5350 ' Material 5360 DATA 0.008, 0, 0.28 5370 DATA 0.5, 1, 0.467 5380 DATA 0, 0 5390 ' Red 5400 DATA 0.8, 0.001, 0.005 5410 DATA 0.5, 0.14, 0 5420 DATA 0.177, 1 5430 ' Mirror 5440 DATA 0.3, 0.3, 0.3 5450 DATA 0.4, 0.14, 1 5460 DATA 1, 6 5470 ' Green 5480 DATA 0, 0.8, 0.02 5490 DATA 0.17, 1, 0.076 5500 DATA 1, 8