p_malin_raymarch.bas

      MODE8:OFF:PROCdc:tc%=TRUE
      FORU=0TO639
      x=U/256-1.25
      FORV=0TO511
      y=V/256-1
      X=0:Y=X:Z=-2
      s=y/9:B=9:R=1:G=2
   80 d=FNd(X,Y,Z)
      IFd<.04GOTO130
      IFp>99GOTO160
      X=X+x*d:Y=Y+y*d:Z=Z+d
      GOTO80
  130 s=(.03+FNd(X,Y+.02,Z-.02)-d)*3/(2+Z)^2
      IFr<1.2R=8:G=6:B=4
      IFY<-.8B=2:G=8+1/(p*p):R=G/2:IFp<1s=s/4
  160 IFtc%PROCc(s*R,s*G,s*B)ELSEGCOL0,-(RND(1)<s*R)-(RND(1)<s*G)*2-(RND(1)<s*B)*4
      PLOT69,U*2,V*2
      NEXT,
      REPEATUNTIL0
      DEFFNd(s,t,q)p=s*s+q*q:r=SQR(p+t*t*4):a=r-1
      b=t*30
      h=t+1
      IFh<a a=h:b=p*10
      =a+.1*SINb
      DEFPROCc(r,g,b)
      IFr<0r=0ELSEIFr>1r=1
      IFg<0g=0ELSEIFg>1g=1
      IFb<0b=0ELSEIFb>1b=1
      COLOUR15,r*255,g*255,b*255:GCOL0,15
      ENDPROC
      DEFPROCdc
      FORc%=1TO7
      COLOURc%,(c%AND1)*255,(c%AND2)DIV2*255,(c%AND4)DIV4*255
      NEXT
      ENDPROC