include c:\cxpl\codes;

proc DrawBranch(Lev, Dir, Len, X, Y);
int  Lev; real Dir, Len; int X, Y;
int  Red, Grn;
[Move(X, Y);
X:= X + fix(Len*Cos(Dir));
Y:= Y + fix(Len*Sin(Dir));
Red:= 255-Lev*8;  Grn:= Lev*12+100;
Line(X, Y, Red<<16+Grn<<8);
if Lev < 12 then                \limit level of recursion
        [DrawBranch(Lev+1, Dir-0.4, Len*0.8, X, Y);     \left
         DrawBranch(Lev+1, Dir+0.1, Len*0.8, X, Y);     \right
        ];
];

[SetVid($112);                  \set 640x480x24 video graphics mode
DrawBranch(0, -3.14159/2.0, 80.0, 360, 460);
if ChIn(1) then [];             \wait for keystroke
SetVid(3);                      \restore normal text mode
]