I have reformatted the text from
The picture shows a multiplication graph of the number ring 105 (=3*5*7).
And this is the simple code to generate that quite organic-looking picture with a turtle in C++ (I first did this in Logo, but it was a bit slow):
pencolor.alpha=0.01;
for (int i=1; i<=255; i++)
{
for (int j=1; j<=255; j++)
{
pencolor.r=i;
pencolor.g=byte(j*i);
pencolor.b=j;
quadrat(500); // like "repeat 4 [fd 500 rt 90]" in Logo
forward(25);
right(3.7); // turns right by 3.7 degrees
}
forward(100);
left(17);
if (kbhit()) break;
}
To get it working you only need a rgba line routine,
the turtle commands are then written in a few lines of code.
This is nearly the same code as for Iris. Only the line
right(3.7); // turns right by 3.7 degreesis changed to
right(3.7*i);
Similar code again, but this time monochrome.
pencolor.alpha=0.01;
for (int i=1; i<=255; i++)
{
for (int j=1; j<=255; j++)
{
quadrat(200);
right(0.1);
pen=off;
forwd(j/200);
pen=on;
}
pen=off;
forwd(i/200);
pen=on;
left(i);
if(kbhit())break;
}
Same mechanism again, nothing really new, but I like it so much.
This is a snapshot of my rain simulation. First two triangle landscape fractals are computed on a torus, then rain falls on random positions and flows down the mountains. If it dams up a sea is filled until a river breaks through. (So I have a rough little erosion model here ;-)