### Sierpinski for printers

Sierpinski triangle made up of straight lines

```const recursion_depth = 7.; // min=1, max=10, step=1
const angle = 45.; // min=0.0, max=360, step=0.1
const start_len = 100; // min=0, max=200, step=0.1
const start_x = 0; // min=-200, max=200, step=0.1
const start_y = 0; // min=-200, max=200, step=0.1
// How do I get the size of the Canvas?

Canvas.setpenopacity(1);

const turtle = new Turtle();

function walk(i) {
current_len = start_len;
current_x_y = [start_x,start_y];

stack = [[current_len,current_x_y]];

for(let i=0; i<recursion_depth; i++){
new_stack = [];
console.log(i, stack);
for(let j=0; j<stack.length; j++){
[drawlen, x_y] = stack[j];
turtle.penup();
turtle.goto(x_y[0], x_y[1]);
turtle.backward(drawlen);

turtle.pendown();

turtle.forward(drawlen/2.);
new_stack.push([drawlen/2.,turtle.pos()]);
turtle.forward(drawlen);
new_stack.push([drawlen/2.,turtle.pos()]);
turtle.forward(drawlen/2.);

[x,y] = turtle.pos();

turtle.penup();
turtle.goto(x-drawlen*Math.cos(Math.PI/4.),y);

turtle.pendown();

turtle.backward(drawlen/2.);
new_stack.push([drawlen/2.,turtle.pos()]);
turtle.backward(drawlen/2.);

}
stack = new_stack;
}

return false;
}

```