/*
    Pattern from Ak Medrese, Nigde, Turkey
    construction as suggested in
    "Pattern Papers, Issue 1" by Eric Broug (2016) https://www.academia.edu/28244436/Pattern_Papers_Issue_1_Ak_Medrese_Nigde
    
    scruss - 2016 - wtfpl
*/

r=50;           // repeat unit size
p=r/16;         // thickess of lines
repeat=[5,3];   // how many repeats in [x,y]

module oc() {
    // filled 8-point star tilted 1/16 turn left
    // size 2r x 2r units
    rotate(360/16)union() {
        square(2*r/sqrt(2), center=true);
        rotate(45)square(2*r/sqrt(2), center=true);
    }
}

module oct() {
    // outlined 8-point star using oc() from above
    difference() {
        scale((r+p/2)/r)oc();
        scale((r-p/2)/r)oc();
    }
}

// make a trellis of these stars in a square grid
// [r, r] units each axis
intersection() {
    for (x=[0:repeat[0]]) {
        for (y=[0:repeat[1]]) {
            translate([x*r,y*r,0])oct();
        }
    }
    // clip to requested size
    square(r*repeat);
}