// functions.scad
// all by Prusa

module belt(len, side = 0){
    //belt. To be substracted from model
    //len is in +Z, smooth side in +X, Y centered
    translate([-0.5, 0, 0]) maketeeth(len);
    translate([0, -4.5, -0.01]) cube([belt_thickness, 9, len + 0.02]);
    if (side != 0) {
    translate([0, -4.5 + side, -0.01]) cube_fillet([belt_thickness, 9, len + 0.02], vertical = [3, 0, 0, 0]);
    }
}

module maketeeth(len){
    //Belt teeth. 
    for (i = [0 : len / belt_tooth_distance]) {
        translate([0, 0, i * belt_tooth_distance]) cube([2, 9, belt_tooth_distance * belt_tooth_ratio], center = true);
    }
}
module plate_screw(long=0) {
        translate([0, 0, -long]) screw(head_drop=14 + long, h=30 + long, r_head=3.6, r=1.7, $fn=24, slant=false);
}
module screw(h=20, r=2, r_head=3.5, head_drop=0, slant=0, poly=false, $fn=0){
    //makes screw with head
    //for substraction as screw hole
    if (poly) {
        cylinder_poly(h=h, r=r, $fn=$fn);
    } else {
        cylinder(h=h, r=r, $fn=$fn);
    }
    if (slant) {
        translate([0, 0, head_drop-0.01]) cylinder(h=r_head, r2=0, r1=r_head, $fn=$fn);
    }

    if (head_drop > 0) {
        translate([0, 0, -0.01]) cylinder(h=head_drop+0.01, r=r_head, $fn=$fn);
    }
}
module nut(d,h,horizontal=true){
    cornerdiameter =  (d / 2) / cos (180 / 6);
    cylinder(h = h, r = cornerdiameter, $fn = 6);
    if(horizontal){
        for(i = [1:6]){
            rotate([0,0,60*i]) translate([-cornerdiameter-0.2,0,0]) rotate([0,0,-45]) cube([2,2,h]);
        }
    }
}

module fillet(radius, height=100, $fn=0) {
    //this creates acutal fillet
    translate([-radius, -radius, -height / 2 - 0.02]) difference() {
        cube([radius * 2, radius * 2, height + 0.04]);
        if ($fn == 0 && (radius == 2 || radius == 3 || radius == 4)) {
            cylinder(r=radius, h=height + 0.04, $fn=4 * radius);
        } else {
            cylinder(r=radius, h=height + 0.04, $fn=$fn);
        }

    }
}

module cube_fillet(size, radius=-1, vertical=[3,3,3,3], top=[0,0,0,0], bottom=[0,0,0,0], center=false, $fn=0){
    //
    if (use_fillets == 1) {
        if (center) {
            cube_fillet_inside(size, radius, vertical, top, bottom, $fn);
        } else {
            translate([size[0]/2, size[1]/2, size[2]/2])
                cube_fillet_inside(size, radius, vertical, top, bottom, $fn);
        }
    } else {
        if (use_fillets == 2) {
            if (center) {
                cube_fillet_inside(size, radius, vertical, top, bottom, 4);
            } else {
                translate([size[0]/2, size[1]/2, size[2]/2])
                    cube_fillet_inside(size, radius, vertical, top, bottom, 4);
            }

        } else {
            cube(size, center);
        }
    }

}

module cube_negative_fillet(size, radius=-1, vertical=[3,3,3,3], top=[0,0,0,0], bottom=[0,0,0,0], $fn=0){

    j=[1,0,1,0];

    for (i=[0:3]) {
        if (radius > -1) {
            rotate([0, 0, 90*i]) translate([size[1-j[i]]/2, size[j[i]]/2, 0]) fillet(radius, size[2], $fn=$fn);
        } else {
            rotate([0, 0, 90*i]) translate([size[1-j[i]]/2, size[j[i]]/2, 0]) fillet(vertical[i], size[2], $fn=$fn);
        }
        rotate([90*i, -90, 0]) translate([size[2]/2, size[j[i]]/2, 0 ]) fillet(top[i], size[1-j[i]], $fn=$fn);
        rotate([90*(4-i), 90, 0]) translate([size[2]/2, size[j[i]]/2, 0]) fillet(bottom[i], size[1-j[i]], $fn=$fn);

    }
}

module cube_fillet_inside(size, radius=-1, vertical=[3,3,3,3], top=[0,0,0,0], bottom=[0,0,0,0], $fn=0){
    //makes CENTERED cube with round corners
    // if you give it radius, it will fillet vertical corners.
    //othervise use vertical, top, bottom arrays
    //when viewed from top, it starts in upper right corner (+x,+y quadrant) , goes counterclockwise
    //top/bottom fillet starts in direction of Y axis and goes CCW too


    if (radius == 0) {
        cube(size, center=true);
    } else {
        difference() {
            cube(size, center=true);
            cube_negative_fillet(size, radius, vertical, top, bottom, $fn);
        }
    }
}