/*
    This is a modular wing. This produces regular wing (same profile all accross).
    Each module plugs into a similar one, extending the wing.
*/
depth=100;      // Everything is computed based on this number
                // It represents the distance from the front of the wing to the end.
profile_w = 3;  // width of the robust part of the profile
profile_hw = 7; // width of the weak part of the profile
profile_hwo=20; // width of the weak oversize part of the profile
angletop=20;

module arc(ray,angle_start,angle_end,thick,width){
    difference(){
        // First we draw the full cylinder, but with a hole
        difference(){
            cylinder(h=width,r=ray);
            cylinder(h=width,r=ray-thick);
        }
        // Then using cubes, we remove the unwanted part.
        // We have to use 3 cubes. One large to cleanup most of the unwanted
        // cylinder and two small to make the cut perpendicular.
        {
            // First cube is running from one end of the arc to the other
            subray=ray-thick;
            translate([cos(angle_start)*subray,sin(angle_start)*subray,0]){
                diff_angle = angle_end - angle_start;
                rotate(a=angle_start+diff_angle/2+90)
                    translate([0,-ray,0])
                    cube([2*sin(diff_angle/2)*subray,ray,width+1]);
            }
            // The other cube are running from the center of the cylinder to the outside
            // using a suitable thickness to make the cut perpendicular.
            // Now for large angle, using the thick parameter is not enough
            // and for small angle, it is too small.
            rotate (a=angle_start) cube ([ray,thick,width]);
            rotate (a=angle_end) translate([0,-thick,0]) cube ([ray,thick,width]);
        }
    }
}

module profile(thick,width){
    // the nose is simply a round
    // The bottom of the wing is flat.
    // The top of the wing raise a little and then goes meat the end
    // The end is simply the connection between the top and the bottom
    ray=depth/5;
    difference(){
        cylinder(h=width,r=ray);
        {
        cylinder(h=width,r=ray-thick);
        translate([-ray,0,0]) cube([ray*2,ray,width]);
        }
    }
    // bottom
    translate([ray-thick,0,0]) cube ([thick,depth,width]);
    // top raise
    rlen=depth/5;
    translate([-cos(angletop)*ray,-sin(angletop)*ray,0]){
        rotate (a=10){
            cube([thick,rlen,width]);
            // top connect
            // translate([-(ray+sin(angletop)*rlen)+thick,-sin(angletop)*ray+rlen,0])
            translate([0,rlen,0]){
                rotate (a=-34) cube([thick,depth,width]);
            }
        }
    }
}
arc(20,20,180,3,10);
if(false){
    profile(profile_w,profile_w);
    translate([0,0,-profile_hw]) profile(0.5,profile_hw);
    translate([0,0,-(profile_hw+profile_hwo)]) profile (0.25,profile_hwo);
}