// -*- C -*-

include <funcs.scad>

module FArcSegment_mask(beta) {
  for (i=[0 : 0.75 : 3]) {
    rotate(i*beta/4)
      polygon([[0, 0],
	       [1, 0],
	       [cos(beta/4), sin(beta/4)]]);
  }
}

module FArcSegment(xc,yc,inrad,outrad,alpha,delta) {
  translate([xc,yc]) {
    intersection() {
      difference() {
	circle(r=outrad, $fn=70);
	circle(r=inrad, $fn=70);
      }
      rotate(alpha) scale(outrad*2) {
	FArcSegment_mask(delta);
      }
    }
  }
}

tubeslop = 0.5;
tubeheight = 30 + tubeslop;
tubewidth = 15 + tubeslop;
mainthick = 4;

clipthick = 2;
clipang = 135;

$stemlen = 40;

topwidth = 20;

hookinrad = 7.5;
hookcurl = 60;
hookwidth = 4;

tuberad = tubewidth/2;
mainoutrad = tuberad + mainthick;
hookoutrad = hookinrad + hookwidth;
$hookcy = -($stemlen - hookoutrad);

$eltop = [topwidth/2, -tuberad + tubeheight + mainthick + 0.1];
$elmid = [topwidth/2, -tuberad];
$ellow = tangent_intersect_b([0,$hookcy], hookinrad, $elmid);
$ellowextra = 180 - tangent_intersect_beta([0,$hookcy], hookinrad, $elmid);

$bend = 0;

module Howly(acrossly_x, frontbackly_x){
  if (acrossly_x >= 0) {
    translate([acrossly_x,0,0])
      assign($bend = atan(tuberad/$stemlen),
	     $frontbackly = 0)
      child();
  }
  if (frontbackly_x >= 0) {
    translate([frontbackly_x,0,0])
      assign($bend = 0,
	     $frontbackly = 1)
      child();
  }
}

module Plan(){
  dy = tubeheight - tuberad*2;
  FArcSegment(0, dy, tuberad, mainoutrad, -1, 181);
  FArcSegment(0, 0,  tuberad, mainoutrad, -$bend, $bend+1);
  translate([tuberad, 0]) square(center=false, size=[mainthick,dy]);
  FArcSegment(0, 0, tuberad, tuberad + clipthick, 360-clipang, clipang+1);
  rotate(-$bend) translate([tuberad, 0]) mirror([0,1])
    square(center=false, size=[mainthick, $stemlen/cos($bend)]);
}

module ElevationCore(){
  FArcSegment(0, $hookcy, hookinrad, hookoutrad,
	      180 - $ellowextra,
	      90 + hookcurl + $ellowextra);
  translate([-hookoutrad*sqrt(0.5),
	      $hookcy - hookoutrad*sqrt(0.5) + 0.1])
    mirror([1,0])
    square(center=false, size=[topwidth, $stemlen + tubeheight + 20]);
  polygon([[-hookoutrad, $ellow[1]],
	   reflect_in_y($eltop),
	   $eltop,
	   $elmid,
	   $ellow]);
}

// after here is all 3D

module Primary(){
  intersection(){
    translate([0,0, -(topwidth+10)/2])
      linear_extrude(height=topwidth+10) Plan();
    translate([50,0])
      rotate([0,-90,0])
      linear_extrude(height=100)
      ElevationCore();
  }
}

module PlaneAbove(){
  translate([-100,-100,0]) cube(center=false,size=[200,200,200]);
}

taperangle = -270 + tangent_intersect_beta([-$hookcy, 0],
					  hookoutrad,
					  [-$eltop[1], -$eltop[0]]);
module Hook(){ ////toplevel
  difference(){
    rotate([taperangle,0,0])
      translate([0,-$eltop[1],0])
      Primary();
    translate([0,0,topwidth/2])
      rotate([taperangle*2,0,0])
      PlaneAbove();
    translate([0,0,-topwidth/2])
      mirror([0,0,1]) PlaneAbove(0);
  }
}

module RightHook(){ ////toplevel
  mirror([1,0,0]) Hook();
}

module Bothly() {
  Acrossly() child(0);
  translate([70,0,0]) Frontbackly() child(0);
}

Howly(0,70) {
  Plan();
  //ElevationCore();
  //RightHook();
}