use <snapper.scad>;
extrusion_width=.5; layer_height=.2;		// print parameters

epsilon=.005;		// for finer cuts

heater_w = 16;		// heatblock width
heater_l = 20;		// heatblock length
nozzle_offset=4.5;	// nozzle offset from the edge of heatblock

fanduct_elevation = 3;							// fanduct elevation above nozzle tip
fanduct_h = 6;								// inner height of the duct
fanduct_w = 6;								// inner width of the duct
fanduct_shell=1.2;							// shell thickness
fanduct_ir = sqrt(pow(heater_w/2,2)+pow(heater_l-nozzle_offset,2))+5;	// inner radius

jet_angle = 60;		// angular width of the jet

inlet_w = 12.5;		// inlet width
inlet_h = 17;		// inlet height
inlet_l = 7;		// inlet length of protrusion (or depth of intrusion:))
inlet_away = 15;	// how far away inlet is

hotend_clearance = 12;

snapper_d = 8; snapper_overlap=0.2;	// snip snap

smooth_f = 120;

type="3jets"; // "3jets" ; // circular|3jets


module fanduct(type=type) {

 //	***	duct is all around!
 module duct(what) {
  if(what=="in") {
   sh = fanduct_w+2*fanduct_shell; sv = fanduct_h+2*fanduct_shell;
   smax = max(sh,sv);
   rotate_extrude($fn=smooth_f)
   translate([sh/2+fanduct_ir,sv/2])
   scale([sh/smax,sv/smax])
   circle(d=smax,$fn=4*smax);
  }else if(what=="out") {
   sh = fanduct_w; sv = fanduct_h;
   smax = max(sh,sv);
   rotate_extrude($fn=smooth_f)
   translate([sh/2+fanduct_shell+fanduct_ir,sv/2+fanduct_shell])
   scale([sh/smax,sv/smax])
   circle(d=smax,$fn=4*smax);
  }
 }

 //	***	bumps for easier position adjustments in line with hotend
 module marks(what) {
  if(what=="in") {
   for(y=[-1,1])
    hull() for(z=[0,-fanduct_shell-fanduct_h/2])
     translate([0,y*(fanduct_ir+fanduct_shell+fanduct_w/2),fanduct_shell*2+fanduct_h+z])
     rotate([90,0,0]) {
      cylinder(r=fanduct_shell,h=fanduct_w,center=true,$fn=30);
      for(z=[-1,1]) translate([0,0,z*fanduct_w/2])
       sphere(r=fanduct_shell,$fn=30);
     }
  }
 }

 //	***	output
 module output(what,type=type) {
  module guideline(xyxy) {
   module pin(xy) {
    translate([xy[0],xy[1],0])
    cylinder(d=2*extrusion_width,h=2*fanduct_shell+inlet_h,$fn=6);
   }
   xyxyxy=concat(xyxy,[[0,0]]);
   for(i=[0:1:len(xyxyxy)-2])
    hull() for(j=[i,i+1]) pin(xyxyxy[j]);
  }

  module circus(what) {
   if(what=="in") {
    difference() {
     rotate_extrude($fn=smooth_f)
      polygon([
       [0,-fanduct_elevation],
       [fanduct_ir+fanduct_shell,fanduct_shell+fanduct_h/2],
       [fanduct_ir+fanduct_shell+fanduct_w/2,0],
       [0,-fanduct_elevation-.1]]);
     translate([0,0,-1])
     cylinder(r=hotend_clearance,h=fanduct_h+2*fanduct_shell+2,$fn=smooth_f);
     mirror([0,0,1])
     translate([0,0,-epsilon])
     cylinder(r=fanduct_ir+fanduct_shell+1,h=fanduct_elevation+.1+2);
    }
   }else if(what=="out") {
    difference() {
     rotate_extrude($fn=smooth_f)
     polygon([
      [0,-fanduct_elevation],
      [fanduct_ir+fanduct_shell+1,fanduct_h/2],
      [fanduct_ir+fanduct_w/2+fanduct_shell+1,fanduct_shell],
      [0,-fanduct_elevation-.1]]);
     circus("airguides");
    }
   }else if(what=="airguides") {
    inr = fanduct_ir+fanduct_shell; our = inr+fanduct_w;
    union() {
     for(my=[0,1]) mirror([0,my,0]) {
      guideline([
       [-our,inlet_w/6],
       [-inr*sin(60),inr*cos(60)]
      ]);
      a0=30; as=15; a1=180;
      for(a=[a0+as:as:a1]) {
       f = as/(a1-a+as);
       rotate([0,0,a]) guideline([[-inr-fanduct_w*f,0]]);
      }
      guideline([
       [-our+fanduct_w*cos(30)*3/4,fanduct_w*sin(30)*3/4],
       [-inr*cos(10),inr*sin(10)]
      ]);
     }
    }/*union*/
   }/*airguides*/
  }

  module jets(what) {
   od = fanduct_h/2+fanduct_shell;
   md = fanduct_ir+fanduct_shell+fanduct_w/2;
   jww = 2*md*sin(jet_angle/2);
   render(convexity=8) difference() {
    for(a=[0:120:359]) rotate([0,0,a]) {
     if(what=="in") {
      hull() {
       render(convexity=4) intersection() {
	translate([md-fanduct_shell-fanduct_w/2,-jww/2,0])
	cube(size=[fanduct_shell+fanduct_w/2,jww,od]);
	duct(what=what);
       }
       translate([0,0,-fanduct_elevation]) sphere(r=.5);
      }
     }else if(what=="out") {
      hull() {
       render(convexity=4) intersection() {
	translate([md-fanduct_w/2-fanduct_shell,-jww/2+fanduct_shell,fanduct_shell])
	cube(size=[fanduct_w/2+fanduct_shell,jww-2*fanduct_shell,od-2*fanduct_shell]);
	duct(what=what);
       }
       translate([0,0,-fanduct_elevation]) sphere(r=.2);
      }
     }
    }
    if(what=="in") {
     translate([0,0,-fanduct_elevation-2+epsilon])
     cylinder(r=fanduct_ir+fanduct_shell*2+fanduct_w+1,h=fanduct_elevation+2);
     translate([0,0,-hotend_clearance])
     rotate([0,0,30])
     cylinder(r1=hotend_clearance*2,r2=0,h=hotend_clearance*2,$fn=6);
    }
   }
  }

  if(type=="circular") circus(what);
  else if(type=="3jets") jets(what);
 }

 //	***	air intake
 module intake(what) {
  module placeit() {
   translate([-fanduct_ir-2*fanduct_shell-fanduct_w-inlet_away,0,fanduct_shell])
   rotate([0,-90,0])
   children();
  }
  if(what=="in") {
   placeit() translate([0,-inlet_w/2,0]) {
    cube(size=[inlet_h,inlet_w,inlet_l+fanduct_shell]);
    // supports
    for(i=[-1,0,1])
     translate([-fanduct_shell,
      (i+1)*(inlet_w-extrusion_width)/2,
     -inlet_away-fanduct_w/2])
     cube(size=[fanduct_shell,
      extrusion_width,
      inlet_l+fanduct_shell+inlet_away+fanduct_w/2]);
   }
   hull() {
    placeit() translate([-fanduct_shell,-inlet_w/2-fanduct_shell,0])
    cube(size=[inlet_h+2*fanduct_shell,inlet_w+2*fanduct_shell,fanduct_shell]);
    translate([-fanduct_ir-fanduct_shell-fanduct_w/2,0,0])
    translate([0,-inlet_w/2-fanduct_shell/2,0])
    cube(size=[1,inlet_w+fanduct_shell,fanduct_shell*2+fanduct_h]);
   }
  }else if(what=="out") {
   placeit() translate([fanduct_shell,-inlet_w/2+fanduct_shell,0])
   cube(size=[inlet_h-2*fanduct_shell,inlet_w-2*fanduct_shell,inlet_l+fanduct_shell+1]);
   hull() {
    placeit() translate([fanduct_shell,-inlet_w/2+fanduct_shell,0])
    cube(size=[inlet_h-2*fanduct_shell,inlet_w-2*fanduct_shell,fanduct_shell]);
    translate([-fanduct_ir-fanduct_shell-fanduct_w/2,0,fanduct_shell])
    translate([0,-inlet_w/2+fanduct_shell,0])
    cube(size=[1,inlet_w-2*fanduct_shell,fanduct_h]);
   }
  }
 }

 //	***	DUCT TAILS!!! WOO-OO! (every day they're out there making duct tails…)
 module tails(what) {
  if(what=="in") {
   for(mx=[0,1]) mirror([mx,0,0])
   translate([fanduct_ir+fanduct_shell+fanduct_w/2,0,fanduct_shell+fanduct_h/2])
   rotate([90,0,90])
   translate([0,0,-snapper_d/2])
   snapper(d=snapper_d,o=snapper_overlap,side=0,l=fanduct_h*3/2+fanduct_shell);
  }
 }

 module parts(what) {
  union() {
   duct(what);
   marks(what);
   output(what);
   intake(what);
   tails(what);
  }
 }

 difference() {
  parts("in");
  parts("out");
 }
 
}

view="full"; // hcut|vcut|*

hinfinity=4*(fanduct_ir+fanduct_shell*2+fanduct_w+inlet_away);
vinfinity=2*(fanduct_shell*2+fanduct_h+inlet_h);
if(view=="hcut") {
 difference() {
  fanduct();
  translate([-hinfinity/2,-hinfinity/2,fanduct_shell+fanduct_h/2])
  cube(size=[hinfinity,hinfinity,vinfinity]);
 }
}else if(view=="vcut") {
 difference() {
  fanduct();
  translate([-hinfinity/2,0,-vinfinity/2])
  cube(size=[hinfinity,hinfinity,vinfinity]);
 }
}else fanduct();
/* vim:set sw=1 ai: */