module two_cylinder()
{
	translate( [ 0.8, 0, 0 ] )
		cylinder( 2, 1, 1 );
	translate( [ -0.8, 0, 0 ] )
		cylinder( 2, 1, 1 );
}

module oblong()
{
	diameter = 2;
	width = 4;
	length = 3;

	r = diameter / 2;
	c = width/2 - r;
	color( "#eeeeee" )
	{
		cube([ diameter, c*2, length ], center=true);
		translate( [ 0, c, 0 ] )
			cylinder( length, r, r, center=true );
		translate( [ 0, -c, 0 ] )
			cylinder( length, r, r, center=true );
	}
}

module cylinder_extrude()
{
    translate( [ 0, 0, -1 ] )
	linear_extrude( 2 )
	circle( 1 );
}

module rocket()
{
    translate( [ 0, 0, -4 ] )
	linear_extrude( 4 )
	circle( 1 );
	linear_extrude( 0.5, scale=0.5 )
	circle( 1 );
    translate( [ 0, 0, 0.5 ] )
	linear_extrude( 2 )
	circle( 0.5 );
    translate( [ 0, 0, 2.5 ] )
	linear_extrude( 2, scale=0 )
	circle( 0.5 );
}

module quarter_donut()
{
	r_leg = 0.5;
	bend_r = 2.0;
	rotate( 180, [ 0, 1, 0 ] )
	rotate( 90, [ 1, 0, 0 ] )
	rotate_extrude( angle=90 )
	translate( [ bend_r, 0, 0 ] )
	circle( r_leg );
}

module one_leg_par( leg_dia, bend_dist, bend_r, leg_vlen )
{
	r_leg = leg_dia/2;
	l_h = bend_dist - bend_r;
	color( "#777777" )
	{
		// horizontal part of the leg
		translate( [ 0, 0, -l_h-.001 ] )
		cylinder( l_h+1.002, r_leg, r_leg );
		// vertical part of the leg
		translate( [ bend_r+.00, 0, -bend_dist ] )
		rotate( 90, [ 0, 1, 0 ] )
		cylinder( leg_vlen-bend_r+.001, r_leg, r_leg );
		// curved part of the leg
		translate( [ bend_r, 0, -l_h ] )
		rotate( 180, [ 0, 1, 0 ] )
		rotate( 90, [ 1, 0, 0 ] )
		rotate_extrude( angle=90 )
		translate( [ bend_r, 0, 0 ] )
		circle( r_leg );
	}
}

module legs_par( leg_dist, leg_dia, bend_dist, bend_r, leg_vlen )
{
	translate( [ 0, leg_dist/2, 0 ] )
	one_leg_par( leg_dia, bend_dist, bend_r, leg_vlen );
	// translate( [ 0, -leg_dist/2, 0 ] )
	// one_leg_par( leg_dia, bend_dist, bend_r, leg_vlen );
}

module legs()
{
	diameter = 9;
	leg_dist = 11.8;
	leg_dia = 0.6;
	bend_r = 0.6;
	bend_dist = 2;
	leg_vlen = diameter/2 + 3.5;
	legs_par( leg_dist, leg_dia, bend_dist, bend_r, leg_vlen );
}

module oblong2d()
{
	// square( 2, center=true );
	translate( [ -1, -1, 0 ] )
		square( 2 );
	translate( [ 0, 1, 0 ] )
		circle( 1 );
	translate( [ 0, -1, 0 ] )
		circle( 1 );
}

module oblongext()
{
	linear_extrude( 4 )
		oblong2d();
}

module oblonghalvedonut()
{
	rotate_extrude( angle=180 )
		translate( [ 4, 0, 0 ] )
			oblong2d();
}

module oblong2dgroove()
{
	difference()
	{
		oblong2d();
		translate( [ 1, 0.7, 0 ] )
			circle( 0.2 );
	}
}

module oblonggroovedonut()
{
	rotate_extrude( angle=180 )
		translate( [ 4, 0, 0 ] )
			oblong2dgroove();
}

module green_heat_shrink_shape_p( diameter, width, length, hsdepth )
{
	// fillet radius at the edge
    r_edge = 0.2;
	// radius of the notch
    r_notch = 0.6;
	// inner depth without the fillet
	d_i = hsdepth - r_edge;
	x_notch = d_i + sqrt(0.5) * (r_edge + r_notch);
    y_notch = 3 * r_notch;
	dy_nf = sqrt(0.5) * (r_edge + r_notch);
	y_nfl = y_notch - dy_nf;
	y_nfh = y_notch + dy_nf;

    difference()
    {
        union()
        {
			// main body
			square( [ d_i, length ] );
			// fillet top and bottom
			translate( [ d_i, r_edge, 0 ] )
			circle( r_edge );
			translate( [ d_i, 19.5-r_edge, 0 ] )
			circle( r_edge );
			// notch lower fillet and fill
			translate( [ d_i, y_nfl, 0 ] )
			circle( r_edge );
			translate( [ d_i, r_edge, 0 ] )
			square( [ r_edge, y_nfl - r_edge ] );
			// notch upper fillet and fill
			translate( [ d_i, y_nfh, 0 ] )
			circle( r_edge );
			translate( [ d_i, y_nfh, 0 ] )
			square( [ r_edge, length - y_nfh - r_edge ] );
			// fill the notch up to the cut
			translate( [ d_i, y_nfl, 0 ] )
			square( [ r_edge*sqrt(0.5), y_nfh - y_nfl ] );
        }

        translate( [ x_notch, y_notch, 0 ] )
        circle( r_notch );
    }
}

module green_heat_shrink_halve_p( diameter, width, length, hsdepth )
{
	r_i = diameter/2 - hsdepth;
	w_i2 = width/2 - hsdepth - r_i;

    translate( [ 0, w_i2, 0 ] )
    rotate( 90, [ 1, 0, 0 ] )
    linear_extrude( 2*w_i2 )
    {
        translate( [ r_i, 0, 0 ] )
        green_heat_shrink_shape_p( diameter, width, length, hsdepth );
    }
    translate( [ 0, w_i2, 0 ] )
    rotate_extrude(angle=180)
    {
        translate( [ r_i, 0, 0 ] )
        green_heat_shrink_shape_p( diameter, width, length, hsdepth );
    }
}

module green_heat_shrink_halve()
{
	diameter = 9;
	width = 17.5;
	length = 19.5;
	hsdepth = 1;
	green_heat_shrink_halve_p( diameter, width, length, hsdepth );
}