// A small habitat... or something like that...
// ============================================
// Christoph Nieß, February 28, 2016, CC-BY-SA

// Global Settings
// ---------------
radius = 50; // radius of the dome
wire = 5; // diameter of the dome struts
standoff = 5; // height of the flat area at the bottom

quality_wire = 50;
quality_earth = 500;

// The dome is a half Pentakis Icosidodecahedron, so it has 40 faces, all of
// which are triangles of two different kinds.
// To have a go at building it it is derived from a Icosidodecahedron, of which
// only the pentagons and the triangles inside them are drawn.

// The aequatorial cut through an Icosidodecahedron is a regular Decagon, so we
// can derive a lot of the geometry from that:
// The circumradius of the decagon dives us the habitat radius for a given pentagon
// edge length. We want it the other way round, though:
pentagonEdge = radius * 2 * sin(18);

// Each sectioned pentagon has one vertix in the middle and five around it
// Those five will be placed by their angles from the middle point, referenced
// to the middle of the dome
pentagonOutAngle = asin(pentagonEdge/10*sqrt(50+10*sqrt(5))/radius);

module pentagon()
// Draws one of the base pentagons
{
    union()
    {
        // first part draws the outside circumfence of the pentagon
        hull()
        {
            rotate([0,pentagonOutAngle,0]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([0,pentagonOutAngle,72]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,72]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([0,pentagonOutAngle,144]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,144]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([0,pentagonOutAngle,216]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,216]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([0,pentagonOutAngle,288]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,288]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([0,pentagonOutAngle,0]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        // second part draws the "spokes"
        hull()
        {
            rotate([0,pentagonOutAngle,0]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,72]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,144]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,216]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([0,pentagonOutAngle,288]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
    }
}

module DomeSkirt()
// Draws the upper circle of pentagons of the dome
{
    union()
    {
        rotate([0,2 * pentagonOutAngle,0]) rotate([0,0,180]) pentagon();
        rotate([0,2 * pentagonOutAngle,72]) rotate([0,0,180]) pentagon();
        rotate([0,2 * pentagonOutAngle,144]) rotate([0,0,180]) pentagon();
        rotate([0,2 * pentagonOutAngle,216]) rotate([0,0,180]) pentagon();
        rotate([0,2 * pentagonOutAngle,288]) rotate([0,0,180]) pentagon();
    }
}

module domeBuild()
{
    union()
    {
        pentagon(); // top of dome
        DomeSkirt(); // sides of dome
        // add the missing bottom edges
        hull()
        {
            rotate([90,0,0]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([90,0,-36]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([90,0,-72]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([90,0,-108]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([90,0,-144]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([90,0,-180]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([90,0,-216]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([90,0,-252]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
        hull()
        {
            rotate([90,0,-288]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
            rotate([90,0,-324]) translate([0,0,radius]) sphere($fn=quality_wire, d=wire);
        }
    }
}

module house()
// My home inside of the habitat. leave your shoes at the door, please!
{
    union()
    {
        // a block...house!
        translate([0,0,radius/10]) cube([radius/2,radius/1.5, radius/5], center=true);
        translate([0,0,radius/5]) rotate([0,45,0]) cube([1.5*(radius/4),radius/1.5,1.5*(radius/4)], center=true);
    }
}

translate([0,0,radius + wire - standoff])
{
    union()
    {
        domeBuild();
        house();
        difference()
        {
            sphere($fn=quality_earth, r=radius+(wire/2));
            translate([0,0,1.5*radius]) cube([3*radius,3*radius,3*radius], center=true);
            translate([0,0,-(2*radius + wire - standoff)]) cube([2*radius,2*radius,2*radius], center=true);
        }
    }
}