$fn=64;

// Parametric variables for TinyTown foundation base
base_width = 50;
base_length = 60;
footing_height = 3;
slab_height = 5;
step_inset = 2.5;
peg_spacing_x = 30;
peg_spacing_y = 40;
peg_radius = 2;
peg_height = 2.5;

module foundation() {
    union() {
        // Bottom footing
        translate([-base_width/2, -base_length/2, 0])
            cube([base_width, base_length, footing_height]);
            
        // Main foundation slab
        // Overlapped on Z by 0.1mm to ensure a manifold/watertight mesh
        translate([-(base_width - step_inset*2)/2, -(base_length - step_inset*2)/2, footing_height - 0.1])
            cube([base_width - step_inset*2, base_length - step_inset*2, slab_height + 0.1]);
            
        // Alignment pegs for placing a building on top
        for (x = [-1, 1]) {
            for (y = [-1, 1]) {
                translate([x * (peg_spacing_x/2), y * (peg_spacing_y/2), footing_height + slab_height - 0.1])
                    cylinder(h=peg_height + 0.1, r=peg_radius);
            }
        }
    }
}

foundation();