$fn = 64;

// --- Parameters ---
bottle_diameter = 26.0;   // Vallejo bottles are ~24.5mm, 26mm gives comfortable clearance
columns = 5;              // Number of bottles across (X axis)
rows = 3;                 // Number of tiers (Y axis)
wall_thickness = 2.0;     // Thickness of structural walls
row_spacing = 2.0;        // Extra Y-spacing between rows for easier grabbing
hole_depth = 15.0;        // Depth of the bottle cutouts
base_thickness = 2.0;     // Thickness of the floor under each bottle
step_height = 20.0;       // Z-height increase per tier

// --- Calculated Variables ---
pitch_x = bottle_diameter + wall_thickness;
pitch_y = bottle_diameter + wall_thickness + row_spacing;
total_width = columns * pitch_x + wall_thickness;

// --- Geometry ---
difference() {
    union() {
        // Horizontal shelves
        for (r = [0 : rows - 1]) {
            translate([0, r * pitch_y, r * step_height])
                cube([total_width, pitch_y + wall_thickness, hole_depth + base_thickness]);
        }
        
        // Vertical risers (supports the shelves from the floor, leaving the underside hollow)
        for (r = [1 : rows - 1]) {
            translate([0, r * pitch_y, 0])
                cube([total_width, wall_thickness, r * step_height + 0.1]);
        }
        
        // Back wall
        translate([0, rows * pitch_y, 0])
            cube([total_width, wall_thickness, (rows - 1) * step_height + hole_depth + base_thickness]);
            
        // Left side wall
        for (r = [0 : rows - 1]) {
            translate([0, r * pitch_y, 0])
                cube([wall_thickness, pitch_y + wall_thickness, r * step_height + hole_depth + base_thickness]);
        }
        
        // Right side wall
        for (r = [0 : rows - 1]) {
            translate([total_width - wall_thickness, r * pitch_y, 0])
                cube([wall_thickness, pitch_y + wall_thickness, r * step_height + hole_depth + base_thickness]);
        }
    }
    
    // Bottle cutouts
    for (r = [0 : rows - 1]) {
        for (c = [0 : columns - 1]) {
            translate([
                wall_thickness + bottle_diameter / 2 + c * pitch_x,
                wall_thickness + bottle_diameter / 2 + r * pitch_y,
                r * step_height + base_thickness
            ])
            cylinder(h = hole_depth + 1.0, d = bottle_diameter);
        }
    }
}