include <BOSL2/std.scad>;


red_color = [0.69, 0.15, 0.15]; 


$fn=64;
/**
 * Creates a Swiss cross shape with optional background.
 *
 * @param w - Width of the cross (number, positive)
 * @param h - Height of extrusion (number, positive)
 * @param bg - If true, adds a red background (boolean, default: true)
 *
 * Usage:
 * swiss_x(w, h, bg);
 *
 * Example:
 *
 * swiss_x(50, 10); // Cross without background
 * swiss_x(50, 10, true); // Cross with red background
 */
module swiss_x(w, h, bg = true) {
    // Parameter validation
    assert(is_num(w) && w > 0,  "Width 'w' must be a positive number.");
    assert(is_num(h) && h > 0,  "Height 'h' must be a positive number.");
    assert(is_bool(bg),         "Background 'bg' must be a boolean.");

    // Calculate dimensions
    l = w * 80/110;  // Length of cross arm
    t = w * 24/110;  // Thickness of cross arm
    
    // Half dimensions for point calculation
    hw = l / 2;  // Half width
    ht = t / 2;  // Half thickness
    
    // Points for the cross shape
    pts = [
        [-hw, ht],  // 0
        [-ht, ht],  // 1
        [-ht, hw],  // 2
        [ ht, hw],  // 3
        [ ht, ht],  // 4
        [ hw, ht],  // 5
        [ hw,-ht],  // 6
        [ ht,-ht],  // 7
        [ ht,-hw],  // 8
        [-ht,-hw],  // 9
        [-ht,-ht],  // 10
        [-hw,-ht]   // 11
    ];
    
    // Draw white cross
    color("white")
        linear_extrude(h)
            polygon(pts);

    // Optional red background
    if (bg)             
        color("red")
            linear_extrude(h/2)
                square(w, center=true);    
}

// Example usage
//swiss_x(w = 8, h = 1, bg = false); // Extrude to 10 units in height

module swiss_x_2(w, h, bg = true) {
       // Calculate dimensions
    l = w * 80/110;  // Length of cross arm
    t = w * 24/110;  // Thickness of cross arm
    w2 = l-t;
    echo ("l",l);
    echo ("t",t);
    echo ("x",x);
    
    
    // Half dimensions for point calculation
    hw = l / 2;  // Half width
    ht = t / 2;  // Half thickness    

    // Points for the cross shape
    pts = [
        [-hw, ht],  // 0
        [-ht, ht],  // 1
        [-ht, hw],  // 2
        [ ht, hw],  // 3
        [ ht, ht],  // 4
        [ hw, ht],  // 5
        [ hw,-ht],  // 6
        [ ht,-ht],  // 7
        [ ht,-hw],  // 8
        [-ht,-hw],  // 9
        [-ht,-ht],  // 10
        [-hw,-ht]   // 11
    ];    
    
    x = w * 26/110;  // Thickness of cross arm
    x1 = hw + ht; 
    
    //down(h) %swiss_x( w = w, h = h, bg = false);
    f = 1.8;
    d = 0.14;
    
    s1 = t*1.2;
    s2 = (hw-ht) * 1.1; 
    
    r = w * 3/110;
    
    linear_extrude(h) difference() {
        //color (red_color) round2d(r=3)  {
        color (red_color) round2d(r=r)  {
            translate([0,x1,0]) 
                square((f-0*d) * s1 *0.8,center=true);               
            translate([x,x,0]) 
                square((f-1*d)  * s2,center=true,anchor=LEFT);
            translate([x1,0,0]) 
                square((f-2*d)  * s1,center=true);
            translate([x,-x,0]) 
                square((f-3*d)  * s2,center=true,anchor=LEFT);
            translate([0,-x1,0]) 
                square((f-4*d) * s1,center=true);
            translate([-x,-x,0]) 
                square((f-5*d) *s2,center=true,anchor=LEFT);
            translate([-x1,0,0]) 
                square((f-6*d) * s1,center=true);
            translate([-x,x,0]) 
                square( (f-7*d) * s2* 1.1,center=true,anchor=LEFT);
        };
        round2d(r=r) polygon(pts);    
    }
   

}

//swiss_x_2(w = 110, h = 1, bg = false); // Extrude to 10 units in height
swiss_x_2(w = 10, h = 2, bg = false); // Extrude to 10 units in height