$fa = 5;
$fs = 0.25;


// ===== Parameters =====

gridx = 2;      // number of bases along x-axis
gridy = 2;      // number of bases along y-axis
gridz = 3;      // unit height along z-axis (2, 3, or 6, but can be anything)
n_div = 2;      // number of compartments (ideally, coprime w/ gridx)
                // set n_div to 0 for a solid bin (for custom bins)

length = 42;    // base unit (if you want to go rogue ig)

// type of tab style. alignment only matters if tabs are large enough
// 0:full, 1:automatic, 2:right, 3:center, 4:left, 5:none
style_tab = 0; 

enable_scoop    = true; // the rounded edge that allows for easy removal
enable_holes    = true; // holes on the base for magnet / screw
enable_holeslit = true; // extra cut within holes for better slicing

// ===== Info =====
// the red plane that is the top of the internal bin is d_height+h_base above z=0
// the tab cutter object causes serious lag in the preview, I think it has something to do with cutting the same surfaces as other cutting objects, but I cannot seem to fix it, apologies
// the magnet holes have an extra cut in them to make it easier to print without supports

// ===== Dimensions =====

// base
h_base = 5;     // height of the base
r_base = 4;     // outside rounded radius of bin
r_c1 = 0.8;     // lower base chamfer "radius"
r_c2 = 2.4;     // upper base chamfer "radius"
h_bot = 2.2;    // bottom thiccness of bin

// base holes
r_hole1 = 1.5;  // screw hole radius
r_hole2 = 3.25; // magnet hole radius
d_hole = 26;    // center-to-center distance between holes
h_hole = 2.4;   // magnet hole depth

// fillets
r_f1 = 0.6;     // top edge fillet radius
r_f2 = 2.8;     // internal fillet radius
r_f3 = 0.6;     // lip fillet radius

// misc
d_div = 1.2;    // width of divider between compartments
d_wall = 0.95;   // minimum wall thickness
d_clear = 0.25; // tolerance fit factor

// tabs
d_tabh = 15.85;   // height of tab (yaxis, measured from inner wall)
d_tabw = length; // maximum width of tab
a_tab = 32; 

// calculations
d_height = (gridz-1)*7 + 2;  
r_scoop = length*gridz/12;  // scoop radius
d_wall2 = r_base-r_c1-d_clear*sqrt(2);

d_width = (gridx*length-2*d_wall-(n_div-1)*d_div)/n_div; 
b_notab = style_tab == 5 || gridz < 3; 

// magic numbers (cutter parameters)
v_tab = [r_f2, r_f3, d_height-h_bot-(d_tabh-d_wall)*tan(a_tab), d_tabh-d_wall-r_f3/tan(a_tab/2), d_height-h_bot-r_f3, 179, a_tab, r_f2];
v_edg = [r_f2, 0, d_height-h_bot-d_wall2, d_wall2-d_wall, d_height-h_bot-d_wall, 90, 45];
v_slo = [r_scoop, 0, 2*d_height, 0, 0, 30, 10];



gridfinity();


// ===== Modules =====

module gridfinity() {
    difference() {
        // solid bin
        block_bottom(d_height);
        
        // subtraction blocks
        block_cutter();
    }
    block_base();
    block_wall();
}

module profile_base() {
    polygon([
        [0,0],
        [0,h_base],
        [r_base,h_base],
        [r_base-r_c2,h_base-r_c2],
        [r_base-r_c2,r_c1],
        [r_base-r_c2-r_c1,0]
    ]);
}

module block_base() {
    color("orange")
    pattern_linear(gridx, gridy, length) 
    render() union() {
        sweep_rounded(length-2*r_base,length-2*r_base) profile_base();
        pattern_circular(4) difference() {
            linear_extrude(h_base) square(length/2-r_base);
            if (enable_holes)
            translate([d_hole/2, d_hole/2, 0]) union() {
                cylinder(h = 3*h_base, r = r_hole1, center=true);
                cylinder(h = 2*h_hole, r = r_hole2, center=true);
                if (enable_holeslit) intersection() {
                    cylinder(h = 2*(h_hole+0.2), r = r_hole2, center=true);
                    cube([r_hole1*2,r_hole2*3,2*(h_hole+0.4)], center=true);
                }
            }
        }
    }
}

module profile_wall_sub() {
    difference() {
        polygon([
            [0,0],
            [d_wall/2,0],
            [d_wall/2,d_height-d_wall2-d_wall/2],
            [d_wall2,d_height-d_wall],
            [d_wall2,d_height+h_base],
            [0,d_height+h_base]
        ]);
        offset(delta = 0.25) 
        translate([r_base,d_height,0]) 
        mirror([1,0,0]) 
        profile_base();
    }
}

module profile_wall() {
    translate([r_base,0,0])
    mirror([1,0,0])
    difference() {
        profile_wall_sub();
        difference() {
            translate([0, d_height+h_base-d_clear*sqrt(2), 0]) 
            circle(r_base/2);
            offset(r = r_f1) 
            offset(delta = -r_f1)
            profile_wall_sub();
        }
    }
}

module block_wall() {
    color("royalblue")
    translate([0,0,h_base]) 
    sweep_rounded(gridx*length-2*r_base, gridy*length-2*r_base)
    profile_wall();
}

module block_bottom( h = 2.2 ) {
    color("firebrick")
    translate([0,0,h_base])
    hull()
    sweep_rounded(gridx*length-2*r_base, gridy*length-2*r_base)
    translate([r_base-0.1,0,0])
    mirror([1,0,0])
    square([d_wall, d_height]);
}

module profile_cutter(r = 0, width = 1, stretch = 0) {
    extent = width/2-r_f2+0.1;
    translate([r-r_f2,0,0]) 
    union() {
        difference() {
            union() {
                translate([0,extent,0]) circle(r=r_f2);
                square([r_f2,extent]);
            }
            translate([-r_f2,0,0]) square([r_f2,extent+r_f2]);
        }
        mirror([1,0,0]) square([stretch,extent+r_f2]);
    }
}

module part_bend(t=[0,0], rot, ang, rad, width, s = 0) {
    translate([t.x,t.y,0]) 
    rotate([0,0,rot]) 
    rotate_extrude(angle = ang, convexity = 4) 
    profile_cutter(rad,width,s);
}

module part_line(t=[0,0], rot, d, width, s = 0) {
    translate([t.x,t.y,0])
    rotate([90,0,rot])
    translate([r_f2,0,0])
    linear_extrude(d) 
    profile_cutter(0,width,s);
}

module cutter_main(arr, width, offset = 0) {
    
    r1 = arr[0]; 
    r2 = arr[1];
    a_end = arr[5];
    a_slo = arr[6];
    p_y3 = arr[2] - r1*tan((90-a_slo)/2);
    p_x4 = arr[3];
    p_y4 = arr[4];
    
    d_width = width;
    d_extent = gridy*length/2 - d_wall + 0.1;
    
    l_angle = ([p_x4-r1,p_y4-p_y3] * [[cos(a_slo), -sin(a_slo)], [sin(a_slo), cos(a_slo)]])[0];
    
    translate([0,gridy*length/2-d_wall,h_base+h_bot])
    rotate([90,0,-90])
    union() 
    copy_mirror([0,0,1])
    translate([offset,0,-0.1]) {
        // outside of hull because of its concave geometry
        if (p_x4 != 0 || p_y4 != 0) difference() 
            { 
            union() {
                render() part_bend([p_x4, p_y4], a_slo+90, a_end-a_slo, -r2, d_width, 2*r_f2);
                part_line([p_x4, p_y4]+(r_f2+r2)*ta(a_end-90)-0.1*ta(a_end), a_end+90, d_extent, d_width, 2*r_f2);
                part_line([r1, p_y3]+(r1-r_f2)*-ta(-a_slo)+l_angle*ta(a_slo), a_slo+90, l_angle, d_width, 2*r_f2);
            }
            copy_mirror([0,1,0]) translate([0,-0.1,-0.1]) cube([d_extent+0.1,r_f2,d_width]);
        }
        hull() 
        {
            // left bottom, angle, and scoop fillets
            part_bend([r1, r1], -180, 90, r1, d_width);
            part_bend([r1, p_y3], 90+a_slo, 90-a_slo, r1, d_width);
            
            // bottom, left, right, angle (thin), angle (thicc)
            part_line([d_extent, r_f2], -90, d_extent - r1, d_width);
            part_line([r_f2, r1], 180, p_y3 - r1, d_width);
            part_line([r1, p_y3]+(r1-r_f2)*-ta(-a_slo), a_slo+90, (d_extent-r1+(r1-r_f2)*cos(a_slo))/cos(a_slo), d_width);
            
        }
    }
}

module cutter_tab(s = 1) {
    d_divw = (gridx*length-2*d_wall-(n_div-1)*d_div)/n_div; 
    if ((d_divw > d_tabw && s != 0 && d_divw - d_tabw > 4*r_f2 ) || s == 5) {
        d_w = (d_divw - (s==5?0:length)) / (s==3?2:1);
        mirror([s==2?1:0, 0, 0])
        copy_mirror([s==3?1:0, 0, 0])
        translate([(d_divw-d_w)/2,0,0])
        cutter_main(v_edg, d_w);
    }
}

module block_cutter() {
    if (n_div > 0) {
        pattern_linear(n_div, 1, d_width + d_div) 
        cutter_main(b_notab ? v_edg : v_tab, d_width);
        if (!b_notab) {
            for (i = [1:n_div]) 
            translate([((i-1)-(n_div-1)/2)*(d_width + d_div),0,0])
            cutter_tab(style_tab==1?(i==1?4:(i==n_div?2:3)):style_tab);
        }
        mirror([0,1,0])
        for (i = [1:n_div]) 
        translate(((i-1)-(n_div-1)/2)*(d_width + d_div)*[1,0,0])
        cutter_main(enable_scoop?v_slo:v_edg, d_width, enable_scoop?d_wall2-d_wall : 0);
    }
}


// ==== Utilities =====

ta = function (a) [cos(a), sin(a)];

module copy_mirror(vec=[0,1,0]) {
    children();
    mirror(vec) children();
} 

module pattern_linear(x = 1, y = 1, spacing = 0) {
    translate([-(x-1)*spacing/2,-(y-1)*spacing/2,0])
    for (i = [1:x])
    for (j = [1:y])
    translate([(i-1)*spacing,(j-1)*spacing,0]) 
    children();
}

module pattern_circular(n=2) {
    for (i = [1:n]) 
    rotate(i*360/n) 
    children();
}

module sweep_rounded(w=10, h=10) {
    union() pattern_circular(2) {
        copy_mirror([1,0,0]) 
        translate([w/2,h/2,0])
        rotate_extrude(angle = 90, convexity = 4) 
        children();
        
        translate([w/2,0,0])
        rotate([90,0,0])
        linear_extrude(height = h, center = true)
        children();
        
        rotate([0,0,90])
        translate([h/2,0,0])
        rotate([90,0,0])
        linear_extrude(height = w, center = true)
        children();
    }
}