// -----------------------------------------------------------------------
// Modular LED Matrix Outer Frame / Diffuser Clamp (Through-Holes)
// -----------------------------------------------------------------------
// NATIVE LANDSCAPE LAYOUT (3 columns x 2 rows)
// Select which tile to generate:
// 1 = Top Left      |  2 = Top Mid      |  3 = Top Right
// 4 = Bottom Left   |  5 = Bottom Mid   |  6 = Bottom Right
part = 1; // [1:6]

// --- Matrix Parameters ---
cellsX = 16;
cellsY = 16;
pitch = 10;
borderWidth = 10;

// --- Frame Settings ---
thickness = 3; 
overhang = 1; // 1mm bite inwards to clamp the diffuser without blocking LEDs
overW = borderWidth + overhang; // Total width of the frame bars
lap_len = 6; // Length of the hidden half-lap joint
tol = 0.2; // 0.2mm tolerance for a friction fit without sanding

// --- Logic ---
hasLeft   = (part == 1 || part == 4) ? 1 : 0;
hasRight  = (part == 3 || part == 6) ? 1 : 0;
hasTop    = (part == 1 || part == 2 || part == 3) ? 1 : 0;
hasBottom = (part == 4 || part == 5 || part == 6) ? 1 : 0;

gridWidth = cellsX * pitch;
gridHeight = cellsY * pitch;

leftOffset = hasLeft * borderWidth;
bottomOffset = hasBottom * borderWidth;

totalWidth = gridWidth + (hasLeft * borderWidth) + (hasRight * borderWidth);
totalHeight = gridHeight + (hasTop * borderWidth) + (hasBottom * borderWidth);

$fn = 32;

// --- Countersunk Hole Module ---
module cs_hole(x, y) {
    // M3 shaft clearance (3.2mm diameter)
    translate([x, y, -0.1]) 
        cylinder(h=thickness + 0.2, r=1.6);
    // Countersink cone for 5mm head (using 5.2mm for flush fit)
    // 1mm depth matches standard 90-degree profile for this head size
    translate([x, y, thickness - 1]) 
        cylinder(h=1.1, r1=1.6, r2=2.6);
}

difference() {
    union() {
        // Base Perimeter Bars
        if(hasLeft)   translate([0, 0, 0]) cube([overW, totalHeight, thickness]);
        if(hasRight)  translate([totalWidth - overW, 0, 0]) cube([overW, totalHeight, thickness]);
        if(hasTop)    translate([0, totalHeight - overW, 0]) cube([totalWidth, overW, thickness]);
        if(hasBottom) translate([0, 0, 0]) cube([totalWidth, overW, thickness]);

        // Male Half-Lap Tabs (Hidden on the bottom half, Z = 0 to thickness/2)
        // Extending Right (P1, P2) on Top Bar
        if(hasTop && !hasRight) translate([totalWidth, totalHeight - overW, 0]) cube([lap_len, overW, thickness/2]);
        // Extending Right (P4, P5) on Bottom Bar
        if(hasBottom && !hasRight) translate([totalWidth, 0, 0]) cube([lap_len, overW, thickness/2]);
        // Extending Down (P1) on Left Bar
        if(hasLeft && !hasBottom) translate([0, -lap_len, 0]) cube([overW, lap_len, thickness/2]);
        // Extending Down (P3) on Right Bar
        if(hasRight && !hasBottom) translate([totalWidth - overW, -lap_len, 0]) cube([overW, lap_len, thickness/2]);
    }
    
    // Female Half-Lap Slots (Cut from Z = -0.1 to thickness/2 + tol)
    // Cut from Left (P2, P3) on Top Bar
    if(hasTop && !hasLeft) translate([-0.1, totalHeight - overW - tol, -0.1]) cube([lap_len + 0.1, overW + 2*tol, thickness/2 + tol]);
    // Cut from Left (P5, P6) on Bottom Bar
    if(hasBottom && !hasLeft) translate([-0.1, -tol, -0.1]) cube([lap_len + 0.1, overW + 2*tol, thickness/2 + tol]);
    // Cut from Top (P4) on Left Bar
    if(hasLeft && !hasTop) translate([-tol, totalHeight - lap_len, -0.1]) cube([overW + 2*tol, lap_len + 0.1, thickness/2 + tol]);
    // Cut from Top (P6) on Right Bar
    if(hasRight && !hasTop) translate([totalWidth - overW - tol, totalHeight - lap_len, -0.1]) cube([overW + 2*tol, lap_len + 0.1, thickness/2 + tol]);

    // Countersunk Mounting Holes
    // Left Border
    if (hasLeft) { 
        for (i = [1 : 3]) { 
            cs_hole(borderWidth / 2, bottomOffset + (i * gridHeight/4)); 
        } 
    } 
    // Right Border
    if (hasRight) { 
        for (i = [1 : 3]) { 
            cs_hole(totalWidth - (borderWidth / 2), bottomOffset + (i * gridHeight/4)); 
        } 
    } 
    // Top Border
    if (hasTop) { 
        for (i = [1 : 3]) { 
            cs_hole(leftOffset + (i * gridWidth/4), totalHeight - (borderWidth / 2)); 
        } 
    } 
    // Bottom Border
    if (hasBottom) { 
        for (i = [1 : 3]) { 
            cs_hole(leftOffset + (i * gridWidth/4), borderWidth / 2); 
        } 
    } 
}