// -----------------------------------------------------------------------
// Modular LED Matrix Prismatic Lens Array (Short Pegs / Manifold Fix)
// -----------------------------------------------------------------------
// 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;
meshSolid = 2;
meshSpace = pitch - meshSolid; // 8mm hole space from the Front Grid
borderWidth = 10;

// --- Lens Array Parameters ---
baseThickness = 0.4; // 2 layers at 0.2mm for an ultra-thin sandwich film
clearance = 0.3; // Friction fit tolerance
plugSize = meshSpace - clearance; // ~7.7mm peg
plugHeight = 1.5; // SHORTENED: Snaps into hole but leaves an air gap above the LED
prismSize = 1.5; // Size of the light-scattering pyramids on top
prismHeight = 0.8; // Height of the pyramids

// --- 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);

holeRad = 2; // Clearance for M3 screws

// --- Procedural Prismatic Refractor (Manifold Safe) ---
module pyramid(size, h) {
    // A 4-sided cylinder rotated 45 degrees makes a perfect, render-safe square pyramid
    translate([size/2, size/2, 0])
    rotate([0, 0, 45])
    cylinder(h=h, r1=size/sqrt(2), r2=0, $fn=4);
}

module refractor_top(size, h, step) {
    count = floor(size / step);
    offset = (size - (count * step)) / 2;
    translate([offset, offset, 0])
    for(x=[0:count-1]) {
        for(y=[0:count-1]) {
            translate([x*step, y*step, 0])
            pyramid(step, h);
        }
    }
}

// --- Main Build ---
difference() {
    union() {
        // 1. The Ultra-Thin Sandwich Film Base
        cube([totalWidth, totalHeight, baseThickness]);

        // 2. The Extruded Diffuser Pegs
        for (x = [0 : cellsX - 1]) {
            for (y = [0 : cellsY - 1]) {
                // Calculate position to exactly match the Front Grid holes
                px = leftOffset + (meshSolid/2) + (x * pitch) + (clearance/2);
                py = bottomOffset + (meshSolid/2) + (y * pitch) + (clearance/2);
                
                translate([px, py, baseThickness]) {
                    // Solid Light Pipe
                    cube([plugSize, plugSize, plugHeight]);
                    
                    // Prismatic Scatter Top
                    translate([0, 0, plugHeight])
                    refractor_top(plugSize, prismHeight, prismSize);
                }
            }
        }
    }

    // 3. Punch alignment holes perfectly matched to the outer frame 
    if (hasLeft) { 
        for (i = [1 : 3]) { 
            translate([borderWidth / 2, bottomOffset + (i * gridHeight/4), -0.1])
            cylinder(h=baseThickness + plugHeight + prismHeight + 1, r=holeRad, $fn=32); 
        } 
    } 
    if (hasRight) { 
        for (i = [1 : 3]) { 
            translate([totalWidth - (borderWidth / 2), bottomOffset + (i * gridHeight/4), -0.1])
            cylinder(h=baseThickness + plugHeight + prismHeight + 1, r=holeRad, $fn=32); 
        } 
    } 
    if (hasTop) { 
        for (i = [1 : 3]) { 
            translate([leftOffset + (i * gridWidth/4), totalHeight - (borderWidth / 2), -0.1])
            cylinder(h=baseThickness + plugHeight + prismHeight + 1, r=holeRad, $fn=32); 
        } 
    } 
    if (hasBottom) { 
        for (i = [1 : 3]) { 
            translate([leftOffset + (i * gridWidth/4), borderWidth / 2, -0.1])
            cylinder(h=baseThickness + plugHeight + prismHeight + 1, r=holeRad, $fn=32); 
        } 
    } 
}