/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0
});

/**** 
* Game Code
****/ 
// Game constants for the screen
var SCREEN_SIZE = 64;
var PIXEL_SIZE = 2048 / SCREEN_SIZE;
// Cache children array reference 
var screen = game.children;
function clearScreen() {
	var len = screen.length;
	for (var i = 0; i < len; i++) {
		screen[i].tint = 0;
	}
}
function putPixel(x, y, color) {
	if (x >= 0 && x < SCREEN_SIZE && y >= 0 && y < SCREEN_SIZE) {
		screen[x + y * SCREEN_SIZE].tint = color;
	}
}
// Line drawing function using Bresenham's line algorithm
function drawLine(x0, y0, x1, y1, color) {
	var dx = x1 - x0;
	var dy = y1 - y0;
	var adx = dx < 0 ? -dx : dx;
	var ady = dy < 0 ? -dy : dy;
	var sx = dx < 0 ? -1 : 1;
	var sy = dy < 0 ? -1 : 1;
	var err = adx - ady;
	var x = x0;
	var y = y0;
	while (true) {
		putPixel(x, y, color);
		if (x === x1 && y === y1) {
			break;
		}
		var e2 = 2 * err;
		if (e2 > -ady) {
			err -= ady;
			x += sx;
		}
		if (e2 < adx) {
			err += adx;
			y += sy;
		}
	}
}
function drawTriangle(triangle, color, wireframe) {
	if (wireframe === undefined) {
		wireframe = false;
	}
	// Extract triangle vertices
	var x1 = triangle[0];
	var y1 = triangle[1];
	var x2 = triangle[2];
	var y2 = triangle[3];
	var x3 = triangle[4];
	var y3 = triangle[5];
	// Draw the three sides of the triangle only if wireframe is true
	if (wireframe) {
		drawLine(x1, y1, x2, y2, color); // Side 1-2
		drawLine(x2, y2, x3, y3, color); // Side 2-3
		drawLine(x3, y3, x1, y1, color); // Side 3-1
	} else {
		// Helper to interpolate x between two points at a given y
		// Sort vertices by y (ascending) - reuse pre-allocated array
		if (!drawTriangle.verts) {
			drawTriangle.verts = [{
				x: 0,
				y: 0
			}, {
				x: 0,
				y: 0
			}, {
				x: 0,
				y: 0
			}];
		}
		var verts = drawTriangle.verts;
		verts[0].x = x1;
		verts[0].y = y1;
		verts[1].x = x2;
		verts[1].y = y2;
		verts[2].x = x3;
		verts[2].y = y3;
		var interpX = function interpX(y, x0, y0, x1, y1) {
			if (y1 === y0) {
				return x0;
			}
			return x0 + (x1 - x0) * (y - y0) / (y1 - y0);
		}; // Fill bottom flat triangle (v0, v1, v2) if v1.y != v0.y
		verts.sort(function (a, b) {
			return a.y - b.y;
		});
		var v0 = verts[0];
		var v1 = verts[1];
		var v2 = verts[2];
		if (v1.y !== v0.y) {
			var yStart = Math.ceil(v0.y);
			var yEnd = Math.ceil(v1.y);
			for (var y = yStart; y < yEnd; y++) {
				var xA = interpX(y, v0.x, v0.y, v2.x, v2.y);
				var xB = interpX(y, v0.x, v0.y, v1.x, v1.y);
				var xStart = xA < xB ? Math.ceil(xA) : Math.ceil(xB);
				var xEnd = xA > xB ? Math.floor(xA) : Math.floor(xB);
				for (var x = xStart; x <= xEnd; x++) {
					putPixel(x, y, color);
				}
			}
		}
		// Fill top flat triangle (v1, v2, v0) if v2.y != v1.y
		if (v2.y !== v1.y) {
			var yStart = Math.ceil(v1.y);
			var yEnd = Math.ceil(v2.y);
			for (var y = yStart; y < yEnd; y++) {
				var xA = interpX(y, v0.x, v0.y, v2.x, v2.y);
				var xB = interpX(y, v1.x, v1.y, v2.x, v2.y);
				var xStart = xA < xB ? Math.ceil(xA) : Math.ceil(xB);
				var xEnd = xA > xB ? Math.floor(xA) : Math.floor(xB);
				for (var x = xStart; x <= xEnd; x++) {
					putPixel(x, y, color);
				}
			}
		}
	}
}
var colorIndex = 0;
var offset = 2732 / 2 - SCREEN_SIZE * PIXEL_SIZE / 2;
// Create the screen of pixels
for (var y = 0; y < SCREEN_SIZE; y++) {
	for (var x = 0; x < SCREEN_SIZE; x++) {
		// Get an instance of our pixel asset
		var pixel = LK.getAsset('pixel', {
			x: x * PIXEL_SIZE,
			y: y * PIXEL_SIZE + offset,
			tint: 0
		});
		game.addChild(pixel);
	}
}
function translateTriangle(triangle, dx, dy, dz) {
	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
	// Translate each vertex by dx, dy, dz - reuse pre-allocated array
	if (!translateTriangle.result) {
		translateTriangle.result = [0, 0, 0, 0, 0, 0, 0, 0, 0];
	}
	var result = translateTriangle.result;
	result[0] = triangle[0] + dx;
	result[1] = triangle[1] + dy;
	result[2] = triangle[2] + dz;
	result[3] = triangle[3] + dx;
	result[4] = triangle[4] + dy;
	result[5] = triangle[5] + dz;
	result[6] = triangle[6] + dx;
	result[7] = triangle[7] + dy;
	result[8] = triangle[8] + dz;
	return result;
}
function rotateTriangle(triangle, angleX, angleY, angleZ) {
	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
	// angleX, angleY, angleZ in radians
	// Reuse pre-allocated array for result
	if (!rotateTriangle.result) {
		rotateTriangle.result = [0, 0, 0, 0, 0, 0, 0, 0, 0];
	}
	var result = rotateTriangle.result;
	// Precompute sines and cosines
	var cosX = Math.cos(angleX),
		sinX = Math.sin(angleX);
	var cosY = Math.cos(angleY),
		sinY = Math.sin(angleY);
	var cosZ = Math.cos(angleZ),
		sinZ = Math.sin(angleZ);
	// Helper to rotate a single point
	function rotate(x, y, z) {
		// Rotate around X axis
		var y1 = y * cosX - z * sinX;
		var z1 = y * sinX + z * cosX;
		// Rotate around Y axis
		var x2 = x * cosY + z1 * sinY;
		var z2 = -x * sinY + z1 * cosY;
		// Rotate around Z axis
		var x3 = x2 * cosZ - y1 * sinZ;
		var y3 = x2 * sinZ + y1 * cosZ;
		return [x3, y3, z2];
	}
	// Rotate each vertex
	var p1 = rotate(triangle[0], triangle[1], triangle[2]);
	var p2 = rotate(triangle[3], triangle[4], triangle[5]);
	var p3 = rotate(triangle[6], triangle[7], triangle[8]);
	result[0] = p1[0];
	result[1] = p1[1];
	result[2] = p1[2];
	result[3] = p2[0];
	result[4] = p2[1];
	result[5] = p2[2];
	result[6] = p3[0];
	result[7] = p3[1];
	result[8] = p3[2];
	return result;
}
function isTriangleFacingCamera(triangle) {
	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
	// Calculate two edge vectors
	var edge1x = triangle[3] - triangle[0]; // x2 - x1
	var edge1y = triangle[4] - triangle[1]; // y2 - y1
	var edge1z = triangle[5] - triangle[2]; // z2 - z1
	var edge2x = triangle[6] - triangle[0]; // x3 - x1
	var edge2y = triangle[7] - triangle[1]; // y3 - y1
	var edge2z = triangle[8] - triangle[2]; // z3 - z1
	// Calculate cross product (normal vector)
	var normalX = edge1y * edge2z - edge1z * edge2y;
	var normalY = edge1z * edge2x - edge1x * edge2z;
	var normalZ = edge1x * edge2y - edge1y * edge2x;
	// Calculate center of triangle
	var centerX = (triangle[0] + triangle[3] + triangle[6]) / 3;
	var centerY = (triangle[1] + triangle[4] + triangle[7]) / 3;
	var centerZ = (triangle[2] + triangle[5] + triangle[8]) / 3;
	// Camera is at origin (0, 0, 0), so view vector is from triangle center to camera
	var viewX = 0 - centerX;
	var viewY = 0 - centerY;
	var viewZ = 0 - centerZ;
	// Dot product of normal and view vector
	var dotProduct = normalX * viewX + normalY * viewY + normalZ * viewZ;
	// If dot product is positive, triangle is facing camera
	return dotProduct > 0;
}
function projectTriangle(triangle) {
	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
	// Perspective projection parameters
	var fov = 80; // Focal length (distance from camera to projection plane)
	var cx = SCREEN_SIZE / 2;
	var cy = SCREEN_SIZE / 2;
	function project(x, y, z) {
		// Avoid division by zero
		var zz = z === 0 ? 0.0001 : z;
		return [Math.round(cx + (x - cx) * (fov / (fov + zz))), Math.round(cy + (y - cy) * (fov / (fov + zz)))];
	}
	// Reuse pre-allocated arrays for projection results
	if (!projectTriangle.result) {
		projectTriangle.result = [0, 0, 0, 0, 0, 0];
	}
	var result = projectTriangle.result;
	var p1 = project(triangle[0], triangle[1], triangle[2]);
	var p2 = project(triangle[3], triangle[4], triangle[5]);
	var p3 = project(triangle[6], triangle[7], triangle[8]);
	// Fill result array directly
	result[0] = p1[0];
	result[1] = p1[1];
	result[2] = p2[0];
	result[3] = p2[1];
	result[4] = p3[0];
	result[5] = p3[1];
	return result;
}
//Start of the 3d renderer
var triangles = [[-16, -16, -16, 16, -16, -16, -16, 16, -16], [-16, 16, -16, 16, -16, -16, 16, 16, -16], [16, -16, -16, 16, -16, 16, 16, 16, -16], [16, 16, -16, 16, -16, 16, 16, 16, 16], [-16, -16, 16, -16, 16, 16, 16, -16, 16], [-16, 16, 16, 16, 16, 16, 16, -16, 16], [-16, -16, 16, -16, -16, -16, -16, 16, 16], [-16, 16, 16, -16, -16, -16, -16, 16, -16]];
// Center the cube by translating to the middle of the screen
var centerX = SCREEN_SIZE / 2;
var centerY = SCREEN_SIZE / 2;
var centerZ = 16; // Move slightly back for better perspective
// This is the part where the cube is drawn
var angleY = 0;
LK.setTimeout(function () {
	game.update = function () {
		clearScreen();
		triangles.forEach(function (triangle, i) {
			var rotatedTriangle = rotateTriangle(triangle, 0, angleY, 0);
			var centeredTriangle = translateTriangle(rotatedTriangle, centerX, centerY, centerZ);
			// Only draw triangle if it's facing the camera
			if (isTriangleFacingCamera(centeredTriangle)) {
				drawTriangle(projectTriangle(centeredTriangle), 0xFFFFFF, true);
			}
		});
		angleY += 0.01;
	};
}, 2000);

===================================================================
--- original.js
+++ change.js
@@ -207,31 +207,30 @@
 }
 function isTriangleFacingCamera(triangle) {
 	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
 	// Calculate two edge vectors
-	var v1x = triangle[3] - triangle[0]; // x2 - x1
-	var v1y = triangle[4] - triangle[1]; // y2 - y1
-	var v1z = triangle[5] - triangle[2]; // z2 - z1
-	var v2x = triangle[6] - triangle[0]; // x3 - x1
-	var v2y = triangle[7] - triangle[1]; // y3 - y1
-	var v2z = triangle[8] - triangle[2]; // z3 - z1
-	// Calculate normal vector using cross product
-	var normalX = v1y * v2z - v1z * v2y;
-	var normalY = v1z * v2x - v1x * v2z;
-	var normalZ = v1x * v2y - v1y * v2x;
-	// Camera is at origin looking down negative Z axis
-	// Triangle center point
+	var edge1x = triangle[3] - triangle[0]; // x2 - x1
+	var edge1y = triangle[4] - triangle[1]; // y2 - y1
+	var edge1z = triangle[5] - triangle[2]; // z2 - z1
+	var edge2x = triangle[6] - triangle[0]; // x3 - x1
+	var edge2y = triangle[7] - triangle[1]; // y3 - y1
+	var edge2z = triangle[8] - triangle[2]; // z3 - z1
+	// Calculate cross product (normal vector)
+	var normalX = edge1y * edge2z - edge1z * edge2y;
+	var normalY = edge1z * edge2x - edge1x * edge2z;
+	var normalZ = edge1x * edge2y - edge1y * edge2x;
+	// Calculate center of triangle
 	var centerX = (triangle[0] + triangle[3] + triangle[6]) / 3;
 	var centerY = (triangle[1] + triangle[4] + triangle[7]) / 3;
 	var centerZ = (triangle[2] + triangle[5] + triangle[8]) / 3;
-	// Vector from camera (0,0,0) to triangle center
-	var viewX = centerX;
-	var viewY = centerY;
-	var viewZ = centerZ;
+	// Camera is at origin (0, 0, 0), so view vector is from triangle center to camera
+	var viewX = 0 - centerX;
+	var viewY = 0 - centerY;
+	var viewZ = 0 - centerZ;
 	// Dot product of normal and view vector
 	var dotProduct = normalX * viewX + normalY * viewY + normalZ * viewZ;
-	// If dot product is negative, triangle is facing camera
-	return dotProduct < 0;
+	// If dot product is positive, triangle is facing camera
+	return dotProduct > 0;
 }
 function projectTriangle(triangle) {
 	// triangle: [x1, y1, z1, x2, y2, z2, x3, y3, z3]
 	// Perspective projection parameters
@@ -274,9 +273,9 @@
 		triangles.forEach(function (triangle, i) {
 			var rotatedTriangle = rotateTriangle(triangle, 0, angleY, 0);
 			var centeredTriangle = translateTriangle(rotatedTriangle, centerX, centerY, centerZ);
 			// Only draw triangle if it's facing the camera
-			if (!isTriangleFacingCamera(centeredTriangle)) {
+			if (isTriangleFacingCamera(centeredTriangle)) {
 				drawTriangle(projectTriangle(centeredTriangle), 0xFFFFFF, true);
 			}
 		});
 		angleY += 0.01;