Setting up a custom cursor image in LWJGL 3

Question

How can I load a custom cursor image with LWJGL3? It took me a while to figure this out. Here is how it is done for version 3.0.1. Hope this helps.

Answer 1

    InputStream stream = new FileInputStream("C:\\path\\to\\image.png");
    BufferedImage image = ImageIO.read(stream);

    int width = image.getWidth();
    int height = image.getHeight();

    int[] pixels = new int[width * height];
    image.getRGB(0, 0, width, height, pixels, 0, width);

    // convert image to RGBA format
    ByteBuffer buffer = BufferUtils.createByteBuffer(width * height * 4);

    for (int y = 0; y < height; y++)
    {
        for (int x = 0; x < width; x++)
        {
            int pixel = pixels[y * width + x];

            buffer.put((byte) ((pixel >> 16) & 0xFF));  // red
            buffer.put((byte) ((pixel >> 8) & 0xFF));   // green
            buffer.put((byte) (pixel & 0xFF));          // blue
            buffer.put((byte) ((pixel >> 24) & 0xFF));  // alpha
        }
    }
    buffer.flip(); // this will flip the cursor image vertically

    // create a GLFWImage
    GLFWImage cursorImg= GLFWImage.create();
    cursorImg.width(width);     // set up image width
    cursorImg.height(height);   // set up image height
    cursorImg.pixels(buffer);   // pass image data

    // the hotspot indicates the displacement of the sprite to the 
    // position where mouse clicks are registered (see image below)
    int hotspotX = 3;
    int hotspotY = 6;

    // create custom cursor and store its ID
    long cursorID = GLFW.glfwCreateCursor(cursorImg, hotspotX , hotspotY);

    // set current cursor
    glfwSetCursor(window, cursorID);