Mouse cursor disappearing after changing it multiple times

[tonihele]

Mouse cursor disappearing after changing it multiple times. When you do it often enough and there is no way to get it back. We are using the same JmeCursor object instance. And setting it simply with com.jme3.input.InputManager inputManager.setMouseCursor().

We are changing it often depending on what the user interaction is. Seems that LibGDX has also stumbled upon this feature: libgdx/libgdx#2841.

I also tested with LWJGL 3. And the same problem exists. The problem is present in both JME 3.0 and 3.1.

Forum discussion:
https://hub.jmonkeyengine.org/t/mouse-cursor-disappearing-after-changing-it-multiple-times/36458

[tonihele]

changing it multiple time <- I don't have exact figures but it really isn't that much. We get about 10 min of game time on our project. Depending on how we play of course :)

[tonihele]

As discussed further in the forum. The problem doesn't exist in LWJGL 3. I've made a similar cache to be used with LWJGL 2. And tested it to be working.

I'll try my best to make a PR (for master & 3.1).

[tonihele]

Okay, I hope I didn't mess up too much. The solution is similar (identical) to the one used already with LWJGL 3.

Pull requests:
#543
#541

[tonihele]

My test class (note that it'll only read RGBA format cursor). With 3000 FPS, without these fixes the cursor was soon lost, with the fixes, I could overheat my graphics card before the cursor disappeared.

package mygame;

import com.jme3.app.SimpleApplication;
import com.jme3.cursors.plugins.JmeCursor;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.renderer.RenderManager;
import com.jme3.scene.Geometry;
import com.jme3.scene.shape.Box;
import com.jme3.texture.Image;
import com.jme3.texture.Texture;
import com.jme3.util.BufferUtils;
import java.nio.ByteBuffer;
import java.nio.IntBuffer;

/**
 * test
 *
 * @author normenhansen
 */
public class Main extends SimpleApplication {

    JmeCursor cursor;
    boolean cursorSet = false;

    public static void main(String[] args) {
        Main app = new Main();
        app.start();
    }

    @Override
    public void simpleInitApp() {
        Box b = new Box(1, 1, 1);
        Geometry geom = new Geometry("Box", b);

        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
        mat.setColor("Color", ColorRGBA.Blue);
        geom.setMaterial(mat);

        rootNode.attachChild(geom);

        // Create cursor
        cursor = new JmeCursor();
        Texture tex = assetManager.loadTexture("Interface/Idle.png");
        Image img = tex.getImage();
        // width must be a multiple of 16, otherwise the cursor gets distorted
        int frames = 1;
        int width = img.getWidth() % 16 == 0 ? img.getWidth() : (img.getWidth() - img.getWidth() % 16) + 16;
        int heightFrame = img.getHeight() / frames;
        int height = heightFrame % 16 == 0 ? heightFrame : (heightFrame - heightFrame % 16) + 16;

        // Image data
        ByteBuffer data = img.getData(0);
        data.rewind();
        IntBuffer image = BufferUtils.createIntBuffer(height * width * frames);
        for (int z = 0; z < frames; z++) {
            for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                    int argb = 0;
                    if (x < img.getWidth() && y < heightFrame) {
                        try {
                            int abgr = data.getInt();
                            argb = ((abgr & 255) << 24) | (abgr >> 8);
                        } catch (Exception e) {
                            System.out.println(z + ", " + y + ", " + x);
                        }
                    }

                    image.put(argb);
                }
            }
        }
        image.rewind();
        cursor.setNumImages(1);
        cursor.setWidth(width);
        cursor.setHeight(height);
        cursor.setxHotSpot(2);
        cursor.setyHotSpot(height - 2);
        cursor.setImagesData(image);

        flyCam.setEnabled(false);
        inputManager.setCursorVisible(true);
    }

    @Override
    public void simpleUpdate(float tpf) {
        //TODO: add update code
        if (cursorSet) {
            inputManager.setMouseCursor(null);
        } else {
            inputManager.setMouseCursor(cursor);
        }
        cursorSet = !cursorSet;
    }

    @Override
    public void simpleRender(RenderManager rm) {
        //TODO: add render code
    }
}