LibGDX - My sprite glitches when it moves

Question

My player sprite glitches when it moves across the screen. I've tried multiplying movements by delta time. I've tried rounding. It seems to do this completely at random. Sometimes I can move it all the way across the screen and its fine, other times it glitches and twitches the entire way.

@Override
public void render(float delta) {
    //update the camera
    camera.update();

    //clear the screen with black
    Gdx.gl.glClearColor(0,0,0,1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    //update the renderer and render
    renderer.setView(camera);
    renderer.render();

    //update players movement on x-axis and apply gravity and increase x-axis speed if the player is jumping
    if(player.movingLeft)
        player.movement[0] -= Math.round(player.playerSpeed * delta);
    if(player.movingRight)
        player.movement[0] += Math.round(player.playerSpeed * delta);
    if(player.movingUp)
        player.movement[1] += player.playerSpeed * delta;

    //handle jumping
    if(player.isJumping) {
        if(player.jumpCurrentY < player.MAX_JUMP_DURATION) {
            player.momentum = 0;
            player.jumpSpeed++;
            player.movement[1] = player.jumpSpeed;
            if (player.jumpSpeed > 5)
                player.jumpSpeed = 5;
            player.jumpCurrentY++;
        } else if(player.hangTime < player.MAX_HANG_TIME) {
            player.momentum = 0;
            player.hangTime++;
            player.movement[1] = 2.8f;
        } else {
            player.isJumping = false;
            player.jumpCurrentY = 0;
            player.hangTime = 0;
            player.jumpSpeed = 0;
            player.momentum = gravity;
        }
    } else {
        player.jumpCurrentY = 0;
    }

    updateSprite(delta, player, player.movement, collidableTiles);

    //set sprite batch projection matrix and draw to the screen
    game.batch.setProjectionMatrix(camera.combined);
    game.batch.begin();
    player.draw(game.batch);
    game.batch.end();

    //reset player movement
    Arrays.fill(player.movement, 0);

    //increment player momentum by gravity and assign it to the players y-axis movement
    player.momentum += gravity;
    player.movement[1] = player.momentum;
    player.momentum += -1;
    if(player.momentum < -5)
        player.momentum = -5;

    //TEMPORARY
    camera.position.set(Math.round(player.getX()), Math.round(player.getY()), 0);


}

Answer 1

It happens because you update the camera's position out of sync with the player's position.

In public void render(float delta) in LevelOne you start by updating the camera's transform by calling camera.update, but you really want to do this after you've calculated the new position of the player.

If you change around your code to first calculate the new positions of the player, then call the updateSprite method and then call camera.update the glitching will go away.

Or in code, change your LevelOne render method to:

@Override
public void render(float delta) {

    //clear the screen with black
    Gdx.gl.glClearColor(0,0,0,1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);


    //update players movement on x-axis and apply gravity and increase x-axis speed if the player is jumping
    if(player.movingLeft)
        player.movement[0] -= Math.round(player.playerSpeed * delta);
    if(player.movingRight)
        player.movement[0] += Math.round(player.playerSpeed * delta);
    if(player.movingUp)
        player.movement[1] += player.playerSpeed * delta;

    //handle jumping
    if(player.isJumping) {
        if(player.jumpCurrentY < player.MAX_JUMP_DURATION) {
            player.momentum = 0;
            player.jumpSpeed++;
            player.movement[1] = player.jumpSpeed;
            if (player.jumpSpeed > 5)
                player.jumpSpeed = 5;
            player.jumpCurrentY++;
        } else if(player.hangTime < player.MAX_HANG_TIME) {
            player.momentum = 0;
            player.hangTime++;
            player.movement[1] = 2.8f;
        } else {
            player.isJumping = false;
            player.jumpCurrentY = 0;
            player.hangTime = 0;
            player.jumpSpeed = 0;
            player.momentum = gravity;
        }
    } else {
        player.jumpCurrentY = 0;
    }


    updateSprite(delta, player, player.movement, collidableTiles);
    //TEMPORARY
    camera.position.set(Math.round(player.getX()), Math.round(player.getY()), 0);
    //update the camera
    camera.update();


    //update the renderer and render
    renderer.setView(camera);
    renderer.render();


    //set sprite batch projection matrix and draw to the screen
    game.batch.setProjectionMatrix(camera.combined);
    game.batch.begin();
    player.draw(game.batch);
    game.batch.end();

    //reset player movement
    Arrays.fill(player.movement, 0);

    //increment player momentum by gravity and assign it to the players y-axis movement
    player.momentum += gravity;
    player.movement[1] = player.momentum;
    player.momentum += -1;
    if(player.momentum < -5)
        player.momentum = -5;
}