How to implement "move to touch location" function?

Question

What is the formula/logic to implement moving an object towards a TOUCHED location. I want character A to move to my finger and it must be accurate. Here is what I have tried so far:

    @Override
    public boolean touchDown(int screenX, int screenY, int pointer, int button) {
        // coordinates come in pixels so convert to world units
        scaleX = screenX / (Gdx.graphics.getWidth() / 10f);
        scaleY = screenY / (Gdx.graphics.getHeight() / 7f) * -1;


        float angle = new Vector2(scaleX - mishi.getPosition().x, scaleY
                - mishi.getPosition().y).angle();
....
....
        mishi.getVelocity().x = (float) (Math.cos(angle) * 13);
        mishi.getVelocity().y = (float) (Math.sin(angle) * 13);

This gets my character moving but basically no where in the direction I click. If I click in the same point twice, it will move him in 2 different directions

Answer 1

This simply sets the acceleration to a factor proportional to the distance between the points.

If you want the character to move at a constant velocity, you should instead get the angle between points and cast them to a static vector.

To make the character stop, set its velocity and acceleration to 0.

Answer 2

I can't guarantee that this is your problem, but are you taking into consideration that the coordinate system for input starts at the top left, with x growing to the right as usual, but y growing downwards?

In other words, the x-value is the same in world coordinates as in the screen coordinates, but the y differs. To get the y-value from screen to world coordinates, simply use

yWorld = Gdx.graphics.getHeight() - Gdx.input.getY();

Or do it as outlined in this answer: https://stackoverflow.com/questions/16514152/libgdx-coordinate-system-differences-between-rendering-and-touch-input