CODEWITHSUNDEEP
javaandroidlibgdx
Kiril Raykov
Kiril Raykov

Reputation: 23

LibGDX player movement

I'm developing a 2D space shooter game with the player only moving left and right. I've rendered a button on the left and the right side of the screen and constantly check if it's touched. The problem with this is that you have to lift your finger of the button in order to press the button on the other side of the screen. I want the ship to be moving towards the last touched part of the screen(Even when you actually didn't lift the finger of your first-touched button).

    public void keyListener(float delta){

    //right movement
    if(Gdx.input.isKeyPressed(Keys.RIGHT) || (Gdx.input.isTouched() && game.cam.getInputInGameWorld().x >= arrowMoveX - 40) && !isPlayerHit)
        x+=SPEED*Gdx.graphics.getDeltaTime();


    //left movement
     if(Gdx.input.isKeyPressed(Keys.LEFT) || (Gdx.input.isTouched() && game.cam.getInputInGameWorld().x < arrowMoveWhite.getWidth() + 40) && !isPlayerHit)
        x-=SPEED*Gdx.graphics.getDeltaTime();

I've tried puting another if statements in these to check for a second movement, but this way it only works on one direction. Can you please help me?

Upvotes: 0

Views: 1544

Answers (1)

JoseRivas1998
JoseRivas1998

Reputation: 552

What you need to know about for this is that Android indexes each separate touch in order of when the screen was touched, the index is known as a "pointer". For example, when you touch the screen with only one finger, the touch pointer is 0, and the second touch pointer is 1. The highest pointer that libGDX registers is 20.

For your particular situation, you want to read only the input that is on the highest pointer that is currently reading a touch, and have an int reading the highest touch. You can loop through the pointers, and set the int to whatever touch event is actually the highest pointer which is referring to the most recent press like this:

int highestpointer = -1; // Setting to -1 because if the pointer is -1 at the end of the loop, then it would be clear that there was no touch 
for(int pointer = 0; pointer < 20; pointer++) {
     if(Gdx.input.isTouched(pointer)) { // First check if there is a touch in the first place
          int x = Gdx.input.getX(pointer); // Get x position of touch in screen coordinates (far left of screen will be 0)
          if(x < arrowMoveWhite.getWidth() + 40 || x >= arrowMoveX - 40) {
               highestpinter = pointer; 
          } // Note that if the touch is in neither button, the highestpointer will remain what ever it was previously
     }
} // At the end of the loop, the highest pointer int would be the most recent touch, or -1

// And to handle actual movement you need to pass the highest pointer into Gdx.input.getX()
if(!isPlayerHit) { // Minor improvement: only check this once
     if(Gdx.input.isKeyPressed(Keys.RIGHT) || (highestpointer > -1 && Gdx.input.getX(highestpointer) >= arrowMoveX - 40)) {
        x+=SPEED*Gdx.graphics.getDeltaTime();
     } else if(Gdx.input.isKeyPressed(Keys.LEFT) || (highestpointer > -1 && Gdx.input.getX(highestpointer) < arrowMoveWhite.getWidth() + 40)) {
          x-=SPEED*Gdx.graphics.getDeltaTime();
     }
}

Note that you will probably want a separate camera drawing your buttons (or any hud elements) because you would not need to worry about translating screen coordinates to world coordinates since x goes in the same direction.

Let me know how that works and if you need any changes!

Upvotes: 1

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