LibGDX set the hitbox smaller

Question

at the moment I develop a game in LibGDX and use rectangle for the collisions.

I need help to detect collisions with a rectangle. A had already done this, but i will put the rectangle on its center of texture. So the rectangle is smaller than the texture and will be in the middle of this.

I know already, I can set the size with: rectangle.setSize and put it with rectangle.setPosition, but how I can this put in the middle of my texture?

Answer 1

I would not set the Hitrectangle at the position of the Texture, but the Texture at the position of the Hiterectangle. Why? The Texture is only an optical presentation of your game. But it has no logic it needs to execute. The Hitrectangle instead has only logic, and no optical presentation. Collision detection is (a verry important) part of the logic. So i would set the position of the Hitrectangle where it should be, and then set the Texture depending on the position of that. Lets say the Hitrectangle is 0.5 units (use the unit you want, maybe meters?) wide and high and the Texture is 1 unit wide and high. The position, given by the left, lower corner of the Hitrectangle is P(5,6), so you have to draw the Texture at: P(5 - 0.25, 6 - 0.25). Out of this you have the following formulas:

Texture.x = Hitrect.x - ((Texture.width - Hitrect.width) / 2);
Texture.y = Hitrect.y - ((Texture.height - Hitrect.height) / 2);

Hope it helps.