How to move an object similar to sinusoidal wave movement?-LibGdx - libgdx

Question

I want to move my object vertically in zig-zag motion,similar to sisnusoidal motion;
I am moving my object like this:
public void moveLeavesDown(float delta) {
setY(getY() - (getSpeed()* delta));
}
How can I get this kind of movement?

Answer 1

You can add a timer and use the math.sin function to add an offset to your leaves.
This demo below shows how it can be done:
import com.badlogic.gdx.ApplicationAdapter;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.math.Vector2;
public class Test extends ApplicationAdapter{
float time =0; // timer to store current elapsed time
Vector2 leaf = new Vector2(150,150); // holds the leaf x,y pos
float sinOffset = 0; // the offset for adding to the image
private SpriteBatch sb; // spritebatch for rendering
TextureRegion tx; // a texture region(the leaf)
#Override
public void create() {
sb = new SpriteBatch(); // make spritebatch
tx = DFUtils.makeTextureRegion(10, 10, "FFFFFF"); // makes a textureRegion of 10x10 of pure white
}
#Override
public void render() {
// clear screen
Gdx.gl.glClearColor(0f, 0f, 0f, 0f);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
leaf.y = leaf.y-0.2f; // move downwards
time+= Gdx.graphics.getDeltaTime(); // update sin timer
sinOffset =(float)Math.sin(time)*10; // calculate offset
// draw leaf with offset
sb.begin();
sb.draw(tx, leaf.x+sinOffset, leaf.y);
sb.end();
}
}