How to rotate a sprite on circle in android using Libgdx

Question

Dear Fellow Game Developers
i am newbie to Android Game Development,i like to know how we can develop a sprite rotate in circle on android,with help of libgdx, i do have a image in assets folder,cant load it in emulator,following code is using to load image in texture

texture = new Texture(Gdx.files.internal("1325603701_wordpress.png"));

Answer 1

Create your sprite as following

Texture glowBlock = new Texture(Gdx.files.internal("data/glow-block.png"));
Sprite  glowSprite = new com.badlogic.gdx.graphics.g2d.Sprite(glowBlock);

Then in your render method do this

@Override
public void render () {
    Gdx.graphics.getGL10().glClear(GL10.GL_COLOR_BUFFER_BIT);
    spriteBatch.begin();
    spriteBatch.setColor(Color.WHITE);
    glowSprite.rotate((float) 45.0);
    glowSprite.draw(spriteBatch, 100);
    spriteBatch.end();
}

That should give you sprite rotated for 45 degrees

Answer 2

Here is the simple way how can you rotate a sprite in libGDX. First you need to set the origin:

sprite.setOrigin(sprite.getWidth/2,sprite.getHeight/2);

Then you can rotate clockwise and anticlockwise according to your need:

sprite.rotate(2f); or sprite.rotate(-2f);

Answer 3

If by rotating in a circle you mean WALKING on top of the circumference of a circle, then I guess any of the answers correctly answered your question. So here is my add:

You can continue loading you texture with

texture = new Texture(Gdx.files.internal("1325603701_wordpress.png"));

but it is extremely recommended that you use the AssetManager. About it not loading in the emulator, check if your texture size is power of two. (Like 64x64)

Then create your sprite:

sprite = new Sprite(texture);

you'll possibly want to pass more arguments to cut the sprite, in case you're using a power of two texture for a non power of two sprite.

Create a helper variable on the class body, to keep track of the time, and one to say where will be the sprite center:

private float elapsedTime = 0.0f;
private Vector2 center = new Vector2(10, 10);

on render:

public void render () {
    final float speed = 30.0f; // in degrees per second
    final float radius = 10.0f; // the radius of the circle you'll be rotating
    float angle = elapsedTime * speed;
    Gdx.graphics.getGL10().glClear(GL10.GL_COLOR_BUFFER_BIT);
    spriteBatch.setProjectionMatrix(camera.combined);
    spriteBatch.begin();
    sprite.setRotation(angle - 90);
    sprite.setPosition(center.x + radius * (float)Math.cos(angle * MathUtils.degrad), center.y + radius * (float)Math.sin(angle * MathUtils.degrad));
    sprite.draw(spriteBatch);
    spriteBatch.end();
}

This should work just fine.

Answer 4

Do it like this 1. Load your image into AssestLoader class and store it in sprite

sprite=new Sprite(AssestLoader.1325603701_wordpress);

2.Then set its size , position and color like this

sprite.setColor(1, 1, 1, 1);
sprite.setSize(sprite.getWidth(),sprite.getHeight());
sprite.setPosition((w / 2) - (sprite.getWidth() / 2), (h / 2)
                - (sprite.getHeight() / 2));

3- In your render method use the below code

batch.begin();
sprite.draw(batch);
batch.end();

4.Call the rotate method where u want to rotate

batch.begin();
this.rotate(deltatime); 
deltatime=deltatime+0.5f;       
batch.end();

and

public void rotate(float angle)
{
    sprite.setRotation(angle);

}

where deltatime is float value=1

Hope this Helps You.