2D Game Programming Tricks - Beginning Android Games - page 425

batcher = new SpriteBatcher(glGraphics, NUM_CAVEMEN );
camera = new Camera2D(glGraphics, WORLD_WIDTH , WORLD_HEIGHT );
}
In the constructor, you create the Caveman instances, as well as the SpriteBatcher and Camera2D .
@Override
public void resume() {
texture = new Texture(((GLGame)game), "walkanim.png");
walkAnim = new Animation( 0.2f,
new TextureRegion(texture, 0, 0, 64, 64),
new TextureRegion(texture, 64, 0, 64, 64),
new TextureRegion(texture, 128, 0, 64, 64),
new TextureRegion(texture, 192, 0, 64, 64));
}
In the resume() method, we load the texture atlas containing the animation keyframes from
the asset file walkanim.png , which is the same as seen in Figure 8-25 . Afterward, we create the
Animation instance, setting the frame duration to 0.2 s and passing in a TextureRegion for each
of the keyframes in the texture atlas.
@Override
public void update( float deltaTime) {
int len = cavemen.length;
for ( int i = 0; i < len; i++) {
cavemen[i].update(deltaTime);
}
}
The update() method just loops over all Caveman instances and calls their Caveman.update()
method with the current delta time. This will make the cavemen move and will update their
walking times.
@Override
public void present( float deltaTime) {
GL10 gl = glGraphics.getGL();
gl.glClear(GL10. GL_COLOR_BUFFER_BIT );
camera.setViewportAndMatrices();
gl.glEnable(GL10. GL_BLEND );
gl.glBlendFunc(GL10. GL_SRC_ALPHA , GL10. GL_ONE_MINUS_SRC_ALPHA );
gl.glEnable(GL10. GL_TEXTURE_2D );
batcher.beginBatch(texture);
int len = cavemen.length;
for ( int i = 0; i < len; i++) {
Caveman caveman = cavemen[i];
TextureRegion keyFrame = walkAnim.getKeyFrame(caveman.walkingTime,
Animation. ANIMATION_LOOPING );
batcher.drawSprite(caveman.position.x, caveman.position.y,
caveman.velocity.x < 0?1:-1, 1, keyFrame);
}