首先让我们看一下测试代码：
public class CollisionDetectionTestActivity extends BaseGameActivity
{
private static final int CAMERA_WIDTH = 480;
private static final int CAMERA_HEIGHT = 320;
private Camera mCamera;
@Override
public Engine onLoadEngine()
{
this.mCamera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);
final Engine engine = new Engine(new EngineOptions(true, ScreenOrientation.LANDSCAPE, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), this.mCamera));
return engine;
}
@Override
public void onLoadResources()
{
}
@Override
public Scene onLoadScene()
{
this.mEngine.registerUpdateHandler(new FPSLogger());
final Scene scene = new Scene();
scene.setBackground(new ColorBackground(0.09804f, 0.6274f, 0.8784f));
int centerX = CAMERA_WIDTH / 2;
int centerY = CAMERA_HEIGHT / 2;
final LoopEntityModifier entityModifier =
new LoopEntityModifier(
new ParallelEntityModifier(
new RotationModifier(12, 0, 360)
));
final Rectangle rectangle = new Rectangle(centerX - 50, centerY - 16, 64, 64);
rectangle.registerEntityModifier(entityModifier);
final Line line = new Line(centerX, centerY, 32, 32);
line.registerEntityModifier(entityModifier);
scene.attachChild(rectangle);
scene.attachChild(line);
scene.registerUpdateHandler(new IUpdateHandler(){
@Override
public void onUpdate(float pSecondsElapsed)
{
if(rectangle.collidesWith(line))
{
rectangle.setColor(1, 0, 0);
}
else
{
rectangle.setColor(0, 1, 0);
}
if(line.collidesWith(rectangle))
{
line.setColor(1, 0, 0);
}
else
{
line.setColor(0, 1, 0);
}
}
@Override
public void reset()
{
}});
return scene;
}
@Override
public void onLoadComplete()
{
}
}
OK，让我们逐一解释。
private static final int CAMERA_WIDTH = 480;
private static final int CAMERA_HEIGHT = 320;
private Camera mCamera;
@Override
public Engine onLoadEngine()
{
this.mCamera = new Camera(0, 0, CAMERA_WIDTH, CAMERA_HEIGHT);
final Engine engine = new Engine(new EngineOptions(true, ScreenOrientation.LANDSCAPE, new RatioResolutionPolicy(CAMERA_WIDTH, CAMERA_HEIGHT), this.mCamera));
return engine;
}
@Override
public void onLoadResources()
{
}
@Override
public void onLoadComplete()
{
}
这些应该没什么问题。
我们主要看
public Scene onLoadScene();
这个函数。
在这个函数里边我们定义了一个矩形和一条直线，并且让他们两个旋转
final LoopEntityModifier entityModifier =
new LoopEntityModifier(
new ParallelEntityModifier(
new RotationModifier(12, 0, 360)
));
final Rectangle rectangle = new Rectangle(centerX - 50, centerY - 16, 64, 64);
rectangle.registerEntityModifier(entityModifier);
final Line line = new Line(centerX, centerY, 32, 32);
line.registerEntityModifier(entityModifier);
scene.attachChild(rectangle);
scene.attachChild(line);
然后就是碰撞检测的部分了，当碰撞的时候，让矩形和直线都改变颜色。
scene.registerUpdateHandler(new IUpdateHandler(){
@Override
public void onUpdate(float pSecondsElapsed)
{
if(rectangle.collidesWith(line))
{
rectangle.setColor(1, 0, 0);
}
else
{
rectangle.setColor(0, 1, 0);
}
if(line.collidesWith(rectangle))
{
line.setColor(1, 0, 0);
}
else
{
line.setColor(0, 1, 0);
}
}
OK，由于代码非常简单，也就不多废话了。