我正在使用 Andengine 制作游戏，但我在旋转精灵拍摄时被困了 2 天。我不是几何学的英雄，已经问过老师，但他也不能给我正确的答案。那么谁是数学英雄并帮助我:)。
问题是我无法弄清楚子弹必须在炮塔前产生的位置。旋转并找到子弹必须去的目的地是没有问题的。它只是关于生成点。
我为这个问题删除了很多不感兴趣的代码。
好的，这是炮塔旋转的旋转代码：
public class AlienShip extends Ship {
public static final float BASE_ROTATION_SPEED = 0.25f;
public static final int DEFAULT_IMAGE_ROTATION = 90; //90 degrees
protected PlayerShip ship;
public AlienShip(float pX, float pY, TextureRegion pTextureRegion,
VertexBufferObjectManager pVertexBufferObject,FixedStepPhysicsWorld pw, int baseDurability) {
super(pX, pY, pTextureRegion, pVertexBufferObject, pw, baseDurability);
}
public void rotateToPlayer()
{
if (ship != null) {
float dX = this.getX() - ship.getX();
float dY = this.getY() - ship.getY();
float angle = (float) Math.atan2(-dY, dX);
float rotation = MathUtils.radToDeg(angle) + DEFAULT_IMAGE_ROTATION;
RotationModifier rotMod = new RotationModifier(BASE_ROTATION_SPEED, this.getRotation(), rotation);
this.registerEntityModifier(rotMod);
}
}
public void rotateToInitPos() {
RotationModifier rotMod = new RotationModifier(BASE_ROTATION_SPEED, this.getRotation(), 0);
this.registerEntityModifier(rotMod);
}
}
上面的代码工作正常。
这是船正在射击的激光代码。阅读评论以找出女巫部分不起作用。
public class GameScene extends Scene {
protected PlayerShip playerShip;
private SpawnCallback createShootCallback(boolean player) {
return new SpawnCallback() {
@Override
public void spawn(SpawnTimer spawnTimer) {
PhysicsSprite laser = null;
AlienShip alienShip = (AlienShip) spawnTimer.getPhysicsSprite();
// laser = alienMissilePool.getMissileFromPool(x,y)
//spawn the laser in front of the rotating ship [Not working :( ]
laser = alienMissilePool.getMissileFromPool( ( alienShip.getX() * FloatMath.cos(MathUtils.degToRad(rotation)) - ((1280 - alienShip.getY() - alienShip.getY()/2) * FloatMath.sin(MathUtils.degToRad(rotation)) ) ) ,
( alienShip.getX() * FloatMath.sin(MathUtils.degToRad(rotation)) + ((1280 - alienShip.getY() - alienShip.getY()/2) * FloatMath.cos(MathUtils.degToRad(rotation)) ) ) );
//Set the rotation from the laser same to the ship rotation [Is working perfectly].
float rotation = alienShip.getRotation();
laser.setRotation(rotation);
//Set laser speed and direction [Is working perfectly]
float pX = 0.01f * (playerShip.getX() - laser.getX());
float pY = 0.01f * (playerShip.getY() - laser.getY());
laser.getSpriteBody().setLinearVelocity(pX, pY);
spawnPhysicsSprite(laser);
}
};
}
}
这是显示 x 轴和 y 轴值的绘图的链接。 http://s24.postimg.org/citz29339/gamescene.png
谢谢！