rotate sprite and shooting bullets from the end of a cannon
- by Alberto
Hi all i have a problem in my Andengine code,
I need , when I touch the screen, shoot a bullet from the cannon (in the same direction of the cannon)
The cannon rotates perfectly but when I touch the screen the bullet is not created at the end of the turret
This is my code:
private void shootProjectile(final float pX, final float pY){
int offX = (int) (pX-canon.getSceneCenterCoordinates()[0]);
int offY = (int) (pY-canon.getSceneCenterCoordinates()[1]);
if (offX <= 0)
return ;
if(offY>=0)
return;
double X=canon.getX()+canon.getWidth()*0,5;
double Y=canon.getY()+canon.getHeight()*0,5 ;
final Sprite projectile;
projectile = new Sprite( (float) X, (float) Y,
mProjectileTextureRegion,this.getVertexBufferObjectManager() );
mMainScene.attachChild(projectile);
int realX = (int) (mCamera.getWidth()+ projectile.getWidth()/2.0f);
float ratio = (float) offY / (float) offX;
int realY = (int) ((realX*ratio) + projectile.getY());
int offRealX = (int) (realX- projectile.getX());
int offRealY = (int) (realY- projectile.getY());
float length = (float) Math.sqrt((offRealX*offRealX)+(offRealY*offRealY));
float velocity = (float) 480.0f/1.0f;
float realMoveDuration = length/velocity;
MoveModifier modifier = new MoveModifier(realMoveDuration,projectile.getX(), realX, projectile.getY(), realY);
projectile.registerEntityModifier(modifier);
}
@Override
public boolean onSceneTouchEvent(Scene pScene, TouchEvent pSceneTouchEvent) {
if (pSceneTouchEvent.getAction() == TouchEvent.ACTION_MOVE){
double dx = pSceneTouchEvent.getX() - canon.getSceneCenterCoordinates()[0];
double dy = pSceneTouchEvent.getY() - canon.getSceneCenterCoordinates()[1];
double Radius = Math.atan2(dy,dx);
double Angle = Radius * 180 / Math.PI;
canon.setRotation((float)Angle);
return true;
}
else if (pSceneTouchEvent.getAction() == TouchEvent.ACTION_DOWN){
final float touchX = pSceneTouchEvent.getX();
final float touchY = pSceneTouchEvent.getY();
double dx = pSceneTouchEvent.getX() - canon.getSceneCenterCoordinates()[0];
double dy = pSceneTouchEvent.getY() - canon.getSceneCenterCoordinates()[1];
double Radius = Math.atan2(dy,dx);
double Angle = Radius * 180 / Math.PI;
canon.setRotation((float)Angle);
shootProjectile(touchX, touchY);
}
return false;
}
Anyone know how to calculate the coordinates (X,Y) of the end of the barrel to draw the bullet?
