Collision Error
- by Manji
I am having trouble with collision detection part of the game.
I am using touch events to fire the gun as you will see in the video. Note, the android icon is a temporary graphic for the bullets
When ever the user touches (represented by clicks in the video)the bullet appears and kills random sprites.
As you can see it never touches the sprites it kills or kill the sprites it does touch.
My Question is How do I fix it, so that the sprite dies when the bullet hits it?
Collision Code snippet:
//Handles Collision
private void CheckCollisions(){
synchronized(mSurfaceHolder){
for (int i = sprites.size() - 1; i >= 0; i--){
Sprite sprite = sprites.get(i);
if(sprite.isCollision(bullet)){
sprites.remove(sprite);
mScore++;
if(sprites.size() == 0){
mLevel = mLevel +1;
currentLevel++;
initLevel();
}
break;
}
}
}
}
Sprite Class Code Snippet:
//bounding box left<right and top>bottom
int left ;
int right ;
int top ;
int bottom ;
public boolean isCollision(Beam other) {
// TODO Auto-generated method stub
if(this.left>other.right || other.left<other.right)return false;
if(this.bottom>other.top || other.bottom<other.top)return false;
return true;
}
EDIT 1:
Sprite Class:
public class Sprite {
// direction = 0 up, 1 left, 2 down, 3 right,
// animation = 3 back, 1 left, 0 front, 2 right
int[] DIRECTION_TO_ANIMATION_MAP = { 3, 1, 0, 2 };
private static final int BMP_ROWS = 4;
private static final int BMP_COLUMNS = 3;
private static final int MAX_SPEED = 5;
private HitmanView gameView;
private Bitmap bmp;
private int x;
private int y;
private int xSpeed;
private int ySpeed;
private int currentFrame = 0;
private int width;
private int height;
//bounding box left<right and top>bottom
int left ;
int right ;
int top ;
int bottom ;
public Sprite(HitmanView gameView, Bitmap bmp) {
this.width = bmp.getWidth() / BMP_COLUMNS;
this.height = bmp.getHeight() / BMP_ROWS;
this.gameView = gameView;
this.bmp = bmp;
Random rnd = new Random();
x = rnd.nextInt(gameView.getWidth() - width);
y = rnd.nextInt(gameView.getHeight() - height);
xSpeed = rnd.nextInt(MAX_SPEED * 2) - MAX_SPEED;
ySpeed = rnd.nextInt(MAX_SPEED * 2) - MAX_SPEED;
}
private void update() {
if (x >= gameView.getWidth() - width - xSpeed || x + xSpeed <= 0) {
xSpeed = -xSpeed;
}
x = x + xSpeed;
if (y >= gameView.getHeight() - height - ySpeed || y + ySpeed <= 0) {
ySpeed = -ySpeed;
}
y = y + ySpeed;
currentFrame = ++currentFrame % BMP_COLUMNS;
}
public void onDraw(Canvas canvas) {
update();
int srcX = currentFrame * width;
int srcY = getAnimationRow() * height;
Rect src = new Rect(srcX, srcY, srcX + width, srcY + height);
Rect dst = new Rect(x, y, x + width, y + height);
canvas.drawBitmap(bmp, src, dst, null);
}
private int getAnimationRow() {
double dirDouble = (Math.atan2(xSpeed, ySpeed) / (Math.PI / 2) + 2);
int direction = (int) Math.round(dirDouble) % BMP_ROWS;
return DIRECTION_TO_ANIMATION_MAP[direction];
}
public boolean isCollision(float x2, float y2){
return x2 > x && x2 < x + width && y2 > y && y2 < y + height;
}
public boolean isCollision(Beam other) {
// TODO Auto-generated method stub
if(this.left>other.right || other.left<other.right)return false;
if(this.bottom>other.top || other.bottom<other.top)return false;
return true;
}
}
Bullet Class:
public class Bullet {
int mX;
int mY;
private Bitmap mBitmap;
//bounding box left<right and top>bottom
int left ;
int right ;
int top ;
int bottom ;
public Bullet (Bitmap mBitmap){
this.mBitmap = mBitmap;
}
public void draw(Canvas canvas, int mX, int mY) {
this.mX = mX;
this.mY = mY;
canvas.drawBitmap(mBitmap, mX, mY, null);
}
}
