How to rotate my ship bullets?

Miguelito92

Hey guys, this is my code everything is working fine, I 'm just having trouble making my bullets rotate with my ship image. My ship image moves in all directions apart from the bullets that fire in one direction. How can I do this? What part of the code do I need to change or add?

If you can have a look at my code ill be very grateful, Thank you!

//Variables to store the ships position, direction, and the speed

//Array of intergers, which is used to draw the land
int[] land;

//Where the bullets will be stored 
ArrayList <Bullet> bullets; 

//Game state 
int WAITING =1;
int FINISHED =2;
int state = WAITING;

Ship myShip;


void setup() {
  size(600, 600);

  myShip = new Ship();
  bullets = new ArrayList();
  //Bullet b = new Bullet(X, Y);

  //This will be used to draw the land 
  land = new int [width/10+1];
  for (int i=0; i < land.length; i++) {
    land[i] = int( random(10));
  }
}


void draw() {

  background(155);

  //adding the method to draw
  //myShip.keyPressed();
  drawland();
  myShip.update();
  myShip.drawFinished();
  moveAll();
  displayAll();


  //Checks the state variable it also adds the drawWaiting() method that 
  //get called in the coressponding state
  if (state == WAITING) {
    drawWaiting();
  }
  else if (state == FINISHED) {
  }
}


void drawWaiting() {

  textAlign(CENTER);
  fill(0);
  text("Click to play!", width/2, height/2);
}

void drawland() {

  stroke(0);
  fill(250, 150, 0, 60); 
  //
  //Creates the land using beginShape and endShape
  beginShape();
  vertex(0, height);
  for ( int i=0; i < land.length; i++) {
    vertex( i * 10, height - 50 - land[i] );
  } 
  vertex(width, height);
  endShape(CLOSE);
}

//Mouse clicked method that changes the state from waiting to finished
void mousePressed() {

  if (state == WAITING) {
    state = FINISHED;
  }
} 


void keyPressed() {

  if ( keyCode == LEFT ) {
    myShip.a -= 0.09;
  }
  if ( keyCode == RIGHT ) {
    myShip.a += 0.09;
  }

  if ( keyCode == UP ) {
    myShip.acc += 0.04;

    myShip.accel.x = myShip.acc * sin(myShip.a);
    myShip.accel.y = -myShip.acc * cos(myShip.a);
  }


  if (keyCode == ' ') {

    //I have used myShip because its outside the class and because I used PVector 
    //for my position I have to use that too. 

    Bullet temp = new Bullet(myShip.position.x, myShip.position.y);
    bullets.add(temp);
  }
}




class Bullet//bullet class
        {
          float x;
          float y;
          float speed;
          Bullet(float tx, float ty)
          {  
            x = tx;
            y = ty;
          }
          void display()
          {
            stroke(0);
            fill(255, 0, 0);
            ellipse(x, y, 5, 5);


          }
          void move()
          {
            y -= 5;
          }
        }


        void moveAll()
        {
          for (Bullet temp : bullets)
          {
            temp.move();
          }
        }
        void displayAll()
        {
          for (Bullet temp : bullets)
          {
            temp.display();
          }
        }

    class Ship {

      //Global Variables
      PVector position;
      PVector accel;
      PVector velocity;
      PVector rotation;
      float drag = .9;
      //Ship image
      PImage ship = loadImage("ship.png");

      //How much the ship accelerates 
      float acc = 0;

      //rotation angle
      float a = 0;


      //CONSTRUCTOR
      public Ship() {

        position = new PVector(330, 445);
        accel = new PVector(0, 0);
        velocity = new PVector(0, 0);
      }

      //FUNCTIONS
      void update() {

        drawShip();
        drawFinished();
        velocity.add(accel);
        velocity.mult(drag);
        position.add(velocity);

        acc *= 0.95;

        //Stops the ship when it reaches the surface 
        if (position.y > height - 20 - ship.height/2 ) {
          position.y = height - 20 - ship.height/2;
        }
      }


      void drawShip() {
        pushMatrix();
        //method to use the new pos variable
        translate(position.x, position.y);
        rotate(a);
        stroke(255, 50, 0);
        fill(255, 50, 20);

        for ( int i=4; i >= 0; i--) {
          stroke(255, i*50, 0);
          fill(255, i*50, 20);
          ellipse( 0, 40, min(1, acc*10) *i*4, min(1, acc*10)* i*10);
        }
        image(ship, -ship.width/2, -ship.height/2, ship.width, ship.height);
        popMatrix();
      }

      void drawFinished() {

        textAlign(CENTER);
        fill(0);
        if (position.y > height - 50 - ship.height/2 ) {


          text("you have crashed!", width/2, height/2);
        }
      }
    }

GoToLoop

... bullets that fire in one direction.

What is important is how many angles that direction can be!
For a Bullet which only descends straight south, class below is pretty enough.
You just need to instantiate it w/ the same coordinates as the Ship object currently is, plus desired falling speed:

class Bullet {
  static final int DIM = 4;
  float x, y, s;

  Bullet(float xx, float yy, float vy) {
    x = xx;
    y = yy;
    s = vy;
  }

  void display() {
    ellipse(x, y, DIM, DIM);
  }

  void update() {
    y += s;
  }

  boolean check() {
    return y > height; 
  }
}

However, if there are any non 45° degree angles, you're gonna need a more complex class using PVector for position & speed vectors.
Just like the 1 used in "Multiple Bullets" example:

http://studio.processingtogether.com/sp/pad/export/ro.91kLmk61vAOZp/latest

class Bullet {
  static final short VEL = 5, DIM = 4, FREQ = 2;
  static final color COLOUR = #0000FF;

  final PVector pos = new PVector(), spd = new PVector();
  boolean isInactive;

  Bullet(PVector loc, PVector vel) {
    rez(loc, vel);
  }

  void rez(PVector loc, PVector vel) {
    pos.set(loc);
    spd.set(vel);

    isInactive = false;
  }

  void display() {
    ellipse(pos.x, pos.y, DIM, DIM);
  }

  void update() {
    pos.add(spd);
  }

  boolean check() {
    return pos.x > width | pos.x < 0 | pos.y > height | pos.y < 0;
  }

  boolean script() {
    if (isInactive)  return false;

    display();
    update();

    return isInactive = check();
  }
}

And in order to find correct pos & spd vectors to instantiate a Bullet, we need a function like the 1 below:

void addBullet() {
  bulletSpd.set(mouseX, mouseY);
  bulletSpd.sub(playerPos);
  bulletSpd.setMag(Bullet.VEL);

  bullets.add(new Bullet(playerPos, bulletSpd));
}

Variable playerPos is the Ship's PVector coordinates.
While bulletSpd is a helper PVector in which we calculate direction/speed.

Only diff. is that in your case, target coordinates aren't (mouseX, mouseY) pair.
Perhaps it's something like (playerPos.x, height)? :-??

Chrisir

I posted that in the other thread,,,,

why start a new one?

Chrisir

by now you have three parallel threads for one sketch,,,

http://forum.processing.org/two/discussion/comment/12043#Comment_12043

Chrisir

:-(

Chrisir

and we can't run the code, because we don't have the image

Chrisir

why does the ship rotate so strange?

like on a circle left and right

do you want to have the shooting from the ship towards the current mouse pos or always north? if the latter: North or south or what?

Chrisir

you have speed in class bullets but not in use - why?

TfGuy44

You need to improve the Bullet class so that the bullets have their own velocity too. Here I've added some logic that sets them to the ship's velocity - this is probably NOT what you want. Instead, you'll want to base the direction they go off which way (that is, the angle at) the ship is turned - myShip.a.

class Bullet//bullet class
{
  float x;
  float y;
  float vx, vy;
  float speed;
  Bullet(float ignored1, float ignored2)
  {  
    x = myShip.position.x;
    y = myShip.position.y;
    vx = myShip.velocity.x;
    vy = myShip.velocity.y;
  }
  void display()
  {
    stroke(0);
    fill(255, 0, 0);
    ellipse(x, y, 5, 5);
  }
  void move()
  {
    x+=vx;
    y+=vy;
  }
}

Chrisir

this fires towards mouse, no matter what the ship does

//Array of intergers, which is used to draw the land
int[] land;

//Where the bullets will be stored 
ArrayList <Bullet> bullets; 

//Game state 
int WAITING =1;
int FINISHED =2;
int state = WAITING;

Ship myShip;


void setup() {
  size(600, 600);

  myShip = new Ship();
  bullets = new ArrayList();
  //Bullet b = new Bullet(X, Y);

  //This will be used to draw the land 
  land = new int [width/10+1];
  for (int i=0; i < land.length; i++) {
    land[i] = int( random(10));
  }
}


void draw() {

  background(155);

  //adding the method to draw
  //myShip.keyPressed();
  drawland();
  myShip.update();
  myShip.drawFinished();
  moveAll();
  displayAll();


  //Checks the state variable it also adds the drawWaiting() method that 
  //get called in the coressponding state
  if (state == WAITING) {
    drawWaiting();
  }
  else if (state == FINISHED) {
  }
}


void drawWaiting() {

  textAlign(CENTER);
  fill(0);
  text("Click to play!", width/2, height/2);
}

void drawland() {

  stroke(0);
  fill(250, 150, 0, 60); 
  //
  //Creates the land using beginShape and endShape
  beginShape();
  vertex(0, height);
  for ( int i=0; i < land.length; i++) {
    vertex( i * 10, height - 50 - land[i] );
  } 
  vertex(width, height);
  endShape(CLOSE);
}

//Mouse clicked method that changes the state from waiting to finished
void mousePressed() {

  if (state == WAITING) {
    state = FINISHED;
  }
  else 
  {

    // fire 
    Bullet temp = new Bullet(myShip.position.x, myShip.position.y);
    bullets.add(temp);
  }
} 


void keyPressed() {

  if ( keyCode == LEFT ) {
    myShip.a -= 0.09;
  }
  if ( keyCode == RIGHT ) {
    myShip.a += 0.09;
  }

  if ( keyCode == UP ) {
    myShip.acc += 0.04;

    myShip.accel.x = myShip.acc * sin(myShip.a); // ???????????????????
    myShip.accel.y = -myShip.acc * cos(myShip.a);
  }


  if (keyCode == ' ') {

    //I have used myShip because its outside the class and because I used PVector 
    //for my position I have to use that too. 






    Bullet temp = new Bullet(myShip.position.x, myShip.position.y);
    bullets.add(temp);
  }
}


// ====================================================


class Bullet  
//  bullet class
{
  float x;
  float y;

  PVector  bulletSpd = new PVector();

  Bullet(float tx, float ty)
  {  
    x = tx;
    y = ty;

    bulletSpd.set(mouseX, mouseY);
    bulletSpd.sub( myShip.position );
    bulletSpd.setMag(6);

    // bullets.add(new Bullet(playerPos, bulletSpd));  // ???????????
  }

  void display()
  {
    stroke(0);
    fill(255, 0, 0);
    ellipse(x, y, 5, 5);
  }

  void move()
  {
    x += bulletSpd.x;
    y += bulletSpd.y;
  }
  //
} // class

// ===============================================


void moveAll()
{
  for (Bullet temp : bullets)
  {
    temp.move();
  }
}

void displayAll()
{
  for (Bullet temp : bullets)
  {
    temp.display();
  }
}

// ====================================================

class Ship {

  //Global Variables
  PVector position;
  PVector accel;
  PVector velocity;
  PVector rotation;
  float drag = .9;
  //Ship image
  PImage ship = loadImage("ship.png");



  //How much the ship accelerates 
  float acc = 0;

  //rotation angle
  float a = 0;


  //CONSTRUCTOR
  public Ship() {

    position = new PVector(330, 445);
    accel = new PVector(0, 0);
    velocity = new PVector(0, 0);
  }

  //FUNCTIONS
  void update() {

    drawShip();
    drawFinished();
    velocity.add(accel);
    velocity.mult(drag);
    position.add(velocity);

    acc *= 0.95;

    //Stops the ship when it reaches the surface 
    if (position.y > height - 20 - ship.height/2 ) {
      position.y = height - 20 - ship.height/2;
    }
  }


  void drawShip() {
    pushMatrix();
    //method to use the new pos variable
    translate(position.x, position.y);
    rotate(a);
    stroke(255, 50, 0);
    fill(255, 50, 20);

    for ( int i=4; i >= 0; i--) {
      stroke(255, i*50, 0);
      fill(255, i*50, 20);
      ellipse( 0, 40, min(1, acc*10) *i*4, min(1, acc*10)* i*10);
    }
    image(ship, -ship.width/2, -ship.height/2, ship.width, ship.height);
    // text ("ship", -300/2, -200/2);
    popMatrix();
  }

  void drawFinished() {

    textAlign(CENTER);
    fill(0);
    if (position.y > height - 50 - ship.height/2 ) {


      text("you have crashed!", width/2, height/2);
    }
  }
}

Chrisir

this fires always to the left but from the top of the ship

//Array of intergers, which is used to draw the land
int[] land;

//Where the bullets will be stored 
ArrayList <Bullet> bullets; 

//Game state 
int WAITING =1;
int FINISHED =2;
int state = WAITING;

Ship myShip;


void setup() {
  size(600, 600);

  myShip = new Ship();
  bullets = new ArrayList();
  //Bullet b = new Bullet(X, Y);

  //This will be used to draw the land 
  land = new int [width/10+1];
  for (int i=0; i < land.length; i++) {
    land[i] = int( random(10));
  }
}


void draw() {

  background(155);

  //adding the method to draw
  //myShip.keyPressed();
  drawland();
  myShip.update();
  myShip.drawFinished();
  moveAll();
  displayAll();


  //Checks the state variable it also adds the drawWaiting() method that 
  //get called in the coressponding state
  if (state == WAITING) {
    drawWaiting();
  }
  else if (state == FINISHED) {
    // do nothing
  }
}


void drawWaiting() {

  textAlign(CENTER);
  fill(0);
  text("Click to play!", width/2, height/2);
}

void drawland() {

  stroke(0);
  fill(250, 150, 0, 60); 
  //
  //Creates the land using beginShape and endShape
  beginShape();
  vertex(0, height);
  for ( int i=0; i < land.length; i++) {
    vertex( i * 10, height - 50 - land[i] );
  } 
  vertex(width, height);
  endShape(CLOSE);
}

//Mouse clicked method that changes the state from waiting to finished
void mousePressed() {

  if (state == WAITING) {
    state = FINISHED;
  }
  else 
  {
    // do nothing
  }
} 


void keyPressed() {

  if ( keyCode == LEFT ) {
    myShip.a -= 0.09;
  }
  if ( keyCode == RIGHT ) {
    myShip.a += 0.09;
  }

  if ( keyCode == UP ) {
    myShip.acc += 0.04;

    myShip.accel.x = myShip.acc * sin(myShip.a); // ???????????????????
    myShip.accel.y = -myShip.acc * cos(myShip.a);
  }


  if (keyCode == ' ') {

    //I have used myShip because its outside the class and because I used PVector 
    //for my position I have to use that too. 
    //
    final PVector bulletSpd = new PVector();
    bulletSpd.set(3, 0);
    //bulletSpd.sub(position);
    bulletSpd.normalize();
    bulletSpd.mult(5);

    PVector positionbullet = new PVector();

    positionbullet.x = -(myShip.ship.height-25) * cos ((myShip.a)) + myShip.position.x;
    positionbullet.y = -(myShip.ship.height-25) * sin ((myShip.a)) + myShip.position.y;

    bullets.add( new Bullet(positionbullet, bulletSpd) );
  }
}


// ====================================================


class Bullet  
//  bullet class
{
  float x;
  float y;

  PVector  bulletSpd = new PVector();

  Bullet(PVector pos1, PVector spd1)
  {  
    x = pos1.x;
    y = pos1.y;

    bulletSpd =   spd1.get();

    // bullets.add(new Bullet(playerPos, bulletSpd));  // ???????????
  }

  void display()
  {
    stroke(0);
    fill(255, 0, 0);
    ellipse(x, y, 5, 5);
  }

  void move()
  {
    x += bulletSpd.x;
    y += bulletSpd.y;
  }
  //
} // class

// ===============================================


void moveAll()
{
  for (Bullet temp : bullets)
  {
    temp.move();
  }
}

void displayAll()
{
  for (Bullet temp : bullets)
  {
    temp.display();
  }
}

// ====================================================

class Ship {

  //Global Variables
  PVector position;
  PVector accel;
  PVector velocity;
  PVector rotation;
  float drag = .9;
  //Ship image
  PImage ship = loadImage("ship.png");



  //How much the ship accelerates 
  float acc = 0;

  //rotation angle
  float a = 0;


  //CONSTRUCTOR
  public Ship() {

    position = new PVector(330, 445);
    accel = new PVector(0, 0);
    velocity = new PVector(0, 0);
  }

  //FUNCTIONS
  void update() {

    drawShip();
    drawFinished();
    velocity.add(accel);
    velocity.mult(drag);
    position.add(velocity);

    acc *= 0.95;

    //Stops the ship when it reaches the surface 
    if (position.y > height - 20 - ship.height/2 ) {
      position.y = height - 20 - ship.height/2;
    }
  }


  void drawShip() {
    pushMatrix();
    //method to use the new pos variable
    translate(position.x, position.y);
    rotate(a);
    stroke(255, 50, 0);
    fill(255, 50, 20);

    for ( int i=4; i >= 0; i--) {
      stroke(255, i*50, 0);
      fill(255, i*50, 20);
      ellipse( 0, 40, min(1, acc*10) *i*4, min(1, acc*10)* i*10);
    }
    image(ship, -ship.width/2, -ship.height/2, ship.width, ship.height);
    // text ("ship", -300/2, -200/2);
    popMatrix();
  }

  void drawFinished() {

    textAlign(CENTER);
    fill(0);
    if (position.y > height - 50 - ship.height/2 ) {


      text("you have crashed!", width/2, height/2);
    }
  }
}

Chrisir

this fires from the top of the ship

towards the direction of the ship

I like this the most

//Array of intergers, which is used to draw the land
int[] land;

//Where the bullets will be stored 
ArrayList <Bullet> bullets; 

//Game state 
int WAITING =1;
int FINISHED =2;
int state = WAITING;

Ship myShip;


void setup() {
  size(600, 600);

  myShip = new Ship();
  bullets = new ArrayList();
  //Bullet b = new Bullet(X, Y);

  //This will be used to draw the land 
  land = new int [width/10+1];
  for (int i=0; i < land.length; i++) {
    land[i] = int( random(10));
  }
}


void draw() {

  background(155);

  //adding the method to draw
  //myShip.keyPressed();
  drawland();
  myShip.update();
  myShip.drawFinished();
  moveAll();
  displayAll();


  //Checks the state variable it also adds the drawWaiting() method that 
  //get called in the coressponding state
  if (state == WAITING) {
    drawWaiting();
  }
  else if (state == FINISHED) {
    // do nothing
  }
}


void drawWaiting() {

  textAlign(CENTER);
  fill(0);
  text("Click to play!", width/2, height/2);
}

void drawland() {

  stroke(0);
  fill(250, 150, 0, 60); 
  //
  //Creates the land using beginShape and endShape
  beginShape();
  vertex(0, height);
  for ( int i=0; i < land.length; i++) {
    vertex( i * 10, height - 50 - land[i] );
  } 
  vertex(width, height);
  endShape(CLOSE);
}

//Mouse clicked method that changes the state from waiting to finished
void mousePressed() {

  if (state == WAITING) {
    state = FINISHED;
  }
  else 
  {
    // do nothing
  }
} 


void keyPressed() {

  if ( keyCode == LEFT ) {
    myShip.a -= 0.09;
  }
  if ( keyCode == RIGHT ) {
    myShip.a += 0.09;
  }

  if ( keyCode == UP ) {
    myShip.acc += 0.04;

    myShip.accel.x = myShip.acc * sin(myShip.a); // ???????????????????
    myShip.accel.y = -myShip.acc * cos(myShip.a);
  }


  if (keyCode == ' ') {

    //I have used myShip because its outside the class and because I used PVector 
    //for my position I have to use that too. 
    //
    PVector bulletSpd = new PVector();
    bulletSpd.set(3, 0);
    //bulletSpd.sub(position);
    bulletSpd.normalize();
    bulletSpd.mult(5);

    PVector positionbullet = new PVector();

    positionbullet.x = -(myShip.ship.height-25) * cos ((myShip.a)) + myShip.position.x;
    positionbullet.y = -(myShip.ship.height-25) * sin ((myShip.a)) + myShip.position.y;


    bulletSpd.x = - (myShip.ship.height+25) * cos ((myShip.a)) + positionbullet.x;
    bulletSpd.y = - (myShip.ship.height+25) * sin ((myShip.a)) + positionbullet.y;


    bulletSpd.sub(positionbullet);

    //bulletSpd = positionbullet.get(); 
    bulletSpd.normalize();
    bulletSpd.mult(5);


    bullets.add( new Bullet(positionbullet, bulletSpd) );
  }
}


// ====================================================


class Bullet  
//  bullet class
{
  float x;
  float y;

  PVector  bulletSpd = new PVector();

  Bullet(PVector pos1, PVector spd1)
  {  
    x = pos1.x;
    y = pos1.y;

    bulletSpd =   spd1.get();

    // bullets.add(new Bullet(playerPos, bulletSpd));  // ???????????
  }

  void display()
  {
    stroke(0);
    fill(255, 0, 0);
    ellipse(x, y, 5, 5);
  }

  void move()
  {
    x += bulletSpd.x;
    y += bulletSpd.y;
  }
  //
} // class

// ===============================================


void moveAll()
{
  for (Bullet temp : bullets)
  {
    temp.move();
  }
}

void displayAll()
{
  for (Bullet temp : bullets)
  {
    temp.display();
  }
}

// ====================================================

class Ship {

  //Global Variables
  PVector position;
  PVector accel;
  PVector velocity;
  PVector rotation;
  float drag = .9;
  //Ship image
  PImage ship = loadImage("ship.png");



  //How much the ship accelerates 
  float acc = 0;

  //rotation angle
  float a = 0;


  //CONSTRUCTOR
  public Ship() {

    position = new PVector(330, 445);
    accel = new PVector(0, 0);
    velocity = new PVector(0, 0);
  }

  //FUNCTIONS
  void update() {

    drawShip();
    drawFinished();
    velocity.add(accel);
    velocity.mult(drag);
    position.add(velocity);

    acc *= 0.95;

    //Stops the ship when it reaches the surface 
    if (position.y > height - 20 - ship.height/2 ) {
      position.y = height - 20 - ship.height/2;
    }
  }


  void drawShip() {
    pushMatrix();
    //method to use the new pos variable
    translate(position.x, position.y);
    rotate(a);
    stroke(255, 50, 0);
    fill(255, 50, 20);

    for ( int i=4; i >= 0; i--) {
      stroke(255, i*50, 0);
      fill(255, i*50, 20);
      ellipse( 0, 40, min(1, acc*10) *i*4, min(1, acc*10)* i*10);
    }
    image(ship, -ship.width/2, -ship.height/2, ship.width, ship.height);
    // text ("ship", -300/2, -200/2);
    popMatrix();
  }

  void drawFinished() {

    textAlign(CENTER);
    fill(0);
    if (position.y > height - 50 - ship.height/2 ) {


      text("you have crashed!", width/2, height/2);
    }
  }
}

Miguelito92

Hey, I like the last code better but it fires the bullets from the left side not the top of the Ship. How can I change the starting point of the bullets?

Chrisir

Lines 175 following

Miguelito92

I got it to work, thanks anyway

Chrisir

congrats!