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Nicholas Kong

Drawing every frame causes slow down in other drawings

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I have a ghost that moves in big increments of 2 pixels

Example:

If ghost moves in position x: You see the x coordinates of ghost like this: 18, 20, 22

 

Ghost causes no slowdown when drawing it.

 

However I have an alien that moves smaller increments of .05 pixels - .15 pixels

Example:

If alien moves in position x: You see the x coordinates of alien like this: around 30 drawings in 13.34 which is 30 drawings in the same spot of the screen. Then increment the position by .15 pixels and redraw the alien in that same spot.

 

The idea was to make the alien moves so slow with the alien theme music to add character to the alien. This was done by moving the alien in smaller increments. 

 

While this redrawing technique work for the alien, my suspicion it is this technique that is causing redrawing slowdown to all other projectiles and loot drops from my ghost monsters.

 

Is my suspicion correct? I am really sure if drawing in small increments of pixel for an object really have a slowdown effect on another object that also needs to be redrawn. Let me know.

 

 
 
private static final double zeroPositionLimit = 15;
 
private static final double firstPositionLimit = 16;
 
private static final double secondPositionLimit = 18;
 
private static final double thirdPositionLimit = 20;
 
private static final double fourthPositionLimit = 21;
 

public void draw(Graphics g) {
// Draw the monster image at our position
 
if(position.getX() < zeroPositionLimit)
{
g.drawImage(alienMovementAnimation.get(0), (int)position.getX(), (int)position.getY(), null);
}
else if(position.getX() < firstPositionLimit )
{
g.drawImage(alienMovementAnimation.get(1), (int)position.getX(), (int)position.getY(), null);
} 
else if(position.getX() < secondPositionLimit)
{
g.drawImage(alienMovementAnimation.get(2), (int)position.getX(), (int)position.getY(), null);
 
}
else if(position.getX() < thirdPositionLimit)
{
g.drawImage(alienMovementAnimation.get(3), (int)position.getX(), (int)position.getY(), null);
 
}
 
else if(position.getX() < fourthPositionLimit)
{
g.drawImage(alienMovementAnimation.get(4), (int)position.getX(), (int)position.getY(), null);
}
else
{
 
Game.setGameWon(true);
}
 
 
}
 
@Override
public void update(long milliseconds) {
// Handle all of the alien logic
 
// Update player position base on velocity
 
long time = System.currentTimeMillis();
 
float deltaTime = (time - startTime)/1000.f;
 
startTime = time;
 
position = position.add(velocity.multiply((deltaTime)));
 
 
// object state logic
if(position.getX() < fourthPositionLimit)
{
 
direction = "right";
 
}
 
int speed = 1;
 
if(direction.equals("right"))
{
 
position.setX(position.getX() + speed * deltaTime);
}
 
 
 
}
 
Edited by warnexus

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I still don't know about slowdown because I don't know what determines how often your draw code is called. I do know now that you have simulation logic in your draw code, which is a no-no. Also, that function is a significant violation of DRY.

 

//put the position limits in an array

public void draw(Graphics g) {
  int xpos = position.getX();
  for(int i = 0; i < 5; ++i) {
    if(xpos < positionLimits[i]) {
      g.drawImage(alienMovementAnimation.get(i), xpos, (int)position.getY(), null);
      break;
    }
  }

  //Game.setGameWon(true); //do this in the logic, not in the drawing!

}
Edited by Khatharr

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I still don't know about slowdown because I don't know what determines how often your draw code is called. I do know now that you have simulation logic in your draw code, which is a no-no. Also, that function is a significant violation of DRY.

 

//put the position limits in an array

public void draw(Graphics g) {
  int xpos = position.getX();
  for(int i = 0; i < 5; ++i) {
    if(xpos < positionLimits[i]) {
      g.drawImage(alienMovementAnimation.get(i), xpos, (int)position.getY(), null);
      break;
    }
  }

  //Game.setGameWon(true); //do this in the logic, not in the drawing!

}

Game objects are added to an Arraylist. A for each loop goes through each element in the array list and draws these game objects to the screen for every iteration of the game loop.  

 

What is a violation of DRY? What dictates a simulation logic?

Edited by warnexus

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