problem with sprite animation

Java 2D
#1

I’m making a simple space shooter game and I’m still fighting with timing stuff…

Now, if I have for example 60 aliens to kill on the screen the animation of each one is fine, but when I have less then 10 for example, the animation is very slow (The change of the frames of the animation takes more time to change).

Why this is happing?

#2

Post code.

Kev

#3

There it is:

main loop


      public void gameLoop() {
            long lastTicks, currentTicks, elapsedMs, ticksPerSecond;
            AdvancedTimer timer = new AdvancedTimer();
            ticksPerSecond = AdvancedTimer.getTicksPerSecond();
            long sleepTime = AdvancedTimer.getTicksPerSecond() / FPS;
            long ticks = 0;
            timer.start();
            lastTicks = timer.getClockTicks();
            while (isRunning) {
                  
                  currentTicks = timer.getClockTicks();
                  elapsedMs = ((currentTicks - lastTicks) * 1000) / ticksPerSecond;

                  fps++;
                  lastFpsTime += elapsedMs;

                  // Update fps counter if 1 sec has passed.
                  if(lastFpsTime >= 1000) {
                        this.setTitle("FPS=" + String.valueOf(fps));
                        fps=0;
                        lastFpsTime =0 ;
                  }
                  
                  
            Graphics g = this.strategy.getDrawGraphics();
            g.setColor(Color.black);
            g.fillRect(0, 0, 800, 600);

                  // move/update anim and draw the sprites
            for (int i = 0; i < this.sprites.size(); i++) {
                Sprite sprite = (Sprite) sprites.get(i);
                sprite.move(elapsedMs);
                sprite.draw(g);
            }
                  
                  
                  
                  lastTicks = currentTicks;
                  timer.sleepUntil(ticks + sleepTime);
                  ticks += sleepTime;
            }
            timer.stop();
            System.exit(0);
      }

move method of class Alien that extends Sprite

      
      public void move(long pDelta) {
        this.animation.animate(pDelta);

        if ((dx < 0) && (x < 10)) {
            this.game.updateLogic();
        }

        if ((dx > 0) && (x > 750)) {
            this.game.updateLogic();
        }
            
            // call move on Sprite class
        super.move(pDelta);
    }

This is the code of the move method on Sprite:

      
      // dx is about 100ms
      public void move(long pDelta) {
        this.x += ((pDelta * dx) / 1000);
        this.y += ((pDelta * dy) / 1000);
    }

And this is the animate method of the Animation class. Here that the next frame
of the sprite is determined.


      // each frame takes 250ms(frameDuration)
    public void animate(long pDelta) {
        this.increaseLastFrameChangeBy(pDelta);

        if (this.getLastFrameChange() > this.getFrameDuration()) {
            this.setLastFrameChange(0);
            this.increaseFrameNumber();

            if (this.getFrameNumber() >= this.getTotalFrames()) {
                this.setFrameNumber(0);
            }
        }
    }
    
    public void increaseLastFrameChangeBy(long pDelta) {
        this.lastFrameChange += pDelta;
    }

    public void increaseFrameNumber() {
        this.frameNumber++;
    }
    
    public void draw(Graphics g, int pX, int pY) {
        g.drawImage(this.frames[this.frameNumber], pX, pY, null);
    }
    public void setFrameDuration(long frameDuration) {
        this.frameDuration = frameDuration;
    }
#4

I did not understand why the speed of the animation changes when I have different number of sprites on the screen. For example over 50 sprites the animation is fast and below 10 the animation is slow…

#5

any tips about this? I could not solve it yet

#6

is the animation object you are using shared or is there one for each sprite?

#7

it’s shared. I have a repositry where I load all the animations. Then I create the sprites using this previous loaded animations.

#8

do u think that the shared animation is the problem? I have posted another thread on this subject (with full source) called “animation problem” here in 2D forum

#9

ok, I think that I have solved my problem! 8) The problem was that I was sharing the animations will all sprites. The solution was very simple, I have just created a new method in Animation class for cloning the object. I don’t know if it was the best solution for this kind of situation but it is working much better now.

Thank you JuddMan for the light!!! ;D