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Mike Crenshaw · Guest

Hi

I'm trying to figure out how to make an animation move smoothly.. so i've
been looking around.. i've found 3 other methods besides just using sleep()
at each frame.. i've tried implementing these methods but i cant see much of
a difference.. but which of the following, if any, is the best way to go
about it.. or is there a better way..

method 1: the nono
...
while(true){
x++; //some simple movement
y++;
paint(getGraphics());
try{
Thread.currentThread().sleep(delay);
}
catch(Exception e){}
}

method 2:
....
while(true){
long start = System.currentTimeMillis();
x++; //some simple movement
y++;
paint(getGraphics());
try {
Thread.sleep(Math.max(0, (start + delay) -
System.currentTimeMillis()));
}
catch (InterruptedException e) {};
}

method 3:
....
while(true){
long start = System.currentTimeMillis();
x++; //some simple movement
y++;
paint(getGraphics());
long sleepTime = delay - (System.currentTimeMillis() - start);
if (sleepTime > 0)
try{
Thread.currentThread().sleep(sleepTime);
}
catch(Exception e){}
}

method 4: frame independent

int velocity = 500;
long end_time = 0;
long start_time = System.currentTimeMillis();
float elapsed_time = 0;
float dtime = 0;
while(true){
end_time = System.currentTimeMillis();
elapsed_time = end_time - start_time ;
dtime = elapsed_time / 1000 ;
x += dtime * velocity; //some simple movement
y += dtime * velocity;
start_time = System.currentTimeMillis();
paint(getGraphics());
try{
Thread.currentThread().sleep(delay);
}
catch(Exception e){}
}

thanx
mike

Paul Lutus · Guest

Mike Crenshaw wrote: