Processing 1.0 - Processing Discourse - Variable animation speed with constant framerate

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Variable animation speed with constant framerate (Read 850 times)

vupac

Variable animation speed with constant framerate
Apr 20^th, 2007, 5:28pm

Hello,
I'm about to start my first little processing project but got stuck now. I want to create a little application with a sprite-based animation and some user interface elements. The problem is, that I want the user to control the speed of the sprite animation, or even let him pause it, without changing the framerate. If I'd change the framerate directly, I'd also change the speed of button behaviour, which is not what I want. Are there other options for timing the sprite animation / appearance of the next frame? Do I need to use threads?
(I used the example code for sprites and image-based buttons from the Learning page.)

Thanks in advance for you help,

vupac

JohnG Ex Member	Re: Variable animation speed with constant framera Reply #1 - Apr 20^th, 2007, 7:08pm You just need to create a class for your sprite that stores the number of milliseconds until it shoudl change to the next fream, and then only changes it if the number of milliseconds elapsed is equal or greater than that, and then change to the next frame.

vupac YaBB Newbies Offline Posts: 2	Re: Variable animation speed with constant framera Reply #2 - Apr 20^th, 2007, 8:06pm Sometimes the answer ist just too simple... thanks for your help and sorry for my stupid question.

miffed

Re: Variable animation speed with constant framera
Reply #3 - May 9^th, 2007, 9:47pm

I am trying to do this, borrowing the Animated Sprite example. I tried to add a delay to slow it down, but it instead leaves blank spots in the animation.

Here is the code I'm using:

class AniSprite
{
PImage[] ani;
int frame;
int numFrames;

AniSprite(String imageName, int frameCount) {
numFrames = frameCount;
ani = new PImage[numFrames];
loadImages(imageName);
}

void loadImages(String name) {
for(int i=0; i<numFrames; i++) {
String imageName = name + ((i < 10) ? "0" : "") + i + ".gif";
ani[i] = loadImage(imageName);
}
}

void display(float xpos, float ypos)
{
frame = (frame+1)%numFrames;
int del = 100;
if(lastMillis==0 || millis() > (lastMillis+del))
{
image(ani[frame], xpos, ypos);
lastMillis= millis();
}
}

int getWidth() {
return ani[0].width;
}

}

JohnG

Re: Variable animation speed with constant framera
Reply #4 - May 9^th, 2007, 10:01pm

I think I've seen the problem, though it's hard to tell without the rest of the code/images.

Code:

   void display(float xpos, float ypos)
  {
//    frame = (frame+1)%numFrames;
//you're increasing the frame even if it's not time to do so..
    int del = 100;
    if(lastMillis==0 || millis() > (lastMillis+del))
    {
 image(ani[frame], xpos, ypos);
 lastMillis= millis();
//put it here
	frame = (frame+1)%numFrames;
    }
//you need to draw the previous one if it's not update time
    else
    {
	image(ani[frame], xpos, ypos);
    }
  }

miffed YaBB Newbies Offline Posts: 12 CA	Re: Variable animation speed with constant framera Reply #5 - May 9^th, 2007, 10:11pm beautiful! thanks.

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