Problem converting System.currentTimeMillis() to current time and int

Programming Questions

kelson.ba..

Problem converting System.currentTimeMillis() to current time and int

in Programming Questions • 11 months ago

I have an analog clock applet that runs at 15 frames per second and uses the value 'framecount' to set the angles of the arms.

I get framecount using

framecount = int(System.currentTimeMillis() - 1353555000000L)*(.015);

And the minute arm is drawn using

pushMatrix();

translate(width/2, height/2);

rotate(framecount*TWO_PI/(60*900));

stroke(50, 15);

strokeWeight(2);

line(0, 0, 0, -iR/2);

ellipse(0, -iR/2, 15, 15);

strokeWeight(1);

popMatrix();

the important line being

roate(framecount*TWO_PI/(60*900));

where the angle is set to the frame times 1 full rotation divided by 60 times the number of frames in 1 minute, so that 1 full rotation is made each hour.

The clock does not show the correct minute time. The -1353555000000L just takes off enough digits from the system time to make it an int. Subtracting (42L*365L*24L*60L*60L*1000L) [to get time since Jan 1st 2012] does not make it small enough for int or float values.

Replies(2)

el_dippo

Re: Problem converting System.currentTimeMillis() to current time and int

11 months ago

Using framecount as timer is not a good idea, because when your system is very busy, it drops the framerate of your application, and therefore it's no longer in sync. I do have a small example how to use it the standard way, except i am unsure if this is what you want :

void setup() {
size(240, 240);
frameRate(1);
smooth();
}
void draw() {
background(204);
noStroke();
ellipse (120, 120, 200, 200);
int s = second();
int m = minute();
int h = hour();
stroke(0);
strokeWeight(4);
line(120, 120 , 60*cos((h + m/60.0) % 12 * TWO_PI / 12 - HALF_PI) + 120, 60*sin((h + m/60.0) % 12 * TWO_PI / 12 - HALF_PI) +120); //hour
strokeWeight(2);
line(120, 120 , 80*cos((m + s/60.0) * TWO_PI / 60 - HALF_PI) + 120, 80*sin((m + s/60.0) * TWO_PI / 60 - HALF_PI) +120); //minute
strokeWeight(1);
line(120, 120 , 90*cos(s * TWO_PI / 60 - HALF_PI) + 120, 90*sin(s * TWO_PI / 60 - HALF_PI) +120); //seconds
}

PhiLho

Re: Problem converting System.currentTimeMillis() to current time and int

11 months ago

That's not a real framecount, ie. that's not the frameCount Processing variable...

Now, you can use the Java Calendar to get the time, it would do the hard math for you. But that's actually what does second() and such, as shown above...