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Index › Programming Questions & Help › Programs › Slow program

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Slow program (Read 397 times)

ProcessingFTW

Slow program
Jun 28^th, 2008, 11:57pm

Hello,
I made a very simple program which becomes very slow after a short while.
Basically it draws random noise (black pixels) into a PGraphics, renders it and scales it. At first it's pretty fast, but it becomes slower and slower.

Code:


class BombSquare {
  int x,y;
  int[][] sqrs;
  PGraphics pg;
  BombSquare() {
    x = 580;
    y = 580;
    sqrs = new int[x][y];
    for (int i=0;i<x;i++)
	for (int j=0;j<y;j++)
	  sqrs[i][j] = 0;
    pg = createGraphics(580, 580,JAVA2D);
    pg.beginDraw();
  }
  void clear() {pg.background(255,0);}
  void bomb(int times) {
    for (int i=0;i<times;i++) {
	int rx = (int)random(0,x), ry = (int)random(0,y);
	sqrs[rx][ry] += 1;
    }
  }
  PGraphics getPg() {
    pg.background(255, 0);
    for (int i=0;i<x;i++)
	for (int j=0;j<y;j++)
	  if (sqrs[i][j]>0)
	    pg.point(i,j);
    pg.endDraw();
    return pg;
  }
}
BombSquare bs = new BombSquare();
int x;
void setup() {
  size(580,580);
  x = 0;
}

void draw() {
  background(255,0);
  pushMatrix();
  //it becomes slow even when no scale is used
  //scale(1-0.001*x);
  bs.bomb(100);
  image(bs.getPg(),0,0);
  popMatrix();
  //if (x<700) 
  x++;
}

ProcessingFTW

Re: Slow program
Reply #1 - Jun 29^th, 2008, 12:01am

a slow change shows that the number of millis each draw cycle takes grows:
Code:


class BombSquare {
  int x,y;
  int[][] sqrs;
  PGraphics pg;
  BombSquare() {
    x = 580;
    y = 580;
    sqrs = new int[x][y];
    for (int i=0;i<x;i++)
	for (int j=0;j<y;j++)
	  sqrs[i][j] = 0;
    pg = createGraphics(580, 580,JAVA2D);
    pg.beginDraw();
  }
  void clear() {pg.background(255,0);}
  void bomb(int times) {
    for (int i=0;i<times;i++) {
	int rx = (int)random(0,x), ry = (int)random(0,y);
	sqrs[rx][ry] += 1;
    }
  }
  PGraphics getPg() {
    pg.background(255, 0);
    for (int i=0;i<x;i++)
	for (int j=0;j<y;j++)
	  if (sqrs[i][j]>0)
	    pg.point(i,j);
    pg.endDraw();
    return pg;
  }
}
BombSquare bs = new BombSquare();
int x;
void setup() {
  size(580,580);
  x = 0;
}
int ms = 0;
void draw() {
  int now = millis();
  println(now-ms);
  ms = now;
  background(255,0);
  pushMatrix();
  //scale(1-0.001*x);
  bs.bomb(100);
  image(bs.getPg(),0,0);
  popMatrix();
  //if (x<700) 
  x++;
}

ProcessingFTW

Re: Slow program
Reply #2 - Jun 29^th, 2008, 4:37am

I recently notices that even just feeling all pixels with random color is slow:
Code:


int x=580,y=580;
void setup() {
  size(x,y);
  noSmooth();
}
int ms = 0;
void draw() {
  int tmp = millis();
  println(tmp-ms);
  ms = tmp;
  for (int i=0;i<x;i++) {
    for (int j=0;j<y;j++) {
	stroke(random(0,256),random(0,256),random(0,256));
	point(i,j);
    }
  }
}

antiplastik YaBB Moderator Offline Posts: 699 France	Re: Slow program Reply #3 - Jun 29^th, 2008, 10:05am Actually, using the point() method to fill the screen is slow. You should better write directly into the pixels array, that will speed up your loop : Code: loadPixels(); for (int i=0;i<x;i++) { for (int j=0;j<y;j++) { color c = color(random(0,256),random(0,256),random(0,256)); pixels[j*width+i] = c; } } updatePixels();

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