Program is very slow

ShaiMenz

Hello everyone, I'm new to processing and made a simple visualization of a sorting algorithm. I've noticed it's very slow even though it is not very complicated...

Code:

final int LEN = 91;
int frame = 0, i = 0, j = 0;
float density = 6, cmp1X = 0, cmp2X = 0;
boolean switched = false;
float[] random = new float[LEN];

void setup() 
{
  size(630, 360, P2D);
  frameRate(600);
  background(51);
  noStroke();
  float rnd, temp;

  for(int i = 0; i < LEN; i++)
  {
    random[i] = i * 3.7;
  }

  for(int i = 0; i < LEN; i++)
  {
     for(int j = 0; j < LEN; j++)
     {
         rnd = (int)(Math.random() * 100);
         if(rnd % 2 == 0)
         {
             temp = random[i];
             random[i] = random[j];
             random[j] = temp;
         }
     }
  }
  /**
  for(int i = 0; i < LEN; i++)
  {
    rnd = (float) Math.random() * 360;
    random[i] = rnd;
  }
  */
}

void draw() 
{
  background(51);
  printArr();
  float temp;
  switched = false;
  if((i < LEN && j < LEN) && random[i] > random[j])
  {
    switched = true;
    cmp1X = i;
    cmp2X = j;
    temp = random[i];
    random[i] = random[j];
    random[j] = temp;
  }
  if(switched)
  {
   printArr(); 
  }

  i++;
  if(i > LEN - 1 && j < LEN - 1)
  {
    i = 0;
    j++;
  }
}

void printArr()
{
  background(51);
  for(int x = 0; x < LEN; x++)
  {
    if(x == cmp1X && switched)
    {
      fill(1);
      rect(x*7, 360 - random[x], density, random[x]);
    }  
    else if(x == cmp2X && switched)
    {
      fill(100);
      rect(x*7, 360 - random[x], density, random[x]);
    }
    else
    {
      fill(255);
      rect(x*7, 360 - random[x], density, random[x]);
    }
  }
} 

Chrisir

JUST read it slowly

Line 45 not needed

line 44 not needed

Lines 75 and 80 the && switched is not needed

koogs

first up, random[i] is confusing. don't name variables after keywords.

i suspect that line 48 means that there are lots of frames where nothing happens because the condition isn't true.

in fact, i added

println(frameCount);

inside the condition and it printed

4
9
45
55
63
81
92
184

so, yes, there are sometimes 40 or 90 frames where nothing is drawn.

koogs

this is probably the big problem though

if(i > LEN - 1 && j < LEN - 1)

your i is always iterating all the way through the set. you could stop when you've gone beyond the current end (j)

if(i > j && j < LEN - 1)