How to optmize my code?

Programming Questions

SandroMic..

in Programming Questions • 5 months ago

Hey all!

I'm working on a program that draws a wave using several line() functions, but I think maybe there is a more efficient way to do so. I need to use the line functions because I'm putting some noise in the wave too. Well, I think it's better if you run the code, so here it is:

int val=50;
Wave onda;
void setup(){
size(600,300);
background(255);
strokeWeight(2);
smooth();
frameRate(60);
PVector offset;
offset = new PVector(0,height/2);
// Para onda ficar suave é necessário que a frequência seja uma razão da largura do sketch
onda = new Wave(offset, height/3, width/100, 0.0);
}
void draw(){
//background(244,30);
onda.display();
noStroke();
fill(255,30);
rect(0,0,width,height);
stroke(2);
print(val+"\n");
}
void keyPressed(){
switch(keyCode){
case UP:
val-=5;
break;
case DOWN:
val+=5;
break;
}
}
class Wave {
PVector offset, p, last;
float amplitude;
float frequency;
float angle;
//constructor
Wave(PVector off, float amp, float fre, float ang) {
offset = new PVector(off.x, off.y);
amplitude = amp;
frequency = fre;
angle = ang;
last = new PVector(offset.x, offset.y);
}
void display() {
p = new PVector(0,0);
for (float x=0; x<=width; x+=1){
p.x = offset.x + x;
p.y = offset.y + (amplitude * sin(radians(angle)));
p.y += customRandom(val);
//p.y += 30 * cos(rand);
//print(customRandom()+"\n");
line(last.x, last.y, p.x, p.y);
last.x = p.x;
last.y = p.y;
angle+=frequency/2;
if(angle>360-frequency/2)
angle=0;
}
last.x=offset.x;
}
float customRandom(int amp){
float rand = random(50);
float ret = sin(noise(rand))*amp;
return ret;
}
}

Is there any obvious way to optimize the code so that it can run better?

Replies(5)

PhiLho

Re: How to optmize my code?

5 months ago

" optimize" " more efficient" " run better"
What is wrong with this code? Do you find it slow?

SandroMic..

Re: How to optmize my code?

5 months ago

Well, it's not running smoothly here (maybe I need to upgrade my machine :P), so I thought there could be something that could be done to make it better.

If I use ellipse() instead of line() it gets better, but then I can't do that "noisy" effect on the curve.

PhiLho

Re: How to optmize my code?

5 months ago

Indeed, on my computer, medium level, it is quite smooth. No choppiness or such. And on a quick glance, I saw not the usual stuff that can slow down a sketch (like I/O in draw(), etc.).
Perhaps somebody will take a deeper look and give a more valuable advice.
Or perhaps, indeed, you need to upgrade.

GoToLoop

Re: How to optmize my code?

5 months ago

Well, I've tried to tweak it, but failed! Result is not the same and dunno if it got any faster either!!!

Anyways, at least I'll post my experiment.

Wave onda;
int val = 50;

final static short FPS = 50, BOLD = 2, STEP = 5;
final static color FG = 2, BG = -1, TRANSP = 30;

// Use JAVA2D for Processing 2+:
final static String GFX = P2D;  

void setup() {
  size(600, 300, GFX);
  //smooth();
  frameRate(FPS);
  strokeWeight(BOLD);
  fill(BG, TRANSP);

  PVector offset = new PVector(0, height/2);
  onda = new Wave(offset, height/3, width/100, 0);
}

void draw() {
  noStroke();
  rect(0, 0, width, height);

  stroke(FG);
  onda.display();

  print( (int) frameRate + ", ");
}

void keyPressed() {
  if (keyCode == UP)          val -= STEP;
  else if (keyCode == DOWN)   val += STEP;
}

float noisy() {
  return sin( noise(random(5)) )*val;
}

class Wave {
  final PVector off  = new PVector();
  final PVector last = new PVector();
  final PVector p = new PVector();

  final short amp, freq;
  short ang;

  Wave(PVector offset, int amplifier, 
  int frequency, int angle) {
    off.set(offset);

    amp  = (short) amplifier;
    freq = (short) (frequency >> 1);
    ang  = (short) angle;
  }

  void display() {
    last.x = off.x;

    for (int x=-1; x<=width; last.set(p), ang += freq) {
      p.set(off);
      p.add(x++, sin( radians(ang) )*amp + noisy(), 0);
      line(last.x, last.y, p.x, p.y);
      //point(p.x, p.y);
    }
  }
}

dr.mo

Re: How to optmize my code?

5 months ago

two things that probably slow your code down:

you are drawing 'width' number of lines 60 times a second. and for each you compute sin twice.

it's hard to tell what is the main bottleneck. therefore i would strongly suggest you profile (measure the time it takes) each part of this.

possible solutions:

Lines: your lines are not much longer than a pixel, is it really necessary to draw so many?! using a curve you can probably reduce the number of lines by a factor of 10 and still have smooth lines.

Sin: make a lookup table. i.e. as you are computing the same values of sine over and over just do it once and store them in an array!

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