class KineticForce extends PApplet                          
{ 
	// to declare self-defined variables here...
  
	KineticForce(PGraphics g, int width, int height)   
	{
		// leave it blank   
	}

	void setup()                                          
	{
	}

	void draw()                                             
	{
	}
  
	// self-defined classes or self-defined functions are here...
  
}

void setup()                                              
{
	for (int i=0; i<6; i++)
	{
		stroke(100, random(100,250), 100);
		noFill();
		circle(110, 90, random(90,180));
	}
}

void draw()                                               
{
	background(0,0);
	for (int i=0; i<6; i++)
	{
		stroke(100, random(100,250), 100);
		noFill();
		circle(110, 90, random(90,180));
	}
}

KineticForce(PGraphics g, int width, int height)         
{
	// leave it blank  
}

void setup()                                              
{
	// create variable of color type
	color c;
	// create a dim red color, save it
	c = color(200, 100, 100);
	// apply this color
	fill(c);
	// draw a rectangle
	rect(0, 0, width, height);
}

class KineticForce extends PApplet                               
{
	// alpha value, changed from 0 to 255
	int alpha;
	// either ‘-1’ or ‘1’, the change on ‘alpha’
	int step;	
	
	KineticForce(PGraphics g, int width, int height)               
	{
		// leave it blank    
	}

	void setup()                                             
	{
		alpha = 0;
		step = 1;
	}
 
	void draw()                                              
	{
		// clear the background for upcoming frame
		background(255, 0);
		color c;
		// create a dim red color with alpha channel
		c = color(200, 100, 100, alpha);
		fill(c);		
		rect(0, 0, width, height);
		// increase or decrease the alpha value
		alpha = alpha + step;
		
		// reverse 'step' if alpha is too high
		if (alpha>255)
		{  
			step=-1; 
			alpha=254;
		}
		// reverse ‘step’ if ‘alpha’ is too low
		else if (alpha<0)
		{
			step=1;
			alpha = 1;
		}
	}
}

void draw()                                               
{
	// set the background transparent
	background(255, 0);
			
	// add random points on the painting			
	for (int i=0; i<10000; i++)
	{
		int R = round(200 + 50 * random(0.5,1));
		int G = round(200 + 50 * random(0,1));
		int B = round(200 + 50 * random(0,1));
		int x = random(0,width);
		int y = random(0,height);
		color c = color(R,G,B);
		stroke(c);
		point(x, y);
	}

	delay(200);
}

void draw()                                             
{
	// background color is not transparent
	background(255);
			
	for (int i=0; i<10000; i++)
	{
		int R = round(200 + 50 * random(0.5,1));
		int G = round(200 + 50 * random(0,1));
		int B = round(200 + 50 * random(0,1));
		int x = random(0,width);
		int y = random(0,height);
		color c = color(R,G,B);
		stroke(c);
		point(x, y);
	}

	delay(200);
}

void draw()                                            
{			
	for (int i=0; i<10000; i++)
	{
		int R = round(200 + 50 * random(0.5,1));
		int G = round(200 + 50 * random(0,1));
		int B = round(200 + 50 * random(0,1));
		int x = random(0,width);
		int y = random(0,height);
		color c = color(R,G,B);
		stroke(c);
		point(x, y);
	}
	delay(200);
}

void setup()                                              
{
	// two inclined strokes in dim red
	stroke(100,0,0);
	strokeWeight(0.5);
	line(0,35,width,50);

	// two inclined strokes in dim red
	stroke(100,0,0);
	strokeWeight(0.5);
	line(0,35,width,50);
	line(0,25,width,80);

	// the bigger circle
	stroke(200);
	strokeWeight(2);
	noFill();
	circle(140,86,80);

	// the small black circle
	noStroke();
	fill(0);
	circle(36,28,13);

	// the smallest red circle
	fill(240,100,100);
	circle(172,100,10);
}

void setup()
{
	PImage img = loadImage(“myImage.jpg”);
	image(img, width/2, 0);
}

In this example, if you save your Pure ink file on Desktop, Kinetic Force will look for a folder namely ‘data’ in Desktop and then fetch ‘myImage.jpg’ from it. Thus, if your Kinetic Force involves media file loading, you are recommended to create a working folder with whatever name you like first. Then you save your Pure ink file in it and create a ‘data’ folder in it too. Put all media files into that ‘data’ folder so that you can load them by your Kinetic Force.

Please note that, if you run the Kinetic Force examples provided in Pure ink directly (by selecting 'Kinetic Force > Examples' from the top menu) without your Pure ink file being saved before, Pure ink looks for media files from the ‘data’ folder of the directory where your Pure ink software installed. That should work since the media files are already included in that ‘data’ folder when you install the software. On the other hand, if you try running those Kinetic Force examples but you have saved the Pure ink file to a specific directory before, then the loading does not work anymore unless you move the media files to a ‘data’ folder inside that directory.

void draw()     
{
  background(255,0);
  stroke(128);
  for (int i=0; i<200; i=i+20)
  	for (int j=0; j<200; j=j+20)
    {
      // calculate the distance between (i,j) and (mouseX, mouseY)
      float dist = sqrt(pow((i-mouseX),2)+pow((j-mouseY),2));
	  
	  // 'distRatio' tends to be 0 if 'dist' is small
      float distRatio = (dist/290);
        
      // based on a sigmoid function, 'size' tends to be zero only
      // if 'distRatio' is very small, otherwise it tends to be 20, 
      // this only makes the boxes closed to cursor be very small
	  // but preserves the size of the other boxes
      float size = 20 / (1 + exp(-30*(distRatio-0.1)));
        
      // the boxes closed to cursor is more semi-transparent
      float alpha = 200 + 55 * distRatio;
        
      fill(180, alpha);
      rect(i,j,int(size), int(size));
    } 
}

class KineticForce extends PApplet         
{      
  float alpha;
  
  KineticForce(PGraphics g, int width, int height)              
  {
    // leave it blank    
  }

  void setup()                                                
  {
    alpha = 255; 
  }

  void draw()                        
  {
    background(255,0);
    stroke(128);
    for (int i=0; i<200; i=i+20)
      for (int j=0; j<200; j=j+20)
      {        
        fill(180, alpha);
        rect(i,j,20,20);
      } 
  }
  
  void mousePressed()
  {
    // reduce alpha when user click the mouse 
    alpha = alpha - 30;
    if (alpha<0) alpha = 0;
  }  
}

class KineticForce extends PApplet                           
{ 
  int x;          	// x position of the green dot
  int y;          	// y position of the green dot
  float speed;    	// speed of the green dot
  float size;     	// size of the green fot
  
  KineticForce(PGraphics g, int width, int height)            
  {
    // leave it blank   
  }

  void setup()                                       
  {
    x = 100;
    y = 100;   
    speed = 0;
    size = 11;
    noStroke();
  }

  void draw()                                                   
  {
    // only draw after the dot move a while, 
    // avoid the starting point be too dark
    if (speed>0.3)
    {
      fill(20,60,20,20);
      circle(x, y, size);
    }
  }
  
  // set the start point of the dot 
  // based on a mouse click
  void mousePressed()     
  {
    x = mouseX;
    y = mouseY;
  }
  
  // user control the movement of the dot 
  // by arrow keys. When the dot moves, its 
  // speed increase but size decrease
  void keyPressed()
  {
    if (key == CODED) 
    {
      if (keyCode == UP)
      { 
        y = round(y - speed);
        speed = speed + 0.1;
        size = size - 0.3;
      }
      else if (keyCode == DOWN)
      {
        y = round(y + speed);
        speed = speed + 0.1;
        size = size - 0.3;
      }
      else if (keyCode == LEFT) 
      {
        x = round(x - speed);
        speed = speed + 0.1;
        size = size - 0.3;
      }
      else if (keyCode == RIGHT)
      {
        x = round(x + speed);
        speed = speed + 0.1;
        size = size - 0.3;
      }
    }
  }
  
  // reset the speed and size when user 
  // release any key
  void keyReleased()
  {
    speed = 0;
    size = 15;
  }
}