Task: Image noise

C: #include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <SDL/SDL.h>
 
unsigned int frames = 0;
unsigned int t_acc = 0;
 
void print_fps ()
{
  static Uint32 last_t = 0;
  Uint32 t = SDL_GetTicks();
  Uint32 dt = t - last_t;
  t_acc += dt;
  if (t_acc > 1000)
  {
    unsigned int el_time = t_acc / 1000;
    printf("- fps: %g\n",
            (float) frames / (float) el_time);
    t_acc = 0;
    frames = 0;
  }
  last_t = t;
}
 
void blit_noise(SDL_Surface *surf)
{
  unsigned int i;
  long dim = surf->w * surf->h;
  while (1)
  {
    SDL_LockSurface(surf);
    for (i=0; i < dim; ++i) {
      ((unsigned char *)surf->pixels)[i] = ((rand() & 1) ? 255 : 0);
    }
    SDL_UnlockSurface(surf);
    SDL_Flip(surf);
    ++frames;
    print_fps();
  }
}
 
int main(void)
{
  SDL_Surface *surf = NULL;
  srand((unsigned int)time(NULL));
  SDL_Init(SDL_INIT_TIMER | SDL_INIT_VIDEO);
  surf = SDL_SetVideoMode(320, 240, 8, SDL_DOUBLEBUF | SDL_HWSURFACE);
  blit_noise(surf);
}





Java: import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.util.Arrays;
import java.util.Random;
import javax.swing.*;

public class ImageNoise {
    int framecount = 0;
    int fps = 0;
    BufferedImage image;
    Kernel kernel;
    ConvolveOp cop;
    JFrame frame = new JFrame("Java Image Noise");

    JPanel panel = new JPanel() {
        private int show_fps = 0; 
        private MouseAdapter ma = new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                show_fps = (show_fps + 1) % 3;
            }
        };
        {addMouseListener(ma);}

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(320, 240);
        }

        @Override
        @SuppressWarnings("fallthrough")
        public void paintComponent(Graphics g1) {
            Graphics2D g = (Graphics2D) g1;
            drawNoise();
            g.drawImage(image, 0, 0, null);

            switch (show_fps) {
            case 0: 
                
                int xblur = getWidth() - 130, yblur = getHeight() - 32;
                BufferedImage bc = image.getSubimage(xblur, yblur, 115, 32);
                BufferedImage bs = new BufferedImage(bc.getWidth(), bc.getHeight(),
                                                     BufferedImage.TYPE_BYTE_GRAY);
                cop.filter(bc, bs);
                g.drawImage(bs, xblur, yblur , null);
            case 1: 
                
                g.setColor(Color.RED);
                g.setFont(new Font("Monospaced", Font.BOLD, 20));
                g.drawString("FPS: " + fps, getWidth() - 120, getHeight() - 10);
            }
            framecount++;
        }
    };
    
    
    Timer repainter = new Timer(1, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            panel.repaint();
        }
    });
    
    
    Timer framerateChecker = new Timer(1000, new ActionListener() {
        @Override
        public void actionPerformed(ActionEvent e) {
            fps = framecount;
            framecount = 0;
        }
    });
    
    public ImageNoise() {
        
        float[] vals = new float[121];
        Arrays.fill(vals, 1/121f);
        kernel = new Kernel(11, 11, vals);
        cop = new ConvolveOp(kernel, ConvolveOp.EDGE_NO_OP, null);
        
        
        frame.add(panel);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setVisible(true);
        repainter.start();
        framerateChecker.start();
    }

    void drawNoise() {
        int w = panel.getWidth(), h = panel.getHeight();
        
        
        if (null == image || image.getWidth() != w || image.getHeight() != h) {
            image = new BufferedImage(w, h, BufferedImage.TYPE_BYTE_GRAY);
        }
        Random rand = new Random();
        int[] data = new int[w * h];
        
        for (int x = 0; x < w * h / 32; x++) {
            int r = rand.nextInt();
            for (int i = 0; i < 32; i++) {
                data[x * 32 + i] = (r & 1) * Integer.MAX_VALUE;
                r >>>= 1;
            }
        }
        
        image.getRaster().setPixels(0, 0, w, h, data);
    }
    
    public static void main(String[] args) {
        
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                ImageNoise i = new ImageNoise();
            }
        });
    }
}