// These macros apply atan, square, square root and inverse log functions
// to the current image. The processing speed in microseconds per pixel
// is displayed in the status bar. Press 'z' (Edit>Undo) to undo.

  macro "Atan" {
      setupUndo;
      start = getTime();
      w = getWidth(); h = getHeight();
      for (y=0; y<h; y++) {
          for (x=0; x<w; x++)
              setPixel(x, y, atan(getPixel(x, y)));   
          if (y%20==0) showProgress(y, h);
      }
      showTime(start)
 }

   macro "Sqr" {
      setupUndo;
      start = getTime();
      w = getWidth(); h = getHeight();
      for (y=0; y<h; y++) {
          for (x=0; x<w; x++)
              setPixel(x, y, sqr(getPixel(x, y)));   
          if (y%20==0) showProgress(y, h);
      }
      showTime(start)
   }

   macro "Faster Sqr" {
      setupUndo;
      start = getTime();
      w = getWidth(); h = getHeight();
      for (y=0; y<h; y++) {
          for (x=0; x<w; x++) {
              v = getPixel(x, y);
              setPixel(x, y, v*v); 
          }  
          if (y%20==0) showProgress(y, h);
      }
     showTime(start)
  }

  macro "Sqrt" {
      setupUndo;
      start = getTime();
      w = getWidth(); h = getHeight();
      for (y=0; y<h; y++) {
          for (x=0; x<w; x++)
              setPixel(x, y, sqrt(getPixel(x, y)));   
          if (y%20==0) showProgress(y, h);
      }
      showTime(start)
  }

  macro "Inverse Log" {
      setupUndo;
      E = 2.7182818284590452354;
      start = getTime();
      w = getWidth(); h = getHeight();
      for (y=0; y<h; y++) {
          for (x=0; x<w; x++)
              setPixel(x, y, pow(E, getPixel(x, y)));   
          if (y%20==0) showProgress(y, h);
      }
      showTime(start)
  }

 function showTime(start) {
      resetMinAndMax;
      showStatus(d2s((getTime()-start)*1000/(w*h), 2)+" microseconds/pixel");
  }

  function sqr(x) {
      return x*x;
  }