title: line drawing routine
body: <p>How to optimize this line drawing routine ? Will memcpy work faster ?</p>
  
  <pre><code>void ScreenDriver::HorizontalLine(int wXStart, int wXEnd, int wYPos,
      COLORVAL Color, int wWidth)
  {
      int iLen = wXEnd - wXStart + 1;
  
      if (iLen &lt;= 0)
      {
          return;
      }
      while(wWidth-- &gt; 0)
      {
          COLORVAL *Put = mpScanPointers[wYPos] + wXStart;
          int iLen1 = iLen;
  
          while(iLen1--)
          {
              *Put++ = Color;
          }
          wYPos++;
      }
  }
  </code></pre>