Multiple Clocks

Introduction

This dialog-based application displays several different styles of clocks: analog, binary, decimal, and nixie.

Background

The Nixie tube was used in electronic instruments mainly in the 1960s thru 1980s. It is a neon-filled vacumn tube with 10 elements that can make the neon glow when any one element is grounded. The tube has a common anode with approximately 175 volts DC applied to it. I think it makes a cool clock.

Using the Code

Several methods used in this code are borrowed from other programmers, some from this site (see Credits). The heart of the binary clock is the _itoa(nTime, ibuff, 2); function, where nTime is any integer contaning the hour, minute, or second. ibuff is a char buffer and the 2 is a base, in this case, binary.

Here is the code to display a simple Decimal clock in the Windows Title Bar.

void CMultiClockDlg::DisplayDecimal()
{
   //
   // Get the current time
   //
   CTime time  = CTime::GetCurrentTime();
   int nSecond = time.GetSecond();
   int nMinute = time.GetMinute();
   int nHour   = time.GetHour();
   if (nHour > 12)
      nHour -= 12;
   CString szStr;
   szStr.Format("MultiClock - %.2d:%.2d:%.2d", nHour, nMinute, nSecond);
   ::SetWindowText(m_hWnd, szStr);
}

Points of Interest

The Binary display is grouped: 4 bits for the hour, and 6 bits for the minutes and seconds. I did this because the hour can only be "01" thru "C" and the minutes/seconds "00" thru "3B". The nixie clock uses bitmaps (45X64) for each digit; they are diplayed by calling:

void CMultiClockDlg::FormatTm(CDC *pDC, int nTime, int nPos)
{
   int x, y;
   m_bmp.LoadResource(IDB_BITMAP110);
   x = 8 +(m_bmp.GetWidth() * nPos);
   y = 8;
   switch (nTime)
   {
      case 0:
         m_bmp.LoadResource(IDB_BITMAP100);
         m_bmp.DrawDIB(pDC, x, y);
         break;
   }

One thing I found when writing this code was this: DO NOT USE CDC *pDC = GetDC(); in a loop without using RelaseDC(pDC); My first version would run for 15 to 20 minutes and crash because GetDC() uses 4 bytes of memory every time it is called.

Credits

ClockCtrl—The Analog Clock
Author: P.J. Naughter

Dib256—Load Resource/Paint Bitmap
DibPal
Author: Jorg Konig

History

Version 1.0
Any comments or suggestions are welcome.



Downloads

Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Hurricane Sandy was one of the most destructive natural disasters that the United States has ever experienced. Read this success story to learn how Datto protected its partners and their customers with proactive business continuity planning, heroic employee efforts, and the right mix of technology and support. With storm surges over 12 feet, winds that exceeded 90 mph, and a diameter spanning more than 900 miles, Sandy resulted in power outages to approximately 7.5 million people, and caused an estimated $50 …

  • With JRebel, developers get to see their code changes immediately, fine-tune their code with incremental changes, debug, explore and deploy their code with ease (both locally and remotely), and ultimately spend more time coding instead of waiting for the dreaded application redeploy to finish. Every time a developer tests a code change it takes minutes to build and deploy the application. JRebel keeps the app server running at all times, so testing is instantaneous and interactive.

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds