Creating a 24-Bit Per Pixel Subregion of a 24-Bit Per Pixel Bitmap

Original Bitmap



Click here for larger image

Subregion of the original bitmap

Environment: VC6

This article shows you how to create a portion of a 24-bit/pixel bitmap at runtime. In order to do this, you must add a 24-bit/pixel bitmap to your resources in VC++, decide what portion of the bitmap you wish (specified by the x-y coordinates of the upper left corner and the horizontal/vertical size of the portion), and what .bmp file you want the new portion of the bitmap to be store. The .bmp file created can be used at a later time, but in addition the bitmap of the subregion can be retrieved and used, for example, in your OnDraw function.

In the following code sample, we create a portion of a huge bitmap. The subregion is 416 by 224 pixels, but the original bitmap is well over 100 times this size.

CBitmapSubRegion bsr;
BOOL bSuccess;
// IDB_BITMAP_SCHUMACHERCAR is a 24-bit/pixel 
// resource ID added to VC++
bSuccess = bsr.SetResourceID(IDB_BITMAP_SCHUMACHERCAR);
if (bSuccess)
{
  bSuccess = bsr.SetFileNameOfResourceBitmap(
                          CString("SchumacherCar.bmp"));
  if (bSuccess)
  {
    // Want to create a subregion which starts at 
    // (x,y) of (259,317) and is 416-pixels wide by 
    // 224-pixels tall
    bSuccess = bsr.SetSubRegionOfBitmap(259,317,416,224);
    if (bSuccess)
    {
      //Set where to store the new bitmap
      bSuccess = bsr.SetFileNameForNewBitmap(
                    CString("SuhumacherCarSubRegion.bmp"));
      if (bSuccess)
      {
        bSuccess = bsr.CreateBitmapOfSubRegion();
        if (bSuccess)
        {
          m_pBitmapSubRegion = 
                           bsr.RetrieveBitmapOfSubRegion();
        }
      }
    }
  }
}

Downloads

Download source - 5 Kb


Comments

  • Getting Linking errors..

    Posted by Legacy on 12/27/2001 12:00am

    Originally posted by: GMR

    BitmapSubRegion.obj : error LNK2001: unresolved external symbol "public: __thiscall CString::~CString(void)" (??1CString@@QAE@XZ)
    BitmapSubRegion.obj : error LNK2001: unresolved external symbol "public: __thiscall CString::CString(void)" (??0CString@@QAE@XZ)
    BitmapSubRegion.obj : error LNK2001: unresolved external symbol "public: static void __stdcall CObject::operator delete(void *,char const *,int)" (??3CObject@@SGXPAXPBDH@Z)................................................................

    Reply
  • Where do I find BitmapCopy.h ? (I'm learning C++) thanks

    Posted by Legacy on 10/24/2001 12:00am

    Originally posted by: Bryan

    Hi, I was able to locate the includes for stdafx.h, but never could find BitmapCopy.h. in any of my library files, is it included in Microsoft VC++ libraries or is it a seperate download? thanks
    I'm new to C++ programming (I've just done some OOP stuff)

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

Top White Papers and Webcasts

  • Do you know where your data is? Consumer cloud-based file sharing services store your sensitive company data on servers outside of your control, outside of your policy and regulatory guidelines – maybe even outside your country – and not managed by you. The potential for data leakage, security breaches, and harm to your business is enormous. Download this white paper to learn about file sync and share alternatives that allow you to manage and protect your sensitive data while integrating and …

  • With 81% of employees using their phones at work, companies have stopped asking: "Is corporate data leaking from personal devices?" and started asking: "How do we effectively prevent corporate data from leaking from personal devices?" The answer has not been simple. ZixOne raises the bar on BYOD security by not allowing email data to reside on the device. In addition, Zix allows employees to maintain complete control of their personal device, therefore satisfying privacy demands of valued employees and the …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds