Thread loading images faster until they disapear in Studio - c++

Question

I am pretty new to visual studio. I am trying to load images and display it on a UI with two buttons start and stop. Every time I complete my count of total frames the next time I press start my images load more faster than before and in the end images the speed is so fast that they just disappear or appear as black. The thread speed or loading of images time increases as with each cycle. How can I limit this.. or put a time interval between showing two images. Thank you.
there code is as follows :
void CmirrorImageDlg::OnBnClickedStart()
{
m_play = TRUE;
CString num = NULL;
num.Format(_T("Pause"));
m_start.EnableWindow(false);
m_stop.EnableWindow(true);
m_stop.SetWindowTextW(num);
m_pThread = AfxBeginThread(Operate, (LPVOID)this, THREAD_PRIORITY_NORMAL);
}
void CmirrorImageDlg::OnBnClickedStop()
{
m_play = FALSE;
CString num = NULL;
num.Format(_T("Resume"));
m_start.EnableWindow(true);
m_stop.EnableWindow(false);
m_start.SetWindowTextW(num);
m_count = 0;
//m_pThread = AfxBeginThread(Operate, (LPVOID)this, THREAD_PRIORITY_ABOVE_NORMAL);
// TODO: Add your control notification handler code here
}
UINT CmirrorImageDlg::Operate(LPVOID param)
{
CmirrorImageDlg* pDlg = (CmirrorImageDlg*) param;
CString test;
while ( pDlg->m_play && pDlg->m_count < TOTAL_FRAME_NUMBER)
{
test.Format(_T("images/%.4d.BMP"),pDlg->m_count);
pDlg->hbitmap = (HBITMAP)LoadImage(NULL,test,IMAGE_BITMAP,0,0,LR_LOADFROMFILE);
pDlg->inv_hbitmap = pDlg->GetInvertedBitmap(pDlg->hbitmap, TRUE);
pDlg->inv_hbitmap_1 = pDlg->GetInvertedBitmap(pDlg->hbitmap , FALSE);
//CBitmap map = LoadBitmapW(test);
//filePath = IDB_BITMAP1;
//filePath++;
//IDB_PICTURE2.LoadBitmapW(filePath);
pDlg->m_picture.SetBitmap(pDlg->hbitmap);
pDlg->m_picture_2.SetBitmap(pDlg->inv_hbitmap);
pDlg->m_picture_3.SetBitmap(pDlg->inv_hbitmap_1);
CString num = NULL;
num.Format(_T("%d"),pDlg->m_count);
pDlg->m_label.SetWindowTextW(num);
// TODO: Add your control notification handler code here
pDlg->m_count++;
}
if(pDlg->m_count >= TOTAL_FRAME_NUMBER)
{
CString num = NULL;
num.Format(_T("%d"),0);
pDlg->m_count = 0;
pDlg->m_play= false;
pDlg->m_label.SetWindowTextW(num);
pDlg->m_picture.SetBitmap(NULL);
pDlg->m_picture_2.SetBitmap(NULL);
pDlg->m_picture_3.SetBitmap(NULL);
CString num1 = NULL;
num.Format(_T("Stop"));
pDlg->m_start.EnableWindow(true);
pDlg->m_stop.EnableWindow(false);
pDlg->m_stop.SetWindowTextW(num);
num.Format(_T("Start"));
pDlg->m_start.SetWindowTextW(num);
//pDlg->m_pThread->SuspendThread();
}
return 0;
}

Answer 1

A reasonably simple option:
Set a WM_TIMER for your dialog to fire every 40 milliseconds (if you want 25 frames per second). If not playing, the timer handler will do nothing.
When the user hits play, you'll load the first image, and then set the 'playing' flag. Inside the timer handler, it will take the currently loaded image and blit it to the screen, then load the next image and return. When there are no more images in the sequence you clear your 'playing' flag.
Because you always display the current image when the timer fires, it doesn't matter how long it takes to load the next image (as long as you can do it faster than the playback).