L_ProcessPlayback

#include "l_bitmap.h"

L_LTDIS_API L_INT L_ProcessPlayback(hPlayback, puState)

HPLAYBACK hPlayback;	/* playback handle */
L_UINT* puState;	/* address of the variable to be updated */

Processes the next state during an animation playback.

Parameter	Description
hPlayback	Handle that references the animation playback.
puState	Address of the variable to be updated with a constant that describes the new state of the animation playback engine. For possible values, refer to Animation Playback States.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

This function does not support signed data images. It returns the error code ERROR_SIGNED_DATA_NOT_SUPPORTED if a signed data image is passed to this function.

This function is called in a loop to continually process the playback.

Required DLLs and Libraries

LTDIS

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Windows 2000 / XP/Vista, Windows CE.

See Also

Functions:	L_CreatePlayback, L_DestroyPlayback, L_GetPlaybackDelay, L_CancelPlaybackWait, L_ClearPlaybackUpdateRect, L_GetPlaybackIndex, L_GetPlaybackState, L_GetPlaybackUpdateRect, L_SetPlaybackIndex, L_AppendPlayback, L_ValidatePlaybackLines
Topics:	Raster Image Functions: Creating and Maintaining Lists of Images
	Implementing Animation

Example

For an example, refer to L_AppendPlayback. This example loads a bitmap list from an animated GIF or AVI file. It then plays the animation, using the current bitmap as the target.

 L_INT ProcessPlaybackExample(L_HWND           hWnd,
                                             pBITMAPHANDLE  pBitmap,
                                             L_TCHAR*       pszFilename,
                                             HPALETTE       hpalPaint)
{
   L_INT nRet;
   HBITMAPLIST    hList;            /* Bitmap list */
   BITMAPHANDLE   TmpBitmap;        /* Temporary bitmap for building the list */
   HPLAYBACK      hPlayback;        /* Animation playback */
   L_UINT         uState;           /* Next state in the playback */
   RECT           rcUpdate;         /* Source clipping rectangle used in playback */
   RECT           rcDisplay;        /* Display rectangle used in playback */
   HDC            hdc;              /* Device context of the current window */
   HPALETTE       hPalette = NULL;  /* Temporary copy of the current system palette */

   /* Create the bitmap list from the input file (GIF or AVI) */
   nRet = L_LoadBitmapList(pszFilename, &hList, 0, 0, NULL, NULL);
   if(nRet != SUCCESS)
      return nRet;
   /* Get a copy of the first image's bitmap handle */
   nRet = L_GetBitmapListItem(hList, 0, &TmpBitmap, sizeof(BITMAPHANDLE));
   if(nRet != SUCCESS)
      return nRet;
   /* Create the palette that is used for playback */
   hdc = GetDC (hWnd);
   hpalPaint = L_CreatePaintPalette(hdc, &TmpBitmap);
   ReleaseDC (hWnd, hdc);
   /* Use the client area as the display rectangle, 
   assuming that the window is properly sized */
   GetClientRect(hWnd,&rcDisplay);
   /* Create the target bitmap that is used for playback */
   if(pBitmap->Flags.Allocated)
      L_FreeBitmap(pBitmap);
   nRet = L_CreateBitmap(pBitmap, sizeof(BITMAPHANDLE), TYPE_CONV,
               TmpBitmap.Width,
               TmpBitmap.Height,
               TmpBitmap.BitsPerPixel,
               TmpBitmap.Order,
               NULL,
               TmpBitmap.ViewPerspective, NULL, 0);
   if(nRet != SUCCESS)
      return nRet;
   /* Update the palette of the target bitmap */
   nRet = L_CopyBitmapPalette(pBitmap, &TmpBitmap);
   if(nRet != SUCCESS)
      return nRet;
   /* Create and run the playback */
   nRet = L_CreatePlayback(&hPlayback, pBitmap, hList);
   if(nRet != SUCCESS)
      return nRet;
   do
   {
      nRet = L_ProcessPlayback(hPlayback, &uState);
      if(nRet != SUCCESS)
         return nRet;
      switch(uState)
      {
      case PLAYSTATE_WAITINPUT:
            nRet = L_CancelPlaybackWait(hPlayback);
            if(nRet != SUCCESS)
               return nRet;
            break;
      case PLAYSTATE_POSTCLEAR:
      case PLAYSTATE_POSTRENDER:
         nRet = L_GetPlaybackUpdateRect(hPlayback, &rcUpdate, TRUE);
         if(nRet != SUCCESS)
            return nRet;
         hdc = GetDC(hWnd);
         if (hpalPaint)
         {
            hPalette = SelectPalette (hdc, hpalPaint, TRUE);
            RealizePalette(hdc);
         }
         nRet = L_PaintDC(hdc, pBitmap, NULL, &rcUpdate, &rcDisplay, &rcDisplay, SRCCOPY);
         if(nRet != SUCCESS)
            return nRet;
         if (hpalPaint)
            SelectPalette (hdc, hPalette, TRUE);
         ReleaseDC(hWnd, hdc);
         break;
      }
   } while(uState != PLAYSTATE_END);
   /* Clean up */
   L_DestroyPlayback(hPlayback, NULL);
   L_DestroyBitmapList(hList);
   return SUCCESS;
}