L_ProcessPlayback (original) (raw)

Summary

Processes the next state during an animation playback.

Syntax

#include "l_bitmap.h"

L_LTDIS_API L_INT L_ProcessPlayback(hPlayback, puState)

Parameters

HPLAYBACK hPlayback

Handle that references the animation playback.

L_UINT* 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

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

Win32, x64, Linux.

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

This example loads a bitmap list from an animated GIF or WEBP file.
It then plays the animation, using the current bitmap as the target.

L_INT ProcessPlaybackExample(L_HWND hWnd, pBITMAPHANDLE pBitmap, L_TCHAR * pszFilename) { 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 */ HPALETTE hpalPaint; /* 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) { L_DestroyBitmapList(hList); return nRet; } /* Create the palette that is used for playback. Not necessary for WEBP animations */ 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) { L_DestroyBitmapList(hList); return nRet; } /* Update the palette of the target bitmap. Not necessary for WEBP animations */ nRet = L_CopyBitmapPalette(pBitmap, &TmpBitmap); if (nRet != SUCCESS) { L_DestroyBitmapList(hList); return nRet; } /* Create and run the playback */ nRet = L_CreatePlayback(&hPlayback, pBitmap, hList); if (nRet != SUCCESS) { L_DestroyBitmapList(hList); return nRet; } do { nRet = L_ProcessPlayback(hPlayback, &uState); if (nRet != SUCCESS) break; switch (uState) { case PLAYSTATE_WAITINPUT: /* This is necessary only for GIF animations. Normally, you will have to wait for the user to press a key here. But we will keep it simple and call L_CancelPlaybackWait to cancel the wait for a key */ nRet = L_CancelPlaybackWait(hPlayback); if (nRet != SUCCESS) break; break; case PLAYSTATE_POSTCLEAR: case PLAYSTATE_POSTRENDER: nRet = L_GetPlaybackUpdateRect(hPlayback, &rcUpdate, TRUE); if (nRet != SUCCESS) break; 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, we will release the DC and break out of the loop because nRet is not SUCCESS */ if (hpalPaint) SelectPalette(hdc, hPalette, TRUE); ReleaseDC(hWnd, hdc); break; } } while (uState != PLAYSTATE_END && nRet == SUCCESS); /* Clean up */ nRet = L_DestroyPlayback(hPlayback, NULL); if (nRet != SUCCESS) return nRet; nRet = L_DestroyBitmapList(hList); return nRet; }