X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/464122b639263c81fcbd698bae3826313d2165a2..24528b0c1421ca7bde29027cecc005643dfae8cb:/src/common/gifdecod.cpp diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp index 047189cc51..923685e552 100644 --- a/src/common/gifdecod.cpp +++ b/src/common/gifdecod.cpp @@ -2,8 +2,8 @@ // Name: gifdecod.cpp // Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation // Author: Guillermo Rodriguez Garcia -// Version: 3.01 -// Last rev: 1999/08/14 +// Version: 3.04 +// RCS-ID: $Id$ // Copyright: (c) Guillermo Rodriguez Garcia // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// @@ -20,16 +20,15 @@ #endif #ifndef WX_PRECOMP -# include "wx/setup.h" +# include "wx/defs.h" #endif -#if wxUSE_STREAMS +#if wxUSE_STREAMS && wxUSE_GIF #include #include -#include "wx/defs.h" #include "wx/gifdecod.h" - + //--------------------------------------------------------------------------- // wxGIFDecoder constructor and destructor @@ -37,7 +36,7 @@ wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim) { - m_f = s; + m_f = s; m_anim = anim; m_background = -1; @@ -58,7 +57,7 @@ wxGIFDecoder::~wxGIFDecoder() void wxGIFDecoder::Destroy() { - IMAGEN *pimg, *paux; + GIFImage *pimg, *paux; pimg = m_pfirst; @@ -67,9 +66,15 @@ void wxGIFDecoder::Destroy() paux = pimg->next; free(pimg->p); free(pimg->pal); - free(pimg); + delete pimg; pimg = paux; } + + m_pimage = NULL; + m_pfirst = NULL; + m_plast = NULL; + m_image = 0; + m_nimages = 0; } @@ -85,6 +90,9 @@ bool wxGIFDecoder::ConvertToImage(wxImage *image) const unsigned long i; int transparent; + /* just in case... */ + image->Destroy(); + /* create the image */ image->Create(GetWidth(), GetHeight()); @@ -129,7 +137,7 @@ bool wxGIFDecoder::ConvertToImage(wxImage *image) const return TRUE; } - + //--------------------------------------------------------------------------- // Data accessors //--------------------------------------------------------------------------- @@ -200,7 +208,7 @@ bool wxGIFDecoder::GoNextFrame(bool cyclic) } else return FALSE; -} +} bool wxGIFDecoder::GoPrevFrame(bool cyclic) { @@ -280,10 +288,14 @@ int wxGIFDecoder::getcode(int bits, int ab_fin) code = ab_fin; break; } + + /* prefetch data */ + m_f->Read((void *) m_buffer, m_restbyte); + m_bufp = m_buffer; } /* read next byte and isolate the bits we need */ - m_lastbyte = (unsigned char)m_f->GetC(); + m_lastbyte = (unsigned char) (*m_bufp++); mask = (1 << (bits - m_restbits)) - 1; code = code + ((m_lastbyte & mask) << m_restbits); m_restbyte--; @@ -291,7 +303,7 @@ int wxGIFDecoder::getcode(int bits, int ab_fin) /* adjust total number of bits extracted from the buffer */ m_restbits = m_restbits + 8; } - + /* find number of bits remaining for next code */ m_restbits = (m_restbits - bits); @@ -303,7 +315,7 @@ int wxGIFDecoder::getcode(int bits, int ab_fin) // GIF decoding function. The initial code size (aka root size) // is 'bits'. Supports interlaced images (interl == 1). // -int wxGIFDecoder::dgif(IMAGEN *img, int interl, int bits) +int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits) { int ab_prefix[4096]; /* alphabet (prefixes) */ int ab_tail[4096]; /* alphabet (tails) */ @@ -333,7 +345,7 @@ int wxGIFDecoder::dgif(IMAGEN *img, int interl, int bits) pass = 1; pos = x = y = 0; - /* reset static globals */ + /* reset decoder vars */ m_restbits = 0; m_restbyte = 0; m_lastbyte = 0; @@ -436,14 +448,28 @@ int wxGIFDecoder::dgif(IMAGEN *img, int interl, int bits) } +// CanRead: +// Returns TRUE if the file looks like a valid GIF, FALSE otherwise. +// +bool wxGIFDecoder::CanRead() +{ + unsigned char buf[3]; + + m_f->Read(buf, 3); + m_f->SeekI(-3, wxFromCurrent); + + return (memcmp(buf, "GIF", 3) == 0); +} + + // ReadGIF: // Reads and decodes one or more GIF images, depending on whether // animated GIF support is enabled. Can read GIFs with any bit // size (color depth), but the output images are always expanded // to 8 bits per pixel. Also, the image palettes always contain -// 256 colors, although some of them may be unused. Returns E_OK -// (== 0) on success, or an error code if something fails. Error -// codes are E_ARCHIVO, E_FORMATO, E_MEMORIA (see header file). +// 256 colors, although some of them may be unused. Returns wxGIF_OK +// (== 0) on success, or an error code if something fails (see +// header file for details) // int wxGIFDecoder::ReadGIF() { @@ -453,15 +479,15 @@ int wxGIFDecoder::ReadGIF() unsigned char type; unsigned char pal[768]; unsigned char buf[16]; - IMAGEN **ppimg, *pimg, *pprev; + GIFImage **ppimg, *pimg, *pprev; + /* check GIF signature */ + if (!CanRead()) + return wxGIF_INVFORMAT; - /* check GIF signature and animated GIF support (ver. >= 89a) */ + /* check for animated GIF support (ver. >= 89a) */ m_f->Read(buf, 6); - if (memcmp(buf, "GIF", 3) != 0) - return E_FORMATO; - if (memcmp(buf + 3, "89a", 3) < 0) m_anim = FALSE; @@ -489,14 +515,18 @@ int wxGIFDecoder::ReadGIF() pprev = NULL; pimg = NULL; - while (1) + bool done = FALSE; + + while(!done) { type = (unsigned char)m_f->GetC(); /* end of data? */ if (type == 0x3B) - break; - + { + done = TRUE; + } + else /* extension block? */ if (type == 0x21) { @@ -517,29 +547,24 @@ int wxGIFDecoder::ReadGIF() } else /* other extension, skip */ - { + { while ((i = (unsigned char)m_f->GetC()) != 0) { - /* This line should not be neccessary! - * Some images are not loaded correctly - * without it. A bug in wxStream? - */ - // m_f->SeekI(m_f->TellI(), wxFromStart); m_f->SeekI(i, wxFromCurrent); } } } - + else /* image descriptor block? */ if (type == 0x2C) { /* allocate memory for IMAGEN struct */ - pimg = (*ppimg) = (IMAGEN *) malloc(sizeof(IMAGEN)); + pimg = (*ppimg) = new GIFImage(); if (pimg == NULL) { Destroy(); - return E_MEMORIA; + return wxGIF_MEMERR; } /* fill in the data */ @@ -560,13 +585,13 @@ int wxGIFDecoder::ReadGIF() ppimg = &pimg->next; /* allocate memory for image and palette */ - pimg->p = (unsigned char *) malloc(size); + pimg->p = (unsigned char *) malloc((size_t)size); pimg->pal = (unsigned char *) malloc(768); if ((!pimg->p) || (!pimg->pal)) { Destroy(); - return E_MEMORIA; + return wxGIF_MEMERR; } /* load local color map if available, else use global map */ @@ -583,16 +608,15 @@ int wxGIFDecoder::ReadGIF() /* decode image */ dgif(pimg, interl, bits); - m_nimages++; - } - /* if we have one image and no animated GIF support, exit */ - if (m_nimages == 1 && !m_anim) - break; + /* if this is not an animated GIF, exit after first image */ + if (!m_anim) + done = TRUE; + } } - /* finish successfully :-) */ + /* setup image pointers */ if (m_nimages != 0) { m_image = 1; @@ -600,7 +624,51 @@ int wxGIFDecoder::ReadGIF() m_pimage = m_pfirst; } - return E_OK; + /* try to read to the end of the stream */ + while (type != 0x3B) + { + type = (unsigned char)m_f->GetC(); + + if (type == 0x21) + { + /* extension type */ + (void) m_f->GetC(); + + /* skip all data */ + while ((i = (unsigned char)m_f->GetC()) != 0) + { + m_f->SeekI(i, wxFromCurrent); + } + } + else if (type == 0x2C) + { + /* image descriptor block */ + m_f->Read(buf, 9); + + /* local color map */ + if ((buf[8] & 0x80) == 0x80) + { + ncolors = 2 << (buf[8] & 0x07); + m_f->SeekI(3 * ncolors, wxFromCurrent); + } + + /* initial code size */ + (void) m_f->GetC(); + + /* skip all data */ + while ((i = (unsigned char)m_f->GetC()) != 0) + { + m_f->SeekI(i, wxFromCurrent); + } + } + else if ((type != 0x3B) && (type != 00)) /* testing */ + { + /* images are OK, but couldn't read to the end of the stream */ + return wxGIF_TRUNCATED; + } + } + + return wxGIF_OK; } -#endif // wxUSE_STREAM +#endif // wxUSE_STREAMS && wxUSE_GIF