external/giflib 4.1.6

1 files changed, 1098 insertions, 0 deletions

diff --git a/dgif_lib.c b/dgif_lib.c
new file mode 100644
index 0000000..760d053
--- /dev/null
+++ b/dgif_lib.c
@@ -0,0 +1,1098 @@
+/******************************************************************************
+ *   "Gif-Lib" - Yet another gif library.
+ *
+ * Written by:  Gershon Elber            IBM PC Ver 1.1,    Aug. 1990
+ ******************************************************************************
+ * The kernel of the GIF Decoding process can be found here.
+ ******************************************************************************
+ * History:
+ * 16 Jun 89 - Version 1.0 by Gershon Elber.
+ *  3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names).
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#if defined (__MSDOS__) && !defined(__DJGPP__) && !defined(__GNUC__)
+#include <io.h>
+#include <alloc.h>
+#include <sys\stat.h>
+#else
+#include <sys/types.h>
+#include <sys/stat.h>
+#endif /* __MSDOS__ */
+
+#ifdef HAVE_IO_H
+#include <io.h>
+#endif
+
+#ifdef HAVE_FCNTL_H
+#include <fcntl.h>
+#endif /* HAVE_FCNTL_H */
+#ifdef HAVE_UNISTD_H
+#include <unistd.h>
+#endif /* HAVE_UNISTD_H */
+#include <stdio.h>
+#include <string.h>
+#include "gif_lib.h"
+#include "gif_lib_private.h"
+
+#define COMMENT_EXT_FUNC_CODE 0xfe  /* Extension function code for
+                                       comment. */
+
+/* avoid extra function call in case we use fread (TVT) */
+#define READ(_gif,_buf,_len)                                     \
+  (((GifFilePrivateType*)_gif->Private)->Read ?                   \
+    ((GifFilePrivateType*)_gif->Private)->Read(_gif,_buf,_len) : \
+    fread(_buf,1,_len,((GifFilePrivateType*)_gif->Private)->File))
+
+static int DGifGetWord(GifFileType *GifFile, GifWord *Word);
+static int DGifSetupDecompress(GifFileType *GifFile);
+static int DGifDecompressLine(GifFileType *GifFile, GifPixelType *Line,
+                              int LineLen);
+static int DGifGetPrefixChar(GifPrefixType *Prefix, int Code, int ClearCode);
+static int DGifDecompressInput(GifFileType *GifFile, int *Code);
+static int DGifBufferedInput(GifFileType *GifFile, GifByteType *Buf,
+                             GifByteType *NextByte);
+#ifndef _GBA_NO_FILEIO
+
+/******************************************************************************
+ * Open a new gif file for read, given by its name.
+ * Returns GifFileType pointer dynamically allocated which serves as the gif
+ * info record. _GifError is cleared if succesfull.
+ *****************************************************************************/
+GifFileType *
+DGifOpenFileName(const char *FileName) {
+    int FileHandle;
+    GifFileType *GifFile;
+
+    if ((FileHandle = open(FileName, O_RDONLY
+#if defined(__MSDOS__) || defined(WINDOWS32) || defined(_OPEN_BINARY)
+                           | O_BINARY
+#endif /* __MSDOS__ || _OPEN_BINARY */
+         )) == -1) {
+        _GifError = D_GIF_ERR_OPEN_FAILED;
+        return NULL;
+    }
+
+    GifFile = DGifOpenFileHandle(FileHandle);
+    return GifFile;
+}
+
+/******************************************************************************
+ * Update a new gif file, given its file handle.
+ * Returns GifFileType pointer dynamically allocated which serves as the gif
+ * info record. _GifError is cleared if succesfull.
+ *****************************************************************************/
+GifFileType *
+DGifOpenFileHandle(int FileHandle) {
+
+    unsigned char Buf[GIF_STAMP_LEN + 1];
+    GifFileType *GifFile;
+    GifFilePrivateType *Private;
+    FILE *f;
+
+    GifFile = (GifFileType *)malloc(sizeof(GifFileType));
+    if (GifFile == NULL) {
+        _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+        close(FileHandle);
+        return NULL;
+    }
+
+    memset(GifFile, '\0', sizeof(GifFileType));
+
+    Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
+    if (Private == NULL) {
+        _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+        close(FileHandle);
+        free((char *)GifFile);
+        return NULL;
+    }
+#if defined(__MSDOS__) || defined(WINDOWS32) || defined(_OPEN_BINARY)
+    setmode(FileHandle, O_BINARY);    /* Make sure it is in binary mode. */
+#endif /* __MSDOS__ */
+
+    f = fdopen(FileHandle, "rb");    /* Make it into a stream: */
+
+#if defined(__MSDOS__) || defined(WINDOWS32)
+    setvbuf(f, NULL, _IOFBF, GIF_FILE_BUFFER_SIZE);    /* And inc. stream
+                                                          buffer. */
+#endif /* __MSDOS__ */
+
+    GifFile->Private = (VoidPtr)Private;
+    Private->FileHandle = FileHandle;
+    Private->File = f;
+    Private->FileState = FILE_STATE_READ;
+    Private->Read = 0;    /* don't use alternate input method (TVT) */
+    GifFile->UserData = 0;    /* TVT */
+
+    /* Lets see if this is a GIF file: */
+    if (READ(GifFile, Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        fclose(f);
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    /* The GIF Version number is ignored at this time. Maybe we should do
+     * something more useful with it.  */
+    Buf[GIF_STAMP_LEN] = 0;
+    if (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) {
+        _GifError = D_GIF_ERR_NOT_GIF_FILE;
+        fclose(f);
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
+        fclose(f);
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    _GifError = 0;
+
+    return GifFile;
+}
+
+#endif /* _GBA_NO_FILEIO */
+
+/******************************************************************************
+ * GifFileType constructor with user supplied input function (TVT)
+ *****************************************************************************/
+GifFileType *
+DGifOpen(void *userData,
+         InputFunc readFunc) {
+
+    unsigned char Buf[GIF_STAMP_LEN + 1];
+    GifFileType *GifFile;
+    GifFilePrivateType *Private;
+
+    GifFile = (GifFileType *)malloc(sizeof(GifFileType));
+    if (GifFile == NULL) {
+        _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+        return NULL;
+    }
+
+    memset(GifFile, '\0', sizeof(GifFileType));
+
+    Private = (GifFilePrivateType *)malloc(sizeof(GifFilePrivateType));
+    if (!Private) {
+        _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    GifFile->Private = (VoidPtr)Private;
+    Private->FileHandle = 0;
+    Private->File = 0;
+    Private->FileState = FILE_STATE_READ;
+
+    Private->Read = readFunc;    /* TVT */
+    GifFile->UserData = userData;    /* TVT */
+
+    /* Lets see if this is a GIF file: */
+    if (READ(GifFile, Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    /* The GIF Version number is ignored at this time. Maybe we should do
+     * something more useful with it. */
+    Buf[GIF_STAMP_LEN] = 0;
+    if (strncmp(GIF_STAMP, Buf, GIF_VERSION_POS) != 0) {
+        _GifError = D_GIF_ERR_NOT_GIF_FILE;
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
+        free((char *)Private);
+        free((char *)GifFile);
+        return NULL;
+    }
+
+    _GifError = 0;
+
+    return GifFile;
+}
+
+/******************************************************************************
+ * This routine should be called before any other DGif calls. Note that
+ * this routine is called automatically from DGif file open routines.
+ *****************************************************************************/
+int
+DGifGetScreenDesc(GifFileType * GifFile) {
+
+    int i, BitsPerPixel;
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    /* Put the screen descriptor into the file: */
+    if (DGifGetWord(GifFile, &GifFile->SWidth) == GIF_ERROR ||
+        DGifGetWord(GifFile, &GifFile->SHeight) == GIF_ERROR)
+        return GIF_ERROR;
+
+    if (READ(GifFile, Buf, 3) != 3) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+    GifFile->SColorResolution = (((Buf[0] & 0x70) + 1) >> 4) + 1;
+    BitsPerPixel = (Buf[0] & 0x07) + 1;
+    GifFile->SBackGroundColor = Buf[1];
+    if (Buf[0] & 0x80) {    /* Do we have global color map? */
+
+        GifFile->SColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
+        if (GifFile->SColorMap == NULL) {
+            _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+
+        /* Get the global color map: */
+        for (i = 0; i < GifFile->SColorMap->ColorCount; i++) {
+            if (READ(GifFile, Buf, 3) != 3) {
+                FreeMapObject(GifFile->SColorMap);
+                GifFile->SColorMap = NULL;
+                _GifError = D_GIF_ERR_READ_FAILED;
+                return GIF_ERROR;
+            }
+            GifFile->SColorMap->Colors[i].Red = Buf[0];
+            GifFile->SColorMap->Colors[i].Green = Buf[1];
+            GifFile->SColorMap->Colors[i].Blue = Buf[2];
+        }
+    } else {
+        GifFile->SColorMap = NULL;
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * This routine should be called before any attempt to read an image.
+ *****************************************************************************/
+int
+DGifGetRecordType(GifFileType * GifFile,
+                  GifRecordType * Type) {
+
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    if (READ(GifFile, &Buf, 1) != 1) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+
+    switch (Buf) {
+      case ',':
+          *Type = IMAGE_DESC_RECORD_TYPE;
+          break;
+      case '!':
+          *Type = EXTENSION_RECORD_TYPE;
+          break;
+      case ';':
+          *Type = TERMINATE_RECORD_TYPE;
+          break;
+      default:
+          *Type = UNDEFINED_RECORD_TYPE;
+          _GifError = D_GIF_ERR_WRONG_RECORD;
+          return GIF_ERROR;
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * This routine should be called before any attempt to read an image.
+ * Note it is assumed the Image desc. header (',') has been read.
+ *****************************************************************************/
+int
+DGifGetImageDesc(GifFileType * GifFile) {
+
+    int i, BitsPerPixel;
+    GifByteType Buf[3];
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+    SavedImage *sp;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    if (DGifGetWord(GifFile, &GifFile->Image.Left) == GIF_ERROR ||
+        DGifGetWord(GifFile, &GifFile->Image.Top) == GIF_ERROR ||
+        DGifGetWord(GifFile, &GifFile->Image.Width) == GIF_ERROR ||
+        DGifGetWord(GifFile, &GifFile->Image.Height) == GIF_ERROR)
+        return GIF_ERROR;
+    if (READ(GifFile, Buf, 1) != 1) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+    BitsPerPixel = (Buf[0] & 0x07) + 1;
+    GifFile->Image.Interlace = (Buf[0] & 0x40);
+    if (Buf[0] & 0x80) {    /* Does this image have local color map? */
+
+        /*** FIXME: Why do we check both of these in order to do this? 
+         * Why do we have both Image and SavedImages? */
+        if (GifFile->Image.ColorMap && GifFile->SavedImages == NULL)
+            FreeMapObject(GifFile->Image.ColorMap);
+
+        GifFile->Image.ColorMap = MakeMapObject(1 << BitsPerPixel, NULL);
+        if (GifFile->Image.ColorMap == NULL) {
+            _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+
+        /* Get the image local color map: */
+        for (i = 0; i < GifFile->Image.ColorMap->ColorCount; i++) {
+            if (READ(GifFile, Buf, 3) != 3) {
+                FreeMapObject(GifFile->Image.ColorMap);
+                _GifError = D_GIF_ERR_READ_FAILED;
+                GifFile->Image.ColorMap = NULL;
+                return GIF_ERROR;
+            }
+            GifFile->Image.ColorMap->Colors[i].Red = Buf[0];
+            GifFile->Image.ColorMap->Colors[i].Green = Buf[1];
+            GifFile->Image.ColorMap->Colors[i].Blue = Buf[2];
+        }
+    } else if (GifFile->Image.ColorMap) {
+        FreeMapObject(GifFile->Image.ColorMap);
+        GifFile->Image.ColorMap = NULL;
+    }
+
+    if (GifFile->SavedImages) {
+        if ((GifFile->SavedImages = (SavedImage *)realloc(GifFile->SavedImages,
+                                      sizeof(SavedImage) *
+                                      (GifFile->ImageCount + 1))) == NULL) {
+            _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+    } else {
+        if ((GifFile->SavedImages =
+             (SavedImage *) malloc(sizeof(SavedImage))) == NULL) {
+            _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+    }
+
+    sp = &GifFile->SavedImages[GifFile->ImageCount];
+    memcpy(&sp->ImageDesc, &GifFile->Image, sizeof(GifImageDesc));
+    if (GifFile->Image.ColorMap != NULL) {
+        sp->ImageDesc.ColorMap = MakeMapObject(
+                                 GifFile->Image.ColorMap->ColorCount,
+                                 GifFile->Image.ColorMap->Colors);
+        if (sp->ImageDesc.ColorMap == NULL) {
+            _GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
+            return GIF_ERROR;
+        }
+    }
+    sp->RasterBits = (unsigned char *)NULL;
+    sp->ExtensionBlockCount = 0;
+    sp->ExtensionBlocks = (ExtensionBlock *) NULL;
+
+    GifFile->ImageCount++;
+
+    Private->PixelCount = (long)GifFile->Image.Width *
+       (long)GifFile->Image.Height;
+
+    DGifSetupDecompress(GifFile);  /* Reset decompress algorithm parameters. */
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * Get one full scanned line (Line) of length LineLen from GIF file.
+ *****************************************************************************/
+int
+DGifGetLine(GifFileType * GifFile,
+            GifPixelType * Line,
+            int LineLen) {
+
+    GifByteType *Dummy;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    if (!LineLen)
+        LineLen = GifFile->Image.Width;
+
+#if defined(__MSDOS__) || defined(WINDOWS32) || defined(__GNUC__)
+    if ((Private->PixelCount -= LineLen) > 0xffff0000UL) {
+#else
+    if ((Private->PixelCount -= LineLen) > 0xffff0000) {
+#endif /* __MSDOS__ */
+        _GifError = D_GIF_ERR_DATA_TOO_BIG;
+        return GIF_ERROR;
+    }
+
+    if (DGifDecompressLine(GifFile, Line, LineLen) == GIF_OK) {
+        if (Private->PixelCount == 0) {
+            /* We probably would not be called any more, so lets clean
+             * everything before we return: need to flush out all rest of
+             * image until empty block (size 0) detected. We use GetCodeNext. */
+            do
+                if (DGifGetCodeNext(GifFile, &Dummy) == GIF_ERROR)
+                    return GIF_ERROR;
+            while (Dummy != NULL) ;
+        }
+        return GIF_OK;
+    } else
+        return GIF_ERROR;
+}
+
+/******************************************************************************
+ * Put one pixel (Pixel) into GIF file.
+ *****************************************************************************/
+int
+DGifGetPixel(GifFileType * GifFile,
+             GifPixelType Pixel) {
+    
+    GifByteType *Dummy;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+#if defined(__MSDOS__) || defined(WINDOWS32) || defined(__GNUC__)
+    if (--Private->PixelCount > 0xffff0000UL)
+#else
+    if (--Private->PixelCount > 0xffff0000)
+#endif /* __MSDOS__ */
+    {
+        _GifError = D_GIF_ERR_DATA_TOO_BIG;
+        return GIF_ERROR;
+    }
+
+    if (DGifDecompressLine(GifFile, &Pixel, 1) == GIF_OK) {
+        if (Private->PixelCount == 0) {
+            /* We probably would not be called any more, so lets clean
+             * everything before we return: need to flush out all rest of
+             * image until empty block (size 0) detected. We use GetCodeNext. */
+            do
+                if (DGifGetCodeNext(GifFile, &Dummy) == GIF_ERROR)
+                    return GIF_ERROR;
+            while (Dummy != NULL) ;
+        }
+        return GIF_OK;
+    } else
+        return GIF_ERROR;
+}
+
+/******************************************************************************
+ * Get an extension block (see GIF manual) from gif file. This routine only
+ * returns the first data block, and DGifGetExtensionNext should be called
+ * after this one until NULL extension is returned.
+ * The Extension should NOT be freed by the user (not dynamically allocated).
+ * Note it is assumed the Extension desc. header ('!') has been read.
+ *****************************************************************************/
+int
+DGifGetExtension(GifFileType * GifFile,
+                 int *ExtCode,
+                 GifByteType ** Extension) {
+
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    if (READ(GifFile, &Buf, 1) != 1) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+    *ExtCode = Buf;
+
+    return DGifGetExtensionNext(GifFile, Extension);
+}
+
+/******************************************************************************
+ * Get a following extension block (see GIF manual) from gif file. This
+ * routine should be called until NULL Extension is returned.
+ * The Extension should NOT be freed by the user (not dynamically allocated).
+ *****************************************************************************/
+int
+DGifGetExtensionNext(GifFileType * GifFile,
+                     GifByteType ** Extension) {
+    
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (READ(GifFile, &Buf, 1) != 1) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+    if (Buf > 0) {
+        *Extension = Private->Buf;    /* Use private unused buffer. */
+        (*Extension)[0] = Buf;  /* Pascal strings notation (pos. 0 is len.). */
+        if (READ(GifFile, &((*Extension)[1]), Buf) != Buf) {
+            _GifError = D_GIF_ERR_READ_FAILED;
+            return GIF_ERROR;
+        }
+    } else
+        *Extension = NULL;
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * This routine should be called last, to close the GIF file.
+ *****************************************************************************/
+int
+DGifCloseFile(GifFileType * GifFile) {
+    
+    GifFilePrivateType *Private;
+    FILE *File;
+
+    if (GifFile == NULL)
+        return GIF_ERROR;
+
+    Private = (GifFilePrivateType *) GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    File = Private->File;
+
+    if (GifFile->Image.ColorMap) {
+        FreeMapObject(GifFile->Image.ColorMap);
+        GifFile->Image.ColorMap = NULL;
+    }
+
+    if (GifFile->SColorMap) {
+        FreeMapObject(GifFile->SColorMap);
+        GifFile->SColorMap = NULL;
+    }
+
+    if (Private) {
+        free((char *)Private);
+        Private = NULL;
+    }
+
+    if (GifFile->SavedImages) {
+        FreeSavedImages(GifFile);
+        GifFile->SavedImages = NULL;
+    }
+
+    free(GifFile);
+
+    if (File && (fclose(File) != 0)) {
+        _GifError = D_GIF_ERR_CLOSE_FAILED;
+        return GIF_ERROR;
+    }
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * Get 2 bytes (word) from the given file:
+ *****************************************************************************/
+static int
+DGifGetWord(GifFileType * GifFile,
+            GifWord *Word) {
+
+    unsigned char c[2];
+
+    if (READ(GifFile, c, 2) != 2) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+
+    *Word = (((unsigned int)c[1]) << 8) + c[0];
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * Get the image code in compressed form.  This routine can be called if the
+ * information needed to be piped out as is. Obviously this is much faster
+ * than decoding and encoding again. This routine should be followed by calls
+ * to DGifGetCodeNext, until NULL block is returned.
+ * The block should NOT be freed by the user (not dynamically allocated).
+ *****************************************************************************/
+int
+DGifGetCode(GifFileType * GifFile,
+            int *CodeSize,
+            GifByteType ** CodeBlock) {
+
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    *CodeSize = Private->BitsPerPixel;
+
+    return DGifGetCodeNext(GifFile, CodeBlock);
+}
+
+/******************************************************************************
+ * Continue to get the image code in compressed form. This routine should be
+ * called until NULL block is returned.
+ * The block should NOT be freed by the user (not dynamically allocated).
+ *****************************************************************************/
+int
+DGifGetCodeNext(GifFileType * GifFile,
+                GifByteType ** CodeBlock) {
+
+    GifByteType Buf;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (READ(GifFile, &Buf, 1) != 1) {
+        _GifError = D_GIF_ERR_READ_FAILED;
+        return GIF_ERROR;
+    }
+
+    if (Buf > 0) {
+        *CodeBlock = Private->Buf;    /* Use private unused buffer. */
+        (*CodeBlock)[0] = Buf;  /* Pascal strings notation (pos. 0 is len.). */
+        if (READ(GifFile, &((*CodeBlock)[1]), Buf) != Buf) {
+            _GifError = D_GIF_ERR_READ_FAILED;
+            return GIF_ERROR;
+        }
+    } else {
+        *CodeBlock = NULL;
+        Private->Buf[0] = 0;    /* Make sure the buffer is empty! */
+        Private->PixelCount = 0;    /* And local info. indicate image read. */
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * Setup the LZ decompression for this image:
+ *****************************************************************************/
+static int
+DGifSetupDecompress(GifFileType * GifFile) {
+
+    int i, BitsPerPixel;
+    GifByteType CodeSize;
+    GifPrefixType *Prefix;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    READ(GifFile, &CodeSize, 1);    /* Read Code size from file. */
+    BitsPerPixel = CodeSize;
+
+    Private->Buf[0] = 0;    /* Input Buffer empty. */
+    Private->BitsPerPixel = BitsPerPixel;
+    Private->ClearCode = (1 << BitsPerPixel);
+    Private->EOFCode = Private->ClearCode + 1;
+    Private->RunningCode = Private->EOFCode + 1;
+    Private->RunningBits = BitsPerPixel + 1;    /* Number of bits per code. */
+    Private->MaxCode1 = 1 << Private->RunningBits;    /* Max. code + 1. */
+    Private->StackPtr = 0;    /* No pixels on the pixel stack. */
+    Private->LastCode = NO_SUCH_CODE;
+    Private->CrntShiftState = 0;    /* No information in CrntShiftDWord. */
+    Private->CrntShiftDWord = 0;
+
+    Prefix = Private->Prefix;
+    for (i = 0; i <= LZ_MAX_CODE; i++)
+        Prefix[i] = NO_SUCH_CODE;
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * The LZ decompression routine:
+ * This version decompress the given gif file into Line of length LineLen.
+ * This routine can be called few times (one per scan line, for example), in
+ * order the complete the whole image.
+ *****************************************************************************/
+static int
+DGifDecompressLine(GifFileType * GifFile,
+                   GifPixelType * Line,
+                   int LineLen) {
+
+    int i = 0;
+    int j, CrntCode, EOFCode, ClearCode, CrntPrefix, LastCode, StackPtr;
+    GifByteType *Stack, *Suffix;
+    GifPrefixType *Prefix;
+    GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
+
+    StackPtr = Private->StackPtr;
+    Prefix = Private->Prefix;
+    Suffix = Private->Suffix;
+    Stack = Private->Stack;
+    EOFCode = Private->EOFCode;
+    ClearCode = Private->ClearCode;
+    LastCode = Private->LastCode;
+
+    if (StackPtr > LZ_MAX_CODE) {
+        return GIF_ERROR;
+    }
+
+    if (StackPtr != 0) {
+        /* Let pop the stack off before continueing to read the gif file: */
+        while (StackPtr != 0 && i < LineLen)
+            Line[i++] = Stack[--StackPtr];
+    }
+
+    while (i < LineLen) {    /* Decode LineLen items. */
+        if (DGifDecompressInput(GifFile, &CrntCode) == GIF_ERROR)
+            return GIF_ERROR;
+
+        if (CrntCode == EOFCode) {
+            /* Note however that usually we will not be here as we will stop
+             * decoding as soon as we got all the pixel, or EOF code will
+             * not be read at all, and DGifGetLine/Pixel clean everything.  */
+            if (i != LineLen - 1 || Private->PixelCount != 0) {
+                _GifError = D_GIF_ERR_EOF_TOO_SOON;
+                return GIF_ERROR;
+            }
+            i++;
+        } else if (CrntCode == ClearCode) {
+            /* We need to start over again: */
+            for (j = 0; j <= LZ_MAX_CODE; j++)
+                Prefix[j] = NO_SUCH_CODE;
+            Private->RunningCode = Private->EOFCode + 1;
+            Private->RunningBits = Private->BitsPerPixel + 1;
+            Private->MaxCode1 = 1 << Private->RunningBits;
+            LastCode = Private->LastCode = NO_SUCH_CODE;
+        } else {
+            /* Its regular code - if in pixel range simply add it to output
+             * stream, otherwise trace to codes linked list until the prefix
+             * is in pixel range: */
+            if (CrntCode < ClearCode) {
+                /* This is simple - its pixel scalar, so add it to output: */
+                Line[i++] = CrntCode;
+            } else {
+                /* Its a code to needed to be traced: trace the linked list
+                 * until the prefix is a pixel, while pushing the suffix
+                 * pixels on our stack. If we done, pop the stack in reverse
+                 * (thats what stack is good for!) order to output.  */
+                if (Prefix[CrntCode] == NO_SUCH_CODE) {
+                    /* Only allowed if CrntCode is exactly the running code:
+                     * In that case CrntCode = XXXCode, CrntCode or the
+                     * prefix code is last code and the suffix char is
+                     * exactly the prefix of last code! */
+                    if (CrntCode == Private->RunningCode - 2) {
+                        CrntPrefix = LastCode;
+                        Suffix[Private->RunningCode - 2] =
+                           Stack[StackPtr++] = DGifGetPrefixChar(Prefix,
+                                                                 LastCode,
+                                                                 ClearCode);
+                    } else {
+                        _GifError = D_GIF_ERR_IMAGE_DEFECT;
+                        return GIF_ERROR;
+                    }
+                } else
+                    CrntPrefix = CrntCode;
+
+                /* Now (if image is O.K.) we should not get an NO_SUCH_CODE
+                 * During the trace. As we might loop forever, in case of
+                 * defective image, we count the number of loops we trace
+                 * and stop if we got LZ_MAX_CODE. obviously we can not
+                 * loop more than that.  */
+                j = 0;
+                while (j++ <= LZ_MAX_CODE &&
+                       CrntPrefix > ClearCode && CrntPrefix <= LZ_MAX_CODE) {
+                    Stack[StackPtr++] = Suffix[CrntPrefix];
+                    CrntPrefix = Prefix[CrntPrefix];
+                }
+                if (j >= LZ_MAX_CODE || CrntPrefix > LZ_MAX_CODE) {
+                    _GifError = D_GIF_ERR_IMAGE_DEFECT;
+                    return GIF_ERROR;
+                }
+                /* Push the last character on stack: */
+                Stack[StackPtr++] = CrntPrefix;
+
+                /* Now lets pop all the stack into output: */
+                while (StackPtr != 0 && i < LineLen)
+                    Line[i++] = Stack[--StackPtr];
+            }
+            if (LastCode != NO_SUCH_CODE) {
+                Prefix[Private->RunningCode - 2] = LastCode;
+
+                if (CrntCode == Private->RunningCode - 2) {
+                    /* Only allowed if CrntCode is exactly the running code:
+                     * In that case CrntCode = XXXCode, CrntCode or the
+                     * prefix code is last code and the suffix char is
+                     * exactly the prefix of last code! */
+                    Suffix[Private->RunningCode - 2] =
+                       DGifGetPrefixChar(Prefix, LastCode, ClearCode);
+                } else {
+                    Suffix[Private->RunningCode - 2] =
+                       DGifGetPrefixChar(Prefix, CrntCode, ClearCode);
+                }
+            }
+            LastCode = CrntCode;
+        }
+    }
+
+    Private->LastCode = LastCode;
+    Private->StackPtr = StackPtr;
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * Routine to trace the Prefixes linked list until we get a prefix which is
+ * not code, but a pixel value (less than ClearCode). Returns that pixel value.
+ * If image is defective, we might loop here forever, so we limit the loops to
+ * the maximum possible if image O.k. - LZ_MAX_CODE times.
+ *****************************************************************************/
+static int
+DGifGetPrefixChar(GifPrefixType *Prefix,
+                  int Code,
+                  int ClearCode) {
+
+    int i = 0;
+
+    while (Code > ClearCode && i++ <= LZ_MAX_CODE) {
+        if (Code > LZ_MAX_CODE) {
+            return NO_SUCH_CODE;
+        }
+        Code = Prefix[Code];
+    }
+    return Code;
+}
+
+/******************************************************************************
+ * Interface for accessing the LZ codes directly. Set Code to the real code
+ * (12bits), or to -1 if EOF code is returned.
+ *****************************************************************************/
+int
+DGifGetLZCodes(GifFileType * GifFile,
+               int *Code) {
+    
+    GifByteType *CodeBlock;
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    if (!IS_READABLE(Private)) {
+        /* This file was NOT open for reading: */
+        _GifError = D_GIF_ERR_NOT_READABLE;
+        return GIF_ERROR;
+    }
+
+    if (DGifDecompressInput(GifFile, Code) == GIF_ERROR)
+        return GIF_ERROR;
+
+    if (*Code == Private->EOFCode) {
+        /* Skip rest of codes (hopefully only NULL terminating block): */
+        do {
+            if (DGifGetCodeNext(GifFile, &CodeBlock) == GIF_ERROR)
+                return GIF_ERROR;
+        } while (CodeBlock != NULL) ;
+
+        *Code = -1;
+    } else if (*Code == Private->ClearCode) {
+        /* We need to start over again: */
+        Private->RunningCode = Private->EOFCode + 1;
+        Private->RunningBits = Private->BitsPerPixel + 1;
+        Private->MaxCode1 = 1 << Private->RunningBits;
+    }
+
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * The LZ decompression input routine:
+ * This routine is responsable for the decompression of the bit stream from
+ * 8 bits (bytes) packets, into the real codes.
+ * Returns GIF_OK if read succesfully.
+ *****************************************************************************/
+static int
+DGifDecompressInput(GifFileType * GifFile,
+                    int *Code) {
+    
+    GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
+
+    GifByteType NextByte;
+    static unsigned short CodeMasks[] = {
+        0x0000, 0x0001, 0x0003, 0x0007,
+        0x000f, 0x001f, 0x003f, 0x007f,
+        0x00ff, 0x01ff, 0x03ff, 0x07ff,
+        0x0fff
+    };
+    /* The image can't contain more than LZ_BITS per code. */
+    if (Private->RunningBits > LZ_BITS) {
+        _GifError = D_GIF_ERR_IMAGE_DEFECT;
+        return GIF_ERROR;
+    }
+    
+    while (Private->CrntShiftState < Private->RunningBits) {
+        /* Needs to get more bytes from input stream for next code: */
+        if (DGifBufferedInput(GifFile, Private->Buf, &NextByte) == GIF_ERROR) {
+            return GIF_ERROR;
+        }
+        Private->CrntShiftDWord |=
+           ((unsigned long)NextByte) << Private->CrntShiftState;
+        Private->CrntShiftState += 8;
+    }
+    *Code = Private->CrntShiftDWord & CodeMasks[Private->RunningBits];
+
+    Private->CrntShiftDWord >>= Private->RunningBits;
+    Private->CrntShiftState -= Private->RunningBits;
+
+    /* If code cannot fit into RunningBits bits, must raise its size. Note
+     * however that codes above 4095 are used for special signaling.
+     * If we're using LZ_BITS bits already and we're at the max code, just
+     * keep using the table as it is, don't increment Private->RunningCode.
+     */
+    if (Private->RunningCode < LZ_MAX_CODE + 2 &&
+            ++Private->RunningCode > Private->MaxCode1 &&
+            Private->RunningBits < LZ_BITS) {
+        Private->MaxCode1 <<= 1;
+        Private->RunningBits++;
+    }
+    return GIF_OK;
+}
+
+/******************************************************************************
+ * This routines read one gif data block at a time and buffers it internally
+ * so that the decompression routine could access it.
+ * The routine returns the next byte from its internal buffer (or read next
+ * block in if buffer empty) and returns GIF_OK if succesful.
+ *****************************************************************************/
+static int
+DGifBufferedInput(GifFileType * GifFile,
+                  GifByteType * Buf,
+                  GifByteType * NextByte) {
+
+    if (Buf[0] == 0) {
+        /* Needs to read the next buffer - this one is empty: */
+        if (READ(GifFile, Buf, 1) != 1) {
+            _GifError = D_GIF_ERR_READ_FAILED;
+            return GIF_ERROR;
+        }
+        /* There shouldn't be any empty data blocks here as the LZW spec
+         * says the LZW termination code should come first.  Therefore we
+         * shouldn't be inside this routine at that point.
+         */
+        if (Buf[0] == 0) {
+            _GifError = D_GIF_ERR_IMAGE_DEFECT;
+            return GIF_ERROR;
+        }
+        if (READ(GifFile, &Buf[1], Buf[0]) != Buf[0]) {
+            _GifError = D_GIF_ERR_READ_FAILED;
+            return GIF_ERROR;
+        }
+        *NextByte = Buf[1];
+        Buf[1] = 2;    /* We use now the second place as last char read! */
+        Buf[0]--;
+    } else {
+        *NextByte = Buf[Buf[1]++];
+        Buf[0]--;
+    }
+
+    return GIF_OK;
+}
+#ifndef _GBA_NO_FILEIO
+
+/******************************************************************************
+ * This routine reads an entire GIF into core, hanging all its state info off
+ * the GifFileType pointer.  Call DGifOpenFileName() or DGifOpenFileHandle()
+ * first to initialize I/O.  Its inverse is EGifSpew().
+ ******************************************************************************/
+int
+DGifSlurp(GifFileType * GifFile) {
+
+    int ImageSize;
+    GifRecordType RecordType;
+    SavedImage *sp;
+    GifByteType *ExtData;
+    SavedImage temp_save;
+
+    temp_save.ExtensionBlocks = NULL;
+    temp_save.ExtensionBlockCount = 0;
+
+    do {
+        if (DGifGetRecordType(GifFile, &RecordType) == GIF_ERROR)
+            return (GIF_ERROR);
+
+        switch (RecordType) {
+          case IMAGE_DESC_RECORD_TYPE:
+              if (DGifGetImageDesc(GifFile) == GIF_ERROR)
+                  return (GIF_ERROR);
+
+              sp = &GifFile->SavedImages[GifFile->ImageCount - 1];
+              ImageSize = sp->ImageDesc.Width * sp->ImageDesc.Height;
+
+              sp->RasterBits = (unsigned char *)malloc(ImageSize *
+                                                       sizeof(GifPixelType));
+              if (sp->RasterBits == NULL) {
+                  return GIF_ERROR;
+              }
+              if (DGifGetLine(GifFile, sp->RasterBits, ImageSize) ==
+                  GIF_ERROR)
+                  return (GIF_ERROR);
+              if (temp_save.ExtensionBlocks) {
+                  sp->ExtensionBlocks = temp_save.ExtensionBlocks;
+                  sp->ExtensionBlockCount = temp_save.ExtensionBlockCount;
+
+                  temp_save.ExtensionBlocks = NULL;
+                  temp_save.ExtensionBlockCount = 0;
+
+                  /* FIXME: The following is wrong.  It is left in only for
+                   * backwards compatibility.  Someday it should go away. Use 
+                   * the sp->ExtensionBlocks->Function variable instead. */
+                  sp->Function = sp->ExtensionBlocks[0].Function;
+              }
+              break;
+
+          case EXTENSION_RECORD_TYPE:
+              if (DGifGetExtension(GifFile, &temp_save.Function, &ExtData) ==
+                  GIF_ERROR)
+                  return (GIF_ERROR);
+              while (ExtData != NULL) {
+
+                  /* Create an extension block with our data */
+                  if (AddExtensionBlock(&temp_save, ExtData[0], &ExtData[1])
+                      == GIF_ERROR)
+                      return (GIF_ERROR);
+
+                  if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)
+                      return (GIF_ERROR);
+                  temp_save.Function = 0;
+              }
+              break;
+
+          case TERMINATE_RECORD_TYPE:
+              break;
+
+          default:    /* Should be trapped by DGifGetRecordType */
+              break;
+        }
+    } while (RecordType != TERMINATE_RECORD_TYPE);
+
+    /* Just in case the Gif has an extension block without an associated
+     * image... (Should we save this into a savefile structure with no image
+     * instead? Have to check if the present writing code can handle that as
+     * well.... */
+    if (temp_save.ExtensionBlocks)
+        FreeExtension(&temp_save);
+
+    return (GIF_OK);
+}
+#endif /* _GBA_NO_FILEIO */