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tge/lib/lungif/egif_lib.c
Eagle517 7cad314c94 Initial commit
2025-02-17 23:17:30 -06:00

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/******************************************************************************
* "Gif-Lib" - Yet another gif library. *
* *
* Written by: Gershon Elber Ver 1.1, Aug. 1990 *
*******************************************************************************
* The kernel of the GIF Encoding process can be found here. *
*******************************************************************************
* History: *
* 14 Jun 89 - Version 1.0 by Gershon Elber. *
* 3 Sep 90 - Version 1.1 by Gershon Elber (Support for Gif89, Unique names). *
* 26 Jun 96 - Version 3.0 by Eric S. Raymond (Full GIF89 support)
******************************************************************************/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#if defined(__MWERKS__)
#pragma warn_unusedarg off
#pragma warn_unusedvar off
#endif
#ifdef __MSDOS__
#include <io.h>
#include <alloc.h>
#include <sys\stat.h>
#else
//#include <sys/types.h>
//#include <sys/stat.h>
#ifdef R6000
/* FIXME: What is sys/mode.h? Can we substitute a check for this file rather
* than a check based on machine type?
*/
#include <sys/mode.h>
#endif
#endif /* __MSDOS__ */
//#include <fcntl.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "gif_lib.h"
#include "gif_lib_private.h"
/* #define DEBUG_NO_PREFIX Dump only compressed data. */
/* Masks given codes to BitsPerPixel, to make sure all codes are in range: */
static GifPixelType CodeMask[] = {
0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff
};
static char GifVersionPrefix[GIF_STAMP_LEN + 1] = GIF87_STAMP;
#define WRITE(_gif,_buf,_len) \
((GifFilePrivateType*)_gif->Private)->Write(_gif,(GifByteType*)_buf,_len)
// (((GifFilePrivateType*)_gif->Private)->Write ? \
// ((GifFilePrivateType*)_gif->Private)->Write(_gif,_buf,_len) : \
// fwrite(_buf, 1, _len, ((GifFilePrivateType*)_gif->Private)->File))
static int EGifPutWord(int Word, GifFileType *GifFile);
static int EGifSetupCompress(GifFileType *GifFile);
static int EGifCompressLine(GifFileType *GifFile, GifPixelType *Line,
int LineLen);
static int EGifCompressOutput(GifFileType *GifFile, int Code);
static int EGifBufferedOutput(GifFileType *GifFile, GifByteType *Buf, int c);
/******************************************************************************
* Open a new gif file for write, given by its name. If TestExistance then *
* if the file exists this routines fails (returns NULL). *
* Returns GifFileType pointer dynamically allocated which serves as the gif *
* info record. _GifError is cleared if succesfull. *
******************************************************************************/
//GifFileType *EGifOpenFileName(const char *FileName, int TestExistance)
//{
// int FileHandle;
// GifFileType *GifFile;
//
// if (TestExistance)
// FileHandle = open(FileName,
// O_WRONLY | O_CREAT | O_EXCL
//#ifdef __MSDOS__
// | O_BINARY
//#endif /* __MSDOS__ */
// ,
// S_IREAD | S_IWRITE);
// else
// FileHandle = open(FileName,
// O_WRONLY | O_CREAT | O_TRUNC
//#ifdef __MSDOS__
// | O_BINARY
//#endif /* __MSDOS__ */
// ,
// S_IREAD | S_IWRITE);
//
// if (FileHandle == -1) {
// _GifError = E_GIF_ERR_OPEN_FAILED;
// return NULL;
// }
// GifFile = EGifOpenFileHandle(FileHandle);
// if (GifFile == (GifFileType*)NULL)
// close(FileHandle);
// return GifFile;
//}
/******************************************************************************
* Update a new gif file, given its file handle, which must be opened for *
* write in binary mode. *
* Returns GifFileType pointer dynamically allocated which serves as the gif *
* info record. _GifError is cleared if succesfull. *
******************************************************************************/
//GifFileType *EGifOpenFileHandle(int FileHandle)
//{
// GifFileType *GifFile;
// GifFilePrivateType *Private;
// FILE *f;
//
// if ((GifFile = (GifFileType *) malloc(sizeof(GifFileType))) == NULL) {
// _GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
// return NULL;
// }
//
// memset(GifFile, '\0', sizeof(GifFileType));
//
// if ((Private = (GifFilePrivateType *)
// malloc(sizeof(GifFilePrivateType))) == NULL) {
// free(GifFile);
// _GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
// return NULL;
// }
//
//#ifdef __MSDOS__
// setmode(FileHandle, O_BINARY); /* Make sure it is in binary mode. */
//#endif /* __MSDOS__ */
//
// f = fdopen(FileHandle, "wb"); /* Make it into a stream: */
//
//#ifdef __MSDOS__
// 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_WRITE;
//
// Private->Write = (OutputFunc)0; /* No user write routine (MRB) */
// GifFile->UserData = (VoidPtr)0; /* No user write handle (MRB) */
//
// _GifError = 0;
//
// return GifFile;
//}
/******************************************************************************
* Output constructor that takes user supplied output function. *
* Basically just a copy of EGifOpenFileHandle. (MRB) *
******************************************************************************/
GifFileType* EGifOpen(void* userData, OutputFunc writeFunc)
{
GifFileType* GifFile;
GifFilePrivateType* Private;
if ((GifFile = (GifFileType *) malloc(sizeof(GifFileType))) == NULL) {
_GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return NULL;
}
memset(GifFile, '\0', sizeof(GifFileType));
if ((Private = (GifFilePrivateType *)
malloc(sizeof(GifFilePrivateType))) == NULL) {
free(GifFile);
_GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return NULL;
}
GifFile->Private = (VoidPtr) Private;
Private->FileHandle = 0;
Private->File = 0;
Private->FileState = FILE_STATE_WRITE;
Private->Write = writeFunc; /* User write routine (MRB) */
GifFile->UserData = userData; /* User write handle (MRB) */
_GifError = 0;
return GifFile;
}
/******************************************************************************
* Routine to set current GIF version. All files open for write will be *
* using this version until next call to this routine. Version consists of *
* 3 characters as "87a" or "89a". No test is made to validate the version. *
******************************************************************************/
void EGifSetGifVersion(const char *Version)
{
strncpy(GifVersionPrefix + GIF_VERSION_POS, Version, 3);
}
/******************************************************************************
* This routine should be called before any other EGif calls, immediately *
* follows the GIF file openning. *
******************************************************************************/
int EGifPutScreenDesc(GifFileType *GifFile,
int Width, int Height, int ColorRes, int BackGround,
const ColorMapObject *ColorMap)
{
int i;
GifByteType Buf[3];
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (Private->FileState & FILE_STATE_SCREEN) {
/* If already has screen descriptor - something is wrong! */
_GifError = E_GIF_ERR_HAS_SCRN_DSCR;
return GIF_ERROR;
}
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
/* First write the version prefix into the file. */
#ifndef DEBUG_NO_PREFIX
if (WRITE(GifFile, GifVersionPrefix, strlen(GifVersionPrefix)) !=
strlen(GifVersionPrefix)) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
#endif /* DEBUG_NO_PREFIX */
GifFile->SWidth = Width;
GifFile->SHeight = Height;
GifFile->SColorResolution = ColorRes;
GifFile->SBackGroundColor = BackGround;
if(ColorMap)
GifFile->SColorMap=MakeMapObject(ColorMap->ColorCount,ColorMap->Colors);
else
GifFile->SColorMap=NULL;
/* Put the screen descriptor into the file: */
EGifPutWord(Width, GifFile);
EGifPutWord(Height, GifFile);
Buf[0] = (ColorMap ? 0x80 : 0x00) |
((ColorRes - 1) << 4) |
(ColorMap->BitsPerPixel - 1);
Buf[1] = BackGround;
Buf[2] = 0;
#ifndef DEBUG_NO_PREFIX
WRITE(GifFile, Buf, 3);
#endif /* DEBUG_NO_PREFIX */
/* If we have Global color map - dump it also: */
#ifndef DEBUG_NO_PREFIX
if (ColorMap != NULL)
for (i = 0; i < ColorMap->ColorCount; i++) {
/* Put the ColorMap out also: */
Buf[0] = ColorMap->Colors[i].Red;
Buf[1] = ColorMap->Colors[i].Green;
Buf[2] = ColorMap->Colors[i].Blue;
if (WRITE(GifFile, Buf, 3) != 3) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
#endif /* DEBUG_NO_PREFIX */
/* Mark this file as has screen descriptor, and no pixel written yet: */
Private->FileState |= FILE_STATE_SCREEN;
return GIF_OK;
}
/******************************************************************************
* This routine should be called before any attemp to dump an image - any *
* call to any of the pixel dump routines. *
******************************************************************************/
int EGifPutImageDesc(GifFileType *GifFile,
int Left, int Top, int Width, int Height, int Interlace,
const ColorMapObject *ColorMap)
{
int i;
GifByteType Buf[3];
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (Private->FileState & FILE_STATE_IMAGE &&
#if defined(__MSDOS__) || defined(__GNUC__)
Private->PixelCount > 0xffff0000UL) {
#else
Private->PixelCount > 0xffff0000) {
#endif /* __MSDOS__ */
/* If already has active image descriptor - something is wrong! */
_GifError = E_GIF_ERR_HAS_IMAG_DSCR;
return GIF_ERROR;
}
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
GifFile->Image.Left = Left;
GifFile->Image.Top = Top;
GifFile->Image.Width = Width;
GifFile->Image.Height = Height;
GifFile->Image.Interlace = Interlace;
if(ColorMap)
GifFile->Image.ColorMap =MakeMapObject(ColorMap->ColorCount,ColorMap->Colors);
else
GifFile->Image.ColorMap = NULL;
/* Put the image descriptor into the file: */
Buf[0] = ','; /* Image seperator character. */
#ifndef DEBUG_NO_PREFIX
WRITE(GifFile, Buf, 1);
#endif /* DEBUG_NO_PREFIX */
EGifPutWord(Left, GifFile);
EGifPutWord(Top, GifFile);
EGifPutWord(Width, GifFile);
EGifPutWord(Height, GifFile);
Buf[0] = (ColorMap ? 0x80 : 0x00) |
(Interlace ? 0x40 : 0x00) |
(ColorMap ? ColorMap->BitsPerPixel - 1 : 0);
#ifndef DEBUG_NO_PREFIX
WRITE(GifFile, Buf, 1);
#endif /* DEBUG_NO_PREFIX */
/* If we have Global color map - dump it also: */
#ifndef DEBUG_NO_PREFIX
if (ColorMap != NULL)
for (i = 0; i < ColorMap->ColorCount; i++) {
/* Put the ColorMap out also: */
Buf[0] = ColorMap->Colors[i].Red;
Buf[1] = ColorMap->Colors[i].Green;
Buf[2] = ColorMap->Colors[i].Blue;
if (WRITE(GifFile, Buf, 3) != 3) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
#endif /* DEBUG_NO_PREFIX */
if (GifFile->SColorMap == NULL && GifFile->Image.ColorMap == NULL)
{
_GifError = E_GIF_ERR_NO_COLOR_MAP;
return GIF_ERROR;
}
/* Mark this file as has screen descriptor: */
Private->FileState |= FILE_STATE_IMAGE;
Private->PixelCount = (long) Width * (long) Height;
EGifSetupCompress(GifFile); /* Reset compress algorithm parameters. */
return GIF_OK;
}
/******************************************************************************
* Put one full scanned line (Line) of length LineLen into GIF file. *
******************************************************************************/
int EGifPutLine(GifFileType *GifFile, GifPixelType *Line, int LineLen)
{
int i;
GifPixelType Mask;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (!LineLen)
LineLen = GifFile->Image.Width;
if (Private->PixelCount < (unsigned)LineLen) {
_GifError = E_GIF_ERR_DATA_TOO_BIG;
return GIF_ERROR;
}
Private->PixelCount -= LineLen;
/* Make sure the codes are not out of bit range, as we might generate */
/* wrong code (because of overflow when we combine them) in this case: */
Mask = CodeMask[Private->BitsPerPixel];
for (i = 0; i < LineLen; i++) Line[i] &= Mask;
return EGifCompressLine(GifFile, Line, LineLen);
}
/******************************************************************************
* Put one pixel (Pixel) into GIF file. *
******************************************************************************/
int EGifPutPixel(GifFileType *GifFile, GifPixelType Pixel)
{
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (Private->PixelCount == 0)
{
_GifError = E_GIF_ERR_DATA_TOO_BIG;
return GIF_ERROR;
}
--Private->PixelCount;
/* Make sure the code is not out of bit range, as we might generate */
/* wrong code (because of overflow when we combine them) in this case: */
Pixel &= CodeMask[Private->BitsPerPixel];
return EGifCompressLine(GifFile, &Pixel, 1);
}
/******************************************************************************
* Put a comment into GIF file using the GIF89 comment extension block. *
******************************************************************************/
int EGifPutComment(GifFileType *GifFile, const char *Comment)
{
return EGifPutExtension(GifFile, COMMENT_EXT_FUNC_CODE, strlen(Comment),
Comment);
}
/******************************************************************************
* Put a first extension block (see GIF manual) into gif file. Here more *
* extensions can be dumped using EGifPutExtensionMid until *
* EGifPutExtensionLast is invoked. *
******************************************************************************/
int EGifPutExtensionFirst(GifFileType *GifFile, int ExtCode, int ExtLen,
const VoidPtr Extension)
{
GifByteType Buf[3];
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (ExtCode == 0)
WRITE(GifFile, &ExtLen, 1);
//fwrite(&ExtLen, 1, 1, Private->File);
else
{
Buf[0] = '!';
Buf[1] = ExtCode;
Buf[2] = ExtLen;
WRITE(GifFile, Buf, 3);
//fwrite(Buf, 1, 3, Private->File);
}
WRITE(GifFile, Extension, ExtLen);
//fwrite(Extension, 1, ExtLen, Private->File);
return GIF_OK;
}
/******************************************************************************
* Put a middle extension block (see GIF manual) into gif file. *
******************************************************************************/
int EGifPutExtensionNext(GifFileType *GifFile, int ExtCode, int ExtLen,
const VoidPtr Extension)
{
GifByteType Buf;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
Buf = ExtLen;
WRITE(GifFile, &Buf, 1);
WRITE(GifFile, Extension, ExtLen);
//fwrite(&Buf, 1, 1, Private->File);
//fwrite(Extension, 1, ExtLen, Private->File);
return GIF_OK;
}
/******************************************************************************
* Put a last extension block (see GIF manual) into gif file. *
******************************************************************************/
int EGifPutExtensionLast(GifFileType *GifFile, int ExtCode, int ExtLen,
const VoidPtr Extension)
{
GifByteType Buf;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
Buf = ExtLen;
WRITE(GifFile, &Buf, 1);
WRITE(GifFile, Extension, ExtLen);
//fwrite(&Buf, 1, 1, Private->File);
//fwrite(Extension, 1, ExtLen, Private->File);
Buf = 0;
WRITE(GifFile, &Buf, 1);
//fwrite(&Buf, 1, 1, Private->File);
return GIF_OK;
}
/******************************************************************************
* Put an extension block (see GIF manual) into gif file. *
******************************************************************************/
int EGifPutExtension(GifFileType *GifFile, int ExtCode, int ExtLen,
const VoidPtr Extension)
{
GifByteType Buf[3];
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (ExtCode == 0)
WRITE(GifFile, (GifByteType*)&ExtLen, 1);
else {
Buf[0] = '!';
Buf[1] = ExtCode;
Buf[2] = ExtLen;
WRITE(GifFile, Buf, 3);
}
WRITE(GifFile, Extension, ExtLen);
Buf[0] = 0;
WRITE(GifFile, Buf, 1);
return GIF_OK;
}
/******************************************************************************
* Put 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 EGifPutCodeNext, until NULL block is given. *
* The block should NOT be freed by the user (not dynamically allocated). *
******************************************************************************/
int EGifPutCode(GifFileType *GifFile, int CodeSize, const GifByteType *CodeBlock)
{
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
/* No need to dump code size as Compression set up does any for us: */
/*
Buf = CodeSize;
if (WRITE(GifFile, &Buf, 1) != 1) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
*/
return EGifPutCodeNext(GifFile, CodeBlock);
}
/******************************************************************************
* Continue to put the image code in compressed form. This routine should be *
* called with blocks of code as read via DGifGetCode/DGifGetCodeNext. If *
* given buffer pointer is NULL, empty block is written to mark end of code. *
******************************************************************************/
int EGifPutCodeNext(GifFileType *GifFile, const GifByteType *CodeBlock)
{
GifByteType Buf;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (CodeBlock != NULL) {
if (WRITE(GifFile, CodeBlock, CodeBlock[0] + 1)
!= (unsigned)(CodeBlock[0] + 1)) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
} else {
Buf = 0;
if (WRITE(GifFile, &Buf, 1) != 1) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
Private->PixelCount = 0; /* And local info. indicate image read. */
}
return GIF_OK;
}
/******************************************************************************
* This routine should be called last, to close GIF file. *
******************************************************************************/
int EGifCloseFile(GifFileType *GifFile)
{
GifByteType Buf;
GifFilePrivateType *Private;
int *File;
if (GifFile == NULL) return GIF_ERROR;
Private = (GifFilePrivateType *) GifFile->Private;
if (!IS_WRITEABLE(Private)) {
/* This file was NOT open for writing: */
_GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
File = Private->File;
Buf = ';';
WRITE(GifFile, &Buf, 1);
if (GifFile->Image.ColorMap)
FreeMapObject(GifFile->Image.ColorMap);
if (GifFile->SColorMap)
FreeMapObject(GifFile->SColorMap);
if (Private) {
free((char *) Private);
}
free(GifFile);
// if (File && fclose(File) != 0) {
// _GifError = E_GIF_ERR_CLOSE_FAILED;
// return GIF_ERROR;
// }
return GIF_OK;
}
/******************************************************************************
* Put 2 bytes (word) into the given file: *
******************************************************************************/
static int EGifPutWord(int Word, GifFileType *GifFile)
{
char c[2];
c[0] = Word & 0xff;
c[1] = (Word >> 8) & 0xff;
#ifndef DEBUG_NO_PREFIX
if (WRITE(GifFile, c, 2) == 2)
return GIF_OK;
else
return GIF_ERROR;
#else
return GIF_OK;
#endif /* DEBUG_NO_PREFIX */
}
/******************************************************************************
* Setup the LZ compression for this image: *
******************************************************************************/
static int EGifSetupCompress(GifFileType *GifFile)
{
int BitsPerPixel;
GifByteType Buf;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
/* Test and see what color map to use, and from it # bits per pixel: */
if (GifFile->Image.ColorMap)
BitsPerPixel = GifFile->Image.ColorMap->BitsPerPixel;
else if (GifFile->SColorMap)
BitsPerPixel = GifFile->SColorMap->BitsPerPixel;
else {
_GifError = E_GIF_ERR_NO_COLOR_MAP;
return GIF_ERROR;
}
Buf = BitsPerPixel = (BitsPerPixel < 2 ? 2 : BitsPerPixel);
WRITE(GifFile, &Buf, 1); /* Write the Code size to file. */
Private->Buf[0] = 0; /* Nothing was output yet. */
Private->BitsPerPixel = BitsPerPixel;
Private->ClearCode = (1 << BitsPerPixel);
Private->EOFCode = Private->ClearCode + 1;
Private->RunningCode = 0;
Private->RunningBits = BitsPerPixel + 1; /* Number of bits per code. */
Private->MaxCode1 = 1 << Private->RunningBits; /* Max. code + 1. */
Private->CrntCode = FIRST_CODE; /* Signal that this is first one! */
Private->CrntShiftState = 0; /* No information in CrntShiftDWord. */
Private->CrntShiftDWord = 0;
/* Send Clear to make sure the encoder is initialized. */
if (EGifCompressOutput(GifFile, Private->ClearCode) == GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
return GIF_OK;
}
/******************************************************************************
* The LZ compression routine: *
* This version compress the given buffer 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 EGifCompressLine(GifFileType *GifFile, GifPixelType *Line,
int LineLen)
{
int i = 0, CrntCode, NewCode;
unsigned long NewKey;
GifPixelType Pixel;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (Private->CrntCode == FIRST_CODE) /* Its first time! */
CrntCode = Line[i++];
else
CrntCode = Private->CrntCode; /* Get last code in compression. */
while (i < LineLen) { /* Decode LineLen items. */
Pixel = Line[i++]; /* Get next pixel from stream. */
if (EGifCompressOutput(GifFile, CrntCode)
== GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
Private->RunningCode++;
CrntCode = Pixel;
if (Private->RunningCode >= (1 << (Private->BitsPerPixel)) - 2) {
if (EGifCompressOutput(GifFile, Private->ClearCode)
== GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
Private->RunningCode=0;
}
}
/* Preserve the current state of the compression algorithm: */
Private->CrntCode = CrntCode;
if (Private->PixelCount == 0)
{
/* We are done - output last Code and flush output buffers: */
if (EGifCompressOutput(GifFile, CrntCode)
== GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
if (EGifCompressOutput(GifFile, Private->EOFCode)
== GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
if (EGifCompressOutput(GifFile, FLUSH_OUTPUT) == GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
}
return GIF_OK;
}
/******************************************************************************
* The LZ compression output routine: *
* This routine is responsible for the compression of the bit stream into *
* 8 bits (bytes) packets. *
* Returns GIF_OK if written succesfully. *
******************************************************************************/
static int EGifCompressOutput(GifFileType *GifFile, int Code)
{
GifFilePrivateType *Private = (GifFilePrivateType *)GifFile->Private;
int retval = GIF_OK;
if (Code == FLUSH_OUTPUT) {
while (Private->CrntShiftState > 0) {
/* Get Rid of what is left in DWord, and flush it. */
if (EGifBufferedOutput(GifFile, Private->Buf,
Private->CrntShiftDWord & 0xff) == GIF_ERROR)
retval = GIF_ERROR;
Private->CrntShiftDWord >>= 8;
Private->CrntShiftState -= 8;
}
Private->CrntShiftState = 0; /* For next time. */
if (EGifBufferedOutput(GifFile, Private->Buf,
FLUSH_OUTPUT) == GIF_ERROR)
retval = GIF_ERROR;
}
else {
Private->CrntShiftDWord |= ((long) Code) << Private->CrntShiftState;
Private->CrntShiftState += Private->RunningBits;
while (Private->CrntShiftState >= 8) {
/* Dump out full bytes: */
if (EGifBufferedOutput(GifFile, Private->Buf,
Private->CrntShiftDWord & 0xff) == GIF_ERROR)
retval = GIF_ERROR;
Private->CrntShiftDWord >>= 8;
Private->CrntShiftState -= 8;
}
}
return retval;
}
/******************************************************************************
* This routines buffers the given characters until 255 characters are ready *
* to be output. If Code is equal to -1 the buffer is flushed (EOF). *
* The buffer is Dumped with first byte as its size, as GIF format requires. *
* Returns GIF_OK if written succesfully. *
******************************************************************************/
static int EGifBufferedOutput(GifFileType *GifFile, GifByteType *Buf, int c)
{
if (c == FLUSH_OUTPUT) {
/* Flush everything out. */
if (Buf[0] != 0 && WRITE(GifFile, Buf, Buf[0]+1) != (unsigned)(Buf[0] + 1))
{
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
/* Mark end of compressed data, by an empty block (see GIF doc): */
Buf[0] = 0;
if (WRITE(GifFile, Buf, 1) != 1)
{
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
else {
if (Buf[0] == 255) {
/* Dump out this buffer - it is full: */
if (WRITE(GifFile, Buf, Buf[0] + 1) != (unsigned)(Buf[0] + 1))
{
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
Buf[0] = 0;
}
Buf[++Buf[0]] = c;
}
return GIF_OK;
}
/******************************************************************************
* This routine writes to disk an in-core representation of a GIF previously *
* created by DGifSlurp(). *
******************************************************************************/
int EGifSpew(GifFileType *GifFileOut)
{
int i, j, gif89 = FALSE;
char SavedStamp[GIF_STAMP_LEN + 1];
for (i = 0; i < GifFileOut->ImageCount; i++)
{
for (j = 0; j < GifFileOut->SavedImages[i].ExtensionBlockCount; j++) {
int function=GifFileOut->SavedImages[i].ExtensionBlocks[j].Function;
if (function == COMMENT_EXT_FUNC_CODE
|| function == GRAPHICS_EXT_FUNC_CODE
|| function == PLAINTEXT_EXT_FUNC_CODE
|| function == APPLICATION_EXT_FUNC_CODE)
gif89 = TRUE;
}
}
strncpy(SavedStamp, GifVersionPrefix, GIF_STAMP_LEN);
if (gif89)
{
strncpy(GifVersionPrefix, GIF89_STAMP, GIF_STAMP_LEN);
}
else
{
strncpy(GifVersionPrefix, GIF87_STAMP, GIF_STAMP_LEN);
}
if (EGifPutScreenDesc(GifFileOut,
GifFileOut->SWidth,
GifFileOut->SHeight,
GifFileOut->SColorResolution,
GifFileOut->SBackGroundColor,
GifFileOut->SColorMap) == GIF_ERROR)
{
strncpy(GifVersionPrefix, SavedStamp, GIF_STAMP_LEN);
return(GIF_ERROR);
}
strncpy(GifVersionPrefix, SavedStamp, GIF_STAMP_LEN);
for (i = 0; i < GifFileOut->ImageCount; i++)
{
SavedImage *sp = &GifFileOut->SavedImages[i];
int SavedHeight = sp->ImageDesc.Height;
int SavedWidth = sp->ImageDesc.Width;
ExtensionBlock *ep;
/* this allows us to delete images by nuking their rasters */
if (sp->RasterBits == NULL)
continue;
if (sp->ExtensionBlocks)
{
for ( j = 0; j < sp->ExtensionBlockCount; j++) {
ep = &sp->ExtensionBlocks[j];
if (EGifPutExtension(GifFileOut,
(ep->Function != 0) ? ep->Function : '\0',
ep->ByteCount, ep->Bytes) == GIF_ERROR)
return (GIF_ERROR);
}
}
if (EGifPutImageDesc(GifFileOut,
sp->ImageDesc.Left,
sp->ImageDesc.Top,
SavedWidth,
SavedHeight,
sp->ImageDesc.Interlace,
sp->ImageDesc.ColorMap
) == GIF_ERROR)
return(GIF_ERROR);
for (j = 0; j < SavedHeight; j++)
{
if (EGifPutLine(GifFileOut,
(GifByteType*)(sp->RasterBits + j * SavedWidth),
SavedWidth) == GIF_ERROR)
return(GIF_ERROR);
}
}
if (EGifCloseFile(GifFileOut) == GIF_ERROR)
return(GIF_ERROR);
return(GIF_OK);
}
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