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f397a480c8
darling-cocotron/CoreGraphics/gif_lib.m
Christopher Lloyd c3dead2920 - add FreeBSD targets to all frameworks 
- brought X11 back to current for Darwin and FreeBSD
- removed CairoCacheImage, added O2Surface_cairo
- separated TTFFont into O2FontState_cairo/O2Font_FT/TTFFont
- renamed CairoContext O2Context_cairo
- added O2Context_builtin_FT which implements Onyx2D+FreeType
- moved font queries to X11Display
- added NSPlatform_bsd.m to AppKit
- encoding change/fix(?) in NSColor.m
- moved showText: into abstract class O2Context from _gdi classes
- fix for ObjCModule.m to get executable path
2009-12-16 19:27:00 +00:00

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/*
Gif-Lib by Gershon Elber,Eric S. Raymond,Toshio Kuratomi
The GIFLIB distribution is Copyright (c) 1997 Eric S. Raymond
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/
#import <stdlib.h>
#import <string.h>
#import "gif_lib.h"
#import <Foundation/NSStream.h>
#import <Foundation/NSString.h>
#define READ(_gif,_buf,_len) [(_gif)->inputStream read:_buf maxLength:_len]
#define WRITE(_gif,_buf,_len) [(_gif)->outputStream write:_buf maxLength:_len]
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, uint8_t * Buf,int c);
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, uint8_t *Buf,uint8_t *NextByte);
/* The colors are stripped to 5 bits per primary color if non MSDOS system
* or to 4 (not enough memory...) if MSDOS as first step.
*/
#define COLOR_ARRAY_SIZE 32768
#define BITS_PER_PRIM_COLOR 5
#define MAX_PRIM_COLOR 0x1f
typedef struct QuantizedColorType {
uint8_t RGB[3];
uint8_t NewColorIndex;
long Count;
struct QuantizedColorType *Pnext;
} QuantizedColorType;
typedef struct NewColorMapType {
uint8_t RGBMin[3], RGBWidth[3];
unsigned int NumEntries; /* # of QuantizedColorType in linked list below */
unsigned long Count; /* Total number of pixels in all the entries */
QuantizedColorType *QuantizedColors;
} NewColorMapType;
/* 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;
GifFileType *DGifOpen(NSInputStream *stream) {
uint8_t Buf[GIF_STAMP_LEN + 1];
GifFileType *GifFile;
GifFile = malloc(sizeof(GifFileType));
if (GifFile == NULL) {
//GifFile->GifError = D_GIF_ERR_NOT_ENOUGH_MEM; this will segfault
return NULL;
}
memset(GifFile, '\0', sizeof(GifFileType));
GifFile->FileState = FILE_STATE_READ;
GifFile->inputStream=stream;
/* Lets see if this is a GIF file: */
if (READ(GifFile, Buf, GIF_STAMP_LEN) != GIF_STAMP_LEN) {
GifFile->GifError = D_GIF_ERR_READ_FAILED;
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, (char *)Buf, GIF_VERSION_POS) != 0) {
GifFile->GifError = D_GIF_ERR_NOT_GIF_FILE;
free((char *)GifFile);
return NULL;
}
if (DGifGetScreenDesc(GifFile) == GIF_ERROR) {
free((char *)GifFile);
return NULL;
}
GifFile->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;
uint8_t Buf[3];
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->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) {
GifFile->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) {
GifFile->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;
GifFile->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) {
uint8_t Buf;
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->GifError = D_GIF_ERR_NOT_READABLE;
return GIF_ERROR;
}
if (READ(GifFile, &Buf, 1) != 1) {
GifFile->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;
GifFile->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;
uint8_t Buf[3];
SavedImage *sp;
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->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) {
GifFile->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) {
GifFile->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);
GifFile->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) {
GifFile->GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
return GIF_ERROR;
}
} else {
if ((GifFile->SavedImages =malloc(sizeof(SavedImage))) == NULL) {
GifFile->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) {
GifFile->GifError = D_GIF_ERR_NOT_ENOUGH_MEM;
return GIF_ERROR;
}
}
sp->RasterBits = NULL;
sp->ExtensionBlockCount = 0;
sp->ExtensionBlocks = NULL;
GifFile->ImageCount++;
GifFile->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) {
uint8_t *Dummy;
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->GifError = D_GIF_ERR_NOT_READABLE;
return GIF_ERROR;
}
if (!LineLen)
LineLen = GifFile->Image.Width;
if ((GifFile->PixelCount -= LineLen) > 0xffff0000UL) {
GifFile->GifError = D_GIF_ERR_DATA_TOO_BIG;
return GIF_ERROR;
}
if (DGifDecompressLine(GifFile, Line, LineLen) == GIF_OK) {
if (GifFile->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,uint8_t ** Extension) {
uint8_t Buf;
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->GifError = D_GIF_ERR_NOT_READABLE;
return GIF_ERROR;
}
if (READ(GifFile, &Buf, 1) != 1) {
GifFile->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,uint8_t ** Extension) {
uint8_t Buf;
if (READ(GifFile, &Buf, 1) != 1) {
GifFile->GifError = D_GIF_ERR_READ_FAILED;
return GIF_ERROR;
}
if (Buf > 0) {
*Extension = GifFile->Buf; /* Use private unused buffer. */
(*Extension)[0] = Buf; /* Pascal strings notation (pos. 0 is len.). */
if (READ(GifFile, &((*Extension)[1]), Buf) != Buf) {
GifFile->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) {
if (GifFile == NULL)
return GIF_ERROR;
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->GifError = D_GIF_ERR_NOT_READABLE;
return GIF_ERROR;
}
if (GifFile->Image.ColorMap) {
FreeMapObject(GifFile->Image.ColorMap);
GifFile->Image.ColorMap = NULL;
}
if (GifFile->SColorMap) {
FreeMapObject(GifFile->SColorMap);
GifFile->SColorMap = NULL;
}
if (GifFile->SavedImages) {
FreeSavedImages(GifFile);
GifFile->SavedImages = NULL;
}
free(GifFile);
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) {
GifFile->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,uint8_t ** CodeBlock) {
if (!IS_READABLE(GifFile)) {
/* This file was NOT open for reading: */
GifFile->GifError = D_GIF_ERR_NOT_READABLE;
return GIF_ERROR;
}
*CodeSize = GifFile->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,
uint8_t ** CodeBlock) {
uint8_t Buf;
if (READ(GifFile, &Buf, 1) != 1) {
GifFile->GifError = D_GIF_ERR_READ_FAILED;
return GIF_ERROR;
}
if (Buf > 0) {
*CodeBlock = GifFile->Buf; /* Use private unused buffer. */
(*CodeBlock)[0] = Buf; /* Pascal strings notation (pos. 0 is len.). */
if (READ(GifFile, &((*CodeBlock)[1]), Buf) != Buf) {
GifFile->GifError = D_GIF_ERR_READ_FAILED;
return GIF_ERROR;
}
} else {
*CodeBlock = NULL;
GifFile->Buf[0] = 0; /* Make sure the buffer is empty! */
GifFile->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;
uint8_t CodeSize;
GifPrefixType *Prefix;
READ(GifFile, &CodeSize, 1); /* Read Code size from file. */
BitsPerPixel = CodeSize;
GifFile->Buf[0] = 0; /* Input Buffer empty. */
GifFile->BitsPerPixel = BitsPerPixel;
GifFile->ClearCode = (1 << BitsPerPixel);
GifFile->EOFCode = GifFile->ClearCode + 1;
GifFile->RunningCode = GifFile->EOFCode + 1;
GifFile->RunningBits = BitsPerPixel + 1; /* Number of bits per code. */
GifFile->MaxCode1 = 1 << GifFile->RunningBits; /* Max. code + 1. */
GifFile->StackPtr = 0; /* No pixels on the pixel stack. */
GifFile->LastCode = NO_SUCH_CODE;
GifFile->CrntShiftState = 0; /* No information in CrntShiftDWord. */
GifFile->CrntShiftDWord = 0;
Prefix = GifFile->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;
uint8_t *Stack, *Suffix;
GifPrefixType *Prefix;
StackPtr = GifFile->StackPtr;
Prefix = GifFile->Prefix;
Suffix = GifFile->Suffix;
Stack = GifFile->Stack;
EOFCode = GifFile->EOFCode;
ClearCode = GifFile->ClearCode;
LastCode = GifFile->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 || GifFile->PixelCount != 0) {
GifFile->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;
GifFile->RunningCode = GifFile->EOFCode + 1;
GifFile->RunningBits = GifFile->BitsPerPixel + 1;
GifFile->MaxCode1 = 1 << GifFile->RunningBits;
LastCode = GifFile->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 == GifFile->RunningCode - 2) {
CrntPrefix = LastCode;
Suffix[GifFile->RunningCode - 2] =
Stack[StackPtr++] = DGifGetPrefixChar(Prefix,
LastCode,
ClearCode);
} else {
GifFile->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) {
GifFile->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[GifFile->RunningCode - 2] = LastCode;
if (CrntCode == GifFile->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[GifFile->RunningCode - 2] =
DGifGetPrefixChar(Prefix, LastCode, ClearCode);
} else {
Suffix[GifFile->RunningCode - 2] =
DGifGetPrefixChar(Prefix, CrntCode, ClearCode);
}
}
LastCode = CrntCode;
}
}
GifFile->LastCode = LastCode;
GifFile->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;
}
/******************************************************************************
* 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) {
uint8_t 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 (GifFile->RunningBits > LZ_BITS) {
GifFile->GifError = D_GIF_ERR_IMAGE_DEFECT;
return GIF_ERROR;
}
while (GifFile->CrntShiftState < GifFile->RunningBits) {
/* Needs to get more bytes from input stream for next code: */
if (DGifBufferedInput(GifFile, GifFile->Buf, &NextByte) == GIF_ERROR) {
return GIF_ERROR;
}
GifFile->CrntShiftDWord |=
((unsigned long)NextByte) << GifFile->CrntShiftState;
GifFile->CrntShiftState += 8;
}
*Code = GifFile->CrntShiftDWord & CodeMasks[GifFile->RunningBits];
GifFile->CrntShiftDWord >>= GifFile->RunningBits;
GifFile->CrntShiftState -= GifFile->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 GifFile->RunningCode.
*/
if (GifFile->RunningCode < LZ_MAX_CODE + 2 &&
++GifFile->RunningCode > GifFile->MaxCode1 &&
GifFile->RunningBits < LZ_BITS) {
GifFile->MaxCode1 <<= 1;
GifFile->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,
uint8_t * Buf,
uint8_t * NextByte) {
if (Buf[0] == 0) {
/* Needs to read the next buffer - this one is empty: */
if (READ(GifFile, Buf, 1) != 1) {
GifFile->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) {
GifFile->GifError = D_GIF_ERR_IMAGE_DEFECT;
return GIF_ERROR;
}
if (READ(GifFile, &Buf[1], Buf[0]) != Buf[0]) {
GifFile->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;
}
/******************************************************************************
* 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;
uint8_t *ExtData;
SavedImage temp_save;
int Function=0;
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 = 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;
}
break;
case EXTENSION_RECORD_TYPE:
if (DGifGetExtension(GifFile, &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],Function)
== GIF_ERROR)
return (GIF_ERROR);
if (DGifGetExtensionNext(GifFile, &ExtData) == GIF_ERROR)
return (GIF_ERROR);
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);
}
/******************************************************************************
* Routine to generate an HKey for the hashtable out of the given unique key. *
* The given Key is assumed to be 20 bits as follows: lower 8 bits are the *
* new postfix character, while the upper 12 bits are the prefix code. *
* Because the average hit ratio is only 2 (2 hash references per entry), *
* evaluating more complex keys (such as twin prime keys) does not worth it! *
******************************************************************************/
static inline int KeyItem(uint32_t Item){
return ((Item >> 12) ^ Item) & HT_KEY_MASK;
}
/******************************************************************************
* Routine to clear the HashTable to an empty state. *
* This part is a little machine depended. Use the commented part otherwise. *
******************************************************************************/
void _ClearHashTable(GifHashTableType *HashTable){
memset(HashTable -> HTable, 0xFF, HT_SIZE * sizeof(uint32_t));
}
/******************************************************************************
* Initialize HashTable - allocate the memory needed and clear it. *
******************************************************************************/
GifHashTableType *_InitHashTable(void){
GifHashTableType *HashTable;
if ((HashTable = malloc(sizeof(GifHashTableType)))== NULL)
return NULL;
_ClearHashTable(HashTable);
return HashTable;
}
/******************************************************************************
* Routine to insert a new Item into the HashTable. The data is assumed to be *
* new one. *
******************************************************************************/
void _InsertHashTable(GifHashTableType *HashTable, uint32_t Key, int Code){
int HKey = KeyItem(Key);
uint32_t *HTable = HashTable -> HTable;
while (HT_GET_KEY(HTable[HKey]) != 0xFFFFFL) {
HKey = (HKey + 1) & HT_KEY_MASK;
}
HTable[HKey] = HT_PUT_KEY(Key) | HT_PUT_CODE(Code);
}
/******************************************************************************
* Routine to test if given Key exists in HashTable and if so returns its code *
* Returns the Code if key was found, -1 if not. *
******************************************************************************/
int _ExistsHashTable(GifHashTableType *HashTable, uint32_t Key){
int HKey = KeyItem(Key);
uint32_t *HTable = HashTable -> HTable, HTKey;
while ((HTKey = HT_GET_KEY(HTable[HKey])) != 0xFFFFFL) {
if (Key == HTKey) return HT_GET_CODE(HTable[HKey]);
HKey = (HKey + 1) & HT_KEY_MASK;
}
return -1;
}
/******************************************************************************
* Output constructor that takes user supplied output function.
* Basically just a copy of EGifOpenFileHandle. (MRB)
*****************************************************************************/
GifFileType *EGifOpen(NSOutputStream *stream) {
GifFileType *GifFile;
GifFile = malloc(sizeof(GifFileType));
if (GifFile == NULL) {
GifFile->GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return NULL;
}
memset(GifFile, '\0', sizeof(GifFileType));
GifFile->HashTable = _InitHashTable();
if (GifFile->HashTable == NULL) {
free (GifFile);
GifFile->GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return NULL;
}
GifFile->FileState = FILE_STATE_WRITE;
GifFile->outputStream = stream;
GifFile->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;
uint8_t Buf[3];
if (GifFile->FileState & FILE_STATE_SCREEN) {
/* If already has screen descriptor - something is wrong! */
GifFile->GifError = E_GIF_ERR_HAS_SCRN_DSCR;
return GIF_ERROR;
}
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
/* First write the version prefix into the file. */
if (WRITE(GifFile, (unsigned char *)GifVersionPrefix,strlen(GifVersionPrefix)) != strlen(GifVersionPrefix)) {
GifFile->GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
GifFile->SWidth = Width;
GifFile->SHeight = Height;
GifFile->SColorResolution = ColorRes;
GifFile->SBackGroundColor = BackGround;
if (ColorMap) {
GifFile->SColorMap = MakeMapObject(ColorMap->ColorCount,
ColorMap->Colors);
if (GifFile->SColorMap == NULL) {
GifFile->GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return GIF_ERROR;
}
} else
GifFile->SColorMap = NULL;
/*
* Put the logical screen descriptor into the file:
*/
/* Logical Screen Descriptor: Dimensions */
EGifPutWord(Width, GifFile);
EGifPutWord(Height, GifFile);
/* Logical Screen Descriptor: Packed Fields */
/* Note: We have actual size of the color table default to the largest
* possible size (7+1 == 8 bits) because the decoder can use it to decide
* how to display the files.
*/
Buf[0] = (ColorMap ? 0x80 : 0x00) | /* Yes/no global colormap */
((ColorRes - 1) << 4) | /* Bits allocated to each primary color */
(ColorMap ? ColorMap->BitsPerPixel - 1 : 0x07 ); /* Actual size of the
color table. */
Buf[1] = BackGround; /* Index into the ColorTable for background color */
Buf[2] = 0; /* Pixel Aspect Ratio */
WRITE(GifFile, Buf, 3);
/* If we have Global color map - dump it also: */
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) {
GifFile->GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
/* Mark this file as has screen descriptor, and no pixel written yet: */
GifFile->FileState |= FILE_STATE_SCREEN;
return GIF_OK;
}
/******************************************************************************
* This routine should be called before any attempt 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;
uint8_t Buf[3];
if (GifFile->FileState & FILE_STATE_IMAGE &&
GifFile->PixelCount > 0xffff0000UL) {
/* If already has active image descriptor - something is wrong! */
GifFile->GifError = E_GIF_ERR_HAS_IMAG_DSCR;
return GIF_ERROR;
}
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->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);
if (GifFile->Image.ColorMap == NULL) {
GifFile->GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return GIF_ERROR;
}
} else {
GifFile->Image.ColorMap = NULL;
}
/* Put the image descriptor into the file: */
Buf[0] = ','; /* Image seperator character. */
WRITE(GifFile, Buf, 1);
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);
WRITE(GifFile, Buf, 1);
/* If we have Global color map - dump it also: */
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) {
GifFile->GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
if (GifFile->SColorMap == NULL && GifFile->Image.ColorMap == NULL) {
GifFile->GifError = E_GIF_ERR_NO_COLOR_MAP;
return GIF_ERROR;
}
/* Mark this file as has screen descriptor: */
GifFile->FileState |= FILE_STATE_IMAGE;
GifFile->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;
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (!LineLen)
LineLen = GifFile->Image.Width;
if (GifFile->PixelCount < (unsigned)LineLen) {
GifFile->GifError = E_GIF_ERR_DATA_TOO_BIG;
return GIF_ERROR;
}
GifFile->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[GifFile->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) {
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (GifFile->PixelCount == 0) {
GifFile->GifError = E_GIF_ERR_DATA_TOO_BIG;
return GIF_ERROR;
}
--GifFile->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[GifFile->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) {
unsigned int length = strlen(Comment);
char *buf;
length = strlen(Comment);
if (length <= 255) {
return EGifPutExtension(GifFile, COMMENT_EXT_FUNC_CODE,
length, Comment);
} else {
buf = (char *)Comment;
if (EGifPutExtensionFirst(GifFile, COMMENT_EXT_FUNC_CODE, 255, buf)
== GIF_ERROR) {
return GIF_ERROR;
}
length -= 255;
buf = buf + 255;
/* Break the comment into 255 byte sub blocks */
while (length > 255) {
if (EGifPutExtensionNext(GifFile, 0, 255, buf) == GIF_ERROR) {
return GIF_ERROR;
}
buf = buf + 255;
length -= 255;
}
/* Output any partial block and the clear code. */
if (length > 0) {
if (EGifPutExtensionLast(GifFile, 0, length, buf) == GIF_ERROR) {
return GIF_ERROR;
}
} else {
if (EGifPutExtensionLast(GifFile, 0, 0, NULL) == GIF_ERROR) {
return GIF_ERROR;
}
}
}
return GIF_OK;
}
/******************************************************************************
* Put a first extension block (see GIF manual) into gif file. Here more
* extensions can be dumped using EGifPutExtensionNext until
* EGifPutExtensionLast is invoked.
*****************************************************************************/
int EGifPutExtensionFirst(GifFileType * GifFile,
int ExtCode,
int ExtLen,
const void * Extension) {
uint8_t Buf[3];
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (ExtCode == 0) {
WRITE(GifFile, (uint8_t *)&ExtLen, 1);
} else {
Buf[0] = '!';
Buf[1] = ExtCode;
Buf[2] = ExtLen;
WRITE(GifFile, Buf, 3);
}
WRITE(GifFile, Extension, ExtLen);
return GIF_OK;
}
/******************************************************************************
* Put a middle extension block (see GIF manual) into gif file.
*****************************************************************************/
int EGifPutExtensionNext(GifFileType * GifFile,
int ExtCode,
int ExtLen,
const void * Extension) {
uint8_t Buf;
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
Buf = ExtLen;
WRITE(GifFile, &Buf, 1);
WRITE(GifFile, Extension, ExtLen);
return GIF_OK;
}
/******************************************************************************
* Put a last extension block (see GIF manual) into gif file.
*****************************************************************************/
int EGifPutExtensionLast(GifFileType * GifFile,
int ExtCode,
int ExtLen,
const void * Extension) {
uint8_t Buf;
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
/* If we are given an extension sub-block output it now. */
if (ExtLen > 0) {
Buf = ExtLen;
WRITE(GifFile, &Buf, 1);
WRITE(GifFile, Extension, ExtLen);
}
/* Write the block terminator */
Buf = 0;
WRITE(GifFile, &Buf, 1);
return GIF_OK;
}
/******************************************************************************
* Put an extension block (see GIF manual) into gif file.
* Warning: This function is only useful for Extension blocks that have at
* most one subblock. Extensions with more than one subblock need to use the
* EGifPutExtension{First,Next,Last} functions instead.
*****************************************************************************/
int EGifPutExtension(GifFileType * GifFile,
int ExtCode,
int ExtLen,
const void * Extension) {
uint8_t Buf[3];
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
if (ExtCode == 0)
WRITE(GifFile, (uint8_t *)&ExtLen, 1);
else {
Buf[0] = '!'; /* Extension Introducer 0x21 */
Buf[1] = ExtCode; /* Extension Label */
Buf[2] = ExtLen; /* Extension length */
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 uint8_t * CodeBlock) {
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->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) {
* GifFile->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 uint8_t * CodeBlock) {
uint8_t Buf;
if (CodeBlock != NULL) {
if (WRITE(GifFile, CodeBlock, CodeBlock[0] + 1)
!= (unsigned)(CodeBlock[0] + 1)) {
GifFile->GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
} else {
Buf = 0;
if (WRITE(GifFile, &Buf, 1) != 1) {
GifFile->GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
GifFile->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) {
uint8_t Buf;
if (GifFile == NULL)
return GIF_ERROR;
if (!IS_WRITEABLE(GifFile)) {
/* This file was NOT open for writing: */
GifFile->GifError = E_GIF_ERR_NOT_WRITEABLE;
return GIF_ERROR;
}
Buf = ';';
WRITE(GifFile, &Buf, 1);
if (GifFile->Image.ColorMap) {
FreeMapObject(GifFile->Image.ColorMap);
GifFile->Image.ColorMap = NULL;
}
if (GifFile->SColorMap) {
FreeMapObject(GifFile->SColorMap);
GifFile->SColorMap = NULL;
}
if (GifFile->HashTable) {
free((char *) GifFile->HashTable);
}
free(GifFile);
return GIF_OK;
}
/******************************************************************************
* Put 2 bytes (word) into the given file:
*****************************************************************************/
static int EGifPutWord(int Word,
GifFileType * GifFile) {
unsigned char c[2];
c[0] = Word & 0xff;
c[1] = (Word >> 8) & 0xff;
if (WRITE(GifFile, c, 2) == 2)
return GIF_OK;
else
return GIF_ERROR;
}
/******************************************************************************
* Setup the LZ compression for this image:
*****************************************************************************/
static int EGifSetupCompress(GifFileType * GifFile) {
int BitsPerPixel;
uint8_t Buf;
/* 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 {
GifFile->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. */
GifFile->Buf[0] = 0; /* Nothing was output yet. */
GifFile->BitsPerPixel = BitsPerPixel;
GifFile->ClearCode = (1 << BitsPerPixel);
GifFile->EOFCode = GifFile->ClearCode + 1;
GifFile->RunningCode = GifFile->EOFCode + 1;
GifFile->RunningBits = BitsPerPixel + 1; /* Number of bits per code. */
GifFile->MaxCode1 = 1 << GifFile->RunningBits; /* Max. code + 1. */
GifFile->CrntCode = FIRST_CODE; /* Signal that this is first one! */
GifFile->CrntShiftState = 0; /* No information in CrntShiftDWord. */
GifFile->CrntShiftDWord = 0;
/* Clear hash table and send Clear to make sure the decoder do the same. */
_ClearHashTable(GifFile->HashTable);
if (EGifCompressOutput(GifFile, GifFile->ClearCode) == GIF_ERROR) {
GifFile->GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
return GIF_OK;
}
/******************************************************************************
* The LZ compression routine:
* This version compresses the given buffer Line of length LineLen.
* This routine can be called a few times (one per scan line, for example), in
* order to complete the whole image.
******************************************************************************/
static int EGifCompressLine(GifFileType * GifFile,
GifPixelType * Line,
int LineLen) {
int i = 0, CrntCode, NewCode;
unsigned long NewKey;
GifPixelType Pixel;
GifHashTableType *HashTable;
HashTable = GifFile->HashTable;
if (GifFile->CrntCode == FIRST_CODE) /* Its first time! */
CrntCode = Line[i++];
else
CrntCode = GifFile->CrntCode; /* Get last code in compression. */
while (i < LineLen) { /* Decode LineLen items. */
Pixel = Line[i++]; /* Get next pixel from stream. */
/* Form a new unique key to search hash table for the code combines
* CrntCode as Prefix string with Pixel as postfix char.
*/
NewKey = (((uint32_t) CrntCode) << 8) + Pixel;
if ((NewCode = _ExistsHashTable(HashTable, NewKey)) >= 0) {
/* This Key is already there, or the string is old one, so
* simple take new code as our CrntCode:
*/
CrntCode = NewCode;
} else {
/* Put it in hash table, output the prefix code, and make our
* CrntCode equal to Pixel.
*/
if (EGifCompressOutput(GifFile, CrntCode) == GIF_ERROR) {
GifFile->GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
CrntCode = Pixel;
/* If however the HashTable if full, we send a clear first and
* Clear the hash table.
*/
if (GifFile->RunningCode >= LZ_MAX_CODE) {
/* Time to do some clearance: */
if (EGifCompressOutput(GifFile, GifFile->ClearCode)
== GIF_ERROR) {
GifFile->GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
GifFile->RunningCode = GifFile->EOFCode + 1;
GifFile->RunningBits = GifFile->BitsPerPixel + 1;
GifFile->MaxCode1 = 1 << GifFile->RunningBits;
_ClearHashTable(HashTable);
} else {
/* Put this unique key with its relative Code in hash table: */
_InsertHashTable(HashTable, NewKey, GifFile->RunningCode++);
}
}
}
/* Preserve the current state of the compression algorithm: */
GifFile->CrntCode = CrntCode;
if (GifFile->PixelCount == 0) {
/* We are done - output last Code and flush output buffers: */
if (EGifCompressOutput(GifFile, CrntCode) == GIF_ERROR) {
GifFile->GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
if (EGifCompressOutput(GifFile, GifFile->EOFCode) == GIF_ERROR) {
GifFile->GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
if (EGifCompressOutput(GifFile, FLUSH_OUTPUT) == GIF_ERROR) {
GifFile->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) {
int retval = GIF_OK;
if (Code == FLUSH_OUTPUT) {
while (GifFile->CrntShiftState > 0) {
/* Get Rid of what is left in DWord, and flush it. */
if (EGifBufferedOutput(GifFile, GifFile->Buf,
GifFile->CrntShiftDWord & 0xff) == GIF_ERROR)
retval = GIF_ERROR;
GifFile->CrntShiftDWord >>= 8;
GifFile->CrntShiftState -= 8;
}
GifFile->CrntShiftState = 0; /* For next time. */
if (EGifBufferedOutput(GifFile, GifFile->Buf,
FLUSH_OUTPUT) == GIF_ERROR)
retval = GIF_ERROR;
} else {
GifFile->CrntShiftDWord |= ((long)Code) << GifFile->CrntShiftState;
GifFile->CrntShiftState += GifFile->RunningBits;
while (GifFile->CrntShiftState >= 8) {
/* Dump out full bytes: */
if (EGifBufferedOutput(GifFile, GifFile->Buf,
GifFile->CrntShiftDWord & 0xff) == GIF_ERROR)
retval = GIF_ERROR;
GifFile->CrntShiftDWord >>= 8;
GifFile->CrntShiftState -= 8;
}
}
/* If code cannt fit into RunningBits bits, must raise its size. Note */
/* however that codes above 4095 are used for special signaling. */
if (GifFile->RunningCode >= GifFile->MaxCode1 && Code <= 4095) {
GifFile->MaxCode1 = 1 << ++GifFile->RunningBits;
}
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,
uint8_t * Buf,
int c) {
if (c == FLUSH_OUTPUT) {
/* Flush everything out. */
if (Buf[0] != 0
&& WRITE(GifFile, Buf, Buf[0] + 1) != (unsigned)(Buf[0] + 1)) {
GifFile->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) {
GifFile->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)) {
GifFile->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 = 0;
int bOff; /* Block Offset for adding sub blocks in Extensions */
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 = 1;
}
}
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 (j == sp->ExtensionBlockCount - 1 || (ep+1)->Function != 0) {
/*** FIXME: Must check whether outputting
* <ExtLen><Extension> is ever valid or if we should just
* drop anything with a 0 for the Function. (And whether
* we should drop here or in EGifPutExtension)
*/
if (EGifPutExtension(GifFileOut,
(ep->Function != 0) ? ep->Function : '\0',
ep->ByteCount,
ep->Bytes) == GIF_ERROR) {
return (GIF_ERROR);
}
} else {
EGifPutExtensionFirst(GifFileOut, ep->Function, ep->ByteCount, ep->Bytes);
for (bOff = j+1; bOff < sp->ExtensionBlockCount; bOff++) {
ep = &sp->ExtensionBlocks[bOff];
if (ep->Function != 0) {
break;
}
EGifPutExtensionNext(GifFileOut, 0,
ep->ByteCount, ep->Bytes);
}
EGifPutExtensionLast(GifFileOut, 0, 0, NULL);
j = bOff-1;
}
}
}
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,
sp->RasterBits + j * SavedWidth,
SavedWidth) == GIF_ERROR)
return (GIF_ERROR);
}
}
if (EGifCloseFile(GifFileOut) == GIF_ERROR)
return (GIF_ERROR);
return (GIF_OK);
}
/*****************************************************************************
* Return the last GIF error (0 if none) and reset the error.
****************************************************************************/
int GifLastError(GifFileType *GifFile) {
int i = GifFile->GifError;
GifFile->GifError = 0;
return i;
}
/*****************************************************************************
* Print the last GIF error to stderr.
****************************************************************************/
void
PrintGifError(GifFileType *GifFile) {
char *Err;
switch (GifFile->GifError) {
case E_GIF_ERR_OPEN_FAILED:
Err = "Failed to open given file";
break;
case E_GIF_ERR_WRITE_FAILED:
Err = "Failed to Write to given file";
break;
case E_GIF_ERR_HAS_SCRN_DSCR:
Err = "Screen Descriptor already been set";
break;
case E_GIF_ERR_HAS_IMAG_DSCR:
Err = "Image Descriptor is still active";
break;
case E_GIF_ERR_NO_COLOR_MAP:
Err = "Neither Global Nor Local color map";
break;
case E_GIF_ERR_DATA_TOO_BIG:
Err = "#Pixels bigger than Width * Height";
break;
case E_GIF_ERR_NOT_ENOUGH_MEM:
Err = "Fail to allocate required memory";
break;
case E_GIF_ERR_DISK_IS_FULL:
Err = "Write failed (disk full?)";
break;
case E_GIF_ERR_CLOSE_FAILED:
Err = "Failed to close given file";
break;
case E_GIF_ERR_NOT_WRITEABLE:
Err = "Given file was not opened for write";
break;
case D_GIF_ERR_OPEN_FAILED:
Err = "Failed to open given file";
break;
case D_GIF_ERR_READ_FAILED:
Err = "Failed to Read from given file";
break;
case D_GIF_ERR_NOT_GIF_FILE:
Err = "Given file is NOT GIF file";
break;
case D_GIF_ERR_NO_SCRN_DSCR:
Err = "No Screen Descriptor detected";
break;
case D_GIF_ERR_NO_IMAG_DSCR:
Err = "No Image Descriptor detected";
break;
case D_GIF_ERR_NO_COLOR_MAP:
Err = "Neither Global Nor Local color map";
break;
case D_GIF_ERR_WRONG_RECORD:
Err = "Wrong record type detected";
break;
case D_GIF_ERR_DATA_TOO_BIG:
Err = "#Pixels bigger than Width * Height";
break;
case D_GIF_ERR_NOT_ENOUGH_MEM:
Err = "Fail to allocate required memory";
break;
case D_GIF_ERR_CLOSE_FAILED:
Err = "Failed to close given file";
break;
case D_GIF_ERR_NOT_READABLE:
Err = "Given file was not opened for read";
break;
case D_GIF_ERR_IMAGE_DEFECT:
Err = "Image is defective, decoding aborted";
break;
case D_GIF_ERR_EOF_TOO_SOON:
Err = "Image EOF detected, before image complete";
break;
default:
Err = NULL;
break;
}
if (Err != NULL)
NSLog(@"GIF-LIB error: %s.\n", Err);
else
NSLog( @"GIF-LIB undefined error %d.\n", GifFile->GifError);
}
/* return smallest bitfield size n will fit in */
int BitSize(int n) {
int i;
for (i = 1; i <= 8; i++)
if ((1 << i) >= n)
break;
return i;
}
/*
* Allocate a color map of given size; initialize with contents of
* ColorMap if that pointer is non-NULL.
*/
ColorMapObject *
MakeMapObject(int ColorCount,
const GifColorType * ColorMap) {
ColorMapObject *Object;
/*** FIXME: Our ColorCount has to be a power of two. Is it necessary to
* make the user know that or should we automatically round up instead? */
if (ColorCount != (1 << BitSize(ColorCount))) {
return NULL;
}
Object = malloc(sizeof(ColorMapObject));
if (Object == NULL) {
return NULL;
}
Object->Colors = (GifColorType *)calloc(ColorCount, sizeof(GifColorType));
if (Object->Colors == (GifColorType *) NULL) {
return NULL;
}
Object->ColorCount = ColorCount;
Object->BitsPerPixel = BitSize(ColorCount);
if (ColorMap) {
memcpy((char *)Object->Colors,(char *)ColorMap, ColorCount * sizeof(GifColorType));
}
return (Object);
}
/*
* Free a color map object
*/
void
FreeMapObject(ColorMapObject * Object) {
if (Object != NULL) {
free(Object->Colors);
free(Object);
/*** FIXME:
* When we are willing to break API we need to make this function
* FreeMapObject(ColorMapObject **Object)
* and do this assignment to NULL here:
* *Object = NULL;
*/
}
}
/*
* Compute the union of two given color maps and return it. If result can't
* fit into 256 colors, NULL is returned, the allocated union otherwise.
* ColorIn1 is copied as is to ColorUnion, while colors from ColorIn2 are
* copied iff they didn't exist before. ColorTransIn2 maps the old
* ColorIn2 into ColorUnion color map table.
*/
ColorMapObject *
UnionColorMap(const ColorMapObject * ColorIn1,
const ColorMapObject * ColorIn2,
GifPixelType ColorTransIn2[]) {
int i, j, CrntSlot, RoundUpTo, NewBitSize;
ColorMapObject *ColorUnion;
/*
* Allocate table which will hold the result for sure.
*/
ColorUnion = MakeMapObject(MAX(ColorIn1->ColorCount,
ColorIn2->ColorCount) * 2, NULL);
if (ColorUnion == NULL)
return NULL;
/* Copy ColorIn1 to ColorUnionSize; */
/*** FIXME: What if there are duplicate entries into the colormap to begin
* with? */
for (i = 0; i < ColorIn1->ColorCount; i++)
ColorUnion->Colors[i] = ColorIn1->Colors[i];
CrntSlot = ColorIn1->ColorCount;
/*
* Potentially obnoxious hack:
*
* Back CrntSlot down past all contiguous {0, 0, 0} slots at the end
* of table 1. This is very useful if your display is limited to
* 16 colors.
*/
while (ColorIn1->Colors[CrntSlot - 1].Red == 0
&& ColorIn1->Colors[CrntSlot - 1].Green == 0
&& ColorIn1->Colors[CrntSlot - 1].Blue == 0)
CrntSlot--;
/* Copy ColorIn2 to ColorUnionSize (use old colors if they exist): */
for (i = 0; i < ColorIn2->ColorCount && CrntSlot <= 256; i++) {
/* Let's see if this color already exists: */
/*** FIXME: Will it ever occur that ColorIn2 will contain duplicate
* entries? So we should search from 0 to CrntSlot rather than
* ColorIn1->ColorCount?
*/
for (j = 0; j < ColorIn1->ColorCount; j++)
if (memcmp (&ColorIn1->Colors[j], &ColorIn2->Colors[i],
sizeof(GifColorType)) == 0)
break;
if (j < ColorIn1->ColorCount)
ColorTransIn2[i] = j; /* color exists in Color1 */
else {
/* Color is new - copy it to a new slot: */
ColorUnion->Colors[CrntSlot] = ColorIn2->Colors[i];
ColorTransIn2[i] = CrntSlot++;
}
}
if (CrntSlot > 256) {
FreeMapObject(ColorUnion);
return NULL;
}
NewBitSize = BitSize(CrntSlot);
RoundUpTo = (1 << NewBitSize);
if (RoundUpTo != ColorUnion->ColorCount) {
GifColorType *Map = ColorUnion->Colors;
/*
* Zero out slots up to next power of 2.
* We know these slots exist because of the way ColorUnion's
* start dimension was computed.
*/
for (j = CrntSlot; j < RoundUpTo; j++)
Map[j].Red = Map[j].Green = Map[j].Blue = 0;
/* perhaps we can shrink the map? */
if (RoundUpTo < ColorUnion->ColorCount)
ColorUnion->Colors = (GifColorType *)realloc(Map,
sizeof(GifColorType) * RoundUpTo);
}
ColorUnion->ColorCount = RoundUpTo;
ColorUnion->BitsPerPixel = NewBitSize;
return (ColorUnion);
}
/*
* Apply a given color translation to the raster bits of an image
*/
void
ApplyTranslation(SavedImage * Image,
GifPixelType Translation[]) {
int i;
int RasterSize = Image->ImageDesc.Height * Image->ImageDesc.Width;
for (i = 0; i < RasterSize; i++)
Image->RasterBits[i] = Translation[Image->RasterBits[i]];
}
/******************************************************************************
* Extension record functions
*****************************************************************************/
int AddExtensionBlock(SavedImage * New,
int Len,
unsigned char ExtData[],int Function) {
ExtensionBlock *ep;
if (New->ExtensionBlocks == NULL)
New->ExtensionBlocks=malloc(sizeof(ExtensionBlock));
else
New->ExtensionBlocks = realloc(New->ExtensionBlocks,sizeof(ExtensionBlock) *(New->ExtensionBlockCount + 1));
if (New->ExtensionBlocks == NULL)
return (GIF_ERROR);
ep = &New->ExtensionBlocks[New->ExtensionBlockCount++];
ep->ByteCount=Len;
ep->Bytes = malloc(ep->ByteCount);
if (ep->Bytes == NULL)
return (GIF_ERROR);
if (ExtData) {
memcpy(ep->Bytes, ExtData, Len);
ep->Function = Function;
}
return (GIF_OK);
}
void
FreeExtension(SavedImage * Image)
{
ExtensionBlock *ep;
if ((Image == NULL) || (Image->ExtensionBlocks == NULL)) {
return;
}
for (ep = Image->ExtensionBlocks;
ep < (Image->ExtensionBlocks + Image->ExtensionBlockCount); ep++)
(void)free((char *)ep->Bytes);
free((char *)Image->ExtensionBlocks);
Image->ExtensionBlocks = NULL;
}
/******************************************************************************
* Image block allocation functions
******************************************************************************/
/* Private Function:
* Frees the last image in the GifFile->SavedImages array
*/
void
FreeLastSavedImage(GifFileType *GifFile) {
SavedImage *sp;
if ((GifFile == NULL) || (GifFile->SavedImages == NULL))
return;
/* Remove one SavedImage from the GifFile */
GifFile->ImageCount--;
sp = &GifFile->SavedImages[GifFile->ImageCount];
/* Deallocate its Colormap */
if (sp->ImageDesc.ColorMap) {
FreeMapObject(sp->ImageDesc.ColorMap);
sp->ImageDesc.ColorMap = NULL;
}
/* Deallocate the image data */
if (sp->RasterBits)
free((char *)sp->RasterBits);
/* Deallocate any extensions */
if (sp->ExtensionBlocks)
FreeExtension(sp);
/*** FIXME: We could realloc the GifFile->SavedImages structure but is
* there a point to it? Saves some memory but we'd have to do it every
* time. If this is used in FreeSavedImages then it would be inefficient
* (The whole array is going to be deallocated.) If we just use it when
* we want to free the last Image it's convenient to do it here.
*/
}
/*
* Append an image block to the SavedImages array
*/
SavedImage *
MakeSavedImage(GifFileType * GifFile,
const SavedImage * CopyFrom) {
SavedImage *sp;
if (GifFile->SavedImages == NULL)
GifFile->SavedImages = malloc(sizeof(SavedImage));
else
GifFile->SavedImages = realloc(GifFile->SavedImages,sizeof(SavedImage) * (GifFile->ImageCount + 1));
if (GifFile->SavedImages == NULL)
return ((SavedImage *)NULL);
else {
sp = &GifFile->SavedImages[GifFile->ImageCount++];
memset((char *)sp, '\0', sizeof(SavedImage));
if (CopyFrom) {
memcpy((char *)sp, CopyFrom, sizeof(SavedImage));
/*
* Make our own allocated copies of the heap fields in the
* copied record. This guards against potential aliasing
* problems.
*/
/* first, the local color map */
if (sp->ImageDesc.ColorMap) {
sp->ImageDesc.ColorMap = MakeMapObject(
CopyFrom->ImageDesc.ColorMap->ColorCount,
CopyFrom->ImageDesc.ColorMap->Colors);
if (sp->ImageDesc.ColorMap == NULL) {
FreeLastSavedImage(GifFile);
return (SavedImage *)(NULL);
}
}
/* next, the raster */
sp->RasterBits = malloc(sizeof(GifPixelType) *
CopyFrom->ImageDesc.Height *
CopyFrom->ImageDesc.Width);
if (sp->RasterBits == NULL) {
FreeLastSavedImage(GifFile);
return (SavedImage *)(NULL);
}
memcpy(sp->RasterBits, CopyFrom->RasterBits,
sizeof(GifPixelType) * CopyFrom->ImageDesc.Height *
CopyFrom->ImageDesc.Width);
/* finally, the extension blocks */
if (sp->ExtensionBlocks) {
sp->ExtensionBlocks = malloc(sizeof(ExtensionBlock) *CopyFrom->ExtensionBlockCount);
if (sp->ExtensionBlocks == NULL) {
FreeLastSavedImage(GifFile);
return (SavedImage *)(NULL);
}
memcpy(sp->ExtensionBlocks, CopyFrom->ExtensionBlocks,
sizeof(ExtensionBlock) * CopyFrom->ExtensionBlockCount);
/*
* For the moment, the actual blocks can take their
* chances with free(). We'll fix this later.
*** FIXME: [Better check this out... Toshio]
* 2004 May 27: Looks like this was an ESR note.
* It means the blocks are shallow copied from InFile to
* OutFile. However, I don't see that in this code....
* Did ESR fix it but never remove this note (And other notes
* in gifspnge?)
*/
}
}
return (sp);
}
}
void
FreeSavedImages(GifFileType * GifFile) {
SavedImage *sp;
if ((GifFile == NULL) || (GifFile->SavedImages == NULL)) {
return;
}
for (sp = GifFile->SavedImages;
sp < GifFile->SavedImages + GifFile->ImageCount; sp++) {
if (sp->ImageDesc.ColorMap) {
FreeMapObject(sp->ImageDesc.ColorMap);
sp->ImageDesc.ColorMap = NULL;
}
if (sp->RasterBits)
free((char *)sp->RasterBits);
if (sp->ExtensionBlocks)
FreeExtension(sp);
}
free((char *)GifFile->SavedImages);
GifFile->SavedImages=NULL;
}
/****************************************************************************
* Routine called by qsort to compare to entries.
****************************************************************************/
static int SortCmpRtnR(const void * Entry1,const void * Entry2) {
return (*((QuantizedColorType **) Entry1))->RGB[0] - (*((QuantizedColorType **) Entry2))->RGB[0];
}
static int SortCmpRtnG(const void * Entry1,const void * Entry2) {
return (*((QuantizedColorType **) Entry1))->RGB[1] - (*((QuantizedColorType **) Entry2))->RGB[1];
}
static int SortCmpRtnB(const void * Entry1,const void * Entry2) {
return (*((QuantizedColorType **) Entry1))->RGB[2] - (*((QuantizedColorType **) Entry2))->RGB[2];
}
/******************************************************************************
* Routine to subdivide the RGB space recursively using median cut in each
* axes alternatingly until ColorMapSize different cubes exists.
* The biggest cube in one dimension is subdivide unless it has only one entry.
* Returns GIF_ERROR if failed, otherwise GIF_OK.
******************************************************************************/
static int SubdivColorMap(NewColorMapType * NewColorSubdiv,unsigned int ColorMapSize,unsigned int *NewColorMapSize) {
int MaxSize;
int SortRGBAxis=0;
unsigned int i, j, Index = 0, NumEntries, MinColor, MaxColor;
long Sum, Count;
QuantizedColorType *QuantizedColor, **SortArray;
while (ColorMapSize > *NewColorMapSize) {
/* Find candidate for subdivision: */
MaxSize = -1;
for (i = 0; i < *NewColorMapSize; i++) {
for (j = 0; j < 3; j++) {
if ((((int)NewColorSubdiv[i].RGBWidth[j]) > MaxSize) &&
(NewColorSubdiv[i].NumEntries > 1)) {
MaxSize = NewColorSubdiv[i].RGBWidth[j];
Index = i;
SortRGBAxis = j;
}
}
}
if (MaxSize == -1)
return GIF_OK;
/* Split the entry Index into two along the axis SortRGBAxis: */
/* Sort all elements in that entry along the given axis and split at
* the median. */
SortArray = malloc(sizeof(QuantizedColorType *) * NewColorSubdiv[Index].NumEntries);
if (SortArray == NULL)
return GIF_ERROR;
for (j = 0, QuantizedColor = NewColorSubdiv[Index].QuantizedColors;
j < NewColorSubdiv[Index].NumEntries && QuantizedColor != NULL;
j++, QuantizedColor = QuantizedColor->Pnext)
SortArray[j] = QuantizedColor;
int (*compare)(const void * Entry1,const void * Entry2);
if(SortRGBAxis==0)
compare=SortCmpRtnR;
else if(SortRGBAxis==1)
compare=SortCmpRtnG;
else
compare=SortCmpRtnB;
qsort(SortArray, NewColorSubdiv[Index].NumEntries,sizeof(QuantizedColorType *), compare);
/* Relink the sorted list into one: */
for (j = 0; j < NewColorSubdiv[Index].NumEntries - 1; j++)
SortArray[j]->Pnext = SortArray[j + 1];
SortArray[NewColorSubdiv[Index].NumEntries - 1]->Pnext = NULL;
NewColorSubdiv[Index].QuantizedColors = QuantizedColor = SortArray[0];
free((char *)SortArray);
/* Now simply add the Counts until we have half of the Count: */
Sum = NewColorSubdiv[Index].Count / 2 - QuantizedColor->Count;
NumEntries = 1;
Count = QuantizedColor->Count;
while ((Sum -= QuantizedColor->Pnext->Count) >= 0 &&
QuantizedColor->Pnext != NULL &&
QuantizedColor->Pnext->Pnext != NULL) {
QuantizedColor = QuantizedColor->Pnext;
NumEntries++;
Count += QuantizedColor->Count;
}
/* Save the values of the last color of the first half, and first
* of the second half so we can update the Bounding Boxes later.
* Also as the colors are quantized and the BBoxes are full 0..255,
* they need to be rescaled.
*/
MaxColor = QuantizedColor->RGB[SortRGBAxis]; /* Max. of first half */
MinColor = QuantizedColor->Pnext->RGB[SortRGBAxis]; /* of second */
MaxColor <<= (8 - BITS_PER_PRIM_COLOR);
MinColor <<= (8 - BITS_PER_PRIM_COLOR);
/* Partition right here: */
NewColorSubdiv[*NewColorMapSize].QuantizedColors =
QuantizedColor->Pnext;
QuantizedColor->Pnext = NULL;
NewColorSubdiv[*NewColorMapSize].Count = Count;
NewColorSubdiv[Index].Count -= Count;
NewColorSubdiv[*NewColorMapSize].NumEntries =
NewColorSubdiv[Index].NumEntries - NumEntries;
NewColorSubdiv[Index].NumEntries = NumEntries;
for (j = 0; j < 3; j++) {
NewColorSubdiv[*NewColorMapSize].RGBMin[j] =
NewColorSubdiv[Index].RGBMin[j];
NewColorSubdiv[*NewColorMapSize].RGBWidth[j] =
NewColorSubdiv[Index].RGBWidth[j];
}
NewColorSubdiv[*NewColorMapSize].RGBWidth[SortRGBAxis] =
NewColorSubdiv[*NewColorMapSize].RGBMin[SortRGBAxis] +
NewColorSubdiv[*NewColorMapSize].RGBWidth[SortRGBAxis] - MinColor;
NewColorSubdiv[*NewColorMapSize].RGBMin[SortRGBAxis] = MinColor;
NewColorSubdiv[Index].RGBWidth[SortRGBAxis] =
MaxColor - NewColorSubdiv[Index].RGBMin[SortRGBAxis];
(*NewColorMapSize)++;
}
return GIF_OK;
}
/******************************************************************************
* Quantize high resolution image into lower one. Input image consists of a
* 2D array for each of the RGB colors with size Width by Height. There is no
* Color map for the input. Output is a quantized image with 2D array of
* indexes into the output color map.
* Note input image can be 24 bits at the most (8 for red/green/blue) and
* the output has 256 colors at the most (256 entries in the color map.).
* ColorMapSize specifies size of color map up to 256 and will be updated to
* real size before returning.
* Also non of the parameter are allocated by this routine.
* This function returns GIF_OK if succesfull, GIF_ERROR otherwise.
******************************************************************************/
int QuantizeBuffer(unsigned int Width,unsigned int Height,int *ColorMapSize,uint8_t * RedInput,uint8_t * GreenInput,uint8_t * BlueInput,uint8_t * OutputBuffer,GifColorType * OutputColorMap) {
unsigned int Index, NumOfEntries;
int i, j, MaxRGBError[3];
unsigned int NewColorMapSize;
long Red, Green, Blue;
NewColorMapType NewColorSubdiv[256];
QuantizedColorType *ColorArrayEntries, *QuantizedColor;
ColorArrayEntries = malloc(sizeof(QuantizedColorType) * COLOR_ARRAY_SIZE);
if (ColorArrayEntries == NULL) {
return GIF_ERROR;
}
for (i = 0; i < COLOR_ARRAY_SIZE; i++) {
ColorArrayEntries[i].RGB[0] = i >> (2 * BITS_PER_PRIM_COLOR);
ColorArrayEntries[i].RGB[1] = (i >> BITS_PER_PRIM_COLOR) &
MAX_PRIM_COLOR;
ColorArrayEntries[i].RGB[2] = i & MAX_PRIM_COLOR;
ColorArrayEntries[i].Count = 0;
}
/* Sample the colors and their distribution: */
for (i = 0; i < (int)(Width * Height); i++) {
Index = ((RedInput[i] >> (8 - BITS_PER_PRIM_COLOR)) <<
(2 * BITS_PER_PRIM_COLOR)) +
((GreenInput[i] >> (8 - BITS_PER_PRIM_COLOR)) <<
BITS_PER_PRIM_COLOR) +
(BlueInput[i] >> (8 - BITS_PER_PRIM_COLOR));
ColorArrayEntries[Index].Count++;
}
/* Put all the colors in the first entry of the color map, and call the
* recursive subdivision process. */
for (i = 0; i < 256; i++) {
NewColorSubdiv[i].QuantizedColors = NULL;
NewColorSubdiv[i].Count = NewColorSubdiv[i].NumEntries = 0;
for (j = 0; j < 3; j++) {
NewColorSubdiv[i].RGBMin[j] = 0;
NewColorSubdiv[i].RGBWidth[j] = 255;
}
}
/* Find the non empty entries in the color table and chain them: */
for (i = 0; i < COLOR_ARRAY_SIZE; i++)
if (ColorArrayEntries[i].Count > 0)
break;
QuantizedColor = NewColorSubdiv[0].QuantizedColors = &ColorArrayEntries[i];
NumOfEntries = 1;
while (++i < COLOR_ARRAY_SIZE)
if (ColorArrayEntries[i].Count > 0) {
QuantizedColor->Pnext = &ColorArrayEntries[i];
QuantizedColor = &ColorArrayEntries[i];
NumOfEntries++;
}
QuantizedColor->Pnext = NULL;
NewColorSubdiv[0].NumEntries = NumOfEntries; /* Different sampled colors */
NewColorSubdiv[0].Count = ((long)Width) * Height; /* Pixels */
NewColorMapSize = 1;
if (SubdivColorMap(NewColorSubdiv, *ColorMapSize, &NewColorMapSize) !=
GIF_OK) {
free((char *)ColorArrayEntries);
return GIF_ERROR;
}
if (NewColorMapSize < *ColorMapSize) {
/* And clear rest of color map: */
for (i = NewColorMapSize; i < *ColorMapSize; i++)
OutputColorMap[i].Red = OutputColorMap[i].Green =
OutputColorMap[i].Blue = 0;
}
/* Average the colors in each entry to be the color to be used in the
* output color map, and plug it into the output color map itself. */
for (i = 0; i < NewColorMapSize; i++) {
if ((j = NewColorSubdiv[i].NumEntries) > 0) {
QuantizedColor = NewColorSubdiv[i].QuantizedColors;
Red = Green = Blue = 0;
while (QuantizedColor) {
QuantizedColor->NewColorIndex = i;
Red += QuantizedColor->RGB[0];
Green += QuantizedColor->RGB[1];
Blue += QuantizedColor->RGB[2];
QuantizedColor = QuantizedColor->Pnext;
}
OutputColorMap[i].Red = (Red << (8 - BITS_PER_PRIM_COLOR)) / j;
OutputColorMap[i].Green = (Green << (8 - BITS_PER_PRIM_COLOR)) / j;
OutputColorMap[i].Blue = (Blue << (8 - BITS_PER_PRIM_COLOR)) / j;
} else
NSLog(@"GIF-LIB: Null entry in quantized color map - that's weird.\n");
}
/* Finally scan the input buffer again and put the mapped index in the
* output buffer. */
MaxRGBError[0] = MaxRGBError[1] = MaxRGBError[2] = 0;
for (i = 0; i < (int)(Width * Height); i++) {
Index = ((RedInput[i] >> (8 - BITS_PER_PRIM_COLOR)) <<
(2 * BITS_PER_PRIM_COLOR)) +
((GreenInput[i] >> (8 - BITS_PER_PRIM_COLOR)) <<
BITS_PER_PRIM_COLOR) +
(BlueInput[i] >> (8 - BITS_PER_PRIM_COLOR));
Index = ColorArrayEntries[Index].NewColorIndex;
OutputBuffer[i] = Index;
if (MaxRGBError[0] < ABS(OutputColorMap[Index].Red - RedInput[i]))
MaxRGBError[0] = ABS(OutputColorMap[Index].Red - RedInput[i]);
if (MaxRGBError[1] < ABS(OutputColorMap[Index].Green - GreenInput[i]))
MaxRGBError[1] = ABS(OutputColorMap[Index].Green - GreenInput[i]);
if (MaxRGBError[2] < ABS(OutputColorMap[Index].Blue - BlueInput[i]))
MaxRGBError[2] = ABS(OutputColorMap[Index].Blue - BlueInput[i]);
}
free((char *)ColorArrayEntries);
*ColorMapSize = NewColorMapSize;
return GIF_OK;
}
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