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gl2gif.cpp 36.25 KiB
/*
This file is a big hack from
The GIFLIB distribution is Copyright (c) 1997 Eric S. Raymond
*/
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <ctype.h>
#include <unistd.h>
#include <GL/gl.h>
#include "gl2gif.h"
static int _GifError = 0;
static int ExpNumOfColors = 8, ColorMapSize = 256;
/******************************************************************************
* Initialize HashTable - allocate the memory needed and clear it. *
******************************************************************************/
GifHashTableType *_InitHashTable(void)
{
GifHashTableType *HashTable;
if ((HashTable = (GifHashTableType *) malloc(sizeof(GifHashTableType)))
== NULL)
return NULL;
_ClearHashTable(HashTable);
return HashTable;
}
/******************************************************************************
* 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)
{
int index = HT_SIZE;
unsigned long* HTable = HashTable->HTable;
while (--index>=0)
HTable[index] = 0xfffffffful;
}
/******************************************************************************
* 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 int KeyItem(unsigned long Item)
{
return ((Item >> 12) ^ Item) & HT_KEY_MASK;
}
/******************************************************************************
* Routine to insert a new Item into the HashTable. The data is assumed to be *
* new one. *
******************************************************************************/
void _InsertHashTable(GifHashTableType *HashTable, unsigned long Key, int Code)
{ int HKey = KeyItem(Key);
unsigned long *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, unsigned long Key)
{
int HKey = KeyItem(Key);
unsigned long *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;
}
/******************************************************************************
* Miscellaneous utility functions *
******************************************************************************/
int BitSize(int n)
/* return smallest bitfield size n will fit in */
{
register int i;
for (i = 1; i <= 8; i++)
if ((1 << i) >= n)
break;
return(i);
}
/******************************************************************************
* Color map object functions *
******************************************************************************/
ColorMapObject *MakeMapObject(int ColorCount, GifColorType *ColorMap)
{
ColorMapObject *Object;
if (ColorCount != (1 << BitSize(ColorCount))){
printf("Arrrrrgggg\n");
return((ColorMapObject *)NULL);
}
Object = (ColorMapObject *)malloc(sizeof(ColorMapObject));
if (Object == (ColorMapObject *)NULL)
return((ColorMapObject *)NULL);
Object->Colors = (GifColorType *)calloc(ColorCount, sizeof(GifColorType));
if (Object->Colors == (GifColorType *)NULL)
return((ColorMapObject *)NULL);
Object->ColorCount = ColorCount;
Object->BitsPerPixel = BitSize(ColorCount);
if (ColorMap)
memcpy((char *)Object->Colors,
(char *)ColorMap, ColorCount * sizeof(GifColorType));
return(Object);
}
void FreeMapObject(ColorMapObject *Object)
{
free(Object->Colors);
free(Object);
}
/*****************************************************************************
* Print the last GIF error to stderr. *
*****************************************************************************/
void PrintGifError(void)
{
char *Err;
switch(_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;
default:
Err = NULL;
break;
}
if (Err != NULL)
fprintf(stderr, "Error: %s\n", Err);
else
fprintf(stderr, "Error: GIF undefined error %d\n", _GifError);
}
#define ABS(x) ((x) > 0 ? (x) : (-(x)))
#define COLOR_ARRAY_SIZE 32768
#define BITS_PER_PRIM_COLOR 5
#define MAX_PRIM_COLOR 0x1f
static int SortRGBAxis;
typedef struct QuantizedColorType {
GifByteType RGB[3];
GifByteType NewColorIndex;
long Count;
struct QuantizedColorType *Pnext;} QuantizedColorType;
typedef struct NewColorMapType {
GifByteType RGBMin[3], RGBWidth[3];
int NumEntries; /* # of QuantizedColorType in linked list below. */
long Count; /* Total number of pixels in all the entries. */
QuantizedColorType *QuantizedColors;
} NewColorMapType;
static int SubdivColorMap(NewColorMapType *NewColorSubdiv,
int ColorMapSize,
int *NewColorMapSize);
static int SortCmpRtn(const VoidPtr Entry1, const VoidPtr Entry2);
/******************************************************************************
* 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(int Width, int Height, int *ColorMapSize,
GifByteType *RedInput, GifByteType *GreenInput, GifByteType *BlueInput,
GifByteType *OutputBuffer, GifColorType *OutputColorMap)
{
int Index, NumOfEntries;
int i, j, MaxRGBError[3];
int NewColorMapSize;
long Red, Green, Blue;
NewColorMapType NewColorSubdiv[256];
QuantizedColorType *ColorArrayEntries, *QuantizedColor;
if ((ColorArrayEntries = (QuantizedColorType *)
malloc(sizeof(QuantizedColorType) * COLOR_ARRAY_SIZE)) == NULL) {
_GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
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
fprintf(stderr, "Warning, 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;
}
/******************************************************************************
* 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,
int ColorMapSize,
int *NewColorMapSize)
{
int MaxSize;
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. */
if ((SortArray = (QuantizedColorType **)
malloc(sizeof(QuantizedColorType *) *
NewColorSubdiv[Index].NumEntries)) == NULL)
return GIF_ERROR;
for (j = 0, QuantizedColor = NewColorSubdiv[Index].QuantizedColors;
j < NewColorSubdiv[Index].NumEntries && QuantizedColor != NULL;
j++, QuantizedColor = QuantizedColor -> Pnext)
SortArray[j] = QuantizedColor;
qsort(SortArray, NewColorSubdiv[Index].NumEntries,
sizeof(QuantizedColorType *), SortCmpRtn);
/* 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;
}
/******************************************************************************
* Routine called by qsort to compare to entries. *
******************************************************************************/
static int SortCmpRtn(const VoidPtr Entry1, const VoidPtr Entry2)
{
return (* ((QuantizedColorType **) Entry1)) -> RGB[SortRGBAxis] -
(* ((QuantizedColorType **) Entry2)) -> RGB[SortRGBAxis];
}
#define GIF87_STAMP "GIF87a" /* First chars in file - GIF stamp. */
#define GIF89_STAMP "GIF89a" /* First chars in file - GIF stamp. */
/* 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 = GIF87_STAMP;
#define 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);
/******************************************************************************
* 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(FILE *f, int FileHandle)
{
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;
}
if ((Private->HashTable = _InitHashTable()) == NULL) {
free(GifFile);
free(Private);
_GifError = E_GIF_ERR_NOT_ENOUGH_MEM;
return NULL;
}
GifFile->Private = (VoidPtr) Private;
Private->FileHandle = FileHandle;
Private->File = f;
Private->FileState = FILE_STATE_WRITE;
_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(char *Version)
{
strncpy(&GifVersionPrefix[3], 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,
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. */
if (WRITE(GifFile, GifVersionPrefix, strlen(GifVersionPrefix)) != strlen(GifVersionPrefix)) {
_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);
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;
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) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
/* 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,
ColorMapObject *ColorMap)
{
int i;
GifByteType Buf[3];
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
if (Private->FileState & FILE_STATE_IMAGE &&
#if defined(__GNUC__)
Private->PixelCount > 0xffff0000UL) {
#else
Private->PixelCount > 0xffff0000) {
#endif
/* 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. */
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) {
_GifError = E_GIF_ERR_WRITE_FAILED;
return GIF_ERROR;
}
}
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);
}
/******************************************************************************
* This routine should be called last, to close GIF file. *
******************************************************************************/
int EGifCloseFile(GifFileType *GifFile)
{
GifByteType Buf;
GifFilePrivateType *Private;
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;
}
Buf = ';';
WRITE(GifFile, &Buf, 1);
if (GifFile->Image.ColorMap)
FreeMapObject(GifFile->Image.ColorMap);
if (GifFile->SColorMap)
FreeMapObject(GifFile->SColorMap);
if (Private) {
if (Private->HashTable) free((char *) Private->HashTable);
free((char *) Private);
}
free(GifFile);
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;
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;
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 = Private->EOFCode + 1;
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;
/* Clear hash table and send Clear to make sure the decoder do the same. */
_ClearHashTable(Private->HashTable);
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;
GifHashTableType *HashTable;
GifFilePrivateType *Private = (GifFilePrivateType *) GifFile->Private;
HashTable = Private->HashTable;
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. */
/* Form a new unique key to search hash table for the code combines */
/* CrntCode as Prefix string with Pixel as postfix char. */
NewKey = (((unsigned long) 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) {
_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 (Private->RunningCode >= LZ_MAX_CODE) {
/* Time to do some clearance: */
if (EGifCompressOutput(GifFile, Private->ClearCode)
== GIF_ERROR) {
_GifError = E_GIF_ERR_DISK_IS_FULL;
return GIF_ERROR;
}
Private->RunningCode = Private->EOFCode + 1;
Private->RunningBits = Private->BitsPerPixel + 1;
Private->MaxCode1 = 1 << Private->RunningBits;
_ClearHashTable(HashTable);
}
else {
/* Put this unique key with its relative Code in hash table: */
_InsertHashTable(HashTable, NewKey, Private->RunningCode++);
}
}
}
/* 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;
}
}
/* If code cannt fit into RunningBits bits, must raise its size. Note */
/* however that codes above 4095 are used for special signaling. */
if (Private->RunningCode >= Private->MaxCode1 && Code <= 4095) {
Private->MaxCode1 = 1 << ++Private->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, 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;
}
static void QuitGifError(GifFileType *GifFile)
{
PrintGifError();
if (GifFile != NULL) EGifCloseFile(GifFile);
}
static void SaveGif(FILE *fp,
GifByteType *OutputBuffer,
ColorMapObject *OutputColorMap,
int ExpColorMapSize, int Width, int Height){
int i;
GifFileType *GifFile;
GifByteType *Ptr;
if ((GifFile = EGifOpenFileHandle(fp, 1)) == NULL){
QuitGifError(GifFile);
return;
}
if (EGifPutScreenDesc(GifFile, Width, Height, ExpColorMapSize, 0, OutputColorMap) == GIF_ERROR){
QuitGifError(GifFile);
return;
}
if (EGifPutImageDesc(GifFile, 0, 0, Width, Height, FALSE, NULL) == GIF_ERROR){
QuitGifError(GifFile);
return;
}
Ptr = &OutputBuffer[(Height-1)*Width] ;
for (i = 0; i < Height; i++) {
if (EGifPutLine(GifFile, Ptr, Width) == GIF_ERROR){
QuitGifError(GifFile);
return;
}
Ptr -= Width;
}
if (EGifCloseFile(GifFile) == GIF_ERROR)
QuitGifError(GifFile);
}
void create_gif(FILE *fp, int width, int height){
GifByteType *RedBuffer, *GreenBuffer, *BlueBuffer, *OutputBuffer = NULL;
ColorMapObject *OutputColorMap = NULL;
_GifError = 0;
ExpNumOfColors = 8;
ColorMapSize = 256;
RedBuffer = (unsigned char *)malloc(height*width*sizeof(unsigned char));
GreenBuffer = (unsigned char *)malloc(height*width*sizeof(unsigned char));
BlueBuffer = (unsigned char *)malloc(height*width*sizeof(unsigned char));
if(!RedBuffer || !GreenBuffer || !BlueBuffer){
fprintf(stderr, "Error: Failed to allocate memory for RGB Buffers\n");
return;
}
glReadPixels(0,0,width,height,GL_RED,GL_UNSIGNED_BYTE,RedBuffer);
glReadPixels(0,0,width,height,GL_GREEN,GL_UNSIGNED_BYTE,GreenBuffer);
glReadPixels(0,0,width,height,GL_BLUE,GL_UNSIGNED_BYTE,BlueBuffer);
if (!(OutputColorMap = MakeMapObject(ColorMapSize, NULL))){
fprintf(stderr, "Warning: Failed to allocate memory for ColorMap\n");
return;
}
if(!(OutputBuffer = (GifByteType *) malloc(width * height * sizeof(GifByteType)))){ fprintf(stderr, "Error: Failed to allocate memory for Output Buffer\n");
return;
}
if (QuantizeBuffer(width, height, &ColorMapSize,
RedBuffer, GreenBuffer, BlueBuffer,
OutputBuffer, OutputColorMap->Colors) == GIF_ERROR)
fprintf(stderr, "Warning: Quantize Buffer Failed\n");
free(RedBuffer);
free(GreenBuffer);
free(BlueBuffer);
SaveGif(fp, OutputBuffer, OutputColorMap, ExpNumOfColors, width, height);
}