406 lines
13 KiB
C
406 lines
13 KiB
C
|
/*****************************************************************************
|
||
|
|
||
|
GIF construction tools
|
||
|
|
||
|
****************************************************************************/
|
||
|
|
||
|
#include <stdlib.h>
|
||
|
/* #include <stdio.h> */
|
||
|
#include <string.h>
|
||
|
|
||
|
#include "gif_lib.h"
|
||
|
|
||
|
#ifndef MAX
|
||
|
#define MAX(x, y) (((x) > (y)) ? (x) : (y))
|
||
|
#endif
|
||
|
|
||
|
/******************************************************************************
|
||
|
Miscellaneous utility functions
|
||
|
******************************************************************************/
|
||
|
|
||
|
/* return smallest bitfield size n will fit in */
|
||
|
int
|
||
|
GifBitSize(int n)
|
||
|
{
|
||
|
register int i;
|
||
|
|
||
|
for (i = 1; i <= 8; i++)
|
||
|
if ((1 << i) >= n)
|
||
|
break;
|
||
|
return (i);
|
||
|
}
|
||
|
|
||
|
/******************************************************************************
|
||
|
Color map object functions
|
||
|
******************************************************************************/
|
||
|
|
||
|
/*
|
||
|
* Allocate a color map of given size; initialize with contents of
|
||
|
* ColorMap if that pointer is non-NULL.
|
||
|
*/
|
||
|
ColorMapObject *
|
||
|
GifMakeMapObject(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 << GifBitSize(ColorCount))) {
|
||
|
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) {
|
||
|
free(Object);
|
||
|
return ((ColorMapObject *) NULL);
|
||
|
}
|
||
|
|
||
|
Object->ColorCount = ColorCount;
|
||
|
Object->BitsPerPixel = GifBitSize(ColorCount);
|
||
|
|
||
|
if (ColorMap != NULL) {
|
||
|
memcpy((char *)Object->Colors,
|
||
|
(char *)ColorMap, ColorCount * sizeof(GifColorType));
|
||
|
}
|
||
|
|
||
|
return (Object);
|
||
|
}
|
||
|
|
||
|
/*******************************************************************************
|
||
|
Free a color map object
|
||
|
*******************************************************************************/
|
||
|
void
|
||
|
GifFreeMapObject(ColorMapObject *Object)
|
||
|
{
|
||
|
if (Object != NULL) {
|
||
|
(void)free(Object->Colors);
|
||
|
(void)free(Object);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* #ifdef DEBUG */
|
||
|
#if 0
|
||
|
void
|
||
|
DumpColorMap(ColorMapObject *Object,
|
||
|
FILE * fp)
|
||
|
{
|
||
|
if (Object != NULL) {
|
||
|
int i, j, Len = Object->ColorCount;
|
||
|
|
||
|
for (i = 0; i < Len; i += 4) {
|
||
|
for (j = 0; j < 4 && j < Len; j++) {
|
||
|
(void)fprintf(fp, "%3d: %02x %02x %02x ", i + j,
|
||
|
Object->Colors[i + j].Red,
|
||
|
Object->Colors[i + j].Green,
|
||
|
Object->Colors[i + j].Blue);
|
||
|
}
|
||
|
(void)fprintf(fp, "\n");
|
||
|
}
|
||
|
}
|
||
|
}
|
||
|
#endif /* DEBUG */
|
||
|
|
||
|
/*******************************************************************************
|
||
|
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 the ColorUnion color map table./
|
||
|
*******************************************************************************/
|
||
|
ColorMapObject *
|
||
|
GifUnionColorMap(const ColorMapObject *ColorIn1,
|
||
|
const ColorMapObject *ColorIn2,
|
||
|
GifPixelType ColorTransIn2[])
|
||
|
{
|
||
|
int i, j, CrntSlot, RoundUpTo, NewGifBitSize;
|
||
|
ColorMapObject *ColorUnion;
|
||
|
|
||
|
/*
|
||
|
* We don't worry about duplicates within either color map; if
|
||
|
* the caller wants to resolve those, he can perform unions
|
||
|
* with an empty color map.
|
||
|
*/
|
||
|
|
||
|
/* Allocate table which will hold the result for sure. */
|
||
|
ColorUnion = GifMakeMapObject(MAX(ColorIn1->ColorCount,
|
||
|
ColorIn2->ColorCount) * 2, NULL);
|
||
|
|
||
|
if (ColorUnion == NULL)
|
||
|
return (NULL);
|
||
|
|
||
|
/*
|
||
|
* Copy ColorIn1 to ColorUnion.
|
||
|
*/
|
||
|
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 ColorUnion (use old colors if they exist): */
|
||
|
for (i = 0; i < ColorIn2->ColorCount && CrntSlot <= 256; i++) {
|
||
|
/* Let's see if this color already exists: */
|
||
|
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) {
|
||
|
GifFreeMapObject(ColorUnion);
|
||
|
return ((ColorMapObject *) NULL);
|
||
|
}
|
||
|
|
||
|
NewGifBitSize = GifBitSize(CrntSlot);
|
||
|
RoundUpTo = (1 << NewGifBitSize);
|
||
|
|
||
|
if (RoundUpTo != ColorUnion->ColorCount) {
|
||
|
register 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 = NewGifBitSize;
|
||
|
|
||
|
return (ColorUnion);
|
||
|
}
|
||
|
|
||
|
/*******************************************************************************
|
||
|
Apply a given color translation to the raster bits of an image
|
||
|
*******************************************************************************/
|
||
|
void
|
||
|
GifApplyTranslation(SavedImage *Image, GifPixelType Translation[])
|
||
|
{
|
||
|
register int i;
|
||
|
register 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
|
||
|
GifAddExtensionBlock(int *ExtensionBlockCount,
|
||
|
ExtensionBlock **ExtensionBlocks,
|
||
|
int Function,
|
||
|
unsigned int Len,
|
||
|
unsigned char ExtData[])
|
||
|
{
|
||
|
ExtensionBlock *ep;
|
||
|
|
||
|
if (*ExtensionBlocks == NULL)
|
||
|
*ExtensionBlocks=(ExtensionBlock *)malloc(sizeof(ExtensionBlock));
|
||
|
else
|
||
|
*ExtensionBlocks = (ExtensionBlock *)realloc(*ExtensionBlocks,
|
||
|
sizeof(ExtensionBlock) *
|
||
|
(*ExtensionBlockCount + 1));
|
||
|
|
||
|
if (*ExtensionBlocks == NULL)
|
||
|
return (GIF_ERROR);
|
||
|
|
||
|
ep = &(*ExtensionBlocks)[(*ExtensionBlockCount)++];
|
||
|
|
||
|
ep->Function = Function;
|
||
|
ep->ByteCount=Len;
|
||
|
ep->Bytes = (GifByteType *)malloc(ep->ByteCount);
|
||
|
if (ep->Bytes == NULL)
|
||
|
return (GIF_ERROR);
|
||
|
|
||
|
if (ExtData != NULL) {
|
||
|
memcpy(ep->Bytes, ExtData, Len);
|
||
|
}
|
||
|
|
||
|
return (GIF_OK);
|
||
|
}
|
||
|
|
||
|
void
|
||
|
GifFreeExtensions(int *ExtensionBlockCount,
|
||
|
ExtensionBlock **ExtensionBlocks)
|
||
|
{
|
||
|
ExtensionBlock *ep;
|
||
|
|
||
|
if (*ExtensionBlocks == NULL)
|
||
|
return;
|
||
|
|
||
|
for (ep = *ExtensionBlocks;
|
||
|
ep < (*ExtensionBlocks + *ExtensionBlockCount);
|
||
|
ep++)
|
||
|
(void)free((char *)ep->Bytes);
|
||
|
(void)free((char *)*ExtensionBlocks);
|
||
|
*ExtensionBlocks = NULL;
|
||
|
*ExtensionBlockCount = 0;
|
||
|
}
|
||
|
|
||
|
/******************************************************************************
|
||
|
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 != NULL) {
|
||
|
GifFreeMapObject(sp->ImageDesc.ColorMap);
|
||
|
sp->ImageDesc.ColorMap = NULL;
|
||
|
}
|
||
|
|
||
|
/* Deallocate the image data */
|
||
|
if (sp->RasterBits != NULL)
|
||
|
free((char *)sp->RasterBits);
|
||
|
|
||
|
/* Deallocate any extensions */
|
||
|
GifFreeExtensions(&sp->ExtensionBlockCount, &sp->ExtensionBlocks);
|
||
|
|
||
|
/*** 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 GifFreeSavedImages 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 *
|
||
|
GifMakeSavedImage(GifFileType *GifFile, const SavedImage *CopyFrom)
|
||
|
{
|
||
|
SavedImage *sp;
|
||
|
|
||
|
if (GifFile->SavedImages == NULL)
|
||
|
GifFile->SavedImages = (SavedImage *)malloc(sizeof(SavedImage));
|
||
|
else
|
||
|
GifFile->SavedImages = (SavedImage *)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 != NULL) {
|
||
|
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 != NULL) {
|
||
|
sp->ImageDesc.ColorMap = GifMakeMapObject(
|
||
|
CopyFrom->ImageDesc.ColorMap->ColorCount,
|
||
|
CopyFrom->ImageDesc.ColorMap->Colors);
|
||
|
if (sp->ImageDesc.ColorMap == NULL) {
|
||
|
FreeLastSavedImage(GifFile);
|
||
|
return (SavedImage *)(NULL);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* next, the raster */
|
||
|
sp->RasterBits = (unsigned char *)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 != NULL) {
|
||
|
sp->ExtensionBlocks = (ExtensionBlock *)malloc(
|
||
|
sizeof(ExtensionBlock) *
|
||
|
CopyFrom->ExtensionBlockCount);
|
||
|
if (sp->ExtensionBlocks == NULL) {
|
||
|
FreeLastSavedImage(GifFile);
|
||
|
return (SavedImage *)(NULL);
|
||
|
}
|
||
|
memcpy(sp->ExtensionBlocks, CopyFrom->ExtensionBlocks,
|
||
|
sizeof(ExtensionBlock) * CopyFrom->ExtensionBlockCount);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
return (sp);
|
||
|
}
|
||
|
}
|
||
|
|
||
|
void
|
||
|
GifFreeSavedImages(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 != NULL) {
|
||
|
GifFreeMapObject(sp->ImageDesc.ColorMap);
|
||
|
sp->ImageDesc.ColorMap = NULL;
|
||
|
}
|
||
|
|
||
|
if (sp->RasterBits != NULL)
|
||
|
free((char *)sp->RasterBits);
|
||
|
|
||
|
GifFreeExtensions(&sp->ExtensionBlockCount, &sp->ExtensionBlocks);
|
||
|
}
|
||
|
free((char *)GifFile->SavedImages);
|
||
|
GifFile->SavedImages = NULL;
|
||
|
}
|
||
|
|
||
|
/* end */
|