// ****************************************************************************
// * LoadGIF *
// * Load a GIF File into the CAnimatedGifSet object *
// * (c) Nov 2000, Juan Soulie <*****@*****.**> *
// ****************************************************************************
int CAnimatedGifSet::LoadGIF (const char * szFileName)
{
int n;
// Global GIF variables:
int GlobalBPP; // Bits per Pixel.
COLOR * GlobalColorMap; // Global colormap (allocate)
struct GIFGCEtag
{ // GRAPHIC CONTROL EXTENSION
unsigned char BlockSize; // Block Size: 4 bytes
unsigned char PackedFields; // 3.. Packed Fields. Bits detail:
// 0: Transparent Color Flag
// 1: User Input Flag
// 2-4: Disposal Method
unsigned short Delay; // 4..5 Delay Time (1/100 seconds)
unsigned char Transparent; // 6.. Transparent Color Index
}
gifgce;
struct GIFNetscapeTag
{
unsigned char comment[11]; //4...14 NETSCAPE2.0
unsigned char SubBlockLength; //15 0x3
unsigned char reserved; //16 0x1
unsigned short iIterations ; //17..18 number of iterations (lo-hi)
}
gifnetscape;
int GraphicExtensionFound = 0;
// OPEN FILE
FILE *fd = fopen_utf8(CSpecialProtocol::TranslatePath(szFileName), "rb");
if (!fd)
{
return 0;
}
// *1* READ HEADERBLOCK (6bytes) (SIGNATURE + VERSION)
char szSignature[6]; // First 6 bytes (GIF87a or GIF89a)
int iRead = fread(szSignature, 1, 6, fd);
if (iRead != 6)
{
fclose(fd);
return 0;
}
if ( memcmp(szSignature, "GIF", 2) != 0)
{
fclose(fd);
return 0;
}
// *2* READ LOGICAL SCREEN DESCRIPTOR
struct GIFLSDtag
{
unsigned short ScreenWidth; // Logical Screen Width
unsigned short ScreenHeight; // Logical Screen Height
unsigned char PackedFields; // Packed Fields. Bits detail:
// 0-2: Size of Global Color Table
// 3: Sort Flag
// 4-6: Color Resolution
// 7: Global Color Table Flag
unsigned char Background; // Background Color Index
unsigned char PixelAspectRatio; // Pixel Aspect Ratio
}
giflsd;
iRead = fread(&giflsd, 1, sizeof(giflsd), fd);
if (iRead != sizeof(giflsd))
{
fclose(fd);
return 0;
}
// endian swap
SWAP16(giflsd.ScreenWidth);
SWAP16(giflsd.ScreenHeight);
GlobalBPP = (giflsd.PackedFields & 0x07) + 1;
// fill some animation data:
FrameWidth = giflsd.ScreenWidth;
FrameHeight = giflsd.ScreenHeight;
nLoops = 1; //default=play animation 1 time
// *3* READ/GENERATE GLOBAL COLOR MAP
GlobalColorMap = new COLOR [1 << GlobalBPP];
if (giflsd.PackedFields & 0x80) // File has global color map?
for (n = 0;n < 1 << GlobalBPP;n++)
{
GlobalColorMap[n].r = getbyte(fd);
GlobalColorMap[n].g = getbyte(fd);
GlobalColorMap[n].b = getbyte(fd);
GlobalColorMap[n].x = 0;
}
else // GIF standard says to provide an internal default Palette:
for (n = 0;n < 256;n++)
{
GlobalColorMap[n].r = GlobalColorMap[n].g = GlobalColorMap[n].b = n;
GlobalColorMap[n].x = 0;
}
// *4* NOW WE HAVE 3 POSSIBILITIES:
// 4a) Get and Extension Block (Blocks with additional information)
// 4b) Get an Image Separator (Introductor to an image)
// 4c) Get the trailer Char (End of GIF File)
do
{
int charGot = getbyte(fd);
if (charGot == 0x21) // *A* EXTENSION BLOCK
{
unsigned char extensionType = getbyte(fd);
switch (extensionType)
{
case 0xF9: // Graphic Control Extension
{
if (fread((char*)&gifgce, 1, sizeof(gifgce), fd) == sizeof(gifgce))
SWAP16(gifgce.Delay);
GraphicExtensionFound++;
getbyte(fd); // Block Terminator (always 0)
}
break;
case 0xFE: // Comment Extension: Ignored
{
while (int nBlockLength = getbyte(fd))
for (n = 0;n < nBlockLength;n++) getbyte(fd);
}
break;
case 0x01: // PlainText Extension: Ignored
{
while (int nBlockLength = getbyte(fd))
for (n = 0;n < nBlockLength;n++) getbyte(fd);
}
break;
case 0xFF: // Application Extension: Ignored
{
int nBlockLength = getbyte(fd);
if (nBlockLength == 0x0b)
{
struct GIFNetscapeTag tag;
if (fread((char*)&tag, 1, sizeof(gifnetscape), fd) == sizeof(gifnetscape))
{
SWAP16(tag.iIterations);
nLoops = tag.iIterations;
}
else
nLoops = 0;
if (nLoops) nLoops++;
getbyte(fd);
}
else
{
do
{
for (n = 0;n < nBlockLength;n++) getbyte(fd);
}
while ((nBlockLength = getbyte(fd)) != 0);
}
}
break;
default: // Unknown Extension: Ignored
{
// read (and ignore) data sub-blocks
while (int nBlockLength = getbyte(fd))
for (n = 0;n < nBlockLength;n++) getbyte(fd);
}
break;
}
}
else if (charGot == 0x2c)
{ // *B* IMAGE (0x2c Image Separator)
// Create a new Image Object:
CAnimatedGif* NextImage = new CAnimatedGif();
// Read Image Descriptor
struct GIFIDtag
{
unsigned short xPos; // Image Left Position
unsigned short yPos; // Image Top Position
unsigned short Width; // Image Width
unsigned short Height; // Image Height
unsigned char PackedFields; // Packed Fields. Bits detail:
// 0-2: Size of Local Color Table
// 3-4: (Reserved)
// 5: Sort Flag
// 6: Interlace Flag
// 7: Local Color Table Flag
}
gifid;
memset(&gifid, 0, sizeof(gifid));
int LocalColorMap = 0;
if (fread((char*)&gifid, 1, sizeof(gifid), fd) == sizeof(gifid))
{
SWAP16(gifid.xPos);
SWAP16(gifid.yPos);
SWAP16(gifid.Width);
SWAP16(gifid.Height);
LocalColorMap = (gifid.PackedFields & 0x08) ? 1 : 0;
}
NextImage->Init(gifid.Width, gifid.Height, LocalColorMap ? (gifid.PackedFields&7) + 1 : GlobalBPP);
// Fill NextImage Data
NextImage->xPos = gifid.xPos;
NextImage->yPos = gifid.yPos;
if (GraphicExtensionFound)
{
NextImage->Transparent = (gifgce.PackedFields & 0x01) ? gifgce.Transparent : -1;
NextImage->Transparency = (gifgce.PackedFields & 0x1c) > 1 ? 1 : 0;
NextImage->Delay = gifgce.Delay * 10;
}
if (NextImage->Transparent != -1)
memset(NextImage->Raster, NextImage->Transparent, NextImage->BytesPerRow * NextImage->Height);
else
memset(NextImage->Raster, giflsd.Background, NextImage->BytesPerRow * NextImage->Height);
// Read Color Map (if descriptor says so)
size_t palSize = sizeof(COLOR)*(1 << NextImage->BPP);
bool isPalRead = false;
if (LocalColorMap && fread((char*)NextImage->Palette, 1, palSize, fd) == palSize)
isPalRead = true;
// Copy global, if no palette
if (!isPalRead)
memcpy(NextImage->Palette, GlobalColorMap, palSize);
short firstbyte = getbyte(fd); // 1st byte of img block (CodeSize)
// Calculate compressed image block size
// to fix: this allocates an extra byte per block
long ImgStart, ImgEnd;
ImgEnd = ImgStart = ftell(fd);
while ((n = getbyte(fd)) != 0) fseek (fd, ImgEnd += n + 1, SEEK_SET );
fseek (fd, ImgStart, SEEK_SET);
// Allocate Space for Compressed Image
char * pCompressedImage = new char [ImgEnd - ImgStart + 4];
// Read and store Compressed Image
char * pTemp = pCompressedImage;
while (int nBlockLength = getbyte(fd))
{
if (fread(pTemp, 1, nBlockLength, fd) != (size_t)nBlockLength)
{
// Error?
}
pTemp += nBlockLength;
}
// Call LZW/GIF decompressor
n = LZWDecoder(
(char*) pCompressedImage,
(char*) NextImage->Raster,
firstbyte, NextImage->BytesPerRow, //NextImage->AlignedWidth,
gifid.Width, gifid.Height,
((gifid.PackedFields & 0x40) ? 1 : 0) //Interlaced?
);
if (n)
AddImage(NextImage);
else
{
delete NextImage;
ERRORMSG("GIF File Corrupt");
}
// Some cleanup
delete[] pCompressedImage;
GraphicExtensionFound = 0;
}
else if (charGot == 0x3b)
{
// *C* TRAILER: End of GIF Info
break; // Ok. Standard End.
}
}
while ( !feof(fd) );
delete[] GlobalColorMap;
fclose(fd);
if ( GetImageCount() == 0) ERRORMSG("Premature End Of File");
return GetImageCount();
}
// ****************************************************************************
// * LoadGIF *
// * Load a GIF File into the C_ImageSet object *
// * (c) Nov 2000, Juan Soulie <*****@*****.**> *
// ****************************************************************************
int C_ImageSet::LoadGIF (char * szFileName)
{
int n;
// Global GIF variables:
int GlobalBPP; // Bits per Pixel.
COLOR * GlobalColorMap; // Global colormap (allocate)
struct GIFGCEtag { // GRAPHIC CONTROL EXTENSION
unsigned char BlockSize; // Block Size: 4 bytes
unsigned char PackedFields; // Packed Fields. Bits detail:
// 0: Transparent Color Flag
// 1: User Input Flag
// 2-4: Disposal Method
unsigned short Delay; // Delay Time (1/100 seconds)
unsigned char Transparent; // Transparent Color Index
} gifgce;
int GraphicExtensionFound = 0;
// OPEN FILE
ifstream giffile (szFileName,ios::in|ios::nocreate|ios::binary);
if (!giffile.is_open()) {ERRORMSG("File not found");return 0;}
// *1* READ HEADER (SIGNATURE + VERSION)
char szSignature[6]; // First 6 bytes (GIF87a or GIF89a)
giffile.read(szSignature,6);
if ( memcmp(szSignature,"GIF",2) != 0)
{ ERRORMSG("Not a GIF File"); return 0; }
// *2* READ LOGICAL SCREEN DESCRIPTOR
struct GIFLSDtag {
unsigned short ScreenWidth; // Logical Screen Width
unsigned short ScreenHeight; // Logical Screen Height
unsigned char PackedFields; // Packed Fields. Bits detail:
// 0-2: Size of Global Color Table
// 3: Sort Flag
// 4-6: Color Resolution
// 7: Global Color Table Flag
unsigned char Background; // Background Color Index
unsigned char PixelAspectRatio; // Pixel Aspect Ratio
} giflsd;
giffile.read((char*)&giflsd,sizeof(giflsd));
GlobalBPP = (giflsd.PackedFields & 0x07) + 1;
// fill some animation data:
FrameWidth = giflsd.ScreenWidth;
FrameHeight = giflsd.ScreenHeight;
nLoops = 0;
// *3* READ/GENERATE GLOBAL COLOR MAP
GlobalColorMap = new COLOR [1<<GlobalBPP];
if (giflsd.PackedFields & 0x80) // File has global color map?
for (n=0;n< 1<<GlobalBPP;n++)
{
GlobalColorMap[n].r=giffile.get();
GlobalColorMap[n].g=giffile.get();
GlobalColorMap[n].b=giffile.get();
}
else // GIF standard says to provide an internal default Palette:
for (n=0;n<256;n++)
GlobalColorMap[n].r=GlobalColorMap[n].g=GlobalColorMap[n].b=n;
// *4* NOW WE HAVE 3 POSSIBILITIES:
// 4a) Get and Extension Block (Blocks with additional information)
// 4b) Get an Image Separator (Introductor to an image)
// 4c) Get the trailer Char (End of GIF File)
do
{
int charGot = giffile.get();
if (charGot == 0x21) // *A* EXTENSION BLOCK
{
switch (giffile.get())
{
case 0xF9: // Graphic Control Extension
giffile.read((char*)&gifgce,sizeof(gifgce));
GraphicExtensionFound++;
giffile.get(); // Block Terminator (always 0)
break;
case 0xFE: // Comment Extension: Ignored
case 0x01: // PlainText Extension: Ignored
case 0xFF: // Application Extension: Ignored
default: // Unknown Extension: Ignored
// read (and ignore) data sub-blocks
while (int nBlockLength = giffile.get())
for (n=0;n<nBlockLength;n++) giffile.get();
break;
}
}
else if (charGot == 0x2c) { // *B* IMAGE (0x2c Image Separator)
// Create a new Image Object:
C_Image* NextImage;
NextImage = new C_Image;
// Read Image Descriptor
struct GIFIDtag {
unsigned short xPos; // Image Left Position
unsigned short yPos; // Image Top Position
unsigned short Width; // Image Width
unsigned short Height; // Image Height
unsigned char PackedFields; // Packed Fields. Bits detail:
// 0-2: Size of Local Color Table
// 3-4: (Reserved)
// 5: Sort Flag
// 6: Interlace Flag
// 7: Local Color Table Flag
} gifid;
giffile.read((char*)&gifid, sizeof(gifid));
int LocalColorMap = (gifid.PackedFields & 0x08)? 1 : 0;
NextImage->Init (gifid.Width, gifid.Height,
LocalColorMap ? (gifid.PackedFields&7)+1 : GlobalBPP);
// Fill NextImage Data
NextImage->xPos = gifid.xPos;
NextImage->yPos = gifid.yPos;
if (GraphicExtensionFound)
{
NextImage->Transparent=
(gifgce.PackedFields&0x01) ? gifgce.Transparent : -1;
NextImage->Transparency=
(gifgce.PackedFields&0x1c)>1 ? 1 : 0;
NextImage->Delay = gifgce.Delay*10;
}
if (LocalColorMap) // Read Color Map (if descriptor says so)
giffile.read((char*)NextImage->Palette,
sizeof(COLOR)*(1<<NextImage->BPP));
else // Otherwise copy Global
memcpy (NextImage->Palette, GlobalColorMap,
sizeof(COLOR)*(1<<NextImage->BPP));
short firstbyte=giffile.get(); // 1st byte of img block (CodeSize)
// Calculate compressed image block size
// to fix: this allocates an extra byte per block
long ImgStart,ImgEnd;
ImgEnd = ImgStart = giffile.tellg();
while (n=giffile.get()) giffile.seekg (ImgEnd+=n+1);
giffile.seekg (ImgStart);
// Allocate Space for Compressed Image
char * pCompressedImage = new char [ImgEnd-ImgStart+4];
// Read and store Compressed Image
char * pTemp = pCompressedImage;
while (int nBlockLength = giffile.get())
{
giffile.read(pTemp,nBlockLength);
pTemp+=nBlockLength;
}
// Call LZW/GIF decompressor
n=LZWDecoder(
(char*) pCompressedImage,
(char*) NextImage->Raster,
firstbyte, NextImage->BytesPerRow,//NextImage->AlignedWidth,
gifid.Width, gifid.Height,
((gifid.PackedFields & 0x40)?1:0) //Interlaced?
);
if (n)
AddImage(NextImage);
else
{
delete NextImage;
ERRORMSG("GIF File Corrupt");
}
// Some cleanup
delete[]pCompressedImage;
GraphicExtensionFound=0;
}
else if (charGot == 0x3b) { // *C* TRAILER: End of GIF Info
break; // Ok. Standard End.
}
} while (giffile.good());
giffile.close();
if (nImages==0) ERRORMSG("Premature End Of File");
return nImages;
}
