static void
write_header(FILE * const fp,
int const cols,
int const rows,
int const BitsPerPixel,
int const Planes,
struct pcxCmapEntry const cmap16[],
unsigned int const xPos,
unsigned int const yPos) {
int i, BytesPerLine;
Putbyte(PCX_MAGIC, fp); /* .PCX magic number */
Putbyte(0x05, fp); /* PC Paintbrush version */
Putbyte(0x01, fp); /* .PCX run length encoding */
Putbyte(BitsPerPixel, fp); /* bits per pixel */
Putword(xPos, fp); /* x1 - image left */
Putword(yPos, fp); /* y1 - image top */
Putword(xPos+cols-1, fp); /* x2 - image right */
Putword(yPos+rows-1, fp); /* y2 - image bottom */
Putword(cols, fp); /* horizontal resolution */
Putword(rows, fp); /* vertical resolution */
/* Write out the Color Map for images with 16 colors or less */
if (cmap16)
for (i = 0; i < 16; ++i) {
Putbyte(cmap16[i].r, fp);
Putbyte(cmap16[i].g, fp);
Putbyte(cmap16[i].b, fp);
}
else {
unsigned int i;
for (i = 0; i < 16; ++i) {
Putbyte(0, fp);
Putbyte(0, fp);
Putbyte(0, fp);
}
}
Putbyte(0, fp); /* reserved byte */
Putbyte(Planes, fp); /* number of color planes */
BytesPerLine = ((cols * BitsPerPixel) + 7) / 8;
Putword(BytesPerLine, fp); /* number of bytes per scanline */
Putword(1, fp); /* palette info */
{
unsigned int i;
for (i = 0; i < 58; ++i) /* fill to end of header */
Putbyte(0, fp);
}
}
/*
* public GIFEncode
*/
static void
GIFEncode(
FILE *fp,
int GWidth,
int GHeight,
int GInterlace,
int Background,
int BitsPerPixel,
int Red[],
int Green[],
int Blue[],
ifun_t* GetPixel
)
{
int B;
int RWidth, RHeight;
int LeftOfs, TopOfs;
int Resolution;
int ColorMapSize;
int InitCodeSize;
int i;
cur_accum = 0; /* globals */
cur_bits = 0;
Interlace = GInterlace;
ColorMapSize = 1 << BitsPerPixel;
RWidth = Width = GWidth;
RHeight = Height = GHeight;
LeftOfs = TopOfs = 0;
Resolution = BitsPerPixel;
CountDown = (long)Width * (long)Height;
Pass = 0;
if( BitsPerPixel <= 1 )
InitCodeSize = 2;
else
InitCodeSize = BitsPerPixel;
curx = cury = 0;
fwrite( "GIF87a", 1, 6, fp );
Putword( RWidth, fp );
Putword( RHeight, fp );
B = 0x80; /* Yes, there is a color map */
B |= (Resolution - 1) << 5;
B |= (BitsPerPixel - 1);
fputc( B, fp );
fputc( Background, fp );
fputc( 0, fp );
for( i=0; i<ColorMapSize; i++ ) {
fputc( Red[i], fp );
fputc( Green[i], fp );
fputc( Blue[i], fp );
}
fputc( ',', fp );
Putword( LeftOfs, fp );
Putword( TopOfs, fp );
Putword( Width, fp );
Putword( Height, fp );
if( Interlace )
fputc( 0x40, fp );
else
fputc( 0x00, fp );
fputc( InitCodeSize, fp );
compress( InitCodeSize+1, fp, GetPixel );
fputc( 0, fp );
fputc( ';', fp );
fclose( fp );
}
