#include <stdio.h>
#include <math.h>
#include <string.h>
#include <stdlib.h>
#include "gd.h"
typedef int code_int;
#ifdef SIGNED_COMPARE_SLOW
typedef unsigned long int count_int;
typedef unsigned short int count_short;
#else
typedef long int count_int;
#endif
#define maxbits GIFBITS
#define maxmaxcode ((code_int)1 << GIFBITS)
#define HSIZE 5003
#define hsize HSIZE
typedef struct {
int Width, Height;
int curx, cury;
long CountDown;
int Pass;
int Interlace;
int n_bits;
code_int maxcode;
count_int htab [HSIZE];
unsigned short codetab [HSIZE];
code_int free_ent;
int clear_flg;
int offset;
long int in_count;
long int out_count;
int g_init_bits;
gdIOCtx * g_outfile;
int ClearCode;
int EOFCode;
unsigned long cur_accum;
int cur_bits;
int a_count;
char accum[ 256 ];
} GifCtx;
static int gifPutWord(int w, gdIOCtx *out);
static int colorstobpp(int colors);
static void BumpPixel (GifCtx *ctx);
static int GIFNextPixel (gdImagePtr im, GifCtx *ctx);
static void GIFEncode (gdIOCtxPtr fp, int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im);
static void compress (int init_bits, gdIOCtx *outfile, gdImagePtr im, GifCtx *ctx);
static void output (code_int code, GifCtx *ctx);
static void cl_block (GifCtx *ctx);
static void cl_hash (register count_int chsize, GifCtx *ctx);
static void char_init (GifCtx *ctx);
static void char_out (int c, GifCtx *ctx);
static void flush_char (GifCtx *ctx);
void * gdImageGifPtr (gdImagePtr im, int *size)
{
void *rv;
gdIOCtx *out = gdNewDynamicCtx (2048, NULL);
gdImageGifCtx (im, out);
rv = gdDPExtractData (out, size);
out->gd_free (out);
return rv;
}
void gdImageGif (gdImagePtr im, FILE * outFile)
{
gdIOCtx *out = gdNewFileCtx (outFile);
gdImageGifCtx (im, out);
out->gd_free (out);
}
void gdImageGifCtx(gdImagePtr im, gdIOCtxPtr out)
{
gdImagePtr pim = 0, tim = im;
int interlace, BitsPerPixel;
interlace = im->interlace;
if (im->trueColor) {
pim = gdImageCreatePaletteFromTrueColor(im, 1, 256);
if (!pim) {
return;
}
tim = pim;
}
BitsPerPixel = colorstobpp(tim->colorsTotal);
GIFEncode(
out, tim->sx, tim->sy, tim->interlace, 0, tim->transparent, BitsPerPixel,
tim->red, tim->green, tim->blue, tim);
if (pim) {
gdImageDestroy( pim);
}
}
static int
colorstobpp(int colors)
{
int bpp = 0;
if ( colors <= 2 )
bpp = 1;
else if ( colors <= 4 )
bpp = 2;
else if ( colors <= 8 )
bpp = 3;
else if ( colors <= 16 )
bpp = 4;
else if ( colors <= 32 )
bpp = 5;
else if ( colors <= 64 )
bpp = 6;
else if ( colors <= 128 )
bpp = 7;
else if ( colors <= 256 )
bpp = 8;
return bpp;
}
#define TRUE 1
#define FALSE 0
static void
BumpPixel(GifCtx *ctx)
{
++(ctx->curx);
if( ctx->curx == ctx->Width ) {
ctx->curx = 0;
if( !ctx->Interlace )
++(ctx->cury);
else {
switch( ctx->Pass ) {
case 0:
ctx->cury += 8;
if( ctx->cury >= ctx->Height ) {
++(ctx->Pass);
ctx->cury = 4;
}
break;
case 1:
ctx->cury += 8;
if( ctx->cury >= ctx->Height ) {
++(ctx->Pass);
ctx->cury = 2;
}
break;
case 2:
ctx->cury += 4;
if( ctx->cury >= ctx->Height ) {
++(ctx->Pass);
ctx->cury = 1;
}
break;
case 3:
ctx->cury += 2;
break;
}
}
}
}
static int
GIFNextPixel(gdImagePtr im, GifCtx *ctx)
{
int r;
if( ctx->CountDown == 0 )
return EOF;
--(ctx->CountDown);
r = gdImageGetPixel(im, ctx->curx, ctx->cury);
BumpPixel(ctx);
return r;
}
static void
GIFEncode(gdIOCtxPtr fp, int GWidth, int GHeight, int GInterlace, int Background, int Transparent, int BitsPerPixel, int *Red, int *Green, int *Blue, gdImagePtr im)
{
int B;
int RWidth, RHeight;
int LeftOfs, TopOfs;
int Resolution;
int ColorMapSize;
int InitCodeSize;
int i;
GifCtx ctx;
memset(&ctx, 0, sizeof(ctx));
ctx.Interlace = GInterlace;
ctx.in_count = 1;
ColorMapSize = 1 << BitsPerPixel;
RWidth = ctx.Width = GWidth;
RHeight = ctx.Height = GHeight;
LeftOfs = TopOfs = 0;
Resolution = BitsPerPixel;
ctx.CountDown = (long)ctx.Width * (long)ctx.Height;
ctx.Pass = 0;
if( BitsPerPixel <= 1 )
InitCodeSize = 2;
else
InitCodeSize = BitsPerPixel;
ctx.curx = ctx.cury = 0;
gdPutBuf(Transparent < 0 ? "GIF87a" : "GIF89a", 6, fp );
gifPutWord( RWidth, fp );
gifPutWord( RHeight, fp );
B = 0x80;
B |= (Resolution - 1) << 5;
B |= (BitsPerPixel - 1);
gdPutC( B, fp );
gdPutC( Background, fp );
gdPutC( 0, fp );
for( i=0; i<ColorMapSize; ++i ) {
gdPutC( Red[i], fp );
gdPutC( Green[i], fp );
gdPutC( Blue[i], fp );
}
if ( Transparent >= 0 ) {
gdPutC( '!', fp );
gdPutC( 0xf9, fp );
gdPutC( 4, fp );
gdPutC( 1, fp );
gdPutC( 0, fp );
gdPutC( 0, fp );
gdPutC( (unsigned char) Transparent, fp );
gdPutC( 0, fp );
}
gdPutC( ',', fp );
gifPutWord( LeftOfs, fp );
gifPutWord( TopOfs, fp );
gifPutWord( ctx.Width, fp );
gifPutWord( ctx.Height, fp );
if( ctx.Interlace )
gdPutC( 0x40, fp );
else
gdPutC( 0x00, fp );
gdPutC( InitCodeSize, fp );
compress( InitCodeSize+1, fp, im, &ctx );
gdPutC( 0, fp );
gdPutC( ';', fp );
}
#define GIFBITS 12
#ifdef NO_UCHAR
typedef char char_type;
#else
typedef unsigned char char_type;
#endif
#include <ctype.h>
#define ARGVAL() (*++(*argv) || (--argc && *++argv))
#ifdef COMPATIBLE
# define MAXCODE(n_bits) ((code_int) 1 << (n_bits) - 1)
#else
# define MAXCODE(n_bits) (((code_int) 1 << (n_bits)) - 1)
#endif
#define HashTabOf(i) ctx->htab[i]
#define CodeTabOf(i) ctx->codetab[i]
#define tab_prefixof(i) CodeTabOf(i)
#define tab_suffixof(i) ((char_type*)(htab))[i]
#define de_stack ((char_type*)&tab_suffixof((code_int)1<<GIFBITS))
static void
output(code_int code, GifCtx *ctx);
static void
compress(int init_bits, gdIOCtxPtr outfile, gdImagePtr im, GifCtx *ctx)
{
register long fcode;
register code_int i ;
register int c;
register code_int ent;
register code_int disp;
register code_int hsize_reg;
register int hshift;
ctx->g_init_bits = init_bits;
ctx->g_outfile = outfile;
ctx->offset = 0;
ctx->out_count = 0;
ctx->clear_flg = 0;
ctx->in_count = 1;
ctx->maxcode = MAXCODE(ctx->n_bits = ctx->g_init_bits);
ctx->ClearCode = (1 << (init_bits - 1));
ctx->EOFCode = ctx->ClearCode + 1;
ctx->free_ent = ctx->ClearCode + 2;
char_init(ctx);
ent = GIFNextPixel( im, ctx );
hshift = 0;
for ( fcode = (long) hsize; fcode < 65536L; fcode *= 2L )
++hshift;
hshift = 8 - hshift;
hsize_reg = hsize;
cl_hash( (count_int) hsize_reg, ctx );
output( (code_int)ctx->ClearCode, ctx );
#ifdef SIGNED_COMPARE_SLOW
while ( (c = GIFNextPixel( im )) != (unsigned) EOF ) {
#else
while ( (c = GIFNextPixel( im, ctx )) != EOF ) {
#endif
++(ctx->in_count);
fcode = (long) (((long) c << maxbits) + ent);
i = (((code_int)c << hshift) ^ ent);
if ( HashTabOf (i) == fcode ) {
ent = CodeTabOf (i);
continue;
} else if ( (long)HashTabOf (i) < 0 )
goto nomatch;
disp = hsize_reg - i;
if ( i == 0 )
disp = 1;
probe:
if ( (i -= disp) < 0 )
i += hsize_reg;
if ( HashTabOf (i) == fcode ) {
ent = CodeTabOf (i);
continue;
}
if ( (long)HashTabOf (i) > 0 )
goto probe;
nomatch:
output ( (code_int) ent, ctx );
++(ctx->out_count);
ent = c;
#ifdef SIGNED_COMPARE_SLOW
if ( (unsigned) ctx->free_ent < (unsigned) maxmaxcode) {
#else
if ( ctx->free_ent < maxmaxcode ) {
#endif
CodeTabOf (i) = ctx->free_ent++;
HashTabOf (i) = fcode;
} else
cl_block(ctx);
}
output( (code_int)ent, ctx );
++(ctx->out_count);
output( (code_int) ctx->EOFCode, ctx );
}
static const unsigned long masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
0x001F, 0x003F, 0x007F, 0x00FF,
0x01FF, 0x03FF, 0x07FF, 0x0FFF,
0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
#define CUR_BITS_FINISHED -1000
static void
output(code_int code, GifCtx *ctx)
{
if (ctx->cur_bits == CUR_BITS_FINISHED) {
return;
}
ctx->cur_accum &= masks[ ctx->cur_bits ];
if( ctx->cur_bits > 0 )
ctx->cur_accum |= ((long)code << ctx->cur_bits);
else
ctx->cur_accum = code;
ctx->cur_bits += ctx->n_bits;
while( ctx->cur_bits >= 8 ) {
char_out( (unsigned int)(ctx->cur_accum & 0xff), ctx );
ctx->cur_accum >>= 8;
ctx->cur_bits -= 8;
}
if ( ctx->free_ent > ctx->maxcode || ctx->clear_flg ) {
if( ctx->clear_flg ) {
ctx->maxcode = MAXCODE (ctx->n_bits = ctx->g_init_bits);
ctx->clear_flg = 0;
} else {
++(ctx->n_bits);
if ( ctx->n_bits == maxbits )
ctx->maxcode = maxmaxcode;
else
ctx->maxcode = MAXCODE(ctx->n_bits);
}
}
if( code == ctx->EOFCode ) {
while( ctx->cur_bits > 0 ) {
char_out( (unsigned int)(ctx->cur_accum & 0xff), ctx);
ctx->cur_accum >>= 8;
ctx->cur_bits -= 8;
}
ctx->cur_bits = CUR_BITS_FINISHED;
flush_char(ctx);
}
}
static void
cl_block (GifCtx *ctx)
{
cl_hash ( (count_int) hsize, ctx );
ctx->free_ent = ctx->ClearCode + 2;
ctx->clear_flg = 1;
output( (code_int)ctx->ClearCode, ctx);
}
static void
cl_hash(register count_int chsize, GifCtx *ctx)
{
register count_int *htab_p = ctx->htab+chsize;
register long i;
register long m1 = -1;
i = chsize - 16;
do {
*(htab_p-16) = m1;
*(htab_p-15) = m1;
*(htab_p-14) = m1;
*(htab_p-13) = m1;
*(htab_p-12) = m1;
*(htab_p-11) = m1;
*(htab_p-10) = m1;
*(htab_p-9) = m1;
*(htab_p-8) = m1;
*(htab_p-7) = m1;
*(htab_p-6) = m1;
*(htab_p-5) = m1;
*(htab_p-4) = m1;
*(htab_p-3) = m1;
*(htab_p-2) = m1;
*(htab_p-1) = m1;
htab_p -= 16;
} while ((i -= 16) >= 0);
for ( i += 16; i > 0; --i )
*--htab_p = m1;
}
static void
char_init(GifCtx *ctx)
{
ctx->a_count = 0;
}
static void
char_out(int c, GifCtx *ctx)
{
ctx->accum[ ctx->a_count++ ] = c;
if( ctx->a_count >= 254 )
flush_char(ctx);
}
static void
flush_char(GifCtx *ctx)
{
if( ctx->a_count > 0 ) {
gdPutC( ctx->a_count, ctx->g_outfile );
gdPutBuf( ctx->accum, ctx->a_count, ctx->g_outfile );
ctx->a_count = 0;
}
}
static int gifPutWord(int w, gdIOCtx *out)
{
gdPutC(w & 0xFF, out);
gdPutC((w >> 8) & 0xFF, out);
return 0;
}