/* === S Y N F I G ========================================================= */
/*! \file trgt_gif.h
** \brief Template Header
**
** $Id$
**
** \legal
** Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
**
** This package is free software; you can redistribute it and/or
** modify it under the terms of the GNU General Public License as
** published by the Free Software Foundation; either version 2 of
** the License, or (at your option) any later version.
**
** This package is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
** General Public License for more details.
** \endlegal
**
** === N O T E S ===========================================================
**
** ========================================================================= */
/* === S T A R T =========================================================== */
#ifndef __SYNFIG_TRGT_GIF_H
#define __SYNFIG_TRGT_GIF_H
/* === H E A D E R S ======================================================= */
#include <synfig/target_scanline.h>
#include <synfig/string.h>
#include <synfig/smartfile.h>
#include <cstdio>
#include <synfig/surface.h>
#include <synfig/palette.h>
#include <synfig/targetparam.h>
/* === M A C R O S ========================================================= */
/* === T Y P E D E F S ===================================================== */
/* === C L A S S E S & S T R U C T S ======================================= */
class gif : public synfig::Target_Scanline
{
SYNFIG_TARGET_MODULE_EXT
private:
// Class for abstracting the
// output of the codes
struct bitstream
{
synfig::SmartFILE file;
unsigned char pool;
char curr_bit;
bitstream():pool(0),curr_bit(0),curr_pos(0) {}
bitstream(synfig::SmartFILE file):file(file),pool(0),curr_bit(0),curr_pos(0) {}
unsigned char buffer[256];
int curr_pos;
// Pushes a single bit onto the bit
void push_bit(bool bit)
{
if(bit)
pool|=(1<<(curr_bit));
curr_bit++;
if(curr_bit==8)
empty();
}
// Empties out the current pool into
// the buffer. Calls 'dump()' if the
// buffer is full.
void empty()
{
buffer[curr_pos++]=pool;
curr_bit=0;
pool=0;
if(curr_pos==255)dump();
}
// If there is anything in the
// buffer or in the pool, it
// dumps it to the filestream.
// Buffer and pool are cleared.
void dump()
{
if(curr_bit)
empty();
if(curr_pos || curr_bit)
{
fputc(curr_pos,file.get());
fwrite(buffer,curr_pos,1,file.get());
curr_pos=0;
}
}
// Pushes a symbol of the given size
// onto the bitstream.
void push_value(int value, int size)
{
int i;
for(i=0;i<size;i++)
push_bit((value>>(i))&1);
}
};
// Class for dealing with the LZW codes
struct lzwcode
{
int value; // the data element or character
int code; // lzwcode
struct lzwcode* kids; // children of this node
struct lzwcode* next; // siblings of this node
lzwcode():value(0),code(0),kids(0),next(0) { }
lzwcode *FindCode(int value)
{
lzwcode *node=this;
// check the children (kids) of the node for the value
for (node = node->kids; node != 0; node = node->next)
if (node->value == value)
return(node);
return(0);
}
void AddNode(unsigned short code, unsigned short value)
{
lzwcode *n = new lzwcode;
// add a new child to node; the child will have code and value
n->value = value;
n->code = code;
n->kids = 0;
n->next = this->kids;
this->kids = n;
}
static lzwcode * NewTable(int values)
{
int i;
lzwcode * table = new lzwcode;
table->kids = 0;
for (i = 0; i < values; i++)
table->AddNode( i, i);
return(table);
}
// Destructor just deletes any
// children and siblings.
~lzwcode()
{
if(kids)
delete kids;
if(next)
delete next;
}
};
private:
bitstream bs;
synfig::String filename;
synfig::SmartFILE file;
int
codesize, // Current code size
rootsize, // Size of pixel bits (will be recalculated)
nextcode; // Next code to use
lzwcode *table,*next,*node;
synfig::Surface curr_surface;
etl::surface<unsigned char> curr_frame;
etl::surface<unsigned char> prev_frame;
int imagecount;
int cur_scanline;
// GIF compression parameters
bool lossy;
bool multi_image;
bool dithering;
int color_bits;
int iframe_density;
int loop_count;
bool local_palette;
synfig::Palette curr_palette;
void output_curr_palette();
public:
gif(const char *filename, const synfig::TargetParam& /* params */);
virtual bool set_rend_desc(synfig::RendDesc *desc);
virtual bool init(synfig::ProgressCallback *cb);
virtual bool start_frame(synfig::ProgressCallback *cb);
virtual void end_frame();
virtual ~gif();
virtual synfig::Color * start_scanline(int scanline);
virtual bool end_scanline(void);
};
/* === E N D =============================================================== */
#endif