/*
 * The 3D Studio File Format Library
 * Copyright (C) 1996-2007 by Jan Eric Kyprianidis <www.kyprianidis.com>
 * All rights reserved.
 *
 * This program is  free  software;  you can redistribute it and/or modify it
 * under the terms of the  GNU Lesser General Public License  as published by 
 * the  Free Software Foundation;  either version 2.1 of the License,  or (at 
 * your option) any later version.
 *
 * This  program  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 Lesser General Public  
 * License for more details.
 *
 * You should  have received  a copy of the GNU Lesser General Public License
 * along with  this program;  if not, write to the  Free Software Foundation,
 * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Id: io.c,v 1.9 2007/06/20 17:04:08 jeh Exp $
 */
#include "io.h"
#include <stdlib.h>
#include <string.h>


/*!
 * \defgroup io Binary Input/Ouput Abstraction Layer
 */

typedef union { 
  Lib3dsDword dword_value; 
  Lib3dsFloat float_value;
} Lib3dsDwordFloat;


struct Lib3dsIo {
  void *self;
  Lib3dsIoErrorFunc error_func;
  Lib3dsIoSeekFunc seek_func;
  Lib3dsIoTellFunc tell_func;
  Lib3dsIoReadFunc read_func;
  Lib3dsIoWriteFunc write_func;
};


Lib3dsIo* 
lib3ds_io_new(void *self, Lib3dsIoErrorFunc error_func, Lib3dsIoSeekFunc seek_func,
  Lib3dsIoTellFunc tell_func, Lib3dsIoReadFunc read_func, Lib3dsIoWriteFunc write_func)
{
  Lib3dsIo *io = calloc(sizeof(Lib3dsIo),1);
  ASSERT(io);
  if (!io) {
    return 0;
  }

  io->self = self;
  io->error_func = error_func;
  io->seek_func = seek_func;
  io->tell_func = tell_func;
  io->read_func = read_func;
  io->write_func = write_func;

  return io;
}


void 
lib3ds_io_free(Lib3dsIo *io)
{
  ASSERT(io);
  if (!io) {
    return;
  }
  free(io);
}


Lib3dsBool
lib3ds_io_error(Lib3dsIo *io)
{
  ASSERT(io);
  if (!io || !io->error_func) {
    return 0;
  }
  return (*io->error_func)(io->self);
}


long
lib3ds_io_seek(Lib3dsIo *io, long offset, Lib3dsIoSeek origin)
{
  ASSERT(io);
  if (!io || !io->seek_func) {
    return 0;
  }
  return (*io->seek_func)(io->self, offset, origin);
}


long
lib3ds_io_tell(Lib3dsIo *io)
{
  ASSERT(io);
  if (!io || !io->tell_func) {
    return 0;
  }
  return (*io->tell_func)(io->self);
}


size_t
lib3ds_io_read(Lib3dsIo *io, void *buffer, size_t size)
{
  ASSERT(io);
  if (!io || !io->read_func) {
    return 0;
  }
  return (*io->read_func)(io->self, buffer, size);
}


size_t
lib3ds_io_write(Lib3dsIo *io, const void *buffer, size_t size)
{
  ASSERT(io);
  if (!io || !io->write_func) {
    return 0;
  }
  return (*io->write_func)(io->self, buffer, size);
}


/*!
 * \ingroup io
 *
 * Read a byte from a file stream.  
 */
Lib3dsByte
lib3ds_io_read_byte(Lib3dsIo *io)
{
  Lib3dsByte b;

  ASSERT(io);
  lib3ds_io_read(io, &b, 1);
  return(b);
}


/**
 * Read a word from a file stream in little endian format.   
 */
Lib3dsWord
lib3ds_io_read_word(Lib3dsIo *io)
{
  Lib3dsByte b[2];
  Lib3dsWord w;

  ASSERT(io);
  lib3ds_io_read(io, b, 2);
  w=((Lib3dsWord)b[1] << 8) |
    ((Lib3dsWord)b[0]);
  return(w);
}


/*!
 * \ingroup io
 *
 * Read a dword from file a stream in little endian format.   
 */
Lib3dsDword
lib3ds_io_read_dword(Lib3dsIo *io)
{
  Lib3dsByte b[4];
  Lib3dsDword d;        
                         
  ASSERT(io);
  lib3ds_io_read(io, b, 4);
  d=((Lib3dsDword)b[3] << 24) |
    ((Lib3dsDword)b[2] << 16) |
    ((Lib3dsDword)b[1] << 8) |
    ((Lib3dsDword)b[0]);
  return(d);
}


/*!
 * \ingroup io
 *
 * Read a signed byte from a file stream.   
 */
Lib3dsIntb
lib3ds_io_read_intb(Lib3dsIo *io)
{
  Lib3dsIntb b;

  ASSERT(io);
  lib3ds_io_read(io, &b, 1);
  return(b);
}


/*!
 * \ingroup io
 *
 * Read a signed word from a file stream in little endian format.   
 */
Lib3dsIntw
lib3ds_io_read_intw(Lib3dsIo *io)
{
  Lib3dsByte b[2];
  Lib3dsWord w;

  ASSERT(io);
  lib3ds_io_read(io, b, 2);
  w=((Lib3dsWord)b[1] << 8) |
    ((Lib3dsWord)b[0]);
  return((Lib3dsIntw)w);
}


/*!
 * \ingroup io
 *
 * Read a signed dword a from file stream in little endian format.   
 */
Lib3dsIntd
lib3ds_io_read_intd(Lib3dsIo *io)
{
  Lib3dsByte b[4];
  Lib3dsDword d;        
                         
  ASSERT(io);
  lib3ds_io_read(io, b, 4);
  d=((Lib3dsDword)b[3] << 24) |
    ((Lib3dsDword)b[2] << 16) |
    ((Lib3dsDword)b[1] << 8) |
    ((Lib3dsDword)b[0]);
  return((Lib3dsIntd)d);
}


/*!
 * \ingroup io
 *
 * Read a float from a file stream in little endian format.   
 */
Lib3dsFloat
lib3ds_io_read_float(Lib3dsIo *io)
{
  Lib3dsByte b[4];
  Lib3dsDwordFloat d;

  ASSERT(io);
  lib3ds_io_read(io, b, 4);
  d.dword_value=((Lib3dsDword)b[3] << 24) |
    ((Lib3dsDword)b[2] << 16) |
    ((Lib3dsDword)b[1] << 8) |
    ((Lib3dsDword)b[0]);
  return d.float_value;
}


/*!
 * \ingroup io
 *
 * Read a vector from a file stream in little endian format.   
 *
 * \param io IO input handle. 
 * \param v  The vector to store the data. 
 */
Lib3dsBool
lib3ds_io_read_vector(Lib3dsIo *io, Lib3dsVector v)
{
  ASSERT(io);
  
  v[0]=lib3ds_io_read_float(io);
  v[1]=lib3ds_io_read_float(io);
  v[2]=lib3ds_io_read_float(io);

  return(!lib3ds_io_error(io));
}


/*!
 * \ingroup io
 */
Lib3dsBool
lib3ds_io_read_rgb(Lib3dsIo *io, Lib3dsRgb rgb)
{
  ASSERT(io);

  rgb[0]=lib3ds_io_read_float(io);
  rgb[1]=lib3ds_io_read_float(io);
  rgb[2]=lib3ds_io_read_float(io);

  return(!lib3ds_io_error(io));
}


/*!
 * \ingroup io
 *
 * Read a zero-terminated string from a file stream.
 *
 * \param io      IO input handle. 
 * \param s       The buffer to store the read string.
 * \param buflen  Buffer length.
 *
 * \return        True on success, False otherwise.
 */
Lib3dsBool
lib3ds_io_read_string(Lib3dsIo *io, char *s, int buflen)
{
  char c;
  int k=0;

  ASSERT(io);
  for (;;) {
    if (lib3ds_io_read(io, &c, 1)!=1) {
      return LIB3DS_FALSE;
    }
    *s++ = c;
    if (!c) {
      break;
    }
    ++k;
    if (k>=buflen) {
      return(LIB3DS_FALSE);
    }
  }

  return(!lib3ds_io_error(io));
}


/*!
 * \ingroup io
 *
 * Writes a byte into a file stream.
 */
Lib3dsBool
lib3ds_io_write_byte(Lib3dsIo *io, Lib3dsByte b)
{
  ASSERT(io);
  if (lib3ds_io_write(io, &b, 1)!=1) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a word into a little endian file stream.
 */
Lib3dsBool
lib3ds_io_write_word(Lib3dsIo *io, Lib3dsWord w)
{
  Lib3dsByte b[2];

  ASSERT(io);
  b[1]=((Lib3dsWord)w & 0xFF00) >> 8;
  b[0]=((Lib3dsWord)w & 0x00FF);
  if (lib3ds_io_write(io, b, 2)!=2) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a dword into a little endian file stream.
 */
Lib3dsBool
lib3ds_io_write_dword(Lib3dsIo *io, Lib3dsDword d)
{
  Lib3dsByte b[4];

  ASSERT(io);
  b[3]=(Lib3dsByte)(((Lib3dsDword)d & 0xFF000000) >> 24);
  b[2]=(Lib3dsByte)(((Lib3dsDword)d & 0x00FF0000) >> 16);
  b[1]=(Lib3dsByte)(((Lib3dsDword)d & 0x0000FF00) >> 8);
  b[0]=(Lib3dsByte)(((Lib3dsDword)d & 0x000000FF));
  if (lib3ds_io_write(io, b, 4)!=4) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a signed byte in a file stream.
 */
Lib3dsBool
lib3ds_io_write_intb(Lib3dsIo *io, Lib3dsIntb b)
{
  ASSERT(io);
  if (lib3ds_io_write(io, &b, 1)!=1) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a signed word into a little endian file stream.
 */
Lib3dsBool
lib3ds_io_write_intw(Lib3dsIo *io, Lib3dsIntw w)
{
  Lib3dsByte b[2];

  ASSERT(io);
  b[1]=((Lib3dsWord)w & 0xFF00) >> 8;
  b[0]=((Lib3dsWord)w & 0x00FF);
  if (lib3ds_io_write(io, b, 2)!=2) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a signed dword into a little endian file stream.
 */
Lib3dsBool
lib3ds_io_write_intd(Lib3dsIo *io, Lib3dsIntd d)
{
  Lib3dsByte b[4];

  ASSERT(io);
  b[3]=(Lib3dsByte)(((Lib3dsDword)d & 0xFF000000) >> 24);
  b[2]=(Lib3dsByte)(((Lib3dsDword)d & 0x00FF0000) >> 16);
  b[1]=(Lib3dsByte)(((Lib3dsDword)d & 0x0000FF00) >> 8);
  b[0]=(Lib3dsByte)(((Lib3dsDword)d & 0x000000FF));
  if (lib3ds_io_write(io, b, 4)!=4) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a float into a little endian file stream.
 */
Lib3dsBool
lib3ds_io_write_float(Lib3dsIo *io, Lib3dsFloat l)
{
  Lib3dsByte b[4];
  Lib3dsDwordFloat d;

  ASSERT(io);
  d.float_value=l;
  b[3]=(Lib3dsByte)(((Lib3dsDword)d.dword_value & 0xFF000000) >> 24);
  b[2]=(Lib3dsByte)(((Lib3dsDword)d.dword_value & 0x00FF0000) >> 16);
  b[1]=(Lib3dsByte)(((Lib3dsDword)d.dword_value & 0x0000FF00) >> 8);
  b[0]=(Lib3dsByte)(((Lib3dsDword)d.dword_value & 0x000000FF));
  if (lib3ds_io_write(io, b, 4)!=4) {
    return(LIB3DS_FALSE);
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a vector into a file stream in little endian format.   
 */
Lib3dsBool
lib3ds_io_write_vector(Lib3dsIo *io, Lib3dsVector v)
{
  int i;
  for (i=0; i<3; ++i) {
    if (!lib3ds_io_write_float(io, v[i])) {
      return(LIB3DS_FALSE);
    }
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 */
Lib3dsBool
lib3ds_io_write_rgb(Lib3dsIo *io, Lib3dsRgb rgb)
{
  int i;
  for (i=0; i<3; ++i) {
    if (!lib3ds_io_write_float(io, rgb[i])) {
      return(LIB3DS_FALSE);
    }
  }
  return(LIB3DS_TRUE);
}


/*!
 * \ingroup io
 *
 * Writes a zero-terminated string into a file stream.
 */
Lib3dsBool
lib3ds_io_write_string(Lib3dsIo *io, const char *s)
{
  ASSERT(s);
  ASSERT(io);
  lib3ds_io_write(io, s, strlen(s)+1);
  return(!lib3ds_io_error(io));
}
