/*
 *  Baltisot
 *  Copyright (C) 1999-2007 Nicolas "Pixel" Noble
 *
 *  This program 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 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/* $Id: Image.cc,v 1.19 2007-09-28 09:05:55 pixel Exp $ */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "Image.h"
#include "gettext.h"

#ifdef HAVE_LIBJPEG
#include "jpeglib.h"
#include "jerror.h"

extern "C" {

typedef struct {
    struct jpeg_destination_mgr pub; /* public fields */
  
    Handle * outfile;             /* target stream */
    JOCTET * buffer;              /* start of buffer */
} my_destination_mgr;

#define OUTPUT_BUF_SIZE  4096   /* choose an efficiently fwrite'able size */
#define SIZEOF(object)       ((size_t) sizeof(object))


typedef my_destination_mgr * my_dest_ptr;

METHODDEF(void)
init_destination (j_compress_ptr cinfo)
{
  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;

  /* Allocate the output buffer --- it will be released when done with image */
  dest->buffer = (JOCTET *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,
                                  OUTPUT_BUF_SIZE * SIZEOF(JOCTET));

  dest->pub.next_output_byte = dest->buffer;
  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;
}

METHODDEF(boolean)
empty_output_buffer (j_compress_ptr cinfo)
{
  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;

  if (dest->outfile->write(dest->buffer, OUTPUT_BUF_SIZE) !=
      (size_t) OUTPUT_BUF_SIZE)
    ERREXIT(cinfo, JERR_FILE_WRITE);

  dest->pub.next_output_byte = dest->buffer;
  dest->pub.free_in_buffer = OUTPUT_BUF_SIZE;

  return TRUE;
}

METHODDEF(void)
term_destination (j_compress_ptr cinfo)
{
  my_dest_ptr dest = (my_dest_ptr) cinfo->dest;
  size_t datacount = OUTPUT_BUF_SIZE - dest->pub.free_in_buffer;

  /* Write any data remaining in the buffer */
  if (datacount > 0) {
    if (dest->outfile->write(dest->buffer, datacount) != datacount)
      ERREXIT(cinfo, JERR_FILE_WRITE);
  }
}

GLOBAL(void)
jpeg_handle_dest (j_compress_ptr cinfo, Handle * outfile)
{
  my_dest_ptr dest;
  
  /* The destination object is made permanent so that multiple JPEG images
   * can be written to the same file without re-executing jpeg_stdio_dest.
   * This makes it dangerous to use this manager and a different destination
   * manager serially with the same JPEG object, because their private object
   * sizes may be different.  Caveat programmer.
   */
  if (cinfo->dest == NULL) {    /* first time for this JPEG object? */
    cinfo->dest = (struct jpeg_destination_mgr *)
      (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
                                  SIZEOF(my_destination_mgr));
  }

  dest = (my_dest_ptr) cinfo->dest;
  dest->pub.init_destination = init_destination;
  dest->pub.empty_output_buffer = empty_output_buffer;
  dest->pub.term_destination = term_destination;
  dest->outfile = outfile;
}

}
#endif

struct TGAHeader {
    Byte IDLength;
    Byte ColorMapType;
    Byte ImageType;
    Word CM_FirstEntry;
    Word CM_Length;
    Byte CM_EntrySize;
    Word IS_XOrigin;
    Word IS_YOrigin;
    Word IS_Width;
    Word IS_Height;
    Byte IS_Depth;
    Byte IS_Descriptor;
} PACKED;

struct TGAFooter {
    DWord ExtOffset;
    DWord DevOffset;
    char Sig[18];
} PACKED;


Image::Image(unsigned int ax, unsigned int ay) : x(ax), y(ay), img((Color *) malloc(x * y * sizeof(Color))) {
    Fill();
}

Image::~Image() {
    free(img);
}

bool Image::CanWrite() const {
    return false;
}

String Image::GetName() const {
    return String(_("Image ")) + x + "x" + y;
}

void Image::Fill(Color c) {
    for (unsigned int i = 0; i < x * y; i++) {
	img[i] = c;
    }
}

Color Image::GetPixel(unsigned int px, unsigned int py) const {
    if ((px >= x) || (py >= y)) {
	return Color(0, 0, 0, 0);
    }
    
    return img[x * py + px];
}

void Image::SetPixel(unsigned int px, unsigned int py, Color c) {
    if ((px >= x) || (py >= y)) {
	return;
    }

    img[x * py + px] = c;
}

unsigned char * Image::GetBuffer() {
    return (unsigned char *) img;
}

#ifndef WORDS_BIGENDIAN
#define WORDS_BIGENDIAN 0
#else
#undef WORDS_BIGENDIAN
#define WORDS_BIGENDIAN 1
#endif

bool Image::SupportsFormat(unsigned int f) {
    switch(f) {
    case FORMAT_TGA_BASIC:
        return true;
    case FORMAT_JPEG:
#ifndef HAVE_LIBJPEG
        return false;
#else
        return true;
#endif
    }
    return false;
}

bool Image::Prepare(unsigned int f) throw (GeneralException) {
    int ix, iy;

    if (GetSize())
        throw GeneralException("Image already prepared.");
    
    switch (f) {
	case FORMAT_TGA_BASIC:
	    TGAHeader Header;
	    TGAFooter Footer;
	    
	    Header.IDLength = 0;
	    Header.ColorMapType = 0;
	    Header.ImageType = 2;
	    Header.CM_FirstEntry = 0;
	    Header.CM_Length = 0;
	    Header.CM_EntrySize = 0;
	    Header.IS_XOrigin = 0;
	    Header.IS_YOrigin = 0;
	    Header.IS_Width = WORDS_BIGENDIAN ? ((x & 0xff) << 8) | ((x & 0xff00) >> 8) : x;
	    Header.IS_Height = WORDS_BIGENDIAN ? ((y & 0xff) << 8) | ((y & 0xff00) >> 8) : y;
	    Header.IS_Depth = 32;
	    Header.IS_Descriptor = 0x20;

	    Footer.ExtOffset = 0;
	    Footer.DevOffset = 0;
	    strcpy(Footer.Sig, "TRUEVISION-XFILE.");
	    
	    write(&Header, sizeof(Header));
	    write(img, x * y * sizeof(Color));
	    write(&Footer, sizeof(Footer));
	    
	    return true;
	    
	    break;
        case FORMAT_JPEG:
#ifndef HAVE_LIBJPEG
            throw GeneralException("You can't create a jpeg image when the library libjpeg isn't linked in.");
#else
            {
                char * rgb_buffer = (char *) malloc(x * y * 3);
                for (iy = 0; iy < y; iy++) {
                    for (ix = 0; ix < x; ix++) {
                        rgb_buffer[(ix + iy * x) * 3 + 0] = img[ix + iy * x].B;
                        rgb_buffer[(ix + iy * x) * 3 + 1] = img[ix + iy * x].G;
                        rgb_buffer[(ix + iy * x) * 3 + 2] = img[ix + iy * x].R;
                    }
                }
                
                struct jpeg_compress_struct cinfo;
                JSAMPROW row_pointer[1];
                struct jpeg_error_mgr jerr;


                cinfo.err = jpeg_std_error(&jerr);
                jpeg_create_compress(&cinfo);
                jpeg_handle_dest(&cinfo, this);

                cinfo.image_width = x;
                cinfo.image_height = y;
                cinfo.input_components = 3;
                cinfo.in_color_space = JCS_RGB;
                jpeg_set_defaults(&cinfo);
                jpeg_set_quality(&cinfo, 85, TRUE /* limit to baseline-JPEG values */);

                jpeg_start_compress(&cinfo, TRUE);

                int row_stride = x * 3;

                while (cinfo.next_scanline < cinfo.image_height) {
                    row_pointer[0] = (JSAMPLE *) &rgb_buffer[cinfo.next_scanline * row_stride];
                    (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);
                }
                jpeg_finish_compress(&cinfo);
                jpeg_destroy_compress(&cinfo);
                free(rgb_buffer);
            }
#endif
            break;
	default:
            throw GeneralException("Image format unkown.");
	    return false;
    }
}