/*
 * file2pixmap.c
 * Copyright (C) 1996-1998 Teemu Maijala - uucee@sci.fi
 *
 * 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.
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include "file2pixmap.h"
#include "gif_lib.h"
#ifdef USE_JPEG_LIB
#include <jpeglib.h>
#include <jerror.h>
#endif

/* Filetypes */
typedef int FILETYPE;
#define UNKNOWN 0
#define GIF 1
#define JPEG 2
#define TOTAL_NUMBER_OF_FILETYPES 2
char *postfixes[2] = {".gif", ".jpg"};
FILETYPE filetypes[2] = {GIF, JPEG};

typedef unsigned long Pixel;

/* function prototypes */
int load_gif_to_pixmap(char *filename, Display *display, int screennum,
		       int *witdh, int *height, Pixmap *pixmap);
int load_jpeg_to_pixmap(char *filename, Display *display, int screennum,
			int *witdh, int *height, Pixmap *pixmap);
int gif_errorhandler();					       
FILETYPE filetype(char *filename);

/* function definitions */
int load_file_to_pixmap(char *filename, Display *display, int screennum,
			   int *width, int *height, Pixmap *pixmap) {
  switch(filetype(filename)) {
#ifdef USE_JPEG_LIB
  case JPEG:
    return load_jpeg_to_pixmap(filename, display, screennum,
			       width, height, pixmap);
    break;
#endif
  case GIF:
    return load_gif_to_pixmap(filename, display, screennum,
			      width, height, pixmap);
    break;
  case UNKNOWN:
    return NOT_VALID_FILETYPE;
    break;
  }
  return NOT_VALID_FILETYPE;
}

int load_gif_to_pixmap(char *filename, Display *display, int screennum,
			  int *width, int *height, Pixmap *pixmap) {
  int startline[4] = {0, 4, 2, 1};
  int offset[4] = {8, 8, 4, 2};
  int x, y, i, group;
  unsigned char colorvalue;
  GifFileType *giftype;
  Pixel *pixels;
  GC gc;
  XImage *image;
  XColor color;
  if (!(giftype = DGifOpenFileName(filename))) return gif_errorhandler();
  if (DGifSlurp(giftype)!=GIF_OK) return gif_errorhandler();
  *pixmap = XCreatePixmap(display, RootWindow(display, screennum),
			    giftype->SWidth, giftype->SHeight,
			    DefaultDepth(display, screennum));
  image = XGetImage(display, *pixmap, 0,0, giftype->SWidth, giftype->SHeight,
		    AllPlanes, ZPixmap);
  gc = XCreateGC(display, *pixmap, 0, NULL);
  pixels = (Pixel*)malloc(sizeof(Pixel)*giftype->SColorMap->ColorCount);
  for(i=0;i<giftype->SColorMap->ColorCount;i++) {
    color.red = giftype->SColorMap->Colors[i].Red*255;
    color.green = giftype->SColorMap->Colors[i].Green*255;
    color.blue = giftype->SColorMap->Colors[i].Blue*255;
    XAllocColor(display, DefaultColormap(display, screennum), &color);
    pixels[i] = color.pixel;
  }
  if (!giftype->Image.Interlace) {
    for(y=0;y<giftype->SHeight;y++) {
      for(x=0;x<giftype->SWidth;x++) {
	colorvalue = giftype->SavedImages->RasterBits[y*giftype->SWidth+x];
	XPutPixel(image, x, y, pixels[colorvalue]);
      }
    }
  } else {
    for(group=0,i=0;group<4;group++) {
      for(y=startline[group];y<giftype->SHeight;y+=offset[group],i++) {
	for(x=0;x<giftype->SWidth;x++) {
	  colorvalue = giftype->SavedImages->RasterBits[i*giftype->SWidth+x];
	  XPutPixel(image, x, y, pixels[colorvalue]);
	}
      }
    }
  }
  *width = giftype->SWidth;
  *height = giftype->SHeight;
  XPutImage(display, *pixmap, gc, image, 0, 0, 0, 0, giftype->SWidth,
	    giftype->SHeight);
  free(pixels);
  DGifCloseFile(giftype);
  XDestroyImage(image);
  return LOADING_OK;
}

int gif_errorhandler() {
  PrintGifError();
  switch(GifLastError()) {
  case D_GIF_ERR_OPEN_FAILED:
    return CANNOT_OPEN_FILE;
    break;
  case D_GIF_ERR_READ_FAILED:
    return CANNOT_READ_FILE;
    break;
  case D_GIF_ERR_NOT_GIF_FILE:
    return NOT_VALID_FILETYPE;
    break;
  default:
    return NOT_VALID_FILETYPE;
    break;
  }
}

#ifdef USE_JPEG_LIB
int load_jpeg_to_pixmap(char *filename, Display *display, int screennum,
			   int *width, int *height, Pixmap *pixmap) {
  FILE *jpegfile;
  GC gc;
  JSAMPROW scanline;
  Pixel *pixels;
  XColor color;
  XImage *image;
  int i, x, y;
  struct jpeg_decompress_struct cinfo;
  struct jpeg_error_mgr jerr;
  unsigned char colorvalue;
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_decompress(&cinfo);
  if ((jpegfile = fopen(filename, "rb")) == NULL) return 0;
  jpeg_stdio_src(&cinfo, jpegfile);
  jpeg_read_header(&cinfo, TRUE);
  cinfo.quantize_colors = TRUE;  /* colormap wanted */
  cinfo.dither_mode = JDITHER_ORDERED;
  jpeg_start_decompress(&cinfo);
  *pixmap = XCreatePixmap(display, RootWindow(display, screennum),
			    cinfo.output_width, cinfo.output_height,
			    DefaultDepth(display, screennum));
  image = XGetImage(display, *pixmap, 0,0, cinfo.output_width,
		    cinfo.output_height, AllPlanes, ZPixmap);
  gc = XCreateGC(display, *pixmap, 0, NULL);
  pixels = (Pixel*)malloc(sizeof(Pixel)*cinfo.actual_number_of_colors);
  if (cinfo.out_color_components > 1) {
    for(i=0;i<cinfo.actual_number_of_colors;i++) {
      color.red = cinfo.colormap[0][i]*255;
      color.green = cinfo.colormap[1][i]*255;
      color.blue = cinfo.colormap[2][i]*255;
      XAllocColor(display, DefaultColormap(display, screennum), &color);
      pixels[i] = color.pixel;
    }
  } else { /* grayscale */
    for (i=0;i<cinfo.actual_number_of_colors;i++) {
      color.red = color.green = color.blue = i*255;
      XAllocColor(display, DefaultColormap(display, screennum), &color);
      pixels[i] = color.pixel;
    } 
  }
  scanline = (JSAMPLE*)malloc(sizeof(JSAMPLE)*cinfo.output_width);
  for(y=0;y<cinfo.output_height;y++) {
    jpeg_read_scanlines(&cinfo, &scanline, 1);
    for(x=0;x<cinfo.output_width;x++) {
      colorvalue = scanline[x];
      XPutPixel(image, x, y, (unsigned long)pixels[colorvalue]);
    }
  }
  free(pixels);
  free(scanline);
  jpeg_finish_decompress(&cinfo);
  XPutImage(display, *pixmap, gc, image, 0, 0, 0, 0, cinfo.output_width,
	    cinfo.output_height);
  *width = cinfo.output_width;
  *height = cinfo.output_height;
  jpeg_destroy_decompress(&cinfo);
  XFreeGC(display, gc);
  XDestroyImage(image);
  return LOADING_OK;
}
#endif

FILETYPE filetype(char *filename) {
  int i;
  char *postfix;
  if ((postfix = strrchr(filename, '.'))==0) return UNKNOWN;
  for (i=0;i<TOTAL_NUMBER_OF_FILETYPES;i++) {
    if (!strcasecmp(postfix, postfixes[i])) return filetypes[i];
  }
  return UNKNOWN;
}