/* The GIMP -- an image manipulation program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 * Alias|Wavefront pix/matte image reading and writing code 
 * Copyright (C) 1997 Mike Taylor
 * (email: mtaylor@aw.sgi.com, WWW: http://reality.sgi.com/mtaylor)
 *
 * 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.
 *
 */

/* This plug-in was written using the online documentation from 
 * Alias|Wavefront Inc's PowerAnimator product.
 *
 * Bug reports or suggestions should be e-mailed to mtaylor@aw.sgi.com
 */

/* Event history:
 * V 1.0, MT, 02-Jul-97: initial version of plug-in
 * V 1.1, MT, 04-Dec-97: added .als file extension 
 */

/* Features
 *  - loads and saves
 *    - 24-bit (.pix) 
 *    - 8-bit (.matte, .alpha, or .mask) images
 *
 * NOTE: pix and matte files do not support alpha channels or indexed
 *       colour, so neither does this plug-in
 */
 
static char ident[] = "@(#) GIMP Alias|Wavefront pix image file-plugin v1.0  24-jun-97";

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <libgimp/gimp.h>

/* #define PIX_DEBUG */

#ifdef PIX_DEBUG
#    define PIX_DEBUG_PRINT(a,b) fprintf(stderr,a,b)
#else
#    define PIX_DEBUG_PRINT(a,b) 
#endif

/**************
 * Prototypes *
 **************/

/* Standard Plug-in Functions */

static void   query ();
static void   run   ( char *name, int nparams, GParam *param, 
					  int *nreturn_vals, GParam **return_vals );

/* Local Helper Functions */ 

static gint32   load_image( char *filename );
static gint     save_image( char *filename, gint32 image_ID, gint32 drawable_ID );

static guint16  get_short( FILE * file );
static void     put_short( guint16 value, FILE * file );
static guint32  get_long( FILE * file );
static gchar    get_char( FILE * file );

/******************
 * Implementation *
 ******************/

GPlugInInfo PLUG_IN_INFO =
{
  NULL,    /* init_proc */
  NULL,    /* quit_proc */
  query,   /* query_proc */
  run,     /* run_proc */
};

MAIN ()

static void query ()
/*
 * Description:
 *     Register the services provided by this plug-in 
 */
{
	static GParamDef load_args[] = {
		{ PARAM_INT32,  "run_mode", "Interactive, non-interactive" },
		{ PARAM_STRING, "filename", "The name of the file to load" },
		{ PARAM_STRING, "raw_filename", "The name entered" },
	};
	static GParamDef load_return_vals[] = {
		{ PARAM_IMAGE, "image", "Output image" },
	};
	static int nload_args = sizeof (load_args) / sizeof (load_args[0]);
	static int nload_return_vals = sizeof (load_return_vals) / 
		                           sizeof (load_return_vals[0]);

	static GParamDef save_args[] = {
		{ PARAM_INT32, "run_mode", "Interactive, non-interactive" },
		{ PARAM_IMAGE, "image", "Input image" },
		{ PARAM_DRAWABLE, "drawable", "Drawable to save" },
		{ PARAM_STRING, "filename", "The name of the file to save the image in" },
		{ PARAM_STRING, "raw_filename",
		  "The name of the file to save the image in" }
	};
	static int nsave_args = sizeof (save_args) / sizeof (save_args[0]);

	gimp_install_procedure ("file_pix_load",
							"loads files of the PIX file format",
							"loads files of the PIX file format",
							"Michael Taylor",
							"Michael Taylor",
							"1997",
							"<Load>/PIX",
							NULL,
							PROC_PLUG_IN,
							nload_args, nload_return_vals,
							load_args, load_return_vals);

  gimp_install_procedure ("file_pix_save",
                          "save file in the Alias|Wavefront pix/matte file format",
                          "save file in the Alias|Wavefront pix/matte file format",
                          "Michael Taylor",
                          "Michael Taylor",
                          "1997",
                          "<Save>/PIX",
                          "RGB*, GRAY*",
                          PROC_PLUG_IN,
                          nsave_args, 0,
                          save_args, NULL);

	gimp_register_load_handler ("file_pix_load", "pix,matte,mask,alpha,als", "");
	gimp_register_save_handler ("file_pix_save", "pix,matte,mask,alpha,als", "");
}

static void run ( char *name, int nparams, GParam *param, int *nreturn_vals,
				  GParam **return_vals )
/* 
 *  Description:
 *      perform registered plug-in function 
 *
 *  Arguments:
 *      name         - name of the function to perform
 *      nparams      - number of parameters passed to the function
 *      param        - parameters passed to the function
 *      nreturn_vals - number of parameters returned by the function
 *      return_vals  - parameters returned by the function
 */
{
	static GParam values[2];
	GRunModeType run_mode;
	GStatusType status = STATUS_SUCCESS;
	gint32 image_ID;


	run_mode = param[0].data.d_int32;

	*nreturn_vals = 1;
	*return_vals = values;

	values[0].type = PARAM_STATUS;
	values[0].data.d_status = STATUS_CALLING_ERROR;

	if (strcmp (name, "file_pix_load") == 0) {
		/* Perform the image load */
		image_ID = load_image (param[1].data.d_string);
		if (image_ID != -1) {
			/* The image load was successful */
			*nreturn_vals = 2;
			values[0].data.d_status = STATUS_SUCCESS;
			values[1].type = PARAM_IMAGE;
			values[1].data.d_image = image_ID;
		} else {
			/* The image load falied */
			values[0].data.d_status = STATUS_EXECUTION_ERROR;
		}
	} else if (strcmp (name, "file_pix_save") == 0) {
		if (status == STATUS_SUCCESS) {
			if ( !save_image ( param[3].data.d_string, param[1].data.d_int32,
							   param[2].data.d_int32))
			{
				status = STATUS_EXECUTION_ERROR;
			}
		}
		values[0].data.d_status = status;
		
	} else {
		g_assert (FALSE);
	}
}

	
static guint16 get_short( FILE * file )
/* 
 * Description:
 *     Reads a 16-bit integer from a file in such a way that the machine's
 *     bit ordering should not matter 
 */
{
	guchar buf[2];
	
	fread( buf, 2, 1, file);
	return ( buf[0] << 8 ) + ( buf[1] << 0 );
}
	
static void put_short( guint16 value, FILE * file )
/* 
 * Description:
 *     Reads a 16-bit integer from a file in such a way that the machine's
 *     bit ordering should not matter 
 */
{
	guchar buf[2];
	buf[0] = (guchar)( value >> 8 );
	buf[1] = (guchar)( value % 256 );

	fwrite( buf, 2, 1, file);
}

static guint32 get_long( FILE * file )
/* 
 * Description:
 *     Reads a 16-bit integer from a file in such a way that the machine's
 *     bit ordering should not matter 
 */
{
	guchar buf[4];

	fread( buf, 4, 1, file );
	return ( buf[0] << 24 ) + ( buf[1] << 16 ) 
         + ( buf[2] << 8 ) + ( buf[3] << 0 );
}

static gchar get_char( FILE * file )
/* 
 * Description:
 *     Reads a byte from a file.  Provided for convenience; 
 */
{
	gchar result;

	fread( &result, 1, 1, file );
	return result;
}

static gint32 load_image (char *filename)
/*
 *  Description:
 *      load the given image into gimp
 * 
 *  Arguments:
 *      filename      - name on the file to read
 *
 *  Return Value:
 *      Image id for the loaded image
 *      
 */
{
	gint i, j, tile_height, row;	
	FILE      * file = NULL;
	gchar     * progMessage;
	guchar    * dest; 
	guchar    * dest_base;
	GDrawable * drawable;
	gint32      image_ID;
	gint32      layer_ID;
	GPixelRgn   pixel_rgn;
	gushort     width, height, depth;

	GImageType  imgtype;
	GDrawableType gdtype;

	/* Set up progress display */
	progMessage = malloc (strlen (filename) + 12);
	if (!progMessage) gimp_quit ();
	sprintf (progMessage, "Loading %s:", filename);
	gimp_progress_init (progMessage);
	free (progMessage);

	PIX_DEBUG_PRINT("Opening file: %s\n",filename);

	/* Open the file */
	file = fopen( filename, "r" );
	if ( NULL == file ) {
		return -1;
	}
 
    /* Read header information */
	width  = get_short( file );
	height = get_short( file );
	get_short( file ); /* Discard obsolete fields */
	get_short( file ); /* Discard obsolete fields */
	depth  = get_short( file );

	PIX_DEBUG_PRINT( "Width %hu\n", width );
	PIX_DEBUG_PRINT( "Height %hu\n", height );

	if ( depth == 8 ) {
		/* Loading a matte file */
		imgtype = GRAY;
		gdtype = GRAY_IMAGE;
	} else if ( depth == 24 ) {
		/* Loading an RGB file */
		imgtype = RGB;
		gdtype = RGB_IMAGE;
	} else {
		/* Header is invalid */
		fclose( file );
		return -1;
	}
	 
	image_ID = gimp_image_new ( width, height, imgtype );
	gimp_image_set_filename ( image_ID, filename );
	layer_ID = gimp_layer_new ( image_ID, "Background",
								width,
								height,
								gdtype, 100, NORMAL_MODE );
	gimp_image_add_layer ( image_ID, layer_ID, 0);
	drawable = gimp_drawable_get ( layer_ID );
	gimp_pixel_rgn_init ( &pixel_rgn, drawable, 0, 0, drawable->width, 
						  drawable->height, TRUE, FALSE );

	tile_height = gimp_tile_height();   

	if ( depth == 24 ) {
		/* Read a 24-bit Pix image */
		guchar record[4];
		gint   readlen;
		tile_height = gimp_tile_height();   

		dest_base = dest = g_new (guchar, 3 * width * tile_height); 

		for (i = 0; i < height;) {
			for ( dest = dest_base, row = 0;
				  row < tile_height && i < height;
				  i += 1, row += 1)
			{
				guchar count;

				/* Read a row of the image */
				j = 0;
				while ( j < width ) {
					readlen = fread( record, 1, 4, file );
					if ( readlen < 4 ) break;
					
					for ( count = 0; count < record[0]; ++count ) {
						dest[0]   = record[3];
						dest[1]   = record[2];
						dest[2]   = record[1];
						dest += 3;
						j++;
						if ( j >= width ) break;
					}
				}
			}
			gimp_pixel_rgn_set_rect (&pixel_rgn, dest_base, 0, i-row, 
									 width, row);
			gimp_progress_update ((double) i / (double) height);
		}

		free( dest_base );
	} else {
		/* Read an 8-bit Matte image */
		guchar record[2];
		gint   readlen;  

		dest_base = dest = g_new (guchar, width * tile_height); 

		for (i = 0; i < height;) {
			for ( dest = dest_base, row = 0;
				  row < tile_height && i < height;
				  i += 1, row += 1)
			{
				guchar count;

				/* Read a row of the image */
				j = 0;
				while ( j < width ) {
					readlen = fread( record, 1, 2, file );
					if ( readlen < 2 ) break;
					
					for ( count = 0; count < record[0]; ++count ) {
						dest[j]   = record[1];
						j++;
						if ( j >= width ) break;
					}
				}
				dest += width;
			}
			gimp_pixel_rgn_set_rect (&pixel_rgn, dest_base, 0, i-row, 
									 width, row);
			gimp_progress_update ((double) i / (double) height);
		}
		free( dest_base );
	}

	gimp_drawable_flush (drawable);
	gimp_drawable_detach (drawable);
	
	fclose( file );

	return image_ID;
}


static gint save_image( char *filename,  gint32 image_ID, gint32 drawable_ID )
/* 
 *  Description:
 *      save the given file out as an alias pix or matte file
 * 
 *  Arguments: 
 *      filename    - name of file to save to
 *      image_ID    - ID of image to save
 *      drawable_ID - current drawable
 */
{
	gint        depth, i, j, row, tile_height, writelen, rectHeight;
	/* gboolean    savingAlpha = FALSE; */
	gboolean    savingColor = TRUE;
	guchar    * src; 
	guchar    * src_base;
	gchar     * progMessage;
	GDrawable * drawable;
	GPixelRgn   pixel_rgn;
	FILE      * file;

	/* Get info about image */
	drawable = gimp_drawable_get(drawable_ID);

	gimp_pixel_rgn_init(&pixel_rgn, drawable, 0, 0, drawable->width,
						drawable->height, FALSE, FALSE);

	switch (gimp_drawable_type(drawable_ID))
	{
		case GRAY_IMAGE:
			savingColor = FALSE; 
			depth = 1;
			break;
		case GRAYA_IMAGE:
			savingColor = FALSE;
			depth = 2;
			break;
		case RGB_IMAGE:
			savingColor = TRUE;
			depth = 3;
			break;
		case RGBA_IMAGE:
			savingColor = TRUE;
			depth = 4;
			break;
		default:
			return FALSE;
	};

	
	/* Open the output file. */
	file = fopen (filename, "wb");
	if ( !file ) {
		return (FALSE);
	}

	/* Set up progress display */
	progMessage = malloc (strlen (filename) + 12);
	if (!progMessage) gimp_quit ();
	sprintf (progMessage, "Saving %s:", filename);
	gimp_progress_init (progMessage);
	free (progMessage);

	/* Write the image header */
	PIX_DEBUG_PRINT( "Width %hu\n", drawable->width );
	PIX_DEBUG_PRINT( "Height %hu\n", drawable->height );
	put_short( drawable->width, file );
	put_short( drawable->height, file );
	put_short( 0, file );
	put_short( 0, file );
	if ( savingColor ) {
		put_short( 24, file );
	} else {
		put_short( 8, file );
	}
	
	tile_height = gimp_tile_height();
	src_base    = g_new( guchar, tile_height * drawable->width * depth );
	
	if ( savingColor ) {
		/* Writing a 24-bit Pix image */
		guchar record[4];

		for (i = 0; i < drawable->height;) {
			rectHeight = ( tile_height < ( drawable->height - i - 1 ) ) ?
				tile_height : ( drawable->height - i - 1 );
			gimp_pixel_rgn_get_rect (&pixel_rgn, src_base, 0, i, 
									 drawable->width, rectHeight);

			for ( src = src_base, row = 0;
				  row < tile_height && i < drawable->height;
				  i += 1, row += 1)
			{
				/* Write a row of the image */
				record[0] = 1;
				record[3] = src[0];
				record[2] = src[1];
				record[1] = src[2];
				src += depth;
				for ( j = 1; j < drawable->width; ++j ) {
					if ( ( record[3] != src[0] ) ||
						 ( record[2] != src[1] ) ||
						 ( record[1] != src[2] ) ||
						 ( record[0] == 255 ) ) 
					{
						/* Write current RLE record and start a new one */
					  
						writelen = fwrite( record, 1, 4, file );
						record[0] = 1;
 						record[3] = src[0];
 						record[2] = src[1];
						record[1] = src[2];
					} else {
						/* increment run length in current record */
						record[0] ++;
					}
					src += depth;
				}
				/* Write last record in row */
				writelen = fwrite( record, 1, 4, file );
			}
			gimp_progress_update ((double) i / (double) drawable->height);
		}
	} else {
		/* Writing a 8-bit Matte (Mask) image */
		guchar record[2];

		for (i = 0; i < drawable->height;) {
			rectHeight = ( tile_height < ( drawable->height - i - 1 ) ) ?
				tile_height : ( drawable->height - i - 1 );
			gimp_pixel_rgn_get_rect (&pixel_rgn, src_base, 0, i, 
									 drawable->width, rectHeight);

			for ( src = src_base, row = 0;
				  row < tile_height && i < drawable->height;
				  i += 1, row += 1)
			{
				/* Write a row of the image */
				record[0] = 1;
				record[1] = src[0];
				src += depth;
				for ( j = 1; j < drawable->width; ++j ) {
					if ( ( record[1] != src[0] ) ||
						 ( record[0] == 255 ) ) 
					{
						/* Write current RLE record and start a new one */
						writelen = fwrite( record, 1, 2, file );
						record[0] = 1;
 						record[1] = src[0];
					} else {
						/* increment run length in current record */
						record[0] ++;
					}
					src += depth;
				}
				/* Write last record in row */
				writelen = fwrite( record, 1, 2, file );
			}
			gimp_progress_update ((double) i / (double) drawable->height);
		}
	}
	
	free( src_base );

	fclose( file );
	return (1);
}
