/*
   Copyright (C) 1999-2006 Id Software, Inc. and contributors.
   For a list of contributors, see the accompanying CONTRIBUTORS file.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

// by Hydra - hydra@hydras-world.com
//
// HLW = Half-Life-WAD, I don't know if the actual in data in the WAD files
// has it's own name, so I'm just calling the individal textures .HLW files :)
//
// Thanks to the guys that made Wally for releasing an example WAD loader.
// without it this would not have been possible.

#include "hlw.h"

#include <stdlib.h>
#include <string.h>
#include <stdio.h>

typedef unsigned char byte;

#include "ifilesystem.h"

#include "imagelib.h"


/*
   ============================================================================

   HLW IMAGE

   HalfLife WAD files contain files that look like this:

    Mip section
        First mip
            Mip header
            First mip (width * height)
            Second mip (width * height / 4)
            Third mip (width * height / 16)
            Fourth mip (width * height / 64)
            Palette size (WORD)
            Palette (Palette size * 3)
            Padding (WORD)

   ============================================================================
 */

#define GET_MIP_DATA_SIZE( WIDTH, HEIGHT ) ( sizeof( WAD3_MIP ) + ( WIDTH * HEIGHT ) + ( WIDTH * HEIGHT / 4 ) + ( WIDTH * HEIGHT / 16 ) + ( WIDTH * HEIGHT / 64 ) )

typedef struct
{
	char name[16];
	unsigned int width, height;
	unsigned int offsets[4];            // four mip maps stored
} WAD3_MIP, *LPWAD3_MIP;

/*
   =========================================================

   HLW LOADING

   Hydra: this code isn't bullet proof and probably won't
   like corrupt WAD files, but it works for now.

   TODO: make it more robust.
   =========================================================
 */

/*
   =============
   LoadHLW
   =============
 */

Image* LoadHLWBuff( byte* buffer ){
	byte *buf_p;
	unsigned long mipdatasize;
	int columns, rows, numPixels;
	byte *pixbuf;
	int row, column;
	byte *palette;
	LPWAD3_MIP lpMip;
	unsigned char red, green, blue, alphabyte;

	lpMip = (LPWAD3_MIP)buffer; //!\todo Make endian-safe.

	mipdatasize = GET_MIP_DATA_SIZE( lpMip->width,lpMip->height );

	palette = buffer + mipdatasize + 2;

	buf_p = buffer + lpMip->offsets[0];

	columns = lpMip->width;
	rows = lpMip->height;
	numPixels = columns * rows;

	RGBAImage* image = new RGBAImage( columns, rows );

	for ( row = 0; row < rows; row++ )
	{
		pixbuf = image->getRGBAPixels() + row * columns * 4;

		for ( column = 0; column < columns; column++ )
		{
			int palIndex;

			palIndex = *buf_p++;

			red = *( palette + ( palIndex * 3 ) );
			green = *( palette + ( palIndex * 3 ) + 1 );
			blue = *( palette + ( palIndex * 3 ) + 2 );

			// HalfLife engine makes pixels that are BLUE transparent.
			// So show them that way in the editor.
			if ( blue == 0xff && red == 0x00 && green == 0x00 ) {
				alphabyte = 0x00;
				blue = 0x00; // don't set the resulting pixel to blue
			}
			else
			{
				alphabyte = 0xff;
			}

			*pixbuf++ = red;
			*pixbuf++ = green;
			*pixbuf++ = blue;

			*pixbuf++ = alphabyte;
		}
	}

	return image;
}

Image* LoadHLW( ArchiveFile& file ){
	ScopedArchiveBuffer buffer( file );
	return LoadHLWBuff( buffer.buffer );
}