/* -------------------------------------------------------------------------------

Copyright (C) 1999-2007 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

----------------------------------------------------------------------------------

This code has been altered significantly from its original form, to support
several games based on the Quake III Arena engine, in the form of "Q3Map2."

------------------------------------------------------------------------------- */



/* marker */
#define IMAGE_C



/* dependencies */
#include "q3map2.h"



/* -------------------------------------------------------------------------------

this file contains image pool management with reference counting. note: it isn't
reentrant, so only call it from init/shutdown code or wrap calls in a mutex

------------------------------------------------------------------------------- */

/*
LoadDDSBuffer()
loads a dxtc (1, 3, 5) dds buffer into a valid rgba image
*/

static void LoadDDSBuffer( byte *buffer, int size, byte **pixels, int *width, int *height )
{
	int		w, h;
	ddsPF_t	pf;
	
	
	/* dummy check */
	if( buffer == NULL || size <= 0 || pixels == NULL || width == NULL || height == NULL )
		return;
	
	/* null out */
	*pixels = 0;
	*width = 0;
	*height = 0;
	
	/* get dds info */
	if( DDSGetInfo( (ddsBuffer_t*) buffer, &w, &h, &pf ) )
	{
		Sys_Printf( "WARNING: Invalid DDS texture\n" );
		return;
	}
	
	/* only certain types of dds textures are supported */
	if( pf != DDS_PF_ARGB8888 && pf != DDS_PF_DXT1 && pf != DDS_PF_DXT3 && pf != DDS_PF_DXT5 )
	{
		Sys_Printf( "WARNING: Only DDS texture formats ARGB8888, DXT1, DXT3, and DXT5 are supported (%d)\n", pf );
		return;
	}
	
	/* create image pixel buffer */
	*width = w;
	*height = h;
	*pixels = safe_malloc( w * h * 4 );
	
	/* decompress the dds texture */
	DDSDecompress( (ddsBuffer_t*) buffer, *pixels );
}



/*
PNGReadData()
callback function for libpng to read from a memory buffer
note: this function is a total hack, as it reads/writes the png struct directly!
*/

typedef struct pngBuffer_s
{
	byte	*buffer;
	png_size_t		size, offset;
}
pngBuffer_t;

void PNGReadData( png_struct *png, png_byte *buffer, png_size_t size )
{
	pngBuffer_t		*pb = (pngBuffer_t*) png_get_io_ptr( png );
	
	
	if( (pb->offset + size) > pb->size )
		size = (pb->size - pb->offset);
	memcpy( buffer, &pb->buffer[ pb->offset ], size );
	pb->offset += size;
	//%	Sys_Printf( "Copying %d bytes from 0x%08X to 0x%08X (offset: %d of %d)\n", size, &pb->buffer[ pb->offset ], buffer, pb->offset, pb->size );
}



/*
LoadPNGBuffer()
loads a png file buffer into a valid rgba image
*/

static void LoadPNGBuffer( byte *buffer, int size, byte **pixels, int *width, int *height )
{
	png_struct	*png;
	png_info	*info, *end;
	pngBuffer_t	pb;
	int			bitDepth, colorType;
	png_uint_32	w, h, i;
	byte		**rowPointers;
	
	
	/* dummy check */
	if( buffer == NULL || size <= 0 || pixels == NULL || width == NULL || height == NULL )
		return;
	
	/* null out */
	*pixels = 0;
	*width = 0;
	*height = 0;
	
	/* determine if this is a png file */
	if( png_sig_cmp( buffer, 0, 8 ) != 0 )
	{
		Sys_Printf( "WARNING: Invalid PNG file\n" );
		return;
	}
	
	/* create png structs */
	png = png_create_read_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL );
	if( png == NULL )
	{
		Sys_Printf( "WARNING: Unable to create PNG read struct\n" );
		return;
	}
	
	info = png_create_info_struct( png );
	if( info == NULL )
	{
		Sys_Printf( "WARNING: Unable to create PNG info struct\n" );
		png_destroy_read_struct( &png, NULL, NULL );
		return;
	}
	
	end = png_create_info_struct( png );
	if( end == NULL )
	{
		Sys_Printf( "WARNING: Unable to create PNG end info struct\n" );
		png_destroy_read_struct( &png, &info, NULL );
		return;
	}
	
	/* set read callback */
	pb.buffer = buffer;
	pb.size = size;
	pb.offset = 0;
	png_set_read_fn( png, &pb, PNGReadData );
	png->io_ptr = &pb; /* hack! */
	
	/* set error longjmp */
	if( setjmp( png->jmpbuf ) )
	{
		Sys_Printf( "WARNING: An error occurred reading PNG image\n" );
		png_destroy_read_struct( &png, &info, &end );
		return;
	}
	
	/* fixme: add proper i/o stuff here */

	/* read png info */
	png_read_info( png, info );
	
	/* read image header chunk */
	png_get_IHDR( png, info,
		&w, &h, &bitDepth, &colorType, NULL, NULL, NULL );
	
	/* the following will probably bork on certain types of png images, but hey... */

	/* force indexed/gray/trans chunk to rgb */
	if( (colorType == PNG_COLOR_TYPE_PALETTE && bitDepth <= 8) ||
		(colorType == PNG_COLOR_TYPE_GRAY && bitDepth <= 8) ||
		png_get_valid( png, info, PNG_INFO_tRNS ) )
		png_set_expand( png );
	
	/* strip 16bpc -> 8bpc */
	if( bitDepth == 16 )
		png_set_strip_16( png );
	
	/* pad rgb to rgba */
	if( bitDepth == 8 && colorType == PNG_COLOR_TYPE_RGB)
		png_set_filler( png, 255, PNG_FILLER_AFTER );
	
	/* create image pixel buffer */
	*width = w;
	*height = h;
	*pixels = safe_malloc( w * h * 4 );
	
	/* create row pointers */
	rowPointers = safe_malloc( h * sizeof( byte* ) );
	for( i = 0; i < h; i++ )
		rowPointers[ i ] = *pixels + (i * w * 4);
	
	/* read the png */
	png_read_image( png, rowPointers );
	
	/* clean up */
	free( rowPointers );
	png_destroy_read_struct( &png, &info, &end );
	
}



/*
ImageInit()
implicitly called by every function to set up image list
*/

static void ImageInit( void )
{
	int		i;
	
	
	if( numImages <= 0 )
	{
		/* clear images (fixme: this could theoretically leak) */
		memset( images, 0, sizeof( images ) );
		
		/* generate *bogus image */
		images[ 0 ].name = safe_malloc( strlen( DEFAULT_IMAGE ) + 1 );
		strcpy( images[ 0 ].name, DEFAULT_IMAGE );
		images[ 0 ].filename = safe_malloc( strlen( DEFAULT_IMAGE ) + 1 );
		strcpy( images[ 0 ].filename, DEFAULT_IMAGE );
		images[ 0 ].width = 64;
		images[ 0 ].height = 64;
		images[ 0 ].refCount = 1;
		images[ 0 ].pixels = safe_malloc( 64 * 64 * 4 );
		for( i = 0; i < (64 * 64 * 4); i++ )
			images[ 0 ].pixels[ i ] = 255;
	}
}



/*
ImageFree()
frees an rgba image
*/

void ImageFree( image_t *image )
{
	/* dummy check */
	if( image == NULL )
		return;
	
	/* decrement refcount */
	image->refCount--;
	
	/* free? */
	if( image->refCount <= 0 )
	{
		if( image->name != NULL )
			free( image->name );
		image->name = NULL;
		if( image->filename != NULL )
			free( image->filename );
		image->filename = NULL;
		free( image->pixels );
		image->width = 0;
		image->height = 0;
		numImages--;
	}
}



/*
ImageFind()
finds an existing rgba image and returns a pointer to the image_t struct or NULL if not found
*/

image_t *ImageFind( const char *filename )
{
	int			i;
	char		name[ 1024 ];
	
	
	/* init */
	ImageInit();
	
	/* dummy check */
	if( filename == NULL || filename[ 0 ] == '\0' )
		return NULL;
	
	/* strip file extension off name */
	strcpy( name, filename );
	StripExtension( name );
	
	/* search list */
	for( i = 0; i < MAX_IMAGES; i++ )
	{
		if( images[ i ].name != NULL && !strcmp( name, images[ i ].name ) )
			return &images[ i ];
	}
	
	/* no matching image found */
	return NULL;
}



/*
ImageLoad()
loads an rgba image and returns a pointer to the image_t struct or NULL if not found
*/

image_t *ImageLoad( const char *filename )
{
	int			i;
	image_t		*image;
	char		name[ 1024 ];
	int			size;
	byte		*buffer = NULL;
	qboolean	alphaHack = qfalse;

	
	/* init */
	ImageInit();
	
	/* dummy check */
	if( filename == NULL || filename[ 0 ] == '\0' )
		return NULL;
	
	/* strip file extension off name */
	strcpy( name, filename );
	StripExtension( name );
	
	/* try to find existing image */
	image = ImageFind( name );
	if( image != NULL )
	{
		image->refCount++;
		return image;
	}
	
	/* none found, so find first non-null image */
	image = NULL;
	for( i = 0; i < MAX_IMAGES; i++ )
	{
		if( images[ i ].name == NULL )
		{
			image = &images[ i ];
			break;
		}
	}
	
	/* too many images? */
	if( image == NULL )
		Error( "MAX_IMAGES (%d) exceeded, there are too many image files referenced by the map.", MAX_IMAGES );
	
	/* set it up */
	image->name = safe_malloc( strlen( name ) + 1 );
	strcpy( image->name, name );
	
	/* attempt to load tga */
	StripExtension( name );
	strcat( name, ".tga" );
	size = vfsLoadFile( (const char*) name, (void**) &buffer, 0 );
	if( size > 0 )
		LoadTGABuffer( buffer, buffer + size, &image->pixels, &image->width, &image->height );
	else
	{
		/* attempt to load png */
		StripExtension( name );
		strcat( name, ".png" );
		size = vfsLoadFile( (const char*) name, (void**) &buffer, 0 );
		if( size > 0 )
			LoadPNGBuffer( buffer, size, &image->pixels, &image->width, &image->height );
		else
		{
			/* attempt to load jpg */
			StripExtension( name );
			strcat( name, ".jpg" );
			size = vfsLoadFile( (const char*) name, (void**) &buffer, 0 );
			if( size > 0 )
			{
				if( LoadJPGBuff( buffer, size, &image->pixels, &image->width, &image->height ) == -1 && image->pixels != NULL )
					Sys_Printf( "WARNING: LoadJPGBuff: %s\n", (unsigned char*) image->pixels );
				alphaHack = qtrue;
			}
			else
			{
				/* attempt to load dds */
				StripExtension( name );
				strcat( name, ".dds" );
				size = vfsLoadFile( (const char*) name, (void**) &buffer, 0 );
				if( size > 0 )
				{
					LoadDDSBuffer( buffer, size, &image->pixels, &image->width, &image->height );
					
					/* debug code */
					#if 1
					{
						ddsPF_t	pf;
						DDSGetInfo( (ddsBuffer_t*) buffer, NULL, NULL, &pf );
						Sys_Printf( "pf = %d\n", pf );
						if( image->width > 0 )
						{
							StripExtension( name );
							strcat( name, "_converted.tga" );
							WriteTGA( "C:\\games\\quake3\\baseq3\\textures\\rad\\dds_converted.tga", image->pixels, image->width, image->height );
						}
					}
					#endif
				}
			}
		}
	}
	
	/* free file buffer */
	free( buffer );
	
	/* make sure everything's kosher */
	if( size <= 0 || image->width <= 0 || image->height <= 0 || image->pixels == NULL )
	{
		//%	Sys_Printf( "size = %d  width = %d  height = %d  pixels = 0x%08x (%s)\n",
		//%		size, image->width, image->height, image->pixels, name );
		free( image->name );
		image->name = NULL;
		return NULL;
	}
	
	/* set filename */
	image->filename = safe_malloc( strlen( name ) + 1 );
	strcpy( image->filename, name );
	
	/* set count */
	image->refCount = 1;
	numImages++;

	if(alphaHack)
	{
		StripExtension( name );
		strcat( name, "_alpha.jpg" );
		size = vfsLoadFile( (const char*) name, (void**) &buffer, 0 );
		if( size > 0 )
		{
			unsigned char *pixels;
			int width, height;
			if( LoadJPGBuff( buffer, size, &pixels, &width, &height ) == -1 && pixels != NULL )
				Sys_Printf( "WARNING: LoadJPGBuff: %s\n", (unsigned char*) image->pixels );
			if(pixels && width == image->width && height == image->height)
			{
				int i;
				for(i = 0; i < width*height; ++i)
					image->pixels[4*i+3] = pixels[4*i+2]; // copy alpha from blue channel
			}
			free(pixels);
			free(buffer);
		}
	}
	
	/* return the image */
	return image;
}