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

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 SURFACE_FUR_C



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




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

ydnar: fur module

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

/*
Fur()
runs the fur processing algorithm on a map drawsurface
*/

void Fur( mapDrawSurface_t *ds )
{
	int					i, j, k, numLayers;
	float				offset, fade, a;
	mapDrawSurface_t	*fur;
	bspDrawVert_t		*dv;
	
	
	/* dummy check */
	if( ds == NULL || ds->fur || ds->shaderInfo->furNumLayers < 1 )
		return;
	
	/* get basic info */
	numLayers = ds->shaderInfo->furNumLayers;
	offset = ds->shaderInfo->furOffset;
	fade = ds->shaderInfo->furFade * 255.0f;
	
	/* debug code */
	//%	Sys_FPrintf( SYS_VRB, "Fur():  layers: %d  offset: %f   fade: %f  %s\n",
	//%		numLayers, offset, fade, ds->shaderInfo->shader );
	
	/* initial offset */
	for( j = 0; j < ds->numVerts; j++ )
	{
		/* get surface vert */
		dv = &ds->verts[ j ];
			
		/* offset is scaled by original vertex alpha */
		a = (float) dv->color[ 0 ][ 3 ] / 255.0;
		
		/* offset it */
		VectorMA( dv->xyz, (offset * a), dv->normal, dv->xyz );
	}
	
	/* wash, rinse, repeat */
	for( i = 1; i < numLayers; i++ )
	{
		/* clone the surface */
		fur = CloneSurface( ds, ds->shaderInfo );
		if( fur == NULL )
			return;
		
		/* set it to fur */
		fur->fur = qtrue;
		
		/* walk the verts */
		for( j = 0; j < fur->numVerts; j++ )
		{
			/* get surface vert */
			dv = &ds->verts[ j ];
				
			/* offset is scaled by original vertex alpha */
			a = (float) dv->color[ 0 ][ 3 ] / 255.0;
			
			/* get fur vert */
			dv = &fur->verts[ j ];
			
			/* offset it */
			VectorMA( dv->xyz, (offset * a * i), dv->normal, dv->xyz );
			
			/* fade alpha */
			for( k = 0; k < MAX_LIGHTMAPS; k++ )
			{
				a = (float) dv->color[ k ][ 3 ] - fade;
				if( a > 255.0f )
					dv->color[ k ][ 3 ] = 255;
				else if( a < 0 )
					dv->color[ k ][ 3 ] = 0;
				else
					dv->color[ k ][ 3 ] = a;
			}
		}
	}
}



