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

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 = dv->lightColor[0][3] / 255.0f;

		/* 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 = dv->lightColor[0][3] / 255.0f;

			/* 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 = dv->lightColor[k][3] - fade;
				if(a > 255.0f)
					dv->lightColor[k][3] = 255;
				else if(a < 0)
					dv->lightColor[k][3] = 0;
				else
					dv->lightColor[k][3] = a;
			}
		}
	}
}
