/*
** gl_glow.cpp
** Glowing flats like Doomsday
**
**---------------------------------------------------------------------------
** Copyright 2005 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
**    notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
**    notice, this list of conditions and the following disclaimer in the
**    documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
**    derived from this software without specific prior written permission.
** 4. When not used as part of GZDoom or a GZDoom derivative, this code will be
**    covered by the terms of the GNU Lesser General Public License as published
**    by the Free Software Foundation; either version 2.1 of the License, or (at
**    your option) any later version.
** 5. Full disclosure of the entire project's source code, except for third
**    party libraries is mandatory. (NOTE: This clause is non-negotiable!)
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/

#include "w_wad.h"
#include "sc_man.h"
#include "v_video.h"
#include "r_defs.h"
#include "textures/textures.h"

#include "gl/dynlights/gl_glow.h"

//===========================================================================
// 
//	Reads glow definitions from GLDEFS
//
//===========================================================================
void gl_InitGlow(FScanner &sc)
{
	sc.MustGetStringName("{");
	while (!sc.CheckString("}"))
	{
		sc.MustGetString();
		if (sc.Compare("FLATS"))
		{
			sc.MustGetStringName("{");
			while (!sc.CheckString("}"))
			{
				sc.MustGetString();
				FTextureID flump=TexMan.CheckForTexture(sc.String, FTexture::TEX_Flat,FTextureManager::TEXMAN_TryAny);
				FTexture *tex = TexMan[flump];
				if (tex) tex->gl_info.bGlowing = tex->gl_info.bFullbright = true;
			}
		}
		else if (sc.Compare("WALLS"))
		{
			sc.MustGetStringName("{");
			while (!sc.CheckString("}"))
			{
				sc.MustGetString();
				FTextureID flump=TexMan.CheckForTexture(sc.String, FTexture::TEX_Wall,FTextureManager::TEXMAN_TryAny);
				FTexture *tex = TexMan[flump];
				if (tex) tex->gl_info.bGlowing = tex->gl_info.bFullbright = true;
			}
		}
		else if (sc.Compare("TEXTURE"))
		{
			sc.SetCMode(true);
			sc.MustGetString();
			FTextureID flump=TexMan.CheckForTexture(sc.String, FTexture::TEX_Flat,FTextureManager::TEXMAN_TryAny);
			FTexture *tex = TexMan[flump];
			sc.MustGetStringName(",");
			sc.MustGetString();
			PalEntry color = V_GetColor(NULL, sc.String);
			//sc.MustGetStringName(",");
			//sc.MustGetNumber();
			if (sc.CheckString(","))
			{
				if (sc.CheckNumber())
				{
					if (tex) tex->gl_info.GlowHeight = sc.Number;
					if (!sc.CheckString(",")) goto skip_fb;
				}

				sc.MustGetStringName("fullbright");
				if (tex) tex->gl_info.bFullbright = true;
			}
		skip_fb:
			sc.SetCMode(false);

			if (tex && color != 0)
			{
				tex->gl_info.bGlowing = true;
				tex->gl_info.GlowColor = color;
			}
		}
	}
}


//==========================================================================
//
// Checks whether a sprite should be affected by a glow
//
//==========================================================================
int gl_CheckSpriteGlow(sector_t *sec, int lightlevel, const DVector3 &pos)
{
	FTextureID floorpic = sec->GetTexture(sector_t::floor);
	FTexture *tex = TexMan[floorpic];
	if (tex != NULL && tex->isGlowing())
	{
		double floordiff = pos.Z - sec->floorplane.ZatPoint(pos);
		if (floordiff < tex->gl_info.GlowHeight && tex->gl_info.GlowHeight != 0)
		{
			int maxlight = (255 + lightlevel) >> 1;
			double lightfrac = floordiff / tex->gl_info.GlowHeight;
			if (lightfrac < 0) lightfrac = 0;
			lightlevel = int(lightfrac*lightlevel + maxlight*(1 - lightfrac));
		}
	}
	return lightlevel;
}