/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

This program 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 3 of the License, or
(at your option) any later version.

This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/

#ifndef plDistOpacityMod_inc
#define plDistOpacityMod_inc

#include "hsGeometry3.h"
#include "pnModifier/plSingleModifier.h"
#include "hsTemplates.h"

class plPipeline;
class plRenderMsg;
class plFadeOpacityLay;


class plDistOpacityMod : public plSingleModifier
{
public:

    enum {
        kTrackAvatar,
        kTrackCamera
    };
protected:

    enum {
        kRefFadeLay
    };

    // Volatile flag, whether we're setup yet or not.
    UInt8           fSetup;

    enum {
        kNearTrans,
        kNearOpaq,
        kFarOpaq,
        kFarTrans,

        kNumDists
    };
    hsScalar        fDists[kNumDists];

    hsPoint3        fRefPos;

    hsTArray<plFadeOpacityLay*> fFadeLays;

    // We only act in response to messages.
    virtual hsBool IEval(double secs, hsScalar del, UInt32 dirty) { return false; }

    hsScalar ICalcOpacity(const hsPoint3& targPos, const hsPoint3& refPos) const;
    void ISetOpacity();

    void ISetup();

    void ICheckDists()
    {
        hsAssert(fDists[kNearTrans] <= fDists[kNearOpaq], "Bad transition values");
        hsAssert(fDists[kNearOpaq] <= fDists[kFarOpaq], "Bad transition values");
        hsAssert(fDists[kFarOpaq] <= fDists[kFarTrans], "Bad transition values");
    }

public:
    plDistOpacityMod();
    virtual ~plDistOpacityMod();

    CLASSNAME_REGISTER( plDistOpacityMod );
    GETINTERFACE_ANY( plDistOpacityMod, plSingleModifier );

    virtual void            SetKey(plKey k);

    virtual hsBool          MsgReceive(plMessage* msg);

    virtual void            Read(hsStream* s, hsResMgr* mgr);
    virtual void            Write(hsStream* s, hsResMgr* mgr);

    virtual void            SetTarget(plSceneObject* so);

    // Rules are:
    // NearTrans <= NearOpaq <= FarOpaque <= FarTrans
    void SetFarDist(hsScalar opaque, hsScalar transparent);
    void SetNearDist(hsScalar transparent, hsScalar opaque);

    hsScalar GetFarTransparent() const { return fDists[kFarTrans]; }
    hsScalar GetNearTransparent() const { return fDists[kNearTrans]; }
    hsScalar GetFarOpaque() const { return fDists[kFarOpaq]; }
    hsScalar GetNearOpaque() const { return fDists[kNearOpaq]; }
};

#endif // plDistOpacityMod_inc