/*==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 plShadowCaster_inc
#define plShadowCaster_inc

#include "pnModifier/plMultiModifier.h"
#include "hsBounds.h"
#include "hsTemplates.h"

class plDrawableSpans;
class plSpan;
class plMessage;
class hsStream;
class hsResMgr;
class plShadowMaster;
class plRenderMsg;

class plShadowCaster : public plMultiModifier
{
public:
    enum {
        kNone           = 0x0,
        kSelfShadow     = 0x1,
        kPerspective    = 0x2,
        kLimitRes       = 0x4
    };
    class DrawSpan
    {
    public:
        DrawSpan& Set(plDrawableSpans* dr, const plSpan* sp, UInt32 idx) { fDraw = (dr); fSpan = (sp); fIndex = (idx); return *this; }

        plDrawableSpans*    fDraw;
        const plSpan*       fSpan;
        UInt32              fIndex;
    };
protected:

    // Global state to just turn off the whole gig. Not just
    // debugging, we'll probably want a user option for this.
    static hsBool       fShadowCastDisabled;
    static hsBool       fCanShadowCast;


    // Properties really just to be read and written,
    // never expected to change. Anything that might be
    // triggered should go into plMultiModifier::fProps,
    // to be network synced.
    UInt8               fCastFlags;

    hsScalar            fBoost;
    hsScalar            fAttenScale;
    hsScalar            fBlurScale;

    // Casting attributes calculated each frame.
    hsScalar            fMaxOpacity;
    hsTArray<DrawSpan>  fSpans;

    friend plShadowMaster;

    void ICollectAllSpans();

    hsBool IOnRenderMsg(plRenderMsg* msg);

    friend class plDXPipeline;
    static void SetCanShadowCast(hsBool b) { fCanShadowCast = b; }
public:
    plShadowCaster();
    virtual ~plShadowCaster();

    CLASSNAME_REGISTER( plShadowCaster );
    GETINTERFACE_ANY( plShadowCaster, plMultiModifier );
    
    virtual hsBool IEval(double secs, hsScalar del, UInt32 dirty) { return true; }

    virtual hsBool MsgReceive(plMessage* msg);

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

    hsScalar MaxOpacity() const { return fMaxOpacity; }
    const hsTArray<DrawSpan>& Spans() const { return fSpans; }

    hsBool  GetSelfShadow() const { return 0 != (fCastFlags & kSelfShadow); }
    void    SetSelfShadow(hsBool on) { if(on) fCastFlags |= kSelfShadow; else fCastFlags &= ~kSelfShadow; }

    hsBool  GetPerspective() const { return 0 != (fCastFlags & kPerspective); }
    void    SetPerspective(hsBool on) { if(on) fCastFlags |= kPerspective; else fCastFlags &= ~kPerspective; }

    hsBool  GetLimitRes() const { return 0 != (fCastFlags & kLimitRes); }
    void    SetLimitRes(hsBool on) { if(on) fCastFlags |= kLimitRes; else fCastFlags &= ~kLimitRes; }

    hsScalar GetAttenScale() const { return fAttenScale; }
    void SetAttenScale(hsScalar s) { fAttenScale = s; }

    hsScalar GetBlurScale() const { return fBlurScale; }
    void SetBlurScale(hsScalar s) { fBlurScale = s; }

    hsScalar GetBoost() const { return fBoost; }
    void SetBoost(hsScalar s) { fBoost = s; }

    // These are usually handled internally, activating on read and deactivating
    // on destruct. Made public in case they need to be manually handled, like
    // on dynamic construction and use.
    void Deactivate() const;
    void Activate() const;

    static void DisableShadowCast(hsBool on=true) { fShadowCastDisabled = on; }
    static void EnableShadowCast(hsBool on=true) { fShadowCastDisabled = !on; }
    static void ToggleShadowCast() { fShadowCastDisabled = !fShadowCastDisabled; }
    static hsBool ShadowCastDisabled() { return !CanShadowCast() || fShadowCastDisabled; }

    static hsBool CanShadowCast() { return fCanShadowCast; }
};

typedef plShadowCaster::DrawSpan plShadowCastSpan;

#endif // plShadowCaster_inc