/*==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/>.

Additional permissions under GNU GPL version 3 section 7

If you modify this Program, or any covered work, by linking or
combining it with any of RAD Game Tools Bink SDK, Autodesk 3ds Max SDK,
NVIDIA PhysX SDK, Microsoft DirectX SDK, OpenSSL library, Independent
JPEG Group JPEG library, Microsoft Windows Media SDK, or Apple QuickTime SDK
(or a modified version of those libraries),
containing parts covered by the terms of the Bink SDK EULA, 3ds Max EULA,
PhysX SDK EULA, DirectX SDK EULA, OpenSSL and SSLeay licenses, IJG
JPEG Library README, Windows Media SDK EULA, or QuickTime SDK EULA, the
licensors of this Program grant you additional
permission to convey the resulting work. Corresponding Source for a
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the parts of OpenSSL and IJG JPEG Library used as well as that of the covered
work.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
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*==LICENSE==*/

#ifndef plLoadMask_inc
#define plLoadMask_inc

#include "HeadSpin.h"

template <class T> class hsTArray;
class hsStream;

class plLoadMask
{
public:
    enum {
        kMaxCap = 1
    };
protected:
    static uint8_t    fGlobalQuality;
    static uint8_t    fGlobalCapability;
    union {
        uint8_t           fQuality[kMaxCap+1];
        uint16_t          fMask;
    };

    static void SetGlobalQuality(int q) { fGlobalQuality = IBitToMask(q); }
    static void SetGlobalCapability(int c) { if( c > kMaxCap ) c = kMaxCap; else if( c < 0 ) c = 0; fGlobalCapability = c; }

    static uint8_t IBitToMask(int b) { hsAssert(b<8, "LoadMask: bit too large for uint8_t"); return (1 << b); }

    friend class plQuality;
public:
    // Change this to a for loop on kMaxCap+1 if we ever get more caps.
    plLoadMask() { fQuality[0] = fQuality[1] = 0xff; }
    plLoadMask(uint8_t qLo, uint8_t qHi) { fQuality[0] = qLo; fQuality[1] = qHi; }
    ~plLoadMask() {}

    hsBool      DontLoad() const { return !(fQuality[fGlobalCapability] & fGlobalQuality); }

    hsBool      NeverLoads() const { return !(fQuality[0] && fQuality[1]); }

    hsBool      IsUsed() const { return (fQuality[0] != uint8_t(-1)) || (fQuality[1] != uint8_t(-1));   }

    hsBool      MatchesQuality(int q) const { return (IBitToMask(q) & (fQuality[0] | fQuality[1])) != 0; }
    hsBool      MatchesCapability(int c) const { return fQuality[c] != 0; }
    hsBool      MatchesQualityAndCapability(int q, int c) const { return IBitToMask(q) & fQuality[c]; }

    hsBool      MatchesCurrentQuality() const { return MatchesQuality(fGlobalQuality); }
    hsBool      MatchesCurrentCapability() const { return MatchesCapability(fGlobalCapability); }
    hsBool      MatchesCurrent() const { return !DontLoad(); }

    uint8_t       GetQualityMask(int cap) const { return fQuality[cap]; }

    plLoadMask&     SetMask(uint8_t lo, uint8_t hi) { fQuality[0] = lo; fQuality[1] = hi; return *this; }
    plLoadMask&     SetNever() { return SetMask(0,0); }
    plLoadMask&     SetAlways() { return SetMask(uint8_t(-1), uint8_t(-1)); }

    plLoadMask& operator|=(const plLoadMask& m) { fMask |= m.fMask; return *this; }
    plLoadMask& operator&=(const plLoadMask& m) { fMask &= m.fMask; return *this; }

    int operator==(const plLoadMask& m) const { return fMask == m.fMask; }
    int operator!=(const plLoadMask& m) const { return !(*this == m); }

    // Only useful for sorting.
    int operator<(const plLoadMask& m) const { return fMask < m.fMask; }

    friend plLoadMask operator|(const plLoadMask& lhs, const plLoadMask& rhs) { plLoadMask r(lhs); r |= rhs; return r; }
    friend plLoadMask operator&(const plLoadMask& lhs, const plLoadMask& rhs) { plLoadMask r(lhs); r &= rhs; return r; }

    void        Read(hsStream* s);
    void        Write(hsStream* s) const;

    static const plLoadMask     kAlways;


    // Input lists are in order of preference, i.e. if rep[0] and rep[1] are both loadable based
    // on the current settings, only rep[0] will be loaded. This implies some rules
    // to avoid wasted reps (reps that would never get loaded). Basically:
    //  if( i < j ) then
    //      (quals[i] > quals[j]) || (caps[i] > caps[j])
    //
    // It doesn't break anything if that condition isn't met, it just means
    // the latter one will never get loaded (have a load mask of zero).
    // So, just to be a pal, we'll detect that condition and return based on it.
    // i.e. Return true on invalid input (something will never get loaded).
    // 
    // You can also pre-validate your input with ValidateReps, and/or validate
    // the output with ValidateMasks. The return value is a bitmask of which
    // items in the list had problems, so return of zero means A-OK.
    //
    static hsBool ComputeRepMasks(int num, const int quals[], const int caps[], plLoadMask masks[]);
    static uint32_t ValidateReps(int num, const int quals[], const int caps[]);
    static uint32_t ValidateMasks(int num, plLoadMask masks[]);
};

#endif // plLoadMask_inc