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# Random.h

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    00001 //------------------------------------------------------------------------------
    00002 // Lamp : Open source game middleware
    00003 // Copyright (C) 2004  Junpei Ohtani ( Email : junpee@users.sourceforge.jp )
    00004 //
    00005 // This library is free software; you can redistribute it and/or
    00006 // modify it under the terms of the GNU Lesser General Public
    00007 // License as published by the Free Software Foundation; either
    00008 // version 2.1 of the License, or (at your option) any later version.
    00009 //
    00010 // This library is distributed in the hope that it will be useful,
    00011 // but WITHOUT ANY WARRANTY; without even the implied warranty of
    00012 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00013 // Lesser General Public License for more details.
    00014 //
    00015 // You should have received a copy of the GNU Lesser General Public
    00016 // License along with this library; if not, write to the Free Software
    00017 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    00018 //------------------------------------------------------------------------------
    00019
    00020 /** @file
    00021  * ランダムヘッダ
    00022  * @author Junpee
    00023  */
    00024
    00025 #ifndef RANDOM_H_
    00026 #define RANDOM_H_
    00027
    00028 namespace Lamp{
    00029
    00030 //------------------------------------------------------------------------------
    00031 /**
    00032  * ランダム
    00033  *
    00034  * このクラスは継承しないで下さい。
    00035  */
    00036 class Random{
    00037 public:
    00038     /**
    00039      * コンストラクタ
    00040      * @param initialSeed 初期化種
    00041      */
    00042     explicit Random(u_int initialSeed = 1){ setSeed(initialSeed); }
    00043
    00044     /**
    00045      * 種の設定
    00046      * @param seed 設定する種
    00047      */
    00048     void setSeed(u_int seed){ seed_ = seed; }
    00049
    00050     /**
    00051      * ランダム値の取得
    00052      * @return 0以上、Random::max以下のランダム値。
    00053      */
    00054     inline u_int get(){
    00055         seed_ = 1664525 * seed_ + 1013904223;
    00056         return seed_;
    00057     }
    00058
    00059     /**
    00060      * byteランダム値の取得
    00061      * @return 0以上、255以下のランダム値
    00062      */
    00063     inline int getByte(){
    00064         return (get() & 0xff);
    00065     }
    00066
    00067     /**
    00068      * floatランダム値の取得
    00069      * @return -1.f以上、1.f未満のランダム値を返す
    00070      */
    00071     inline float getSignedFloat(){
    00072         float result;
    00073         (*(u_int*)&result) = 0x3f800000 | (0x7fffff & get());
    00074         return (result * 2.f) - 3.f;
    00075     }
    00076
    00077     /**
    00078      * unsigned floatランダム値の取得
    00079      * @return 0.f以上、1.f未満のランダム値を返す
    00080      */
    00081     inline float getUnsignedFloat(){
    00082         float result;
    00083         (*(u_int*)&result) = 0x3f800000 | (0x7fffff & get());
    00084         return result - 1.0f;
    00085     }
    00086
    00087 private:
    00088     // コピーコンストラクタの隠蔽
    00089     Random(const Random& copy);
    00090
    00091     // 代入コピーの隠蔽
    00092     void operator =(const Random& copy);
    00093
    00094     // ランダムの種
    00095     u_int seed_;
    00096 };
    00097
    00098 //------------------------------------------------------------------------------
    00099 } // End of namespace Lamp
    00100 #endif // End of RANDOM_H_
    00101 //------------------------------------------------------------------------------