sample25-fps

#include <math.h>
#include <stdio.h>
#include <stdlib.h>//glut.hより先にインクルード
#include <gl/glew.h>//glut.hより先にインクルード
#include <gl/glut.h>

//static unsigned int fps_start=0;
//static unsigned int fps_frames=0;
//  The number of frames
int frameCount = 0;
float fps = 0;

//  currentTime - previousTime is the time elapsed
//  between every call of the Idle function
int currentTime = 0, previousTime = 0;

//  printf prints to file. printw prints to window
//void printw (float x, float y, float z, char* format, ...);

void calculateFPS();

//void drawFPS();

//------- 頂点データ-----------//
//｢6｣面､｢4｣頂点､1頂点はx,y,zの｢3｣要素
GLfloat vertexAry[6][4][3] =
{
    //1つめの面(v0-v1-v2-v3)
    {
        {0.f,0.f,0.f},{1.f,0.f,0.f},
        {1.f,1.f,0.f},{0.f,1.f,0.f}
    },
    //2つめの面(v1-v5-v6-v2)
    {
        {1.f,0.f,0.f},{1.f,0.f,-1.f},
        {1.f,1.f,-1.f},{1.f,1.f,0.f}
    },
    //3つめの面(v4-v7-v6-v5)
    {
        {0.f,0.f,-1.f},{0.f,1.f,-1.f},
        {1.f,1.f,-1.f},{1.f,0.f,-1.f}
    },
    //4つめの面(v4-v0-v3-v7)
    {
        {0.f,0.f,-1.f},{0.f,0.f,0.f},
        {0.f,1.f,0.f},{0.f,1.f,-1.f}
    },
    //5つめの面(v3-v2-v6-v7)
    {
        {0.f,1.f,0.f},{1.f,1.f,0.f},
        {1.f,1.f,-1.f},{0.f,1.f,-1.f}
    },
    //6つめの面(v0-v4-v5-v1)
    {
        {0.f,0.f,0.f},{0.f,0.f,-1.f},
        {1.f,0.f,-1.f},{1.f,0.f,0.f}
    }
};

//法線データ
GLfloat normalAry[6][4][3] =
{
    //1つめの面(v0-v1-v2-v3)
    {
        {0.f,0.f,1.f},{0.f,0.f,1.f},
        {0.f,0.f,1.f},{0.f,0.f,1.f}
    },
    //2つめの面(v1-v5-v6-v2)
    {
        {1.f,0.f,0.f},{1.f,0.f,0.f},
        {1.f,0.f,0.f},{1.f,0.f,0.f}
    },
    //3つめの面(v4-v7-v6-v5)
    {
        {0.f,0.f,-1.f},{0.f,0.f,-1.f},
        {0.f,0.f,-1.f},{0.f,0.f,-1.f}
    },
    //4つめの面(v4-v0-v3-v7)
    {
        {-1.f,0.f,0.f},{-1.f,0.f,0.f},
        {-1.f,0.f,0.f},{-1.f,0.f,0.f}
    },
    //5つめの面(v3-v2-v6-v7)
    {
        {0.f,1.f,0.f},{0.f,1.f,0.f},
        {0.f,1.f,0.f},{0.f,1.f,0.f}
    },
    //6つめの面(v0-v4-v5-v1)
    {
        {0.f,-1.f,0.f},{0.f,-1.f,0.f},
        {0.f,-1.f,0.f},{0.f,-1.f,0.f}
    }
};

//色データ
GLfloat colorAry[6][4][3] =
{
    //1つめの面(v0-v1-v2-v3)
    {
        {0.f,0.f,1.f},{0.f,0.f,1.f},
        {0.f,0.f,1.f},{0.f,0.f,1.f}
    },
    //2つめの面(v1-v5-v6-v2)
    {
        {1.f,0.f,0.f},{1.f,0.f,0.f},
        {1.f,0.f,0.f},{1.f,0.f,0.f}
    },
    //3つめの面(v4-v7-v6-v5)
    {
        {0.f,1.f,1.f},{0.f,1.f,1.f},
        {0.f,1.f,1.f},{0.f,1.f,1.f}
    },
    //4つめの面(v4-v0-v3-v7)
    {
        {1.f,1.f,0.f},{1.f,1.f,0.f},
        {1.f,1.f,0.f},{1.f,1.f,0.f}
    },
    //5つめの面(v3-v2-v6-v7)
    {
        {0.f,1.f,0.f},{0.f,1.f,0.f},
        {0.f,1.f,0.f},{0.f,1.f,0.f}
    },
    //6つめの面(v0-v4-v5-v1)
    {
        {1.f,0.f,1.f},{1.f,0.f,1.f},
        {1.f,0.f,1.f},{1.f,0.f,1.f}
    }
};
//インデックス
GLubyte indexAry[]=
{
    0,1,2,3,
    4,5,6,7,
    8,9,10,11,
    12,13,14,15,
    16,17,18,19,
    20,21,22,23
};

// π/180の値
const float PI_OVER_180 = 0.0174532925f;

//VBO用ID
GLuint VboId[3];//３つ分
GLuint VboIndex;//インデックス

//描画関数
void drawAry(void)
{
    GLfloat *clientPtr;//クライアント側用
    GLfloat tmp[3];
    int idloop;
    int loop;
    static float angle = 2*PI_OVER_180;

    //データの場所を知らせる
    //座標
    glBindBuffer(GL_ARRAY_BUFFER,VboId[0]);
    glVertexPointer(3, GL_FLOAT, 0, 0);
    //法線
    glBindBuffer(GL_ARRAY_BUFFER,VboId[1]);
    glNormalPointer(GL_FLOAT, 0, 0);
    //色
    glBindBuffer(GL_ARRAY_BUFFER,VboId[2]);
    glColorPointer(3,GL_FLOAT, 0, 0);
    //インデックスもバインド
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, VboIndex);

    glEnableClientState(GL_VERTEX_ARRAY);
    glEnableClientState(GL_NORMAL_ARRAY);
    glEnableClientState(GL_COLOR_ARRAY);
    //描画
    glDrawElements(GL_QUADS,24,GL_UNSIGNED_BYTE,0);

    glDisableClientState(GL_COLOR_ARRAY);
    glDisableClientState(GL_NORMAL_ARRAY);
    glDisableClientState(GL_VERTEX_ARRAY);

    //座標と法線を回転させる
    for(idloop = 0; idloop < 2;++idloop)
    {
        //idloop番目のバッファオブジェクトに注目
        glBindBuffer(GL_ARRAY_BUFFER,VboId[idloop]);

        //対応付け
        clientPtr = (GLfloat *)glMapBuffer(GL_ARRAY_BUFFER,
                                                GL_READ_WRITE);
        if(clientPtr != NULL)
        {
            //24頂点*3座標
             for(loop = 0; loop < 24*3;loop += 3)   {
                //読み出し(READ)
                tmp[0] = clientPtr[loop];
                tmp[1] = clientPtr[loop+1];
                tmp[2] = clientPtr[loop+2];
                //書き込み(WRITE)
                clientPtr[loop] = cos(angle)*tmp[0]
                                    + sin(angle)*tmp[2];
                clientPtr[loop+1] = tmp[1];
                clientPtr[loop+2] = -sin(angle)*tmp[0]
                                        + cos(angle)*tmp[2];
             }
            glUnmapBuffer(GL_ARRAY_BUFFER);//対応付けの解放
        }
    }
    //クライアント側に戻す
    glBindBuffer(GL_ARRAY_BUFFER,0);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
}
//------- 各種コールバック----------//
void display(void)
{
    static int angle = 0;
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    glLoadIdentity();
    gluLookAt(3.0, 4.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

    glPushMatrix();
    glRotatef(float(angle),1.f,0.f,0.f);//x軸回転
    drawAry();
    glPopMatrix();

    calculateFPS();
    //drawFPS();

    glutSwapBuffers();
    if(++angle >= 360) angle = 0;
}

void reshape(int w, int h)
{
    glViewport(0,0,w,h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(30.0, double(w)/h, 0.1, 200.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
}

void idle(void)
{
    glutPostRedisplay();
}

void keyboard(unsigned char key, int x, int y)
{
    switch(key)
    {
    case 'q':
    case 'Q':
    case '\033':
        //終了処理
        glDeleteBuffers(3,&VboId[0]);
        glDeleteBuffers(1,&VboIndex);
        exit(0);
        break;
    }
}
//------ その他初期設定-------//
void otherInit(void)
{
    glClearColor(1.f, 1.f, 1.f, 1.f);
    glEnable(GL_DEPTH_TEST);
    glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE);
    glEnable(GL_COLOR_MATERIAL);
    glEnable(GL_LIGHT0);
    glEnable(GL_LIGHTING);
    glEnable(GL_NORMALIZE);//法線の正規化
}

//---- VBOの作成----//
void buildVBO(void)
{
    glGenBuffers(3,&VboId[0]);//座標､法線､色の３つ

    //頂点
    glBindBuffer(GL_ARRAY_BUFFER,VboId[0]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(vertexAry),
                vertexAry,GL_DYNAMIC_DRAW);//データ変更する

    //法線
    glBindBuffer(GL_ARRAY_BUFFER,VboId[1]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(normalAry),
                normalAry,GL_DYNAMIC_DRAW);//データ変更あり

    //色
    glBindBuffer(GL_ARRAY_BUFFER,VboId[2]);
    glBufferData(GL_ARRAY_BUFFER,sizeof(colorAry),
                    colorAry,GL_STREAM_DRAW);//データ変更なし

    //インデックス
    glGenBuffers(1,&VboIndex);
    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,VboIndex);
    glBufferData(GL_ELEMENT_ARRAY_BUFFER,sizeof(indexAry),
                    indexAry,GL_STATIC_DRAW);//データ変更なし
}


//-------------------------------------------------------------------------
// Calculates the frames per second
//-------------------------------------------------------------------------

void calculateFPS()
{
    //  Increase frame count
    frameCount++;

    //  Get the number of milliseconds since glutInit called
    //  (or first call to glutGet(GLUT ELAPSED TIME)).
    currentTime = glutGet(GLUT_ELAPSED_TIME);

    //  Calculate time passed
    int timeInterval = currentTime - previousTime;

    if(timeInterval > 1000)
    {
        //  calculate the number of frames per second
        fps = frameCount / (timeInterval / 1000.0f);

        //  Set time
        previousTime = currentTime;

        //  Reset frame count
        frameCount = 0;
    }

    printf ("FPS: %4.2f\n", fps);

}


//-------------------------------------------------------------------------
//  Draw FPS
//-------------------------------------------------------------------------
/*
void drawFPS()
{
    //  Load the identity matrix so that FPS string being drawn
    //  won't get animates
    glLoadIdentity ();

    fps=glutGet(GLUT_ELAPSED_TIME);

    //  Print the FPS to the window
    printf ("FPS: %4.2f\n", fps);
}
 */


//----------- メイン関数------------//
int main(int argc, char *argv[])
{
    //GLUTの初期設定
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGBA|GLUT_DEPTH|GLUT_DOUBLE);
    glutInitWindowSize(640,480);
    glutCreateWindow("VBO Sample");
    //GLEWの初期設定
    GLenum err = glewInit();
    if(err != GLEW_OK)
    {
        fprintf(stderr,"Err:%s\n",
            glewGetErrorString(err));
        return -1;
    }
    //拡張チェック
    if(!glewIsExtensionSupported(
                    "GL_ARB_vertex_buffer_object")){
        puts("you Can't use VBO");
        return -1;
    }

    //コールバック
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutIdleFunc(idle);
    glutKeyboardFunc(keyboard);

    otherInit();

    buildVBO();//VBOの作成
    calculateFPS();
    //drawFPS();
    //fps=glutGet(GLUT_ELAPSED_TIME);
    glutMainLoop();

    return 0;
}