openGL_VBO

#include <math.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include "glew.h"
#include <GLUT/glut.h>


//------- 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();

	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
}
//----------- 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
	glutMainLoop();

	return 0;
}