頂点配列 - OpenGLプログラミングメモ

頂点配列です。
今までは　glBegin()　と　glEnd()　で囲んで　glVertex3d　や　glTexCoord2f　を
記述してきました。
わかりやすいですが、これでは何度も何度も関数を呼び出し、機能を切り替えて
値を設定している事になり、少ないポリゴン数であれば問題ありませんが、大量の
ポリゴンを描画する時には描画速度に影響します。
頂点は頂点でまとめ、法線は法線、マテリアルはマテリアルというようにデータが
まとまっていた方が機能切り替えが最小限になり効率が良くなります。
頂点配列はすべてCPUが処理します。

 

ファイル

main.cpp

main.cpp

#pragma comment(linker, "/SUBSYSTEM:WINDOWS /ENTRY:mainCRTStartup") #include <GL/freeglut/freeglut.h> #define WIDTH 320 #define HEIGHT 240 float angle=0.0f; //頂点データ 3面を4頂点で作成する 1頂点はx,y,zの3要素 GLfloat Vertex[3][4][3] ={  {{1.0f,0.0f,0.0f},{1.0f,0.0f,0.5f},{0.0f,1.0f,0.5f},{0.0f,1.0f,0.0f}},//1枚目  {{1.0f,0.0f,0.0f},{1.0f,0.0f,0.5f},{-1.0f,0.0f,0.5f},{-1.0f,0.0f,0.0f}},//2枚目  {{-1.0f,0.0f,0.0f},{-1.0f,0.0f,0.5f},{0.0f,1.0f,0.5f},{0.0f,1.0f,0.0f}},//3枚目 }; GLfloat Normal[6][4][3] ={  {{1.0f,0.5f,0.0f},{1.0f,0.5f,0.0f},{1.0f,0.5f,0.0f},{1.0f,0.5f,0.0f}},//右上  {{0.0f,-1.0f,0.0f},{0.0f,-1.0f,0.0f},{0.0f,-1.0f,0.0f},{0.0f,-1.0f,0.0f}},//下  {{-1.0f,0.5f,0.0f},{-1.0f,0.5f,0.0f},{-1.0f,0.5f,0.0f},{-1.0f,0.5f,0.0f}},//左上 }; GLfloat Color[6][4][3] ={  {{1.0f,0.0f,0.0f},{1.0f,0.0f,0.0f},{1.0f,0.0f,0.0f},{1.0f,0.0f,0.0f}},//赤  {{0.0f,0.0f,1.0f},{0.0f,0.0f,1.0f},{0.0f,0.0f,1.0f},{0.0f,0.0f,1.0f}},//青  {{0.0f,1.0f,0.0f},{0.0f,1.0f,0.0f},{0.0f,1.0f,0.0f},{0.0f,1.0f,0.0f}},//緑 }; void DrawArray(void) {  //有効化  glEnableClientState(GL_VERTEX_ARRAY);  glEnableClientState(GL_NORMAL_ARRAY);  glEnableClientState(GL_COLOR_ARRAY);  //データの関連付け  glVertexPointer(3, GL_FLOAT, 0, Vertex);//座標  glNormalPointer(GL_FLOAT, 0, Normal);//法線  glColorPointer(3,GL_FLOAT, 0, Color);//色  glDrawArrays(GL_QUADS,0,4*3); //描画(4頂点*3面)  //無効化  glDisableClientState(GL_COLOR_ARRAY);  glDisableClientState(GL_NORMAL_ARRAY);  glDisableClientState(GL_VERTEX_ARRAY); } void display(void) {  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);  glViewport(0,0,WIDTH,HEIGHT);  glMatrixMode(GL_PROJECTION);  glLoadIdentity();  gluPerspective(30.0, WIDTH/HEIGHT, 0.1, 200.0);  glMatrixMode(GL_MODELVIEW);  glLoadIdentity();  gluLookAt(0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);  glRotatef(angle,1.0f,0.0f,0.0f);//回転  glRotatef(angle,0.0f,1.0f,0.0f);//回転  DrawArray();  glutSwapBuffers(); } void idle(void) {  angle+=0.2f;  Sleep(1);  glutPostRedisplay(); } void Init(){  glClearColor(0.0, 0.0, 0.0, 1.0);   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 } int main(int argc, char *argv[]) {  glutInitWindowPosition(100, 100);  glutInitWindowSize(WIDTH, HEIGHT);  glutInit(&argc, argv);  glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);  glutCreateWindow("頂点配列");  glutDisplayFunc(display);  glutIdleFunc(idle);  Init();  glutMainLoop();  return 0; }