Opengl 구 그리기

#include <gl/glut.h> #include <stdio.h> #include <math.h> #define PI 3.1415926 #define M 36 #define N 18 float radius = 5; float theta; float phi; float delta_theta; float delta_phi; struct Point3D { float x; float y; float z; }; Point3D vertex[M+1][N+1]; float cameraX = 10; float cameraY = 10; float cameraZ = 10; void init (void) { glClearColor (0.0, 0.0, 0.0, 0.0) ; glColor3f(1.0, 1.0, 0.0); glEnable(GL_DEPTH_TEST); // 깊이 활성화 } void reshape (int w, int h) { glViewport(0, 0, w, h); glMatrixMode (GL_PROJECTION); glLoadIdentity(); //glOrtho (-5.0, 5.0, -5.0, 5.0, -5.0, 5.0); gluPerspective(60.0, 1.0, 1.0, 100.0); // 멀고 가까움을 표현함 } void display (void) { glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glMatrixMode (GL_MODELVIEW); glLoadIdentity(); gluLookAt(cameraX, cameraY, cameraZ, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); glBegin(GL_LINES); // X, Y, Z 선 표시 glColor3f(1.0, 0.0, 0.0); // X축 glVertex3f(0.0, 0.0, 0.0); glVertex3f(10.0, 0.0, 0.0); glColor3f(0.0, 1.0, 0.0); // Y축 glVertex3f(0.0, 0.0, 0.0); glVertex3f(0.0, 10.0, 0.0); glColor3f(0.0, 0.0, 1.0); // Z축 glVertex3f(0.0, 0.0, 0.0); glVertex3f(0.0, 0.0, 10.0); glEnd(); delta_theta = 2 * PI / M; delta_phi = PI / N; int i = 0, j = 0; for(i = 0; i < M; i++) { for(j = 0; j < N; j++) { theta = i * delta_theta; phi = j * delta_phi - ( PI / 2 ); vertex[i][j].x = radius * cos(theta) * cos(phi); vertex[i][j].y = radius * sin(theta) * cos(phi); vertex[i][j].z = radius * sin(phi); } } for(i = 0; i < M; i++) { for(j = 0; j < N; j++) { theta = i * delta_theta; phi = j * delta_phi - ( PI / 2 ); glBegin(GL_POLYGON); glVertex3f(vertex[i][j].x, vertex[i][j].y, vertex[i][j].z); glVertex3f(vertex[i+1][j].x, vertex[i+1][j].y, vertex[i+1][j].z); glVertex3f(vertex[i][j+1].x, vertex[i][j+1].y, vertex[i][j+1].z); glVertex3f(vertex[i+1][j+1].x, vertex[i+1][j+1].y, vertex[i+1][j+1].z); glEnd(); } } glFlush (); glutSwapBuffers(); } void SpecialKey( int key, int x, int y) { switch (key) { case GLUT_KEY_LEFT : theta -= 0.1; break; case GLUT_KEY_RIGHT : theta += 0.1; break; case GLUT_KEY_UP : phi += 0.1; break; case GLUT_KEY_DOWN : phi -= 0.1; break; case GLUT_KEY_F1 : glMatrixMode (GL_PROJECTION); glLoadIdentity(); glOrtho (-1.0*radius, radius, -1.0*radius, radius, -1.0*radius, radius); break; case GLUT_KEY_F2 : glMatrixMode (GL_PROJECTION); glLoadIdentity(); gluPerspective(60.0, 1.0, 1.0, 100.0); break; default : break; } if ( theta > 2.0 * PI ) theta -= (2.0 * PI); else if ( theta < 0.0 ) theta += (2.0 * PI); } void main (int argc, char** argv) { glutInit (&argc, argv); glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH ); glutInitWindowPosition (100, 100); glutInitWindowSize (500, 500); glutCreateWindow ("Cube"); init(); glutDisplayFunc (display); glutReshapeFunc (reshape); glutIdleFunc(display); glutMainLoop(); }