[실습 16] 구르는 공 그리기

#include <GL/glut.h>
#include <stdlib.h>

​

#define PI 3.141592
#define R 10



// 원 둘레 = 2*PI*R = 63
// 호의 길이 = R*angle = 1

​

void drawscene();
void Reshape(int w, int h);
void Keyboard(unsigned char key, int x, int y);

​

static GLfloat direcX = 0.0f;
static GLfloat direcZ = 0.0f;

static GLfloat angleX = 0.0f;
static GLfloat angleY = 0.0f;
static GLfloat angleZ = 0.0f;

static GLfloat pos_Z = -210.0;

​

int main()
{
 glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA | GLUT_DEPTH);
 glutInitWindowPosition(300, 100);
 glutInitWindowSize(800, 600);
 glutCreateWindow("컴그_실습16");
 glutKeyboardFunc(Keyboard);
 glutDisplayFunc(drawscene);
 glutReshapeFunc(Reshape);
 glutMainLoop();

}

​

void Reshape(int w, int h)
{
 //GLfloat nRange = 800.0f;

 // 뷰포트 변환 설정
 glViewport(0, 0, w, h);

 // 투영 행렬 스택 재설정
 glMatrixMode(GL_PROJECTION);
 glLoadIdentity();

 // 원근투영
 gluPerspective(60.0f, w / h, 1.0, 1000.0); // 원근 거리
 glTranslatef(0.0, 0.0, pos_Z); // 투영 공간을 화면 안쪽으로 이동하여 시야를 확보.

 //모델 뷰 행렬 스택 재설정
 glMatrixMode(GL_MODELVIEW);
 glViewport(0, 0, w, h);

 //glLoadIdentity();
}

​

void Keyboard(unsigned char key, int x, int y)
{
 switch (key)
 {
 case 'x': // X축회전
  direcX += 1;
  angleX += 0.1;
  if (direcX >= 100)
  {
   direcX = 100;
  }
  break;
 case 'y': // Y축회전
  angleY += 10;
  break;
 case'z': // Z축회전
  direcZ += 1;
  angleZ += 0.5;
  if (direcZ >= 75)
  {
   direcZ = 75;
  }
  break;
 case 'i': //초기화
  direcX = 0.0f;
  direcZ = 0.0f;

  angleX = 0.0f;
  angleY = 0.0f;
  angleZ = 0.0f;

  pos_Z = -210.0;

  glLoadIdentity();
  break;
 case '+':
  pos_Z += 10;
  break;
 case '-':
  pos_Z -= 10;
  break;
 default:
  break;
 }
 Reshape(800, 600);
 glutPostRedisplay();
}

​

void drawscene()
{
 glClearColor(1.0f, 1.0f, 1.0f, 1.0f); // 바탕색 흰 색
 glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

 // 초기화

 // --- XZ축 바닥
 glColor3f(1.0, 1.0, 0.0);
 glBegin(GL_POLYGON);
  glVertex3f(-100.0, -50.0, 100.0);
  glVertex3f(100.0, -50.0, 100.0);
  glVertex3f(100.0, -50.0, -100.0);
  glVertex3f(-100.0, -50.0, -100.0);
 glEnd();

 // 좌표축
 glPushMatrix();
  glTranslatef(0.0, -60.0, 0.0);
  glLineWidth(3);
 glBegin(GL_LINES);
  glColor3f(1.0, .0, 0.0);
  glVertex3f(30.0, 0.0, 0.0);
  glVertex3f(0.0, 0.0, 0.0);

  glColor3f(0.0, 1.0, 0.0);
  glVertex3f(0.0, 30.0, 0.0);
  glVertex3f(0.0, 0.0, 0.0);

  glColor3f(0.0, 0.0, 1.0);
  glVertex3f(0.0, 0.0, 30.0);
  glVertex3f(0.0, 0.0, 0.0);
 glEnd();
 glPopMatrix();

 // 구
 glPushMatrix();
  glLineWidth(1);
  glColor3f(0.3f, 0.0f, 1.0f);
  glTranslatef(0.0f, -50.0f, 0.0f);
  
  glTranslatef(direcX, 0.0, 0.0);
  glRotatef(angleX, 1.0, 0.0, 0.0);

  glRotatef(angleY, 0.0, 1.0, 0.0);

  glTranslatef(0.0, 0.0, direcZ);
  glRotatef(angleZ, 0.0, 0.0, 1.0);

  glutWireSphere(R, 20, 20);
 glPopMatrix();
 

 glutSwapBuffers();
}