c++ opengl 사각형 피하기

간단한 게임을 만들고 싶어서 고민하다 글을 올려봅니다
타이머로 움직이는 사각형을 피하는 게임인데 도움 구해봅니다
vs2015 C++ 환경입니다.

#include
#include
#include
#include
#include

float vel = 10.0f;
float vel2 = 10.0f;
float vel3 = 10.0f;
float X, C, D = 0.0f;
float A, B;

void MyDisplay() {
glClear(GL_COLOR_BUFFER_BIT);
glBegin(GL_POLYGON); // 1번째 장애물
glColor3f(1.0, 1.0, 1.0);
glVertex3f(-100.0f + X, 80.0f, 0.0f);
glVertex3f(-90.0f + X, 80.0f, 0.0f);
glVertex3f(-90.0f + X, 70.0f, 0.0f);
glVertex3f(-100.0f + X, 70.0f, 0.0f);
glEnd();

glBegin(GL_POLYGON); // 두번째 장애물
glColor3f(1.0, 0.0, 1.0);
glVertex3f(-100.0f + C, 40.0f, 0.0f);
glVertex3f(-80.0f + C, 40.0f, 0.0f);
glVertex3f(-80.0f + C, 30.0f, 0.0f);
glVertex3f(-100.0f + C, 30.0f, 0.0f);
glEnd();

glBegin(GL_POLYGON); // 세번째 장애물
glColor3f(0.0, 0.0, 0.1);
glColor3f(0.0, 1.0, 0.0);
glVertex3f(-10.0f + D, 10.0f, 0.0f);
glVertex3f(10.0f + D, 10.0f, 0.0f);
glVertex3f(10.0f + D, -10.0f, 0.0f);
glVertex3f(-10.0f + D, -10.0f, 0.0f);
glEnd();

glBegin(GL_POLYGON); // 닿으면 끝
glColor3f(1.0, 1.0, 0.0);
glVertex3f(100.0f, 100.0f, 0.0f);
glVertex3f(-100.0f, 100.0f, 0.0f);
glVertex3f(-100.0f, 90.0f, 0.0f);
glVertex3f(100.0f, 90.0f, 0.0f);
glEnd();

glBegin(GL_TRIANGLES); //비행기
glVertex3f(0.0f + B, -95.0f+A , 0.0f);
glVertex3f(-5.0f + B, -100.0f + A, 0.0f);
glVertex3f(5.0f + B, -100.0f + A, 0.0f);
glEnd();
glFlush();
}
void MyReshape(int NewWidth, int NewHeight) {
GLfloat nRange = 100.0f;
if (NewHeight == 0) NewHeight = 1;
glViewport(0, 0, NewWidth, NewHeight);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (NewWidth <= NewHeight)
glOrtho(-nRange, nRange, -nRange*NewHeight / NewWidth,
nRange*NewHeight / NewWidth, -nRange, nRange);
else
glOrtho(-nRange*NewWidth / NewHeight, nRange*NewWidth / NewHeight, -nRange,
nRange, -nRange, nRange);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}

void MyKeyboard(unsigned char KeyPressed, int X, int Y) {
}

void MySpecial(int key, int X, int Y) {
if (A==185) {
exit(0);
}
if (key == GLUT_KEY_UP) {
A += 5.0f;
}
if (key == GLUT_KEY_DOWN) {
A -= 5.0f;
}
if (key == GLUT_KEY_LEFT) {
B -= 5.0f;
}
if (key == GLUT_KEY_RIGHT) {
B += 5.0f;
}
}

void MyTimer(int Value) {
D = D + vel;
if ((D > 80 && vel > 0) || (D < -80 && vel <= 0)) vel *= -1;
glutPostRedisplay();
glutTimerFunc(40, MyTimer, 1); //세번째 장애물 타이머
}
void MyTimer2(int Value) {
X = X + vel2;
if ((X > 180 && vel2 > 0) || (X < 10 && vel2 < 0))
vel2 *= -1;

C = C + vel3;
if ((C > 170 && vel3 > 0) || (C < 10 && vel3 < 0))
vel3 *= -1;

glutPostRedisplay();
glutTimerFunc(40, MyTimer2, 2);
}
void initFunc() {
glClearColor(0.0, 0.0, 0.0, 1.0);
glColor3f(0.0, 0.0, 0.0);

}

int main(int argc, char** argv) {
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowSize(500, 500);
glutInitWindowPosition(0, 0);
glutCreateWindow("네모피하기");
initFunc();
glutDisplayFunc(MyDisplay);
glutReshapeFunc(MyReshape);
glutKeyboardFunc(MyKeyboard);
glutSpecialFunc(MySpecial);
glutTimerFunc(40, MyTimer, 1);
glutTimerFunc(40, MyTimer2, 2);
glutMainLoop();
return 0;
}

문제는 움직이는 오브젝트들에 닿으면 게임이 끝나게 하고싶은데 아무리 생각해봐도 좋은수가 안떠오르더군요
도움을 구해봅니다 ㅠ