两个球体碰撞

我必须编写一个程序来处理两个球体之间的碰撞。我做了这个，但是当球体碰撞时，所有的东西都被阻挡了。我不能再移动球体了。我只让一个球体运动，另一个保持静止。代码是用VB/c++编写的。

#include "GLOS.H"
#include <math.h>
#include <GL/gl.h>
#include <GL/glu.h>
#include <glaux.h>

GLfloat max1=0,max2=0,v,v1;
FLOAT d,distanta=0;
int i,j;
void myinit(void);
void CALLBACK display(void);
void CALLBACK myReshape(GLsizei w, GLsizei h);
void CALLBACK MutaStanga(void);
void CALLBACK MutaDreapta(void);

int k=0,k1=0;
int dist_ramasa;
static float dx1=200,dy1=300,dz1=0; 
int deplasare=100;
float rez;
static int flag=1;
float pxc,pyc,pzc,sum,suma_raze;

void myinit (void) {   //iluminating
   glClearColor(1.0, 1.0, 1.0, 1.0);
   GLfloat mat_ambient[] = { 0.3, 0.3, 0.3, 1.0 };
    GLfloat mat_diffuse[] = { 0.8, 0.8, 0.8, 1.0 };  
    GLfloat mat_specular[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat mat_shininess[] = { 100.0 };
    GLfloat light_ambient[] = { 0.4, 0.4, 0.4, 1.0 };
    GLfloat light_diffuse[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_specular[] = { 1.0, 1.0, 1.0, 1.0 };
    GLfloat light_position[] = { 1.0, 1.0, 0.0, 0.0 };
    GLfloat lmodel_ambient[] = { 0.5, 0.5, 0.5, 1.0 };
    glMaterialfv(GL_FRONT, GL_AMBIENT, mat_ambient);
    glMaterialfv(GL_FRONT, GL_DIFFUSE, mat_diffuse);
    glMaterialfv(GL_FRONT, GL_SPECULAR, mat_specular);
    glMaterialfv(GL_FRONT, GL_SHININESS, mat_shininess);
    glLightfv(GL_LIGHT0, GL_AMBIENT, light_ambient);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, light_diffuse);
    glLightfv(GL_LIGHT0, GL_SPECULAR, light_specular);
    glLightfv(GL_LIGHT0, GL_POSITION, light_position);
    glLightModelfv(GL_LIGHT_MODEL_AMBIENT, lmodel_ambient);
    glEnable(GL_LIGHTING); // activare iluminare
    glEnable(GL_LIGHT0);    // activare sursa 0
    glColorMaterial(GL_FRONT,GL_DIFFUSE);
    glEnable(GL_COLOR_MATERIAL);
    glDepthFunc(GL_LESS);
    glEnable(GL_DEPTH_TEST);
}


struct sfera   //the spheres
{
    GLfloat raza, xcentru, ycentru, zcentru;   //the radius and the centers 

    GLfloat xd1,xd2,yd1,yd2,zd1,zd2;  
}sf[2];
void initRaza(){  //radius init
  sf[0].raza=100;
sf[1].raza=100;
}
int conditie(void){   //this is where I verify if collide
    initRaza();
    double xac1,yac1,zac1,xac2,yac2,zac2;//the new centers after the movement

    xac1=sf[0].xcentru+dx1;
    yac1=sf[0].ycentru+dy1;
    zac1=sf[0].zcentru+dz1;
                                    //static sphere
    xac2=sf[1].xcentru+700;
    yac2=sf[1].ycentru+300;
    zac2=sf[1].zcentru;
     pxc = pow((xac1-xac2),2);      
     pyc = pow((yac1-yac2),2);
     pzc = pow((zac1-zac2),2);
     sum=(pxc + pyc + pzc);        
     distanta=sqrt(sum);          //the distance between the centers
     //the sum of the radiuses
     suma_raze=sf[0].raza+sf[1].raza;
     dist_ramasa=distanta-sf[0].raza-sf[1].raza;
     // we compare the distance and the sum of radiuses
     //if the distance is lower than the sum -> collide
    if(distanta>suma_raze)
        return 1;
    else
        return 0;
}

    void CALLBACK MutaStanga(void)   //movement left
{
    if(conditie()==1){
        if(dist_ramasa<deplasare)
            dx1=dx1-dist_ramasa;
        else
            dx1=dx1-deplasare;
    }
}  
void CALLBACK MutaDreapta(void)   //movement right
{
    if(conditie()==1){
              if(dist_ramasa<deplasare)
                dx1=dx1+dist_ramasa;
             else
                 dx1=dx1+deplasare; 
    }

}
void CALLBACK MutaSus(void)    //movement up
{
        if(conditie()==1){
              if(dist_ramasa<deplasare)
                dy1=dy1+dist_ramasa;
             else
                 dy1=dy1+deplasare; 
    }
}
void CALLBACK MutaJos(void)  //movement down
{
    if(conditie()==1){
              if(dist_ramasa<deplasare)
                dy1=dy1-dist_ramasa;
             else
                 dy1=dy1-deplasare; 
    }
}
void drawBall1()   //the first sphere
{
    glPushMatrix();

    glColor3f(0,1,0);
    glTranslatef(dx1, dy1, 0.0);                
    glRotatef(30,1,0,0);    
    auxSolidSphere(sf[0].raza);
    glPopMatrix();
}
void drawBall2()  //the second sphere
{
    glPushMatrix();
    glColor3f(1,0,0);
    glTranslatef(700,300,0);
    glRotatef(30,1,0,0);

    auxWireSphere(sf[1].raza);
    glPopMatrix();
}
void CALLBACK display (void)  
{   
    initRaza();
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glLoadIdentity ();

    drawBall1();
    drawBall2();            

    auxSwapBuffers();

}

void CALLBACK myReshape(GLsizei w, GLsizei h)   
{
    if (!h) return;
    glViewport(0, 0, w, h); 
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if (w <= h)     
    glOrtho (0, 800.0, 0*(GLfloat)h/(GLfloat)w, 
        -860.0*(GLfloat)h/(GLfloat)w, -200.0, 200.0);
    else 
    glOrtho (0*(GLfloat)w/(GLfloat)h, 
        900.0*(GLfloat)w/(GLfloat)h, 0, 900.0, -500.0, 500.0);
    glMatrixMode(GL_MODELVIEW);
}
int main(int argc, char** argv)
{
    auxInitDisplayMode (AUX_SINGLE | AUX_RGB | AUX_DEPTH16);
    auxInitPosition (0, 0, 900, 700);
    auxInitWindow ("Bounding sphere collision");
    myinit ();

        auxKeyFunc (AUX_LEFT, MutaStanga);
        auxKeyFunc (AUX_RIGHT, MutaDreapta);
        auxKeyFunc (AUX_UP, MutaSus);
        auxKeyFunc(AUX_DOWN,MutaJos);

    auxReshapeFunc (myReshape);
    auxMainLoop(display);
    return(0);
}

我不知道什么不工作。当它们碰撞时，我想要拒绝对方。我希望你能帮助我。