I want to detect collision between two 2D squares, one square is static and the other one moves according to keyboard arrows. I have implemented some code, however nothing happens when they overlap each other and what I tried to achieve in the code was to detect an overlapping between them. I think I am either not understanding the concept really well or that because one of the squares is moving this is not working. Please I would really appreciate your help. Thank you!

float x1=0.05 ,Y1=0.05;
float x2=0.05 ,Y2=0.05;
float posX1 =0.5, posY1 = 0.5;
float movX2 = 0.0 , movY2 = 0.0;

struct box{
    int width=0.1;
    int heigth=0.1;
};

void init(){
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glColor3f(1.0, 1.0, 1.0);
}

void quad1(){
    glTranslatef(posX1, posY1, 0.0);
    glBegin(GL_POLYGON);
    glColor3f(0.5, 1.0, 0.5);
    glVertex2f(-x1, -Y1);
    glVertex2f(-x1, Y1);
    glVertex2f(x1,Y1);
    glVertex2f(x1,-Y1);
    glEnd();
}

void quad2(){
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    glPushMatrix();
    glTranslatef(movX2, movY2, 0.0);
    glBegin(GL_POLYGON);
    glColor3f(1.5, 1.0, 0.5);
    glVertex2f(-x2, -Y2);
    glVertex2f(-x2, Y2);
    glVertex2f(x2,Y2);
    glVertex2f(x2,-Y2);
    glEnd();
    glPopMatrix();

}

void reset(){
    //Reset position of square???
    movX2 = 0.0;
    movY2 = 0.0;
    collisionB = false;
}

bool collision(box A, box B){
    int leftA, leftB;
    int rightA, rightB;
    int topA, topB;
    int bottomA, bottomB;
    //Calculate the sides of box A
    leftA = x1;
    rightA = x1 + A.width;
    topA = Y1;
    bottomA = Y1 + A.heigth;
    //Calculate the sides of box B
    leftB = x2;
    rightB = x2 + B.width;
    topB = Y1;
    bottomB = Y1+ B.heigth ;
    if( bottomA <= topB ) return false;
    if( topA >= bottomB ) return false;
    if( rightA <= leftB ) return false;
    if( leftA >= rightB ) return false; 
    return true;
}

float move_unit = 0.1;
void keyboardown(int key, int x, int y)
{
    switch (key){
        case GLUT_KEY_UP:
            movY2 += move_unit;
            break;

        case GLUT_KEY_RIGHT:
            movX2 += move_unit;
            break;

        case GLUT_KEY_LEFT:
            movX2 -= move_unit;
            break;

        case GLUT_KEY_DOWN:
            movY2 -= move_unit;
            break;

        default:
        break;
    }
    glutPostRedisplay();
}


void display(){
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    cuad1();
    if (!collision) {
        cuad2();
    }
    else{
        reset();
    }
    glFlush();
}

int main(int argc, char** argv){

    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB);
    glutInitWindowSize(500,500);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("Collision Practice");
    glutSpecialFunc(keyboardown);
    glutDisplayFunc(display);
    init();
    glutMainLoop();

}