Moving Bus

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glut.h>
#include <cmath>

void reshape(int w, int h)
{
    glClearColor(255,255,255, 0);
    glViewport(0, 0 ,w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    float h2w= (float)h / (float) w;
    float w2h= (float)w / (float) h;

    if(w<=h)
    {
        gluOrtho2D(0.0, 80.0, 0.0, 80.0*h2w);
    }
    else
    {
        gluOrtho2D(0.0*w2h, 80.0, 0.0, 80.0);
    }
    glMatrixMode(GL_MODELVIEW);
}

//void init()
//{
//    glClearColor(0.0, 0.5, 0.0, 0.0f);
//    glMatrixMode(GL_PROJECTION);
//    glLoadIdentity();
//    gluOrtho2D(0.0, 80.0, 0.0, 80.0 );
//    glMatrixMode(GL_MODELVIEW);
//}
void drawCircle(int r, int x_center, int y_center)
{
    int deg =0;
    double theta, x, y;

    glBegin(GL_POLYGON);
    while (deg<360)
    {
        theta = (deg*M_PI)/180;

        x = r*cos(theta) + x_center;
        y = r*sin(theta) + y_center;
        deg++;

        glVertex2d(x , y);
    }
    glEnd();
}
bool ismoving = true;
float bus_pos = 0.0;
int wheelangle = 0;
float bus1=0.0, bus2=-50.0;
void drawbus( float x, float y)
{
    glColor3ub(200, 100, 10);
    glPushMatrix();
    glTranslatef(x, y, 0.0f);
    glTranslatef(bus_pos, 0.0f, 0.0f);
    glBegin(GL_POLYGON);
    glVertex2i(10,15);
    glVertex2i(10,30);
    glVertex2i(20,30 );
    glVertex2i(20,31);
    glVertex2i(30,31);
    glVertex2i(30,30);
    glVertex2i(39, 30);
    glVertex2i(45, 27);
    glVertex2i(45,15);
    glEnd();

    glColor3ub(100, 100, 100);
    glRecti(16,20, 22,25);
    glRecti(24,20, 30,25);
    glRecti(32,20, 38,25);

    glPushMatrix();

    glTranslatef(18,15 ,0);
    glRotatef(wheelangle, 0, 0, 1);
    glTranslatef(-18, -15, 0);
    glColor3ub(0, 0, 0);
    drawCircle(3, 18,15);

    glColor3ub(255,255,255);
    glBegin(GL_LINES);
    glVertex2i(15,15);
    glVertex2i(21,15);
    glVertex2i(18,12);
    glVertex2i(18,18);
    glEnd();

    glPopMatrix();

    glPushMatrix();

    glTranslatef(36,15 ,0);
    glRotatef(wheelangle, 0, 0, 1);
    glTranslatef(-36, -15, 0);
    glColor3ub(0, 0, 0);
    drawCircle(3, 36,15);
    glColor3ub(255,255,255);
    glLineWidth(2);
    glBegin(GL_LINES);
    glVertex2i(33,15);
    glVertex2i(39,15);
    glVertex2i(36,12);
    glVertex2i(36,18);
    glEnd();
    glPopMatrix();

    glPopMatrix();


}

void timer(int value)
{
    if(ismoving)
    {
        bus_pos +=0.1;
        if(bus_pos>130)
        (bus_pos = -40);
        wheelangle -=10;
    }

    glutPostRedisplay();
    glutTimerFunc(10, timer, 0);
}

void display()
{
    glClear(GL_COLOR_BUFFER_BIT);
    //glLoadIdentity();

    drawbus(bus1, 0.0);
    drawbus(bus2, 0.0);

    glFlush();

}

void keyboard(unsigned char key, int x, int y)
{
    switch(key)
    {
        case 'a':

            ismoving= false;
            glutPostRedisplay();
            break;

        case 's':

            ismoving = true;
            glutPostRedisplay();
            break;

    }
}

int main(int argc, char** argv)
{
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_RGB);

    glutInitWindowPosition(200,0);
    glutInitWindowSize(1000,700);

    glutCreateWindow("Bus");
    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);
    glutTimerFunc(0, timer, 0);
//    init();
    glutMainLoop();

    return 0;

}