Obracające się obrączki

#include <windows.h> //Wymagane dla implementacji OpenGL w Visual Studio.
#include "gl\gl.h"
#include "gl\glut.h"
#include "stdio.h" //Przydatne do wypisywania komunikatów na konsoli
#include "glm\glm.hpp"
#include "glm\gtc\matrix_transform.hpp"
#include "glm\gtc\type_ptr.hpp"

using namespace glm;

float speed=400; //60 stopni/s
int lastTime=0;
float angle;
int direction;



void displayFrame(void) {
    glClearColor(0,0,0,1);
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

    mat4 P=perspective(100.0f,1.0f,1.0f,50.0f);
    mat4 V=lookAt(vec3(0.0f,0.0f,-5.0f),vec3(0.0f,0.0f,0.0f),vec3(0.0f,1.0f,0.0f));
    mat4 M1 = mat4(1.0);
    mat4 M2 = mat4(1.0);

    glMatrixMode(GL_PROJECTION);
    glLoadMatrixf(value_ptr(P));
    glMatrixMode(GL_MODELVIEW);

    M1=translate(M1,vec3(-2,0,0))*rotate(M1,angle,vec3(1.0f,0.0f,1.0f));
    glLoadMatrixf(value_ptr(V*M1));
    glColor3d(1,0.3,0);
    glutSolidTorus(0.5,1.5,20,50);

    M2=translate(M2,vec3(2,0,0))*rotate(M2,-angle,vec3(0.3f,0.5f,0.0f));
    glLoadMatrixf(value_ptr(V*M2));
    glColor3d(1,0,0);
    glutSolidTorus(0.5,1.5,20,50);

    glutSwapBuffers();

}

void nextFrame(void) {
    int actTime=glutGet(GLUT_ELAPSED_TIME);
    int interval=actTime-lastTime;
    lastTime=actTime;
    if (direction == 1) angle-=speed*interval/1000.0;
    if (direction == -1) angle+=speed*interval/1000.0;
    if (angle>360) angle-=360;
    glutPostRedisplay();
}

void keyDown(int c, int x, int y) {
    if (c == GLUT_KEY_LEFT)  direction = 1;
    if (c == GLUT_KEY_RIGHT)  direction = -1;
}

void keyUp(int c, int x, int y) {
    if (c == GLUT_KEY_LEFT)  direction = 0;
    if (c == GLUT_KEY_RIGHT)  direction = 0;
}

int main(int argc, char* argv[]) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(800,800);
    glutInitWindowPosition(0,0);
    glutCreateWindow("Program OpenGL");
    glutDisplayFunc(displayFrame);

    //Tutaj kod inicjujący
    glutIdleFunc(nextFrame);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_COLOR_MATERIAL);

    glutSpecialFunc(keyDown);
    glutSpecialUpFunc(keyUp);

    glutMainLoop();
    return 0;
}