#include <GL/glut.h>

void axes() {
    glBegin(GL_LINES);
		// x tengely
        glColor3f(1, 0, 0);
        glVertex3f(-1, 0, 0);
        glVertex3f(1, 0, 0);

		// y tengely
        glColor3f(0, 1, 0);
        glVertex3f(0, -1, 0);
        glVertex3f(0, 1, 0);

		// z tengely
        glColor3f(0, 0, 1);
        glVertex3f(0, 0, -1);
        glVertex3f(0, 0, 1);
    glEnd();
}

void triangle(void) {
	glColor3f(0.8, 0.8, 0);
	glBegin(GL_POLYGON);
		glVertex3f(0.2, 0.5, 0.0);
		glVertex3f(0.5, 0.5, 0.0);
		glVertex3f(0.5, 0.2, 0.0);
	glEnd();
}
 
void display(void) {
    glClear(GL_COLOR_BUFFER_BIT);

    axes();
    triangle();

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    static float rot = -30;
    
    //forgatás x tengely mentén
    glRotatef(15.0, 0.5, 0.0, 0.0);
    //forgatás y tengely mentén
    glRotatef(rot, 0.0, 0.5, 0.0);

    rot += 1;
    
    glutSwapBuffers();
}
 
int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
    glutInitWindowSize(640, 450);
    glutInitWindowPosition(200, 200);
    glutCreateWindow("Hello Vilag!");
    glutDisplayFunc(display);
    glutIdleFunc(display);    
    glutMainLoop();
    return 0;
}