#include <GL/glut.h>

// forgatás x tengely körül
double rX=15;
// forgatás y tengely körül
double rY=-30;

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();

    glRotatef( rX, 1.0, 0.0, 0.0 );
    glRotatef( rY, 0.0, 1.0, 0.0 );
    
    glutSwapBuffers();
}

void keyboard(int key, int x, int y) {
    if (key == GLUT_KEY_RIGHT) {
                rY += 5;
    } else if (key == GLUT_KEY_LEFT) {
                rY -= 5;
    } else if (key == GLUT_KEY_DOWN) {
                rX -= 5;
    } else if (key == GLUT_KEY_UP) {
                rX += 5;
    }

    // a képernyő újrarajzolása
    glutPostRedisplay();
}
 
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);
    glutSpecialFunc(keyboard);
      
    glutMainLoop();
    return 0;
}