/* Demonstrates the phases of the moon, by looking at it from different
   directions.  It uses distant lighting and a sphere.
   
Written by Scott D. Anderson
scott.anderson@acm.org
Fall 2004
*/

#include <stdio.h>
#include <math.h>
#include <tw.h>

void display(void) {
    // twDisplayInit(100/255.0,149/255.0,237/255.0);
    twDisplayInit(0,0,0);
    twCamera();

    GLfloat sunDir[] = {1, 0, 0, 0};
    twTriple black = {0,0,0};
    twTriple sunLight = {1,1,1};
    glLightfv(GL_LIGHT0, GL_POSITION, sunDir);
    glLightfv(GL_LIGHT0, GL_AMBIENT, black);
    glLightfv(GL_LIGHT0, GL_DIFFUSE, sunLight);
    glLightfv(GL_LIGHT0, GL_SPECULAR, sunLight);

    glEnable(GL_LIGHTING);
    glEnable(GL_LIGHT0);
    glShadeModel(GL_SMOOTH);
    twAmbient(0);

    glPushMatrix();
    twTriple moonColor = {0.99, 0.99, 0.99};
    twColor(moonColor,0.0,1);        // the moon is *not* shiny
    glutSolidSphere(1,30,30);
    glPopMatrix();

    glFlush();
    glutSwapBuffers();
}

int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    twInitWindowSize(500,500);
    glutCreateWindow(argv[0]);
    glutDisplayFunc(display);
    twBoundingBox(-1,1,-1,1,-1,1);
    twMainInit();
    glutMainLoop();
    return 0;
}