#include <stdio.h>
#include "glut.h"


void reshape(int width, int height)
{
	static GLfloat lightPosition[4] = {0.25f, 1.0f, 0.25f, 0.0f};
	static GLfloat lightDiffuse[3] = {1.0f, 1.0f, 1.0f};
	static GLfloat lightAmbient[3] = {0.25f, 0.25f, 0.25f};
	static GLfloat lightSpecular[3] = {1.0f, 1.0f, 1.0f};

	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);

	glShadeModel(GL_SMOOTH);

	glViewport(0, 0, width, height);

	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(45.0, (double)width / (double)height, 0.1, 100.0);

	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(0.5, 1.5, 2.5, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);

	glLightfv(GL_LIGHT0, GL_POSITION, lightPosition);
	glLightfv(GL_LIGHT0, GL_DIFFUSE, lightDiffuse);
	glLightfv(GL_LIGHT0, GL_AMBIENT, lightAmbient);
	glLightfv(GL_LIGHT0, GL_SPECULAR, lightSpecular);
}


void display()
{
	static GLfloat vertices [8][3] =
	{
		{-0.5f, -0.5f,  0.5f},
		{ 0.5f, -0.5f,  0.5f},
		{ 0.5f,  0.5f,  0.5f},
		{-0.5f,  0.5f,  0.5f},
		{ 0.5f, -0.5f, -0.5f},
		{-0.5f, -0.5f, -0.5f},
		{-0.5f,  0.5f, -0.5f},
		{ 0.5f,  0.5f, -0.5f}
	};
	
	static GLfloat normals[6][3] =
	{
		{ 0.0f,  0.0f,  1.0f},
		{ 0.0f,  0.0f, -1.0f},
		{ 1.0f,  0.0f,  0.0f},
		{-1.0f,  0.0f,  0.0f},
		{ 0.0f,  1.0f,  0.0f},
		{ 0.0f, -1.0f,  0.0f}
	};
	
	static GLfloat diffuse[3] = {1.0f, 0.0f, 0.0f};
	static GLfloat ambient[3] = {0.25f, 0.25f, 0.25f};
	static GLfloat specular[3] = {1.0f, 1.0f, 1.0f};
	static GLfloat shininess[1] = {32.0f};

	static float angle = 0.0f;

	glMaterialfv(GL_FRONT, GL_DIFFUSE, diffuse);
	glMaterialfv(GL_FRONT, GL_AMBIENT, ambient);
	glMaterialfv(GL_FRONT, GL_SPECULAR, specular);
	glMaterialfv(GL_FRONT, GL_SHININESS, shininess);

	glEnable(GL_DEPTH_TEST);

	glClearColor(0.0f, 0.0f, 0.0f, 1.0f);
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

	angle += 2.5f;
	if (angle > 360.0f) {
		angle -= 360.0f;
	}

	glPushMatrix();
	glRotatef(angle, 0.0f, 1.0f, 0.0f);

	// 前
	glBegin(GL_QUADS);
		glNormal3fv(normals[0]);
		glVertex3fv(vertices[0]);
		glVertex3fv(vertices[1]);
		glVertex3fv(vertices[2]);
		glVertex3fv(vertices[3]);
	glEnd();

	// 後
	glBegin(GL_QUADS);
		glNormal3fv(normals[1]);
		glVertex3fv(vertices[4]);
		glVertex3fv(vertices[5]);
		glVertex3fv(vertices[6]);
		glVertex3fv(vertices[7]);
	glEnd();

	// 右
	glBegin(GL_QUADS);
		glNormal3fv(normals[2]);
		glVertex3fv(vertices[1]);
		glVertex3fv(vertices[4]);
		glVertex3fv(vertices[7]);
		glVertex3fv(vertices[2]);
	glEnd();

	// 左
	glBegin(GL_QUADS);
		glNormal3fv(normals[3]);
		glVertex3fv(vertices[5]);
		glVertex3fv(vertices[0]);
		glVertex3fv(vertices[3]);
		glVertex3fv(vertices[6]);
	glEnd();

	// 上
	glBegin(GL_QUADS);
		glNormal3fv(normals[4]);
		glVertex3fv(vertices[3]);
		glVertex3fv(vertices[2]);
		glVertex3fv(vertices[7]);
		glVertex3fv(vertices[6]);
	glEnd();

	// 下
	glBegin(GL_QUADS);
		glNormal3fv(normals[5]);
		glVertex3fv(vertices[1]);
		glVertex3fv(vertices[0]);
		glVertex3fv(vertices[5]);
		glVertex3fv(vertices[4]);
	glEnd();

	glPopMatrix();

	glutSwapBuffers();
}


void idle()
{
	glutPostRedisplay();
}


int main(int argc, char* argv[])
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGBA);
	glutInitWindowPosition(100, 100);
	glutInitWindowSize(640, 480);
	glutCreateWindow("Animation Cube");
	glutReshapeFunc(reshape);
	glutIdleFunc(idle);
	glutDisplayFunc(display);
	glutMainLoop();

	return 0;
}