#include <stdlib.h>
#include <GL/glut.h>
GLfloat vertices[][3] = { {-1,-1,-1},{1,-1,-1},{1,1,-1},{-1,1,-1}, {-1,-1,1},{1,-1,1}, {1,1,1},{-1,1,1} };
GLfloat colors[][3] = { {1,0,0},{1,1,0},{0,1,0},{0,0,1}, {1,0,1},{1,1,1},{0,1,1},{0.5,0.5,0.5} };
void polygon(int a, int b, int c, int d)
{
	glBegin(GL_POLYGON);
	glColor3fv(colors[a]);
	glVertex3fv(vertices[a]);
	glColor3fv(colors[b]);
	glVertex3fv(vertices[b]);
	glColor3fv(colors[c]);
	glVertex3fv(vertices[c]);
	glColor3fv(colors[d]);
	glVertex3fv(vertices[d]);
	glEnd();
}
void colorcube(void)
{
	polygon(0, 3, 2, 1);
	polygon(0, 4, 7, 3);
	polygon(5, 4, 0, 1);
	polygon(2, 3, 7, 6);
	polygon(1, 2, 6, 5);
	polygon(4, 5, 6, 7);
}
GLfloat theta[] = { 0.0,0.0,0.0 };
GLint axis = 2;
GLdouble viewer[] = { 0.0, 0.0, 5.0 }; /* initial viewer location */
void display(void)
{
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glLoadIdentity();
	gluLookAt(viewer[0], viewer[1], viewer[2], 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
	glRotatef(theta[0], 1.0, 0.0, 0.0);
	glRotatef(theta[1], 0.0, 1.0, 0.0);
	glRotatef(theta[2], 0.0, 0.0, 1.0);
	colorcube();
	glFlush();
	glutSwapBuffers();
}
void mouse(int btn, int state, int x, int y)
{
	if (btn == GLUT_LEFT_BUTTON && state == GLUT_DOWN) axis = 0; if (btn == GLUT_MIDDLE_BUTTON && state == GLUT_DOWN) axis = 1; if (btn == GLUT_RIGHT_BUTTON && state == GLUT_DOWN) axis = 2; theta[axis] += 2.0;

	if (theta[axis] > 360.0) theta[axis] -= 360.0; display();
}
void keys(unsigned char key, int x, int y)
{
	if (key == 'x') viewer[0] -= 1.0;
	if (key == 'X') viewer[0] += 1.0;
	if (key == 'y') viewer[1] -= 1.0;
	if (key == 'Y') viewer[1] += 1.0;
	if (key == 'z') viewer[2] -= 1.0;
	if (key == 'Z') viewer[2] += 1.0;
	display();
}
void myReshape(int w, int h)
{
	glViewport(0, 0, w, h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	if (w <= h)
		glFrustum(-2.0, 2.0, -2.0 * (GLfloat)h / (GLfloat)w, 2.0 * (GLfloat)h / (GLfloat)w, 2.0, 20.0);
	else
		glFrustum(-2.0, 2.0, -2.0 * (GLfloat)w / (GLfloat)h, 2.0 * (GLfloat)w / (GLfloat)h, 2.0, 20.0);
	glMatrixMode(GL_MODELVIEW);
}
void main(int argc, char** argv)
{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
	glutInitWindowSize(500, 500);
	glutCreateWindow("Colorcube Viewer USN:1AH18CS092");
	glutReshapeFunc(myReshape);
	glutDisplayFunc(display);
	glutMouseFunc(mouse);
	glutKeyboardFunc(keys);
	glEnable(GL_DEPTH_TEST);
	glutMainLoop();
}