---

#include <GL/glut.h>
#pragma comment(lib, "freeglut.lib")
#include <stdlib.h>

GLfloat vertices[8][3] = {
    {-1.0, -1.0, -1.0},
    { 1.0, -1.0, -1.0},
    { 1.0,  1.0, -1.0},
    {-1.0,  1.0, -1.0},
    {-1.0, -1.0,  1.0},
    { 1.0, -1.0,  1.0},
    { 1.0,  1.0,  1.0},
    {-1.0,  1.0,  1.0}
};

GLfloat colors[8][3] = {
    {0.0, 0.0, 0.0},
    {1.0, 0.0, 0.0},
    {1.0, 1.0, 0.0},
    {0.0, 1.0, 0.0},
    {0.0, 0.0, 1.0},
    {1.0, 0.0, 1.0},
    {1.0, 1.0, 1.0},
    {0.0, 1.0, 1.0}
};

float eyeX = 4.0f;
float eyeY = 4.0f;
float eyeZ = 4.0f;

int projectionMode = 1;
int windowWidth = 800;
int windowHeight = 600;

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() {
    polygon(0, 3, 2, 1);
    polygon(2, 3, 7, 6);
    polygon(0, 4, 7, 3);
    polygon(1, 2, 6, 5);
    polygon(4, 5, 6, 7);
    polygon(0, 1, 5, 4);
}

void display() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();

    float aspect = (float)windowWidth / (float)windowHeight;

    if (projectionMode == 1) {
        glOrtho(-3.0 * aspect, 3.0 * aspect, -3.0, 3.0, 1.0, 20.0);
    } else {
        gluPerspective(60.0, aspect, 1.0, 20.0);
    }

    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    gluLookAt(
        eyeX, eyeY, eyeZ,
        0.0, 0.0, 0.0,
        0.0, 1.0, 0.0
    );

    colorcube();

    glutSwapBuffers();
}

void reshape(int w, int h) {
    if (h == 0) h = 1;

    windowWidth = w;
    windowHeight = h;

    glViewport(0, 0, w, h);
}

void keyboard(unsigned char key, int x, int y) {
    float step = 0.3f;

    switch (key) {
    case '1':
        projectionMode = 1;
        break;
    case '2':
        projectionMode = 2;
        break;

    case 'w':
        eyeY += step;
        break;
    case 's':
        eyeY -= step;
        break;
    case 'a':
        eyeX -= step;
        break;
    case 'd':
        eyeX += step;
        break;
    case 'q':
        eyeZ += step;
        break;
    case 'e':
        eyeZ -= step;
        break;

    case 'r':
        eyeX = 4.0f;
        eyeY = 4.0f;
        eyeZ = 4.0f;
        break;

    case 27:
        exit(0);
        break;
    }

    glutPostRedisplay();
}

void init() {
    glClearColor(0.2f, 0.2f, 0.2f, 1.0f);
    glEnable(GL_DEPTH_TEST);
    glShadeModel(GL_SMOOTH);
}

int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(windowWidth, windowHeight);
    glutCreateWindow("Laboratory Work 4");

    init();

    glutDisplayFunc(display);
    glutReshapeFunc(reshape);
    glutKeyboardFunc(keyboard);

    glutMainLoop();

    return 0;
}