Task: Draw a rotating cube
C: #include<gl/freeglut.h>

double rot = 0;
float matCol[] = {1,0,0,0};

void display(){
	glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
	glPushMatrix();
	glRotatef(30,1,1,0);
	glRotatef(rot,0,1,1);
	glMaterialfv(GL_FRONT,GL_DIFFUSE,matCol);
	glutWireCube(1);
	glPopMatrix();
	glFlush();
}


void onIdle(){
	rot += 0.1;
	glutPostRedisplay();
}

void reshape(int w,int h){
	float ar = (float) w / (float) h ;
	
	glViewport(0,0,(GLsizei)w,(GLsizei)h);
	glTranslatef(0,0,-10);
	glMatrixMode(GL_PROJECTION);
	gluPerspective(70,(GLfloat)w/(GLfloat)h,1,12);
	glLoadIdentity();
	glFrustum ( -1.0, 1.0, -1.0, 1.0, 10.0, 100.0 ) ;
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
}

void init(){
	float pos[] = {1,1,1,0};
	float white[] = {1,1,1,0};
	float shini[] = {70};
	
	glClearColor(.5,.5,.5,0);
	glShadeModel(GL_SMOOTH);
	glLightfv(GL_LIGHT0,GL_AMBIENT,white);
	glLightfv(GL_LIGHT0,GL_DIFFUSE,white);
	glMaterialfv(GL_FRONT,GL_SHININESS,shini);
	glEnable(GL_LIGHTING);
	glEnable(GL_LIGHT0);
	glEnable(GL_DEPTH_TEST);
}

int main(int argC, char* argV[])
{
	glutInit(&argC,argV);
	glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
	glutInitWindowSize(600,500);
	glutCreateWindow("Rossetta's Rotating Cube");
	init();
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutIdleFunc(onIdle);
	glutMainLoop();
	return 0;
}

C#: using System;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;
using System.Windows.Threading;

namespace RotatingCube
{
    public partial class Form1 : Form
    {
        double[][] nodes = {
            new double[] {-1, -1, -1}, new double[] {-1, -1, 1}, new double[] {-1, 1, -1},
            new double[] {-1, 1, 1}, new double[] {1, -1, -1}, new double[] {1, -1, 1},
            new double[] {1, 1, -1}, new double[] {1, 1, 1} };

        int[][] edges = {
            new int[] {0, 1}, new int[] {1, 3}, new int[] {3, 2}, new int[] {2, 0}, new int[] {4, 5},
            new int[] {5, 7}, new int[] {7, 6}, new int[] {6, 4}, new int[] {0, 4}, new int[] {1, 5},
            new int[] {2, 6}, new int[] {3, 7}};

        public Form1()
        {
            Width = Height = 640;
            StartPosition = FormStartPosition.CenterScreen;
            SetStyle(
                ControlStyles.AllPaintingInWmPaint |
                ControlStyles.UserPaint |
                ControlStyles.DoubleBuffer,
                true);

            Scale(100, 100, 100);
            RotateCuboid(Math.PI / 4, Math.Atan(Math.Sqrt(2)));

            var timer = new DispatcherTimer();
            timer.Tick += (s, e) => { RotateCuboid(Math.PI / 180, 0); Refresh(); };
            timer.Interval = new TimeSpan(0, 0, 0, 0, 17);
            timer.Start();
        }

        private void RotateCuboid(double angleX, double angleY)
        {
            double sinX = Math.Sin(angleX);
            double cosX = Math.Cos(angleX);

            double sinY = Math.Sin(angleY);
            double cosY = Math.Cos(angleY);

            foreach (var node in nodes)
            {
                double x = node[0];
                double y = node[1];
                double z = node[2];

                node[0] = x * cosX - z * sinX;
                node[2] = z * cosX + x * sinX;

                z = node[2];

                node[1] = y * cosY - z * sinY;
                node[2] = z * cosY + y * sinY;
            }
        }

        private void Scale(int v1, int v2, int v3)
        {
            foreach (var item in nodes)
            {
                item[0] *= v1;
                item[1] *= v2;
                item[2] *= v3;
            }
        }

        protected override void OnPaint(PaintEventArgs args)
        {
            var g = args.Graphics;
            g.SmoothingMode = SmoothingMode.HighQuality;
            g.Clear(Color.White);

            g.TranslateTransform(Width / 2, Height / 2);

            foreach (var edge in edges)
            {
                double[] xy1 = nodes[edge[0]];
                double[] xy2 = nodes[edge[1]];
                g.DrawLine(Pens.Black, (int)Math.Round(xy1[0]), (int)Math.Round(xy1[1]),
                        (int)Math.Round(xy2[0]), (int)Math.Round(xy2[1]));
            }

            foreach (var node in nodes)
            {
                g.FillEllipse(Brushes.Black, (int)Math.Round(node[0]) - 4,
                    (int)Math.Round(node[1]) - 4, 8, 8);
            }
        }
    }
}