Spurious Logic

1.01 Baby, baby steps

So here's the shortest example of getting an OpenGL window open with a polygon displayed inside it OpenTK. This is the effective implementation of the first example in the OpenGL manual. (see below). This is pretty hacky code, designed just to illustrate the differences in approach between OpenGL and OpenTK, so don't use it as a standard to code against (or judge me by it).

using System; using OpenTK; using OpenTK.Graphics.OpenGL; using OpenTK.Input;

namespace ConsoleApplication3 { class Program { static void Main(string[] args) { SimpleGameWindow theWindow = new SimpleGameWindow(); theWindow.VSync = VSyncMode.On; theWindow.Run(30.0); } }

class SimpleGameWindow : GameWindow { public SimpleGameWindow() : base(800, 600, OpenTK.Graphics.GraphicsMode.Default, "Example") { }

protected override void OnLoad(EventArgs e) { base.OnLoad(e);

GL.ClearColor(0.0f, 0.0f, 0.0f, 0.0f); GL.Clear(ClearBufferMask.ColorBufferBit); GL.Color3(1.0f, 1.0f, 1.0f); GL.Ortho(0.0f, 1.0f, 0.0f, 1.0f, -1.0f, 1.0f);

GL.Begin(BeginMode.Polygon); GL.Vertex3(0.25f, 0.25f, 0.0f); GL.Vertex3(0.75f, 0.25f, 0.0f); GL.Vertex3(0.75f, 0.75f, 0.0f); GL.Vertex3(0.25f, 0.75f, 0.0f); GL.End();

GL.Flush(); SwapBuffers(); } } }

The red book has this equivalent code as:

#include <whateverYouNeed.h>

main() {

InitializeAWindowPlease();

glClearColor (0.0, 0.0, 0.0, 0.0); glClear (GL_COLOR_BUFFER_BIT); glColor3f (1.0, 1.0, 1.0); glOrtho(0.0, 1.0, 0.0, 1.0, -1.0, 1.0); glBegin(GL_POLYGON); glVertex3f (0.25, 0.25, 0.0); glVertex3f (0.75, 0.25, 0.0); glVertex3f (0.75, 0.75, 0.0); glVertex3f (0.25, 0.75, 0.0); glEnd(); glFlush();

UpdateTheWindowAndCheckForEvents(); }

Which is not so much a little bit different but rather working off a totally different programming model.

Image from Flickr user Juan Antonio Capó