#region --- License ---
/* Copyright (c) 2006, 2007 Stefanos Apostolopoulos
* See license.txt for license info
*/
#endregion
#region --- Using directives ---
using System;
using System.Collections.Generic;
using System.Text;
using System.Runtime.InteropServices;
using System.Threading;
using OpenTK;
using OpenTK.Graphics;
using OpenTK.Graphics.OpenGL;
using OpenTK.Platform;
#endregion
namespace Examples.Tutorial
{
[Example("Vertex Buffer Objects", ExampleCategory.OpenGL, "1.5", false, Documentation="VertexBufferObject")]
public class T08_VBO : GameWindow
{
#region --- Private Fields ---
Shapes.Shape cube = new Examples.Shapes.Cube();
struct Vbo
{
public int VboID, EboID, NumElements;
}
Vbo[] vbo = new Vbo[2];
public static readonly int order = 8;
#endregion
#region --- Constructor ---
public T08_VBO() : base(800, 600) { }
#endregion
#region OnLoad override
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
string version = GL.GetString(StringName.Version);
int major = (int)version[0];
int minor = (int)version[2];
if (major <= 1 && minor < 5)
{
System.Windows.Forms.MessageBox.Show("You need at least OpenGL 1.5 to run this example. Aborting.", "VBOs not supported",
System.Windows.Forms.MessageBoxButtons.OK, System.Windows.Forms.MessageBoxIcon.Exclamation);
this.Exit();
}
GL.ClearColor(0.1f, 0.1f, 0.5f, 0.0f);
GL.Enable(EnableCap.DepthTest);
// Create the Vertex Buffer Object:
// 1) Generate the buffer handles.
// 2) Bind the Vertex Buffer and upload your vertex buffer. Check that the buffer was uploaded correctly.
// 3) Bind the Index Buffer and upload your index buffer. Check that the buffer was uploaded correctly.
vbo[0] = LoadVBO(cube.Vertices, cube.Indices);
vbo[1] = LoadVBO(cube.Vertices, cube.Indices);
}
#endregion
#region OnResize override
protected override void OnResize(EventArgs e)
{
GL.Viewport(0, 0, Width, Height);
float aspect_ratio = Width / (float)Height;
Matrix4 perpective = Matrix4.CreatePerspectiveFieldOfView(MathHelper.PiOver4, aspect_ratio, 1, 64);
GL.MatrixMode(MatrixMode.Projection);
GL.LoadMatrix(ref perpective);
}
#endregion
#region OnUpdateFrame override
///
/// Prepares the next frame for rendering.
///
///
/// Place your control logic here. This is the place to respond to user input,
/// update object positions etc.
///
protected override void OnUpdateFrame(FrameEventArgs e)
{
if (Keyboard[OpenTK.Input.Key.Escape])
this.Exit();
}
#endregion
#region OnRenderFrame
protected override void OnRenderFrame(FrameEventArgs e)
{
base.OnRenderFrame(e);
GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit);
Matrix4 lookat = Matrix4.LookAt(0, 5, 5, 0, 0, 0, 0, 1, 0);
GL.MatrixMode(MatrixMode.Modelview);
GL.LoadMatrix(ref lookat);
GL.Color4(System.Drawing.Color.Black);
Draw(vbo[0]);
SwapBuffers();
}
#endregion
Vbo LoadVBO(Vector3[] vertices, int[] indices)
{
Vbo handle = new Vbo();
int size;
GL.GenBuffers(1, out handle.VboID);
GL.BindBuffer(BufferTarget.ArrayBuffer, handle.VboID);
GL.BufferData(BufferTarget.ArrayBuffer, (IntPtr)(vertices.Length * Vector3.SizeInBytes), vertices,
BufferUsageHint.StaticDraw);
GL.GetBufferParameter(BufferTarget.ArrayBuffer, BufferParameterName.BufferSize, out size);
if (vertices.Length * Vector3.SizeInBytes != size)
throw new ApplicationException("Vertex array not uploaded correctly");
//GL.BindBuffer(Version15.ArrayBuffer, 0);
GL.GenBuffers(1, out handle.EboID);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, handle.EboID);
GL.BufferData(BufferTarget.ElementArrayBuffer, (IntPtr)(indices.Length * sizeof(int)), indices,
BufferUsageHint.StaticDraw);
GL.GetBufferParameter(BufferTarget.ElementArrayBuffer, BufferParameterName.BufferSize, out size);
if (indices.Length * sizeof(int) != size)
throw new ApplicationException("Element array not uploaded correctly");
//GL.BindBuffer(Version15.ElementArrayBuffer, 0);
handle.NumElements = indices.Length;
return handle;
}
void Draw(Vbo handle)
{
//GL.PushClientAttrib(ClientAttribMask.ClientVertexArrayBit);
//GL.EnableClientState(EnableCap.TextureCoordArray);
GL.EnableClientState(EnableCap.VertexArray);
GL.BindBuffer(BufferTarget.ArrayBuffer, handle.VboID);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, handle.EboID);
//GL.TexCoordPointer(2, TexCoordPointerType.Float, vector2_size, (IntPtr)vector2_size);
GL.VertexPointer(3, VertexPointerType.Float, Vector3.SizeInBytes, IntPtr.Zero);
GL.DrawElements(BeginMode.Triangles, handle.NumElements, DrawElementsType.UnsignedInt, IntPtr.Zero);
//GL.DrawArrays(BeginMode.LineLoop, 0, vbo.element_count);
GL.BindBuffer(BufferTarget.ArrayBuffer, 0);
GL.BindBuffer(BufferTarget.ElementArrayBuffer, 0);
GL.DisableClientState(EnableCap.VertexArray);
//GL.DisableClientState(EnableCap.TextureCoordArray);
//GL.PopClientAttrib();
}
#region public static void Main()
///
/// Entry point of this example.
///
[STAThread]
public static void Main()
{
using (T08_VBO example = new T08_VBO())
{
// Get the title and category of this example using reflection.
ExampleAttribute info = ((ExampleAttribute)example.GetType().GetCustomAttributes(false)[0]);
example.Title = String.Format("OpenTK | {0} {1}: {2}", info.Category, info.Difficulty, info.Title);
example.Run(30.0, 0.0);
}
}
#endregion
}
}