From a8eee8da11811f451b132fecbc6bee4461d94bae Mon Sep 17 00:00:00 2001 From: the_fiddler Date: Mon, 5 May 2008 17:05:11 +0000 Subject: [PATCH] Added Inertia's FrameBufferObject example. --- Source/Examples/OpenGL/FrameBufferObject.cs | 298 ++++++++++++++++++++ 1 file changed, 298 insertions(+) create mode 100644 Source/Examples/OpenGL/FrameBufferObject.cs diff --git a/Source/Examples/OpenGL/FrameBufferObject.cs b/Source/Examples/OpenGL/FrameBufferObject.cs new file mode 100644 index 00000000..811905f5 --- /dev/null +++ b/Source/Examples/OpenGL/FrameBufferObject.cs @@ -0,0 +1,298 @@ +#region --- License --- +/* Licensed under the MIT/X11 license. + * Copyright (c) 2006-2008 the OpenTK Team. + * This notice may not be removed from any source distribution. + * See license.txt for licensing details. + */ +#endregion + +using System; +using System.Diagnostics; + +using OpenTK; +using OpenTK.Input; +using OpenTK.Math; +using OpenTK.Graphics; +using OpenTK.Graphics.OpenGL; + +namespace Examples.Tutorial +{ + [Example("Simple FrameBuffer Object.", ExampleCategory.OpenGL)] + public class SimpleFBO : GameWindow + { + public SimpleFBO() + : base(800, 600) + { + } + + TextureFont sans = new TextureFont(new System.Drawing.Font(System.Drawing.FontFamily.GenericSansSerif, 14.0f)); + ITextPrinter text = new TextPrinter(); + + uint ColorTexture; + uint DepthTexture; + uint FBOHandle; + + const int TextureSize = 512; + + #region Randoms + + Random rnd = new Random(); + public const float scale = 3f; + + /// Returns a random Float in the range [-0.5*scale..+0.5*scale] + public float GetRandom() + { + return (float)(rnd.NextDouble() - 0.5) * scale; + } + + /// Returns a random Float in the range [0..1] + public float GetRandom0to1() + { + return (float)rnd.NextDouble(); + } + + #endregion Randoms + + public override void OnLoad(EventArgs e) + { + GL.Enable(EnableCap.DepthTest); + GL.ClearDepth(1.0f); + GL.DepthFunc(DepthFunction.Lequal); + + GL.Disable(EnableCap.CullFace); + GL.PolygonMode(MaterialFace.Back, PolygonMode.Line); + + // Create Color Tex + GL.GenTextures(1, out ColorTexture); + GL.BindTexture(TextureTarget.Texture2D, ColorTexture); + GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.Rgba8, TextureSize, TextureSize, 0, PixelFormat.Rgba, PixelType.UnsignedByte, IntPtr.Zero); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToBorder); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToBorder); + // GL.Ext.GenerateMipmap( GenerateMipmapTarget.Texture2D ); + + // Create Depth Tex + GL.GenTextures(1, out DepthTexture); + GL.BindTexture(TextureTarget.Texture2D, DepthTexture); + GL.TexImage2D(TextureTarget.Texture2D, 0, (PixelInternalFormat)All.DepthComponent32, TextureSize, TextureSize, 0, PixelFormat.DepthComponent, PixelType.UnsignedInt, IntPtr.Zero); + // things go horribly wrong if DepthComponent's Bitcount does not match the main Framebuffer's Depth + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Linear); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.ClampToBorder); + GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.ClampToBorder); + // GL.Ext.GenerateMipmap( GenerateMipmapTarget.Texture2D ); + + // Create a FBO and attach the textures + GL.Ext.GenFramebuffers(1, out FBOHandle); + GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, FBOHandle); + GL.Ext.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.ColorAttachment0Ext, TextureTarget.Texture2D, ColorTexture, 0); + GL.Ext.FramebufferTexture2D(FramebufferTarget.FramebufferExt, FramebufferAttachment.DepthAttachmentExt, TextureTarget.Texture2D, DepthTexture, 0); + + #region Test for Error + + switch (GL.Ext.CheckFramebufferStatus(FramebufferTarget.FramebufferExt)) + { + case FramebufferErrorCode.FramebufferCompleteExt: + { + Console.WriteLine("FBO: The framebuffer is complete and valid for rendering."); + break; + } + case FramebufferErrorCode.FramebufferIncompleteAttachmentExt: + { + Console.WriteLine("FBO: One or more attachment points are not framebuffer attachment complete. This could mean there’s no texture attached or the format isn’t renderable. For color textures this means the base format must be RGB or RGBA and for depth textures it must be a DEPTH_COMPONENT format. Other causes of this error are that the width or height is zero or the z-offset is out of range in case of render to volume."); + break; + } + case FramebufferErrorCode.FramebufferIncompleteMissingAttachmentExt: + { + Console.WriteLine("FBO: There are no attachments."); + break; + } + /* case FramebufferErrorCode.GL_FRAMEBUFFER_INCOMPLETE_DUPLICATE_ATTACHMENT_EXT: + { + Console.WriteLine("FBO: An object has been attached to more than one attachment point."); + break; + }*/ + case FramebufferErrorCode.FramebufferIncompleteDimensionsExt: + { + Console.WriteLine("FBO: Attachments are of different size. All attachments must have the same width and height."); + break; + } + case FramebufferErrorCode.FramebufferIncompleteFormatsExt: + { + Console.WriteLine("FBO: The color attachments have different format. All color attachments must have the same format."); + break; + } + case FramebufferErrorCode.FramebufferIncompleteDrawBufferExt: + { + Console.WriteLine("FBO: An attachment point referenced by GL.DrawBuffers() doesn’t have an attachment."); + break; + } + case FramebufferErrorCode.FramebufferIncompleteReadBufferExt: + { + Console.WriteLine("FBO: The attachment point referenced by GL.ReadBuffers() doesn’t have an attachment."); + break; + } + case FramebufferErrorCode.FramebufferUnsupportedExt: + { + Console.WriteLine("FBO: This particular FBO configuration is not supported by the implementation."); + break; + } + default: + { + Console.WriteLine("FBO: Status unknown. (yes, this is really bad.)"); + break; + } + } + + // using FBO might have changed states, e.g. the FBO might not support stereoscopic views or double buffering + int[] queryinfo = new int[6]; + GL.GetInteger(GetPName.MaxColorAttachmentsExt, out queryinfo[0]); + GL.GetInteger(GetPName.AuxBuffers, out queryinfo[1]); + GL.GetInteger(GetPName.MaxDrawBuffers, out queryinfo[2]); + GL.GetInteger(GetPName.Stereo, out queryinfo[3]); + GL.GetInteger(GetPName.Samples, out queryinfo[4]); + GL.GetInteger(GetPName.Doublebuffer, out queryinfo[5]); + Console.WriteLine("max. ColorBuffers: " + queryinfo[0] + " max. AuxBuffers: " + queryinfo[1] + " max. DrawBuffers: " + queryinfo[2] + + "\nStereo: " + queryinfo[3] + " Samples: " + queryinfo[4] + " DoubleBuffer: " + queryinfo[5]); + + Console.WriteLine("Last GL Error: " + GL.GetError()); + + #endregion Test for Error + + GL.PushAttrib(AttribMask.ViewportBit); + { + GL.Viewport(0, 0, TextureSize, TextureSize); + + // clear the screen in red, to make it very obvious what the clear affected. only the FBO, not the real framebuffer + GL.ClearColor(1f, 0f, 0f, 0f); + GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); + + // smack 50 random triangles into the FBO's textures + GL.Begin(BeginMode.Triangles); + { + for (int i = 0; i < 50; i++) + { + GL.Color3(GetRandom0to1(), GetRandom0to1(), GetRandom0to1()); + GL.Vertex3(GetRandom(), GetRandom(), GetRandom()); + GL.Color3(GetRandom0to1(), GetRandom0to1(), GetRandom0to1()); + GL.Vertex3(GetRandom(), GetRandom(), GetRandom()); + GL.Color3(GetRandom0to1(), GetRandom0to1(), GetRandom0to1()); + GL.Vertex3(GetRandom(), GetRandom(), GetRandom()); + } + } + GL.End(); + } + GL.PopAttrib(); + GL.Ext.BindFramebuffer(FramebufferTarget.FramebufferExt, 0); // disable rendering into the FBO + + GL.ClearColor(.1f, .2f, .3f, 0f); + GL.Color3(1f, 1f, 1f); + + GL.Enable(EnableCap.Texture2D); // enable Texture Mapping + GL.BindTexture(TextureTarget.Texture2D, 0); // bind default texture + } + + public override void OnUnload(EventArgs e) + { + // Clean up what we allocated before exiting + GL.DeleteTextures(1, ref ColorTexture); + GL.DeleteTextures(1, ref DepthTexture); + GL.Ext.DeleteFramebuffers(1, ref FBOHandle); + + base.OnUnload(e); + } + + protected override void OnResize(OpenTK.Platform.ResizeEventArgs e) + { + GL.Viewport(0, 0, Width, Height); + GL.MatrixMode(MatrixMode.Projection); + GL.LoadIdentity(); + Glu.Perspective(60.0, Width / (double)Height, 1.0, 5.0); + + GL.MatrixMode(MatrixMode.Modelview); + GL.LoadIdentity(); + Glu.LookAt(0.0, 0.0, 3.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0); + + base.OnResize(e); + } + + public override void OnUpdateFrame(UpdateFrameEventArgs e) + { + base.OnUpdateFrame(e); + + if (Keyboard[Key.Space]) + { + ErrorCode err = GL.GetError(); + Console.WriteLine(err + " " + Glu.ErrorString((GluErrorCode)err)); + } + + if (Keyboard[Key.Escape]) + this.Exit(); + } + + public override void OnRenderFrame(RenderFrameEventArgs e) + { + GL.Clear(ClearBufferMask.ColorBufferBit | ClearBufferMask.DepthBufferBit); + + text.Begin(); + text.Draw((1.0 / e.Time).ToString("F2"), sans); + text.End(); + + GL.PushMatrix(); + { + // Draw the Color Texture + GL.Translate(-1.1f, 0f, 0f); + GL.BindTexture(TextureTarget.Texture2D, ColorTexture); + GL.Begin(BeginMode.Quads); + { + GL.TexCoord2(0f, 1f); + GL.Vertex2(-1.0f, 1.0f); + GL.TexCoord2(0.0f, 0.0f); + GL.Vertex2(-1.0f, -1.0f); + GL.TexCoord2(1.0f, 0.0f); + GL.Vertex2(1.0f, -1.0f); + GL.TexCoord2(1.0f, 1.0f); + GL.Vertex2(1.0f, 1.0f); + } + GL.End(); + + // Draw the Depth Texture + GL.Translate(+2.2f, 0f, 0f); + GL.BindTexture(TextureTarget.Texture2D, DepthTexture); + GL.Begin(BeginMode.Quads); + { + GL.TexCoord2(0f, 1f); + GL.Vertex2(-1.0f, 1.0f); + GL.TexCoord2(0.0f, 0.0f); + GL.Vertex2(-1.0f, -1.0f); + GL.TexCoord2(1.0f, 0.0f); + GL.Vertex2(1.0f, -1.0f); + GL.TexCoord2(1.0f, 1.0f); + GL.Vertex2(1.0f, 1.0f); + } + GL.End(); + } + GL.PopMatrix(); + + this.SwapBuffers(); + } + + #region public static void Main() + + /// + /// Entry point of this example. + /// + [STAThread] + public static void Main() + { + using (SimpleFBO example = new SimpleFBO()) + { + Utilities.SetWindowTitle(example); + example.Run(30.0, 0.0); + } + } + + #endregion + } +} \ No newline at end of file