Opentk/Source/OpenTK/OpenGL/GLHelper.cs
the_fiddler 0133eb1222 Corrected critical bug in X11/API.cs: VisualInfo.visualid was int where it should have been IntPtr, causing incorrect visuals to be created on 64bit platforms.
Removed the OnCreate/OnDestroy methods from INativeGLWindow.
Added convenience overloads to OpenTK.OpenGL.GL: Color3 and Color4 can now take a System.Drawing.Color directly.
2007-08-21 09:01:24 +00:00

303 lines
12 KiB
C#

#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.Reflection;
using OpenTK.Platform;
#endregion
[assembly: CLSCompliant(true)]
namespace OpenTK.OpenGL
{
/// <summary>
/// OpenGL binding for .NET, implementing OpenGL 2.1, plus extensions.
/// </summary>
/// <remarks>
/// <para>
/// OpenTK.OpenGL.GL contains all OpenGL enums and functions defined in the 2.1 specification.
/// The official .spec files can be found at: http://opengl.org/registry/.
/// </para>
/// <para>
/// OpenTK.OpenGL.GL relies on static initialization to obtain the entry points for OpenGL functions.
/// Please ensure that a valid OpenGL context has been made current in the pertinent thread <b>before</b>
/// any OpenGL functions are called (toolkits like GLUT, SDL or GLFW will automatically take care of
/// the context initialization process). Without a valid OpenGL context, OpenTK.OpenGL.GL will only be able
/// to retrieve statically exported entry points (typically corresponding to OpenGL version 1.1 under Windows,
/// 1.3 under Linux and 1.4 under Windows Vista), and extension methods will need to be loaded manually.
/// </para>
/// <para>
/// If you prefer not to rely on static initialisation for the Gl class, you can use the
/// ReloadFunctions or ReloadFunction methods to manually force the initialisation of OpenGL entry points.
/// The ReloadFunctions method should be called whenever you change an existing visual or pixelformat. This
/// generally happens when you change the color/stencil/depth buffer associated with a window (but probably
/// not the resolution). This may or may not be necessary under Linux/MacOS, but is generally required for
/// Windows.
/// </para>
/// <para>
/// You can use the Gl.IsExtensionSupported method to check whether any given category of extension functions
/// exists in the current OpenGL context. The results can be cached to speed up future searches.
/// Keep in mind that different OpenGL contexts may support different extensions, and under different entry
/// points. Always check if all required extensions are still supported when changing visuals or pixel
/// formats.
/// </para>
/// <para>
/// You may retrieve the entry point for an OpenGL extension using the Gl.GetDelegateForExtensionMethod
/// and Gl.GetFunctionPointerForExtensionMethod methods. You may retrieve the entry point for an OpenGL
/// function using the Gl.GetDelegateForMethod method. All three methods are cross-platform.
/// </para>
/// <para>
/// <see href="http://opengl.org/registry/"/>
/// <seealso cref="Gl.IsExtensionSupported(string, bool)"/>
/// <seealso cref="Gl.GetDelegateForExtensionMethod"/>
/// <seealso cref="Gl.GetFunctionPointerForExtensionMethod"/>
/// <seealso cref="Gl.GetDelegateForMethod"/>
/// <seealso cref="Gl.ReloadFunctions"/>
/// <seealso cref="Gl.ReloadFunction"/>
/// </para>
/// </remarks>
public static partial class GL
{
static GL()
{
assembly = Assembly.GetExecutingAssembly();//Assembly.Load("OpenTK.OpenGL");
glClass = assembly.GetType("OpenTK.OpenGL.GL");
delegatesClass = glClass.GetNestedType("Delegates", BindingFlags.Static | BindingFlags.NonPublic);
importsClass = glClass.GetNestedType("Imports", BindingFlags.Static | BindingFlags.NonPublic);
}
#region --- Fields ---
internal const string Library = "opengl32.dll";
private static System.Collections.Generic.Dictionary<string, bool> AvailableExtensions = new Dictionary<string, bool>();
private static bool rebuildExtensionList;
private static Assembly assembly;
private static Type glClass;
private static Type delegatesClass;
private static Type importsClass;
#endregion
#region public static bool SupportsExtension(string name)
/// <summary>
/// Determines whether the specified OpenGL extension category is available in
/// the current OpenGL context. Equivalent to IsExtensionSupported(name, true)
/// </summary>
/// <param name="name">The string for the OpenGL extension category (eg. "GL_ARB_multitexture")</param>
/// <returns>True if the specified extension is available, false otherwise.</returns>
public static bool SupportsExtension(string name)
{
if (rebuildExtensionList)
{
BuildExtensionList();
}
// Search the cache for the string. Note that the cache substitutes
// strings "1.0" to "2.1" with "GL_VERSION_1_0" to "GL_VERSION_2_1"
if (AvailableExtensions.ContainsKey(name))
{
return AvailableExtensions[name];
}
return false;
}
#endregion
#region private static void BuildExtensionList()
/// <summary>
/// Builds a cache of the supported extensions to speed up searches.
/// </summary>
private static void BuildExtensionList()
{
// Assumes there is an opengl context current.
string version_string = GL.GetString(OpenTK.OpenGL.GL.Enums.StringName.VERSION);
if (String.IsNullOrEmpty(version_string))
{
throw new ApplicationException("Failed to build extension list. Is there an opengl context current?");
}
string version = version_string.Trim(' ');
if (version.StartsWith("1.2"))
{
AvailableExtensions.Add("VERSION_1_2", true);
}
else if (version.StartsWith("1.3"))
{
AvailableExtensions.Add("VERSION_1_2", true);
AvailableExtensions.Add("VERSION_1_3", true);
}
else if (version.StartsWith("1.4"))
{
AvailableExtensions.Add("VERSION_1_2", true);
AvailableExtensions.Add("VERSION_1_3", true);
AvailableExtensions.Add("VERSION_1_4", true);
}
else if (version.StartsWith("1.5"))
{
AvailableExtensions.Add("VERSION_1_2", true);
AvailableExtensions.Add("VERSION_1_3", true);
AvailableExtensions.Add("VERSION_1_4", true);
AvailableExtensions.Add("VERSION_1_5", true);
}
else if (version.StartsWith("2.0"))
{
AvailableExtensions.Add("VERSION_1_2", true);
AvailableExtensions.Add("VERSION_1_3", true);
AvailableExtensions.Add("VERSION_1_4", true);
AvailableExtensions.Add("VERSION_1_5", true);
AvailableExtensions.Add("VERSION_2_0", true);
}
else if (version.StartsWith("2.1"))
{
AvailableExtensions.Add("VERSION_1_2", true);
AvailableExtensions.Add("VERSION_1_3", true);
AvailableExtensions.Add("VERSION_1_4", true);
AvailableExtensions.Add("VERSION_1_5", true);
AvailableExtensions.Add("VERSION_2_0", true);
AvailableExtensions.Add("VERSION_2_1", true);
}
string extension_string = GL.GetString(OpenTK.OpenGL.GL.Enums.StringName.EXTENSIONS);
if (String.IsNullOrEmpty(extension_string))
return; // no extensions are available
string[] extensions = extension_string.Split(' ');
foreach (string ext in extensions)
{
AvailableExtensions.Add(ext, true);
}
rebuildExtensionList = false;
}
#endregion
#region public static Delegate GetDelegate(string name, Type signature)
/// <summary>
/// Creates a System.Delegate that can be used to call an OpenGL function, core or extension.
/// </summary>
/// <param name="name">The name of the OpenGL function (eg. "glNewList")</param>
/// <param name="signature">The signature of the OpenGL function.</param>
/// <returns>
/// A System.Delegate that can be used to call this OpenGL function, or null if the specified
/// function name did not correspond to an OpenGL function.
/// </returns>
public static Delegate GetDelegate(string name, Type signature)
{
Delegate d;
if (importsClass.GetMethod(name.Substring(2), BindingFlags.NonPublic | BindingFlags.Static) != null)
{
d = Utilities.GetExtensionDelegate(name, signature) ??
Delegate.CreateDelegate(signature, typeof(Imports), name.Substring(2));
}
else
{
d = Utilities.GetExtensionDelegate(name, signature);
}
return d;
}
#endregion
#region public static void LoadAll()
/// <summary>
/// Loads all OpenGL functions (core and extensions).
/// </summary>
/// <remarks>
/// <para>
/// This function will be automatically called the first time you use any opengl function. There is
/// </para>
/// <para>
/// Call this function manually whenever you need to update OpenGL entry points.
/// This need may arise if you change the pixelformat/visual, or in case you cannot
/// (or do not want) to use the automatic initialisation of the GL class.
/// </para>
/// </remarks>
public static void LoadAll()
{
FieldInfo[] v = delegatesClass.GetFields(BindingFlags.Static | BindingFlags.NonPublic);
foreach (FieldInfo f in v)
{
f.SetValue(null, GetDelegate(f.Name, f.FieldType));
}
AvailableExtensions.Clear();
rebuildExtensionList = true;
}
#endregion
#region public static bool Load(string function)
/// <summary>
/// Tries to reload the given OpenGL function (core or extension).
/// </summary>
/// <param name="name">The name of the OpenGL function (i.e. glShaderSource)</param>
/// <returns>True if the function was found and reloaded, false otherwise.</returns>
/// <remarks>
/// <para>
/// Use this function if you require greater granularity when loading OpenGL entry points.
/// </para>
/// <para>
/// While the automatic initialisation will load all OpenGL entry points, in some cases
/// the initialisation can take place before an OpenGL Context has been established.
/// In this case, use this function to load the entry points for the OpenGL functions
/// you will need, or use ReloadFunctions() to load all available entry points.
/// </para>
/// <para>
/// This function returns true if the given OpenGL function is supported, false otherwise.
/// </para>
/// <para>
/// To query for supported extensions use the IsExtensionSupported() function instead.
/// </para>
/// </remarks>
public static bool Load(string function)
{
FieldInfo f = delegatesClass.GetField(function);
if (f == null)
return false;
f.SetValue(null, GetDelegate(f.Name, f.FieldType));
rebuildExtensionList = true;
return f.GetValue(null) != null;
}
#endregion
#region public static void Color3()
public static void Color4(System.Drawing.Color color)
{
GL.Color4(color.R, color.G, color.B, color.A);
}
public static void Color3(System.Drawing.Color color)
{
GL.Color3(color.R, color.G, color.B);
}
#endregion
}
}