Opentk/Source/OpenTK/Graphics/GraphicsBindingsBase.cs
2013-11-24 13:57:43 +01:00

91 lines
3.6 KiB
C#

#region License
//
// The Open Toolkit Library License
//
// Copyright (c) 2006 - 2009 the Open Toolkit library.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do
// so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
// OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
// WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
// OTHER DEALINGS IN THE SOFTWARE.
//
#endregion
using System;
using System.Runtime.InteropServices;
namespace OpenTK.Graphics
{
/// <summary>
/// Implements BindingsBase for the OpenTK.Graphics namespace (OpenGL and OpenGL|ES).
/// </summary>
public abstract class GraphicsBindingsBase : BindingsBase
{
/// <summary>
/// Contains the list of API entry points (function pointers).
/// This field must be set by an inheriting class.
/// </summary>
protected IntPtr[] EntryPointsInstance;
/// <summary>
/// Contains the list of API entry point names.
/// This field must be set by an inheriting class.
/// </summary>
protected string[] EntryPointNamesInstance;
/// <summary>
/// Retrieves an unmanaged function pointer to the specified function.
/// </summary>
/// <param name="funcname">
/// A <see cref="System.String"/> that defines the name of the function.
/// </param>
/// <returns>
/// A <see cref="IntPtr"/> that contains the address of funcname or IntPtr.Zero,
/// if the function is not supported by the drivers.
/// </returns>
/// <remarks>
/// Note: some drivers are known to return non-zero values for unsupported functions.
/// Typical values include 1 and 2 - inheritors are advised to check for and ignore these
/// values.
/// </remarks>
protected override IntPtr GetAddress(string funcname)
{
var context = GraphicsContext.CurrentContext as IGraphicsContextInternal;
if (context == null)
throw new GraphicsContextMissingException();
return context != null ? context.GetAddress(funcname) : IntPtr.Zero;
}
// Loads all available entry points for the current API.
// Note: we prefer IGraphicsContextInternal.GetAddress over
// this.GetAddress to improve loading performance (less
// validation necessary.)
internal override void LoadEntryPoints()
{
IGraphicsContext context = GraphicsContext.CurrentContext;
if (context == null)
throw new GraphicsContextMissingException();
IGraphicsContextInternal context_internal = context as IGraphicsContextInternal;
for (int i = 0; i < EntryPointsInstance.Length; i++)
{
EntryPointsInstance[i] = context_internal.GetAddress(EntryPointNamesInstance[i]);
}
}
}
}