This significantly cleans up the startup sequence on all platforms:
- X11 is not detected on non-Linux platforms unless the user explicitly
requests it
- Supports selection of platform abstractions (SDL) vs native
implementations.
- Returns correct flags on Android and iOS.
This contains a semantic change: OpenTK.Configuration will not return
correct values until OpenTK.Toolkit.Init() has been called, either
directly or indirectly (e.g. by creating a window.)
By mistake, this code would always create a desktop context. The correct
approach is to create an embedded (EGL) context and only fallback to
desktop if that doesn't work.
OpenTK 1.0 and Xamarin Android/iOS do not use strongly-typed enums for
OpenGL ES. Generate overloads with the "All" enum in order to maintain
compatibility.
Only Get*, Gen*, Delete* and New* functions get convenience overloads.
This avoids issues with functions such as Rect() that have similar
signatures but cannot use such overloads.
This restriction will be relaxed in the future.
These are convenience parameters for function receiving a size and an
array parameter, like DeleteTextures(int n, int[] ids). The generator
will now add overloads taking a single parameter, such as
DeleteTexture(int id).
CreateCLSCompliantWrappers must always change return types into
cls-compliant types. The reason is that we cannot overload on return
type alone, so we should always choose the compliant version.
Functions returning a value or array via an 'out' parameter will now get a convenience overload that returns the result via a return statement. In the case of arrays, only single-valued arrays will be supported. For example:
void GetIntegerv(enum pname, out int value)
will be get an overload of
int GetIntegerv(enum pname)
This will reduce the amount of helper overloads that must be maintained manually in GLHelpers.cs.
New WrapperTypes for convenience functions: ConvenienceReturnType to
replace an "out" parameter by a return value, and
ConvenienceArrayReturnType to replace an out array parameter by a
single return value (array count of 1 only).
It is now possible to pass a non-realized GraphicsMode to the X11GLContext and X11GLNative constructors. A non-realized GraphicsMode is a GraphicsMode with a null Index (i.e. which has not passed through SelectGraphicsMode()).
According to the Linux OpenGL ABI, glXGetProcAddressARB must be statically exported by libGL. This does *not* hold true for glXGetProcAddress. We must used the ARB version instead.
Furthermore, glx entry points, unlike wgl, do not depend on any specific OpenGL context. This means we can load them in the constructor of the Glx class.
EnableCap.ColorArray is part of the client state and must be enabled
with GL.EnableClientState, not GL.Enalbe. This is a potential fix for
http://www.opentk.com/node/3430 "Picking example's problem"
WinGraphicsMode no longer creates a temporary context in order to create
the list of available modes. Instead, it requires to be passed an
existing context in its constructor.
WinGLContext now creates one temporary context in its static constructor
and hands that to WinGraphicsMode.
WinFactory no longer supports the CreateGraphicsMode API. This API will
be removed in the future, because the link because contexts and modes
cannot be separated in the general case.
The static initializer of GetCurrentContext would always default to the
desktop PlatformFactory, which caused problems when trying to run OpenGL
ES code on the desktop. The initializer is now removed and
GetCurrentContext is set in the context constructor, before creating any
contexts.
glXGetProcAddress may return a non-null value even if a function is not
supported by the server. We need to check the extension string using
any GLX extensions. Fixes issue http://www.opentk.com/node/3111 "GLX
extension support is not checked correctly".
Furthermore, mode selection is now performed explicitly by the
X11GLContext constructor.
GLX entry points are not bound to a specific context. This means that, unlike WGL, GLX does not require a temporary context in order to load its entry points!
The IGraphicsMode interface is gradually being removed and the
MacOSFactory will now throw an exception if an instance is requested.
AglContext no longer duplicates MacOSGraphicsMode functionality.
Calling SDL_GL_GetAttribute when context construction has failed leads
to erroneous behavior. This call should only be made when a context has
been constructed correctly.
We should only generate delegates for actual OpenGL entry points, not
for overloaded functions that resolve to the same entry point. This
improves loading speeds and reduces the size of the compiled dll.
