GLContext

Object Hierarchy:

Description:

[ CCode ( type_id = "gdk_gl_context_get_type ()" ) ]
public abstract class GLContext : Object

GLContext is an object representing the platform-specific OpenGL drawing context.

GLContexts are created for a Window using create_gl_context, and the context will match the Visual of the window.

A GLContext is not tied to any particular normal framebuffer. For instance, it cannot draw to the Window back buffer. The GDK repaint system is in full control of the painting to that. Instead, you can create render buffers or textures and use cairo_draw_from_gl in the draw function of your widget to draw them. Then GDK will handle the integration of your rendering with that of other widgets.

Support for GLContext is platform-specific, context creation can fail, returning null context.

A GLContext has to be made "current" in order to start using it, otherwise any OpenGL call will be ignored.

Creating a new OpenGL context

In order to create a new GLContext instance you need a Window, which you typically get during the realize call of a widget.

A GLContext is not realized until either make_current, or until it is realized using realize. It is possible to specify details of the GL context like the OpenGL version to be used, or whether the GL context should have extra state validation enabled after calling create_gl_context by calling realize. If the realization fails you have the option to change the settings of the GLContext and try again.

Using a GdkGLContext

You will need to make the GLContext the current context before issuing OpenGL calls; the system sends OpenGL commands to whichever context is current. It is possible to have multiple contexts, so you always need to ensure that the one which you want to draw with is the current one before issuing commands:

  gdk_gl_context_make_current (context);

You can now perform your drawing using OpenGL commands.

You can check which GLContext is the current one by using get_current; you can also unset any GLContext that is currently set by calling clear_current.

Namespace: Gdk

Package: gdk-3.0

Content:

Properties:

public Display display { get; construct; }
The Display used to create the GLContext.
public GLContext shared_context { get; construct; }
The GLContext that this context is sharing data with, or null
public Window window { get; construct; }
The Window the gl context is bound to.

Static methods:

public static void clear_current ()
Clears the current GLContext.
public static unowned GLContext? get_current ()
Retrieves the current GLContext.

Creation methods:

protected GLContext ()

Methods:

public bool get_debug_enabled ()
Retrieves the value set using set_debug_enabled.
public unowned Display? get_display ()
Retrieves the Display the this is created for
public bool get_forward_compatible ()
Retrieves the value set using set_forward_compatible.
public void get_required_version (out int major, out int minor)
Retrieves the major and minor version requested by calling set_required_version.
public unowned GLContext? get_shared_context ()
Retrieves the GLContext that this this share data with.
public bool get_use_es ()
Checks whether the this is using an OpenGL or OpenGL ES profile.
public void get_version (out int major, out int minor)
Retrieves the OpenGL version of the this.
public unowned Window? get_window ()
Retrieves the Window used by the this.
public bool is_legacy ()
Whether the GLContext is in legacy mode or not.
public void make_current ()
Makes the this the current one.
public bool realize () throws Error
Realizes the given GLContext.
public void set_debug_enabled (bool enabled)
Sets whether the GLContext should perform extra validations and run time checking.
public void set_forward_compatible (bool compatible)
Sets whether the GLContext should be forward compatible.
public void set_required_version (int major, int minor)
Sets the major and minor version of OpenGL to request.
public void set_use_es (int use_es)
Requests that GDK create a OpenGL ES context instead of an OpenGL one, if the platform and windowing system allows it.

Inherited Members:

All known members inherited from class GLib.Object