Creating a new OpenGL context

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

A GdkGLContext is not realized until either gdk_gl_context_make_current(), or until it is realized using gdk_gl_context_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 gdk_window_create_gl_context() by calling gdk_gl_context_realize(). If the realization fails you have the option to change the settings of the GdkGLContext and try again.

Using a GdkGLContext

You will need to make the GdkGLContext 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:

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gdk_gl_context_make_current (context);

You can now perform your drawing using OpenGL commands.

You can check which GdkGLContext is the current one by using gdk_gl_context_get_current(); you can also unset any GdkGLContext that is currently set by calling gdk_gl_context_clear_current().

gdk_gl_context_get_display ()

GdkDisplay *
gdk_gl_context_get_display (GdkGLContext *context);

Retrieves the GdkDisplay the context is created for

Since: 3.16

gdk_gl_context_get_window ()

GdkWindow *
gdk_gl_context_get_window (GdkGLContext *context);

Retrieves the GdkWindow used by the context .

Since: 3.16

gdk_gl_context_get_shared_context ()

GdkGLContext *
gdk_gl_context_get_shared_context (GdkGLContext *context);

Retrieves the GdkGLContext that this context share data with.

Since: 3.16

gdk_gl_context_get_version ()

void
gdk_gl_context_get_version (GdkGLContext *context,
                            int *major,
                            int *minor);

Retrieves the OpenGL version of the context .

The context must be realized prior to calling this function.

Since: 3.16

gdk_gl_context_set_required_version ()

void
gdk_gl_context_set_required_version (GdkGLContext *context,
                                     int major,
                                     int minor);

Sets the major and minor version of OpenGL to request.

Setting major and minor to zero will use the default values.

The GdkGLContext must not be realized or made current prior to calling this function.

Since: 3.16

gdk_gl_context_get_required_version ()

void
gdk_gl_context_get_required_version (GdkGLContext *context,
                                     int *major,
                                     int *minor);

Retrieves the major and minor version requested by calling gdk_gl_context_set_required_version().

Since: 3.16

gdk_gl_context_set_debug_enabled ()

void
gdk_gl_context_set_debug_enabled (GdkGLContext *context,
                                  gboolean enabled);

Sets whether the GdkGLContext should perform extra validations and run time checking. This is useful during development, but has additional overhead.

The GdkGLContext must not be realized or made current prior to calling this function.

Since: 3.16

gdk_gl_context_get_debug_enabled ()

gboolean
gdk_gl_context_get_debug_enabled (GdkGLContext *context);

Retrieves the value set using gdk_gl_context_set_debug_enabled().

Since: 3.16

gdk_gl_context_set_forward_compatible ()

void
gdk_gl_context_set_forward_compatible (GdkGLContext *context,
                                       gboolean compatible);

Sets whether the GdkGLContext should be forward compatible.

Forward compatibile contexts must not support OpenGL functionality that has been marked as deprecated in the requested version; non-forward compatible contexts, on the other hand, must support both deprecated and non deprecated functionality.

The GdkGLContext must not be realized or made current prior to calling this function.

Since: 3.16

gdk_gl_context_get_forward_compatible ()

gboolean
gdk_gl_context_get_forward_compatible (GdkGLContext *context);

Retrieves the value set using gdk_gl_context_set_forward_compatible().

Since: 3.16

gdk_gl_context_realize ()

gboolean
gdk_gl_context_realize (GdkGLContext *context,
                        GError **error);

Realizes the given GdkGLContext.

It is safe to call this function on a realized GdkGLContext.

Since: 3.16

gdk_gl_context_make_current ()

void
gdk_gl_context_make_current (GdkGLContext *context);

Makes the context the current one.

Since: 3.16

gdk_gl_context_get_current ()

GdkGLContext *
gdk_gl_context_get_current (void);

Retrieves the current GdkGLContext.

Since: 3.16

gdk_gl_context_clear_current ()

void
gdk_gl_context_clear_current (void);

Clears the current GdkGLContext.

Any OpenGL call after this function returns will be ignored until gdk_gl_context_make_current() is called.

Since: 3.16

GdkGLContext

typedef struct _GdkGLContext GdkGLContext;

enum GdkGLError

Error enumeration for GdkGLContext.

Since: 3.16

The “display” property

  “display”                  GdkDisplay *

The GdkDisplay used to create the GdkGLContext.

Flags: Read / Write / Construct Only

Since: 3.16

The “shared-context” property

  “shared-context”           GdkGLContext *

The GdkGLContext that this context is sharing data with, or NULL

Flags: Read / Write / Construct Only

Since: 3.16

The “window” property

  “window”                   GdkWindow *

The GdkWindow the gl context is bound to.

Flags: Read / Write / Construct Only

Since: 3.16