## Query

Query — Functions to query OpenGL support information

## Synopsis

    #include <gdk/gdkgl.h>

    void        (*GdkGLProc)                    (void);
    gboolean    gdk_gl_query_extension          (void);
    gboolean    gdk_gl_query_extension_for_display
                                                (GdkDisplay *display);
    gboolean    gdk_gl_query_version            (int *major,
                                                 int *minor);
    gboolean    gdk_gl_query_version_for_display
                                                (GdkDisplay *display,
                                                 int *major,
                                                 int *minor);
    gboolean    gdk_gl_query_gl_extension       (const char *extension);
    GdkGLProc   gdk_gl_get_proc_address         (const char *proc_name);

## Description

## Details

### GdkGLProc ()

    void        (*GdkGLProc)                    (void);

### gdk_gl_query_extension ()

    gboolean    gdk_gl_query_extension          (void);

Indicates whether the window system supports the OpenGL extension (GLX, WGL, etc.).

Returns : | TRUE if OpenGL is supported, FALSE otherwise.

### gdk_gl_query_extension_for_display ()

    gboolean    gdk_gl_query_extension_for_display
                                                (GdkDisplay *display);

Indicates whether the window system supports the OpenGL extension (GLX, WGL, etc.).

`display` : | the GdkDisplay where the query is sent to.
Returns : | TRUE if OpenGL is supported, FALSE otherwise.

### gdk_gl_query_version ()

    gboolean    gdk_gl_query_version            (int *major,
                                                 int *minor);

Returns the version numbers of the OpenGL extension to the window system.

In the X Window System, it returns the GLX version.

In the Microsoft Windows, it returns the Windows version.

`major` : | returns the major version number of the OpenGL extension.
`minor` : | returns the minor version number of the OpenGL extension.
Returns : | FALSE if it fails, TRUE otherwise.

### gdk_gl_query_version_for_display ()

    gboolean    gdk_gl_query_version_for_display
                                                (GdkDisplay *display,
                                                 int *major,
                                                 int *minor);

Returns the version numbers of the OpenGL extension to the window system.

In the X Window System, it returns the GLX version.

In the Microsoft Windows, it returns the Windows version.

`display` : | the GdkDisplay where the query is sent to.
`major` : | returns the major version number of the OpenGL extension.
`minor` : | returns the minor version number of the OpenGL extension.
Returns : | FALSE if it fails, TRUE otherwise.

### gdk_gl_query_gl_extension ()

    gboolean    gdk_gl_query_gl_extension       (const char *extension);

Determines whether a given OpenGL extension is supported.

There must be a valid current rendering context to call `gdk_gl_query_gl_extension()`.

`gdk_gl_query_gl_extension()` returns information about OpenGL extensions only. This means that window system dependent extensions (for example, GLX extensions) are not reported by `gdk_gl_query_gl_extension()`.

`extension` : | name of OpenGL extension.
Returns : | TRUE if the OpenGL extension is supported, FALSE if not supported.

### gdk_gl_get_proc_address ()

    GdkGLProc   gdk_gl_get_proc_address         (const char *proc_name);

Returns the address of the OpenGL, GLU, or GLX function.

`proc_name` : | function name.
Returns : | the address of the function named by `proc_name`.