[856/906] context: document it

gst-libs/gst/gl/gstglcontext.c

@@ -18,6 +18,17 @@
  * Boston, MA 02110-1301, USA.
  */
 
+/**
+ * SECTION:gstglcontext
+ * @short_description: OpenGL context abstraction
+ * @title: GstGLContext
+ * @see_also: #GstGLDisplay, #GstGLWindow
+ *
+ * #GstGLContext wraps an OpenGL context object in a uniform API.  As a result
+ * of the limitation on OpenGL context, this object is not thread safe unless
+ * specified and must only be activated in a single thread.
+ */
+
 #if HAVE_CONFIG_H
 # include "config.h"
 #endif
@@ -131,6 +142,14 @@ gst_gl_context_class_init (GstGLContextClass * klass)
   G_OBJECT_CLASS (klass)->finalize = gst_gl_context_finalize;
 }
 
+/**
+ * gst_gl_context_new:
+ * @display: a #GstGLDisplay
+ *
+ * Create a new #GstGLContext with the specified @display
+ *
+ * Returns: a new #GstGLContext
+ */
 GstGLContext *
 gst_gl_context_new (GstGLDisplay * display)
 {
@@ -221,6 +240,18 @@ gst_gl_context_finalize (GObject * object)
   G_OBJECT_CLASS (gst_gl_context_parent_class)->finalize (object);
 }
 
+/**
+ * gst_gl_context_activate:
+ * @context: a #GstGLContext
+ * @activate: %TRUE to activate, %FALSE to deactivate
+ *
+ * (De)activate the OpenGL context represented by this @context.
+ *
+ * In OpenGL terms, calls eglMakeCurrent or similar with this context and the
+ * currently set window.  See gst_gl_context_set_window() for details.
+ *
+ * Returns: Whether the activation succeeded
+ */
 gboolean
 gst_gl_context_activate (GstGLContext * context, gboolean activate)
 {
@@ -236,6 +267,17 @@ gst_gl_context_activate (GstGLContext * context, gboolean activate)
   return result;
 }
 
+/**
+ * gst_gl_context_get_gl_api:
+ * @context: a #GstGLContext
+ *
+ * Get the currently enabled OpenGL api.
+ *
+ * The currently available API may be limited by the #GstGLDisplay in use and/or
+ * the #GstGLWindow chosen.
+ *
+ * Returns: the currently available OpenGL api
+ */
 GstGLAPI
 gst_gl_context_get_gl_api (GstGLContext * context)
 {
@@ -248,6 +290,19 @@ gst_gl_context_get_gl_api (GstGLContext * context)
   return context_class->get_gl_api (context);
 }
 
+/**
+ * gst_gl_context_get_proc_address:
+ * @context: a #GstGLContext
+ * @name: an opengl function name
+ *
+ * Get a function pointer to a specified opengl function, @name.  If the the
+ * specific function does not exist, NULL is returned instead.
+ *
+ * Platform specfic functions (names starting 'egl', 'glX', 'wgl', etc) can also
+ * be retreived using this method.
+ *
+ * Returns: a function pointer or NULL
+ */
 gpointer
 gst_gl_context_get_proc_address (GstGLContext * context, const gchar * name)
 {
@@ -314,6 +369,17 @@ gst_gl_context_default_get_proc_address (GstGLContext * context,
   return ret;
 }
 
+/**
+ * gst_gl_context_set_window:
+ * @context: a #GstGLContext
+ * @window: (transfer full): a #GstGLWindow
+ *
+ * Set's the current window on @context to @window.  The window can only be
+ * changed before gst_gl_context_create() has been called and the @window is not
+ * already running.
+ *
+ * Returns: Whether the window was successfully updated
+ */
 gboolean
 gst_gl_context_set_window (GstGLContext * context, GstGLWindow * window)
 {
@@ -336,6 +402,12 @@ gst_gl_context_set_window (GstGLContext * context, GstGLWindow * window)
   return TRUE;
 }
 
+/**
+ * gst_gl_context_get_window:
+ * @context: a #GstGLContext
+ *
+ * Returns: the currently set window
+ */
 GstGLWindow *
 gst_gl_context_get_window (GstGLContext * context)
 {
@@ -346,7 +418,23 @@ gst_gl_context_get_window (GstGLContext * context)
   return gst_object_ref (context->window);
 }
 
-/* Create an opengl context (one context for one GstGLDisplay) */
+/**
+ * gst_gl_context_create:
+ * @context: a #GstGLContext:
+ * @other_context: (allow-none): a #GstGLContext to share OpenGL objects with
+ * @error: (allow-none): a #GError
+ *
+ * Creates an OpenGL context in the current thread with the specified
+ * @other_context as a context to share shareable OpenGL objects with.  See the
+ * OpenGL specification for what is shared between contexts.
+ *
+ * If an error occurs, and @error is not %NULL, then error will contain details
+ * of the error and %FALSE will be returned.
+ *
+ * Should only be called once.
+ *
+ * Returns: whether the context could successfully be created
+ */
 gboolean
 gst_gl_context_create (GstGLContext * context,
     GstGLContext * other_context, GError ** error)
@@ -689,6 +777,14 @@ failure:
   }
 }
 
+/**
+ * gst_gl_context_get_gl_context:
+ * @context: a #GstGLContext:
+ *
+ * Gets the backing OpenGL context used by @context.
+ *
+ * Returns: The platform specific backing OpenGL context
+ */
 guintptr
 gst_gl_context_get_gl_context (GstGLContext * context)
 {
@@ -704,6 +800,12 @@ gst_gl_context_get_gl_context (GstGLContext * context)
   return result;
 }
 
+/**
+ * gst_gl_context_get_display:
+ * @context: a #GstGLContext:
+ *
+ * Returns: the #GstGLDisplay associated with this @context
+ */
 GstGLDisplay *
 gst_gl_context_get_display (GstGLContext * context)
 {
@@ -727,6 +829,16 @@ _gst_gl_context_thread_run_generic (RunGenericData * data)
   data->func (data->context, data->data);
 }
 
+/**
+ * gst_gl_context_thread_add:
+ * @context: a #GstGLContext
+ * @func: a #GstGLContextThreadFunc
+ * @data: (closure): user data to call @func with
+ *
+ * Execute @func in the OpenGL thread of @context with @data
+ *
+ * MT-safe
+ */
 void
 gst_gl_context_thread_add (GstGLContext * context,
     GstGLContextThreadFunc func, gpointer data)

gst-libs/gst/gl/gstglcontext.h

@@ -40,10 +40,10 @@ GQuark gst_gl_context_error_quark (void);
 
 /**
  * GstGLContextThreadFunc:
- * @display: a #GstGLDisplay
+ * @context: a #GstGLContext
  * @data: user data
  *
- * Represents a function to run in the GL thread
+ * Represents a function to run in the GL thread with @context and @data
  */
 typedef void (*GstGLContextThreadFunc) (GstGLContext * context, gpointer data);
 
@@ -57,23 +57,36 @@ typedef enum
   GST_GL_CONTEXT_ERROR_RESOURCE_UNAVAILABLE,
 } GstGLContextError;
 
+/**
+ * GstGLContext:
+ *
+ * Opaque #GstGLContext object
+ */
 struct _GstGLContext {
   /*< private >*/
   GObject parent;
 
-  /*< public >*/
   GstGLWindow  *window;
 
   GstGLFuncs *gl_vtable;
 
-  /*< private >*/
   gpointer _reserved[GST_PADDING];
 
   GstGLContextPrivate *priv;
 };
 
+/**
+ * GstGLContextClass:
+ * @get_gl_context: get the backing platform specific OpenGL context
+ * @get_gl_api: get the available OpenGL api's that this context can work with
+ * @get_proc_address: get an function pointer to an OpenGL function
+ * @activate: call eglMakeCurrent or similar
+ * @choose_format: choose a format for the framebuffer
+ * @create_context: create the OpenGL context
+ * @destroy_context: destroy the OpenGL context
+ * @swap_buffers: swap the default framebuffer's front/back buffers
+ */
 struct _GstGLContextClass {
-  /*< private >*/
   GObjectClass parent_class;
 
   guintptr (*get_gl_context)     (GstGLContext *context);
@@ -110,7 +123,7 @@ gboolean      gst_gl_context_set_window (GstGLContext *context, GstGLWindow *win
 GstGLWindow * gst_gl_context_get_window (GstGLContext *context);
 
 /* FIXME: remove */
-void gst_gl_context_thread_add (GstGLContext * display,
+void gst_gl_context_thread_add (GstGLContext * context,
     GstGLContextThreadFunc func, gpointer data);
 
 G_END_DECLS