gtk2/gdk/gdkglcontext.c
2014-10-13 10:43:32 -04:00

340 lines
8.9 KiB
C

/* GDK - The GIMP Drawing Kit
*
* gdkglcontext.c: GL context abstraction
*
* Copyright © 2014 Emmanuele Bassi
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* SECTION:gdkglcontext
* @Title: GdkGLContext
* @Short_description: OpenGL context
*
* #GdkGLContext is an object representing the platform-specific
* OpenGL drawing context.
*
* #GdkGLContexts are created for a #GdkWindow using
* gdk_window_create_gl_context(), and the context will match
* the #GdkVisual of the window.
*
* A #GdkGLContext is not tied to any particular normal framebuffer.
* For instance, it cannot draw to the #GdkWindow 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 gdk_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 #GdkGLContext is platform-specific, context creation
* can fail, returning %NULL context.
*
* A #GdkGLContext 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 #GdkGLContext instance you need a
* #GdkWindow, which you typically get during the realize call
* of a widget.
*
* ## 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:
*
* |[<!-- language="C" -->
* 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().
*/
#include "config.h"
#include "gdkglcontextprivate.h"
#include "gdkdisplayprivate.h"
#include "gdkvisual.h"
#include "gdkinternals.h"
#include "gdkintl.h"
typedef struct {
GdkWindow *window;
GdkVisual *visual;
} GdkGLContextPrivate;
enum {
PROP_0,
PROP_WINDOW,
PROP_VISUAL,
LAST_PROP
};
static GParamSpec *obj_pspecs[LAST_PROP] = { NULL, };
G_DEFINE_QUARK (gdk-gl-error-quark, gdk_gl_error)
G_DEFINE_ABSTRACT_TYPE_WITH_PRIVATE (GdkGLContext, gdk_gl_context, G_TYPE_OBJECT)
static void
gdk_gl_context_dispose (GObject *gobject)
{
GdkGLContext *context = GDK_GL_CONTEXT (gobject);
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
gdk_display_destroy_gl_context (gdk_window_get_display (priv->window), context);
g_clear_object (&priv->window);
g_clear_object (&priv->visual);
G_OBJECT_CLASS (gdk_gl_context_parent_class)->dispose (gobject);
}
static void
gdk_gl_context_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private ((GdkGLContext *) gobject);
switch (prop_id)
{
case PROP_WINDOW:
{
GdkWindow *window = g_value_get_object (value);
if (window)
g_object_ref (window);
if (priv->window)
g_object_unref (priv->window);
priv->window = window;
}
break;
case PROP_VISUAL:
{
GdkVisual *visual = g_value_get_object (value);
if (visual != NULL)
priv->visual = g_object_ref (visual);
}
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gdk_gl_context_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private ((GdkGLContext *) gobject);
switch (prop_id)
{
case PROP_WINDOW:
g_value_set_object (value, priv->window);
break;
case PROP_VISUAL:
g_value_set_object (value, priv->visual);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
gdk_gl_context_class_init (GdkGLContextClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
/**
* GdkGLContext:window:
*
* The #GdkWindow the gl context is bound to.
*
* Since: 3.16
*/
obj_pspecs[PROP_WINDOW] =
g_param_spec_object ("window",
P_("Window"),
P_("The GDK window bound to the GL context"),
GDK_TYPE_WINDOW,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_STRINGS);
/**
* GdkGLContext:visual:
*
* The #GdkVisual matching the pixel format used by the context.
*
* Since: 3.16
*/
obj_pspecs[PROP_VISUAL] =
g_param_spec_object ("visual",
P_("Visual"),
P_("The GDK visual used by the GL context"),
GDK_TYPE_VISUAL,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_STRINGS);
gobject_class->set_property = gdk_gl_context_set_property;
gobject_class->get_property = gdk_gl_context_get_property;
gobject_class->dispose = gdk_gl_context_dispose;
g_object_class_install_properties (gobject_class, LAST_PROP, obj_pspecs);
}
static void
gdk_gl_context_init (GdkGLContext *self)
{
}
/**
* gdk_gl_context_get_visual:
* @context: a #GdkGLContext
*
* Retrieves the #GdkVisual associated with the @context.
*
* Returns: (transfer none): the #GdkVisual
*
* Since: 3.16
*/
GdkVisual *
gdk_gl_context_get_visual (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_GL_CONTEXT (context), NULL);
return priv->visual;
}
/*< private >
* gdk_gl_context_flush_buffer:
* @context: a #GdkGLContext
* @painted: The area that has been redrawn this frame
* @damage: The area that we know is actually different from the last frame
*
* Copies the back buffer to the front buffer.
*
* This function may call `glFlush()` implicitly before returning; it
* is not recommended to call `glFlush()` explicitly before calling
* this function.
*
* Since: 3.16
*/
void
gdk_gl_context_flush_buffer (GdkGLContext *context,
cairo_region_t *painted,
cairo_region_t *damage)
{
g_return_if_fail (GDK_IS_GL_CONTEXT (context));
GDK_GL_CONTEXT_GET_CLASS (context)->flush_buffer (context, painted, damage);
}
/**
* gdk_gl_context_make_current:
* @context: a #GdkGLContext
*
* Makes the @context the current one.
*
* Since: 3.16
*/
void
gdk_gl_context_make_current (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
g_return_if_fail (GDK_IS_GL_CONTEXT (context));
gdk_display_make_gl_context_current (gdk_window_get_display (priv->window), context);
}
/**
* gdk_gl_context_get_window:
* @context: a #GdkGLContext
*
* Retrieves the #GdkWindow used by the @context.
*
* Returns: (transfer none): a #GdkWindow or %NULL
*
* Since: 3.16
*/
GdkWindow *
gdk_gl_context_get_window (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_GL_CONTEXT (context), NULL);
return priv->window;
}
/**
* gdk_gl_context_clear_current:
*
* 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
*/
void
gdk_gl_context_clear_current (void)
{
GdkDisplay *display = gdk_display_get_default ();
gdk_display_make_gl_context_current (display, NULL);
}
/**
* gdk_gl_context_get_current:
*
* Retrieves the current #GdkGLContext.
*
* Returns: (transfer none): the current #GdkGLContext, or %NULL
*
* Since: 3.16
*/
GdkGLContext *
gdk_gl_context_get_current (void)
{
GdkDisplay *display = gdk_display_get_default ();
return gdk_display_get_current_gl_context (display);
}