gtk2/gdk/gdkglcontext.c

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gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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/* 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.
*
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* #GdkGLContexts are created for a #GdkWindow using
* gdk_window_create_gl_context(), and the context will match
* the #GdkVisual of the window.
*
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* 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.
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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*
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* Support for #GdkGLContext is platform-specific, context creation
* can fail, returning %NULL context.
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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*
* 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
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* #GdkWindow, which you typically get during the realize call
* of a widget.
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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*
* ## 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 "gdkinternals.h"
#include "gdkintl.h"
#include <epoxy/gl.h>
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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typedef struct {
GdkWindow *window;
GdkGLContext *shared_context;
guint realized : 1;
guint use_texture_rectangle : 1;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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} GdkGLContextPrivate;
enum {
PROP_0,
PROP_WINDOW,
PROP_SHARED_CONTEXT,
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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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 GPrivate thread_current_context = G_PRIVATE_INIT (g_object_unref);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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static void
gdk_gl_context_dispose (GObject *gobject)
{
GdkGLContext *context = GDK_GL_CONTEXT (gobject);
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
GdkGLContext *current;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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current = g_private_get (&thread_current_context);
if (current == context)
g_private_replace (&thread_current_context, NULL);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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g_clear_object (&priv->window);
g_clear_object (&priv->shared_context);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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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_SHARED_CONTEXT:
{
GdkGLContext *context = g_value_get_object (value);
if (context != NULL)
priv->shared_context = g_object_ref (context);
}
break;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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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_SHARED_CONTEXT:
g_value_set_object (value, priv->shared_context);
break;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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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:shared-context:
*
* The #GdkGLContext that this context is sharing data with, or #NULL
*
* Since: 3.16
*/
obj_pspecs[PROP_SHARED_CONTEXT] =
g_param_spec_object ("shared-context",
P_("Shared context"),
P_("The GL context this context share data with"),
GDK_TYPE_GL_CONTEXT,
G_PARAM_READWRITE |
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_STATIC_STRINGS);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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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)
{
}
/*< private >
* gdk_gl_context_end_frame:
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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* @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_end_frame (GdkGLContext *context,
cairo_region_t *painted,
cairo_region_t *damage)
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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{
g_return_if_fail (GDK_IS_GL_CONTEXT (context));
GDK_GL_CONTEXT_GET_CLASS (context)->end_frame (context, painted, damage);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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}
gboolean
gdk_gl_context_use_texture_rectangle (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
return priv->use_texture_rectangle;
}
static void
gdk_gl_context_realize (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
gboolean has_npot, has_texture_rectangle;
has_npot = epoxy_has_gl_extension ("GL_ARB_texture_non_power_of_two");
has_texture_rectangle = epoxy_has_gl_extension ("GL_ARB_texture_rectangle");
if (has_npot)
priv->use_texture_rectangle = FALSE;
else if (has_texture_rectangle)
priv->use_texture_rectangle = TRUE;
else
g_warning ("Gl implementation doesn't support any form of non-power-of-two textures");
priv->realized = TRUE;
}
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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/**
* gdk_gl_context_make_current:
* @context: a #GdkGLContext
*
* Makes the @context the current one.
*
* Since: 3.16
*/
void
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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gdk_gl_context_make_current (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
GdkGLContext *current;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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g_return_if_fail (GDK_IS_GL_CONTEXT (context));
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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current = g_private_get (&thread_current_context);
if (current == context)
return;
if (gdk_display_make_gl_context_current (gdk_window_get_display (priv->window), context))
{
g_private_replace (&thread_current_context, g_object_ref (context));
if (!priv->realized)
gdk_gl_context_realize (context);
}
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
2014-10-09 08:45:44 +00:00
}
/**
* 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_get_shared_context:
* @context: a #GdkGLContext
*
* Retrieves the #GdkGLContext that this @context share data with.
*
* Returns: (transfer none): a #GdkGLContext or %NULL
*
* Since: 3.16
*/
GdkGLContext *
gdk_gl_context_get_shared_context (GdkGLContext *context)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (context);
g_return_val_if_fail (GDK_IS_GL_CONTEXT (context), NULL);
return priv->shared_context;
}
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
2014-10-09 08:45:44 +00:00
/**
* 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)
{
GdkGLContext *current;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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current = g_private_get (&thread_current_context);
if (current != NULL)
{
GdkGLContextPrivate *priv = gdk_gl_context_get_instance_private (current);
if (gdk_display_make_gl_context_current (gdk_window_get_display (priv->window), NULL))
g_private_replace (&thread_current_context, NULL);
}
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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}
/**
* 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)
{
GdkGLContext *current;
current = g_private_get (&thread_current_context);
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
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return current;
gdk: Add support for OpenGL This adds the new type GdkGLContext that wraps an OpenGL context for a particular native window. It also adds support for the gdk paint machinery to use OpenGL to draw everything. As soon as anyone creates a GL context for a native window we create a "paint context" for that GdkWindow and switch to using GL for painting it. This commit contains only an implementation for X11 (using GLX). The way painting works is that all client gl contexts draw into offscreen buffers rather than directly to the back buffer, and the way something gets onto the window is by using gdk_cairo_draw_from_gl() to draw part of that buffer onto the draw cairo context. As a fallback (if we're doing redirected drawing or some effect like a cairo_push_group()) we read back the gl buffer into memory and composite using cairo. This means that GL rendering works in all cases, including rendering to a PDF. However, this is not particularly fast. In the *typical* case, where we're drawing directly to the window in the regular paint loop we hit the fast path. The fast path uses opengl to draw the buffer to the window back buffer, either by blitting or texturing. Then we track the region that was drawn, and when the draw ends we paint the normal cairo surface to the window (using texture-from-pixmap in the X11 case, or texture from cairo image otherwise) in the regions where there is no gl painted. There are some complexities wrt layering of gl and cairo areas though: * We track via gdk_window_mark_paint_from_clip() whenever gtk is painting over a region we previously rendered with opengl (flushed_region). This area (needs_blend_region) is blended rather than copied at the end of the frame. * If we're drawing a gl texture with alpha we first copy the current cairo_surface inside the target region to the back buffer before we blend over it. These two operations allow us full stacking of transparent gl and cairo regions.
2014-10-09 08:45:44 +00:00
}