From 6969cdac8e04e65f00f4fec9f681ebbf243f0945 Mon Sep 17 00:00:00 2001

From: =?UTF-8?q?Caol=C3=A1n=20McNamara?= <caolanm@redhat.com>

Date: Sun, 10 Sep 2017 16:07:49 +0100

Subject: [PATCH] gtk3: flicker-free opengl transitions

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leave the GtkGLArea opengl context alone except for the final render into it,

create a new context for the slide transitions to play with

set up a pair of framebuffers, a scratch one to let the transitions render

into, the other to take a snapshot when the transition is finished with it and

then tell GtkGLArea we're ready to render it and when the callback comes around

copy the snapshot into it.

Change-Id: I3515614baf7eea0ff53c46edbaf9cf66f926eef2

hidpi+gtk3: move setting the opengl slide viewport

to when the window size is set, and adjust to gtk3 hidpi

scaling factor

Change-Id: Id9bd0defd0b6ae640ac57f88133d954202d4bcc3

Reviewed-on: https://gerrit.libreoffice.org/42143

Tested-by: Jenkins <ci@libreoffice.org>

Reviewed-by: Caolán McNamara <caolanm@redhat.com>

Tested-by: Caolán McNamara <caolanm@redhat.com>

(cherry picked from commit 1a547a566eba5943f9e4d9987baf4aee80846dd1)

---

 include/vcl/opengl/OpenGLContext.hxx               |   1 +

 .../source/engine/opengl/TransitionerImpl.cxx      |   1 -

 vcl/source/opengl/OpenGLContext.cxx                |  11 +-

 vcl/unx/gtk3/gtk3gtkinst.cxx                       | 151 ++++++++++++++++++++-

 5 files changed, 166 insertions(+), 23 deletions(-)

diff --git a/include/vcl/opengl/OpenGLContext.hxx b/include/vcl/opengl/OpenGLContext.hxx

index 5796f7e..c9b1c81 100644

--- a/include/vcl/opengl/OpenGLContext.hxx

+++ b/include/vcl/opengl/OpenGLContext.hxx

@@ -158,6 +158,7 @@ public:

 private:

     virtual bool initWindow();

     virtual void destroyCurrentContext();

+    virtual void adjustToNewSize();

 protected:

     bool InitGL();

diff --git a/slideshow/source/engine/opengl/TransitionerImpl.cxx b/slideshow/source/engine/opengl/TransitionerImpl.cxx

index c958389..06e1123 100644

--- a/slideshow/source/engine/opengl/TransitionerImpl.cxx

+++ b/slideshow/source/engine/opengl/TransitionerImpl.cxx

@@ -346,7 +346,6 @@ bool OGLTransitionerImpl::initWindowFromSlideShowView( const Reference< presenta

     mpContext->swapBuffers();

-    glViewport(0, 0, aCanvasArea.Width, aCanvasArea.Height);

     CHECK_GL_ERROR();

     return true;

diff --git a/vcl/source/opengl/OpenGLContext.cxx b/vcl/source/opengl/OpenGLContext.cxx

index 42fba6d..51517ca 100644

--- a/vcl/source/opengl/OpenGLContext.cxx

+++ b/vcl/source/opengl/OpenGLContext.cxx

@@ -338,14 +338,21 @@ void OpenGLContext::restoreDefaultFramebuffer()

 void OpenGLContext::setWinPosAndSize(const Point &rPos, const Size& rSize)

 {

-    if(m_xWindow)

+    if (m_xWindow)

         m_xWindow->SetPosSizePixel(rPos, rSize);

-    if( m_pChildWindow )

+    if (m_pChildWindow)

         m_pChildWindow->SetPosSizePixel(rPos, rSize);

     GLWindow& rGLWin = getModifiableOpenGLWindow();

     rGLWin.Width = rSize.Width();

     rGLWin.Height = rSize.Height();

+    adjustToNewSize();

+}

+

+void OpenGLContext::adjustToNewSize()

+{

+    const GLWindow& rGLWin = getOpenGLWindow();

+    glViewport(0, 0, rGLWin.Width, rGLWin.Height);

 }

 void OpenGLContext::setWinSize(const Size& rSize)

diff --git a/vcl/unx/gtk3/gtk3gtkinst.cxx b/vcl/unx/gtk3/gtk3gtkinst.cxx

index 3d20cca..a37deb0 100644

--- a/vcl/unx/gtk3/gtk3gtkinst.cxx

+++ b/vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -923,12 +923,32 @@ Reference< XInterface > GtkInstance::CreateDragSource()

 class GtkOpenGLContext : public OpenGLContext

 {

     GLWindow m_aGLWin;

+#if GTK_CHECK_VERSION(3,16,0)

     GtkWidget *m_pGLArea;

+    GdkGLContext *m_pContext;

+    guint m_nAreaFrameBuffer;

+    guint m_nFrameBuffer;

+    guint m_nRenderBuffer;

+    guint m_nDepthBuffer;

+    guint m_nFrameScratchBuffer;

+    guint m_nRenderScratchBuffer;

+    guint m_nDepthScratchBuffer;

+#endif

 public:

     GtkOpenGLContext()

         : OpenGLContext()

+#if GTK_CHECK_VERSION(3,16,0)

         , m_pGLArea(nullptr)

+        , m_pContext(nullptr)

+        , m_nAreaFrameBuffer(0)

+        , m_nFrameBuffer(0)

+        , m_nRenderBuffer(0)

+        , m_nDepthBuffer(0)

+        , m_nFrameScratchBuffer(0)

+        , m_nRenderScratchBuffer(0)

+        , m_nDepthScratchBuffer(0)

+#endif

     {

     }

@@ -952,12 +972,78 @@ private:

     virtual const GLWindow& getOpenGLWindow() const override { return m_aGLWin; }

     virtual GLWindow& getModifiableOpenGLWindow() override { return m_aGLWin; }

+#if GTK_CHECK_VERSION(3,16,0)

     static void signalDestroy(GtkWidget*, gpointer context)

     {

         GtkOpenGLContext* pThis = static_cast<GtkOpenGLContext*>(context);

         pThis->m_pGLArea = nullptr;

     }

+    static gboolean signalRender(GtkGLArea*, GdkGLContext*, gpointer window)

+    {

+        GtkOpenGLContext* pThis = static_cast<GtkOpenGLContext*>(window);

+

+        int scale = gtk_widget_get_scale_factor(pThis->m_pGLArea);

+        int width = pThis->m_aGLWin.Width * scale;

+        int height = pThis->m_aGLWin.Height * scale;

+

+        glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);

+

+        glBindFramebuffer(GL_READ_FRAMEBUFFER, pThis->m_nAreaFrameBuffer);

+        glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);

+

+        glBlitFramebuffer(0, 0, width, height, 0, 0, width, height,

+                          GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT, GL_NEAREST);

+

+        gdk_gl_context_make_current(pThis->m_pContext);

+        return true;

+    }

+#endif

+

+    virtual void adjustToNewSize() override

+    {

+#if GTK_CHECK_VERSION(3,16,0)

+        if (m_pGLArea)

+        {

+            int scale = gtk_widget_get_scale_factor(m_pGLArea);

+            int width = m_aGLWin.Width * scale;

+            int height = m_aGLWin.Height * scale;

+

+            gtk_gl_area_make_current(GTK_GL_AREA(m_pGLArea));

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nRenderBuffer);

+            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8, width, height);

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nDepthBuffer);

+            glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);

+            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_nAreaFrameBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nRenderBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nDepthBuffer);

+

+            gdk_gl_context_make_current(m_pContext);

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nRenderBuffer);

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nDepthBuffer);

+            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_nFrameBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nRenderBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nDepthBuffer);

+            glViewport(0, 0, width, height);

+

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nRenderScratchBuffer);

+            glRenderbufferStorage(GL_RENDERBUFFER, GL_RGB8, width, height);

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nDepthScratchBuffer);

+            glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, width, height);

+            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_nFrameScratchBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nRenderScratchBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nDepthScratchBuffer);

+            glViewport(0, 0, width, height);

+        }

+#endif

+    }

+

     virtual bool ImplInit() override

     {

 #if GTK_CHECK_VERSION(3,16,0)

@@ -965,14 +1051,28 @@ private:

         GtkWidget *pParent = static_cast<GtkWidget*>(pEnvData->pWidget);

         m_pGLArea = gtk_gl_area_new();

         g_signal_connect(G_OBJECT(m_pGLArea), "destroy", G_CALLBACK(signalDestroy), this);

+        g_signal_connect(G_OBJECT(m_pGLArea), "render", G_CALLBACK(signalRender), this);

         gtk_gl_area_set_has_depth_buffer(GTK_GL_AREA(m_pGLArea), true);

         gtk_gl_area_set_auto_render(GTK_GL_AREA(m_pGLArea), false);

         gtk_widget_set_hexpand(m_pGLArea, true);

         gtk_widget_set_vexpand(m_pGLArea, true);

         gtk_container_add(GTK_CONTAINER(pParent), m_pGLArea);

         gtk_widget_show_all(pParent);

+

         gtk_gl_area_make_current(GTK_GL_AREA(m_pGLArea));

         gtk_gl_area_attach_buffers(GTK_GL_AREA(m_pGLArea));

+        glGenFramebuffersEXT(1, &m_nAreaFrameBuffer);

+

+        GdkWindow *pWindow = gtk_widget_get_window(pParent);

+        m_pContext = gdk_window_create_gl_context(pWindow, nullptr);

+        gdk_gl_context_realize(m_pContext, nullptr);

+        gdk_gl_context_make_current(m_pContext);

+        glGenFramebuffersEXT(1, &m_nFrameBuffer);

+        glGenRenderbuffersEXT(1, &m_nRenderBuffer);

+        glGenRenderbuffersEXT(1, &m_nDepthBuffer);

+        glGenFramebuffersEXT(1, &m_nFrameScratchBuffer);

+        glGenRenderbuffersEXT(1, &m_nRenderScratchBuffer);

+        glGenRenderbuffersEXT(1, &m_nDepthScratchBuffer);

 #endif

         bool bRet = InitGL();

         InitGLDebugging();

@@ -983,7 +1083,9 @@ private:

     {

         OpenGLContext::restoreDefaultFramebuffer();

 #if GTK_CHECK_VERSION(3,16,0)

-        gtk_gl_area_attach_buffers(GTK_GL_AREA(m_pGLArea));

+        glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_nFrameScratchBuffer);

+        glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

+                                     GL_RENDERBUFFER_EXT, m_nRenderScratchBuffer);

 #endif

     }

@@ -996,7 +1098,22 @@ private:

 #if GTK_CHECK_VERSION(3,16,0)

         if (m_pGLArea)

-            gtk_gl_area_make_current(GTK_GL_AREA(m_pGLArea));

+        {

+            int scale = gtk_widget_get_scale_factor(m_pGLArea);

+            int width = m_aGLWin.Width * scale;

+            int height = m_aGLWin.Height * scale;

+

+            gdk_gl_context_make_current(m_pContext);

+

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nRenderScratchBuffer);

+            glBindRenderbuffer(GL_RENDERBUFFER, m_nDepthScratchBuffer);

+            glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, m_nFrameScratchBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nRenderScratchBuffer);

+            glFramebufferRenderbufferEXT(GL_FRAMEBUFFER_EXT, GL_DEPTH_ATTACHMENT_EXT,

+                                         GL_RENDERBUFFER_EXT, m_nDepthScratchBuffer);

+            glViewport(0, 0, width, height);

+        }

 #endif

         registerAsCurrent();

@@ -1012,7 +1129,7 @@ private:

     virtual bool isCurrent() override

     {

 #if GTK_CHECK_VERSION(3,16,0)

-        return m_pGLArea && gdk_gl_context_get_current() == gtk_gl_area_get_context(GTK_GL_AREA(m_pGLArea));

+        return m_pGLArea && gdk_gl_context_get_current() == m_pContext;

 #else

         return false;

 #endif

@@ -1020,9 +1137,6 @@ private:

     virtual void sync() override

     {

-#if GTK_CHECK_VERSION(3,16,0)

-        gtk_gl_area_queue_render(GTK_GL_AREA(m_pGLArea));

-#endif

     }

     virtual void resetCurrent() override

@@ -1036,10 +1150,35 @@ private:

     virtual void swapBuffers() override

     {

 #if GTK_CHECK_VERSION(3,16,0)

+        int scale = gtk_widget_get_scale_factor(m_pGLArea);

+        int width = m_aGLWin.Width * scale;

+        int height = m_aGLWin.Height * scale;

+

+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_nFrameBuffer);

+        glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);

+

+        glBindFramebuffer(GL_READ_FRAMEBUFFER, m_nFrameScratchBuffer);

+        glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);

+

+        glBlitFramebuffer(0, 0, width, height, 0, 0, width, height,

+                          GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT, GL_NEAREST);

+

+        glBindFramebuffer(GL_DRAW_FRAMEBUFFER, m_nFrameScratchBuffer);

+        glDrawBuffer(GL_COLOR_ATTACHMENT0_EXT);

+

         gtk_gl_area_queue_render(GTK_GL_AREA(m_pGLArea));

 #endif

         BuffersSwapped();

     }

+#if GTK_CHECK_VERSION(3,16,0)

+    virtual ~GtkOpenGLContext() override

+    {

+        if (m_pContext)

+        {

+            g_clear_object(&m_pContext);

+        }

+    }

+#endif

 };

 OpenGLContext* GtkInstance::CreateOpenGLContext()

-- 

2.9.5