From 717c023c984e7810395751d5b0e25e1356403142 Mon Sep 17 00:00:00 2001
From: Michael Meeks <michael.meeks@collabora.com>
Date: Fri, 4 Dec 2015 01:50:05 +0000
Subject: Implement idle GL flushing.

Change-Id: I1d3102149cba902e640cbd9bbf47ca66deedbe00
---
 vcl/inc/openglgdiimpl.hxx | 11 ++++++++++-
 vcl/opengl/gdiimpl.cxx    | 46 +++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 49 insertions(+), 8 deletions(-)

diff --git a/vcl/inc/openglgdiimpl.hxx b/vcl/inc/openglgdiimpl.hxx
index d28074364be1..fad5a07b6aef 100644
--- a/vcl/inc/openglgdiimpl.hxx
+++ b/vcl/inc/openglgdiimpl.hxx
@@ -52,6 +52,8 @@ struct TextureCombo
     std::unique_ptr<OpenGLTexture> mpMask;
 };
 
+class OpenGLFlushIdle;
+
 class VCL_DLLPUBLIC OpenGLSalGraphicsImpl : public SalGraphicsImpl
 {
     friend class OpenGLTests;
@@ -73,6 +75,9 @@ protected:
     /// Is it someone else's context we shouldn't be fiddling with ?
     static bool IsForeignContext(const rtl::Reference<OpenGLContext> &xContext);
 
+    /// This idle handler is used to swap buffers after rendering.
+    OpenGLFlushIdle *mpFlush;
+
     // clipping
     vcl::Region maClipRegion;
     bool mbUseScissor;
@@ -347,8 +352,12 @@ public:
 
     virtual bool drawGradient(const tools::PolyPolygon& rPolygon, const Gradient& rGradient) override;
 
-    /// flush contents of the back-buffer to the screen & swap.
+    /// queue an idle flush of contents of the back-buffer to the screen
     virtual void flush() override;
+
+public:
+    /// do flush of contents of the back-buffer to the screen & swap.
+    void doFlush();
 };
 
 #endif
diff --git a/vcl/opengl/gdiimpl.cxx b/vcl/opengl/gdiimpl.cxx
index 31813fb7a0af..13ba0c89bb82 100644
--- a/vcl/opengl/gdiimpl.cxx
+++ b/vcl/opengl/gdiimpl.cxx
@@ -39,12 +39,33 @@
 
 #include <stdlib.h>
 
+class OpenGLFlushIdle : public Idle
+{
+    OpenGLSalGraphicsImpl *m_pImpl;
+public:
+    OpenGLFlushIdle( OpenGLSalGraphicsImpl *pImpl )
+        : Idle( "gl idle swap" )
+        , m_pImpl( pImpl )
+    {
+        SetPriority( SchedulerPriority::HIGHEST );
+    }
+    ~OpenGLFlushIdle()
+    {
+    }
+    virtual void Invoke() override
+    {
+        m_pImpl->doFlush();
+        Stop();
+    }
+};
+
 OpenGLSalGraphicsImpl::OpenGLSalGraphicsImpl(SalGraphics& rParent, SalGeometryProvider *pProvider)
     : mpContext(nullptr)
     , mrParent(rParent)
     , mpProvider(pProvider)
     , mpFramebuffer(nullptr)
     , mpProgram(nullptr)
+    , mpFlush(new OpenGLFlushIdle(this))
     , mbUseScissor(false)
     , mbUseStencil(false)
     , mnLineColor(SALCOLOR_NONE)
@@ -61,13 +82,10 @@ OpenGLSalGraphicsImpl::OpenGLSalGraphicsImpl(SalGraphics& rParent, SalGeometryPr
 
 OpenGLSalGraphicsImpl::~OpenGLSalGraphicsImpl()
 {
-#ifdef DBG_UTIL
-    if( !IsOffscreen() )
-    {
-        // Check that all SalGraphics have flushed before being destroyed
-        assert( mnDrawCountAtFlush == mnDrawCount );
-    }
-#endif
+    if( !IsOffscreen() && mnDrawCountAtFlush != mnDrawCount )
+        VCL_GL_INFO( "Destroying un-flushed on-screen graphics" );
+
+    delete mpFlush;
 
     ReleaseContext();
 }
@@ -1942,6 +1960,20 @@ bool OpenGLSalGraphicsImpl::drawGradient(const tools::PolyPolygon& rPolyPoly,
 }
 
 void OpenGLSalGraphicsImpl::flush()
+{
+    if( IsOffscreen() )
+        return;
+
+    // outside of the application's event loop (e.g. IntroWindow)
+    // nothing would trigger paint event handling
+    // => fall back to synchronous painting
+    if( ImplGetSVData()->maAppData.mnDispatchLevel <= 0 )
+        doFlush();
+    else if( !mpFlush->IsActive() )
+        mpFlush->Start();
+}
+
+void OpenGLSalGraphicsImpl::doFlush()
 {
     if( IsOffscreen() )
         return;
-- 
cgit