vcl: Use a different FBO when rendering using a VirtualDevice

Change-Id: I8cb97a4057c06ca09adfcac8dcd3f61ac9508430

7 files changed, 75 insertions, 7 deletions

diff --git a/vcl/inc/opengl/salbmp.hxx b/vcl/inc/opengl/salbmp.hxx
index 6f7a03af09d4..77ac90bbbc55 100644
--- a/vcl/inc/opengl/salbmp.hxx
+++ b/vcl/inc/opengl/salbmp.hxx
@@ -81,7 +81,7 @@ public:
 
 public:
 
-    bool            Create( OpenGLContext& rContext, long nX, long nY, long nWidth, long nHeight );
+    bool            Create( OpenGLContext& rContext, OpenGLTextureSharedPtr pTex, long nX, long nY, long nWidth, long nHeight );
     bool            Draw( OpenGLContext& rContext, const SalTwoRect& rPosAry );
     GLuint          GetTexture( OpenGLContext& rContext ) const;
 
diff --git a/vcl/inc/opengl/texture.hxx b/vcl/inc/opengl/texture.hxx
index f9d3ad864291..c0b6541d7700 100644
--- a/vcl/inc/opengl/texture.hxx
+++ b/vcl/inc/opengl/texture.hxx
@@ -39,6 +39,9 @@ public:
     virtual ~OpenGLTexture();
 
     GLuint Id() const;
+    int GetWidth() const;
+    int GetHeight() const;
+
     void Bind();
     void Unbind();
     bool Draw();
diff --git a/vcl/inc/openglgdiimpl.hxx b/vcl/inc/openglgdiimpl.hxx
index 9dfa231a7e1b..e9be6653dca0 100644
--- a/vcl/inc/openglgdiimpl.hxx
+++ b/vcl/inc/openglgdiimpl.hxx
@@ -23,6 +23,8 @@
 #include "salgdiimpl.hxx"
 #include <vcl/dllapi.h>
 
+#include "opengl/texture.hxx"
+
 #include <vcl/opengl/OpenGLContext.hxx>
 
 class SalFrame;
@@ -36,6 +38,10 @@ protected:
     SalFrame* mpFrame;
     SalVirtualDevice* mpVDev;
 
+    bool mbOffscreen;
+    GLuint mnFramebufferId;
+    OpenGLTextureSharedPtr mpOffscreenTex;
+
     SalColor mnLineColor;
     SalColor mnFillColor;
 
@@ -90,6 +96,9 @@ protected:
     // operations to do after painting
     virtual void PostDraw();
 
+    // enable/disable offscreen rendering
+    virtual void SetOffscreen( bool bOffscreen );
+
 
 public:
     OpenGLSalGraphicsImpl();
diff --git a/vcl/opengl/gdiimpl.cxx b/vcl/opengl/gdiimpl.cxx
index 6af704eb3c2a..94cba660e413 100644
--- a/vcl/opengl/gdiimpl.cxx
+++ b/vcl/opengl/gdiimpl.cxx
@@ -75,16 +75,21 @@ OpenGLSalGraphicsImpl::~OpenGLSalGraphicsImpl()
 void OpenGLSalGraphicsImpl::PreDraw()
 {
     maContext.makeCurrent();
+    // TODO: lfrb: make sure the render target has the right size
+    if( mbOffscreen )
+        glBindFramebuffer( GL_FRAMEBUFFER, mnFramebufferId );
     glViewport( 0, 0, GetWidth(), GetHeight() );
 }
 
 void OpenGLSalGraphicsImpl::PostDraw()
 {
+    if( mbOffscreen )
+        glBindFramebuffer( GL_FRAMEBUFFER, 0 );
 }
 
 void OpenGLSalGraphicsImpl::freeResources()
 {
-    // Delete shaders, programs and textures if not shared
+    // TODO Delete shaders, programs and textures if not shared
 }
 
 bool OpenGLSalGraphicsImpl::setClipRegion( const vcl::Region& rClip )
@@ -187,6 +192,38 @@ void OpenGLSalGraphicsImpl::SetROPFillColor( SalROPColor /*nROPColor*/ )
 {
 }
 
+// enable/disbale offscreen rendering
+void OpenGLSalGraphicsImpl::SetOffscreen( bool bOffscreen )
+{
+    if( bOffscreen == mbOffscreen )
+    {
+        // Already disabled
+        if( !mbOffscreen )
+            return;
+
+        // Already enabled and same size
+        if( mpOffscreenTex->GetWidth()  == GetWidth() &&
+            mpOffscreenTex->GetHeight() == GetHeight() )
+            return;
+    }
+    else
+    {
+        mbOffscreen = bOffscreen;
+        if( bOffscreen )
+            glGenFramebuffers( 1, &mnFramebufferId );
+        else
+            glDeleteFramebuffers( 1, &mnFramebufferId );
+    }
+
+    if( mbOffscreen )
+    {
+        glBindFramebuffer( GL_FRAMEBUFFER, mnFramebufferId );
+        mpOffscreenTex.reset( new OpenGLTexture( GetWidth(), GetHeight() ) );
+        glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, mpOffscreenTex->Id(), 0 );
+        CHECK_GL_ERROR();
+    }
+}
+
 bool OpenGLSalGraphicsImpl::CreateSolidProgram( void )
 {
     SAL_INFO( "vcl.opengl", "::CreateSolidProgram" );
@@ -879,7 +916,7 @@ SalBitmap* OpenGLSalGraphicsImpl::getBitmap( long nX, long nY, long nWidth, long
     SAL_INFO( "vcl.opengl", "::getBitmap " << nX << "," << nY <<
               " " << nWidth << "x" << nHeight );
     PreDraw();
-    if( !pBitmap->Create( maContext, nX, nY, nWidth, nHeight ) )
+    if( !pBitmap->Create( maContext, mpOffscreenTex, nX, nY, nWidth, nHeight ) )
     {
         delete pBitmap;
         pBitmap = NULL;
diff --git a/vcl/opengl/salbmp.cxx b/vcl/opengl/salbmp.cxx
index d54ace76021f..5a93aaa8b094 100644
--- a/vcl/opengl/salbmp.cxx
+++ b/vcl/opengl/salbmp.cxx
@@ -52,7 +52,7 @@ OpenGLSalBitmap::~OpenGLSalBitmap()
     SAL_INFO( "vcl.opengl", "~OpenGLSalBitmap" );
 }
 
-bool OpenGLSalBitmap::Create( OpenGLContext& rContext, long nX, long nY, long nWidth, long nHeight )
+bool OpenGLSalBitmap::Create( OpenGLContext& rContext, OpenGLTextureSharedPtr pTex, long nX, long nY, long nWidth, long nHeight )
 {
     static const BitmapPalette aEmptyPalette;
 
@@ -60,7 +60,6 @@ bool OpenGLSalBitmap::Create( OpenGLContext& rContext, long nX, long nY, long nW
     SAL_INFO( "vcl.opengl", "OpenGLSalBitmap::Create from FBO" );
 
     mpContext = &rContext;
-    mpContext->makeCurrent();
     mnWidth = nWidth;
     mnHeight = nHeight;
     mnBufWidth = 0;
@@ -70,8 +69,13 @@ bool OpenGLSalBitmap::Create( OpenGLContext& rContext, long nX, long nY, long nW
     mnBits = 32;
     maPalette = aEmptyPalette;
 
-    mpTexture.reset( new OpenGLTexture( nX, nY, nWidth, nHeight ) );
+    // TODO: lfrb: Crop texture if size doesn't match the texture one
+    if( pTex )
+        mpTexture = pTex;
+    else
+        mpTexture.reset( new OpenGLTexture( nX, nY, nWidth, nHeight ) );
     mbDirtyTexture = false;
+    SAL_INFO( "vcl.opengl", "Created texture " << mpTexture->Id() );
 
     return true;
 }
@@ -154,6 +158,7 @@ GLuint OpenGLSalBitmap::GetTexture( OpenGLContext& rContext ) const
         const_cast<OpenGLSalBitmap*>(this)->mpContext = &rContext;
     if( !mpTexture || mbDirtyTexture )
         const_cast<OpenGLSalBitmap*>(this)->CreateTexture();
+    SAL_INFO( "vcl.opengl", "Got texture " << mpTexture->Id() );
     return mpTexture->Id();
 }
 
@@ -388,9 +393,9 @@ GLuint OpenGLSalBitmap::CreateTexture()
         }
     }
 
-    SAL_INFO( "vcl.opengl", "::CreateTexture" );
     mpContext->makeCurrent();
     mpTexture.reset( new OpenGLTexture (mnBufWidth, mnBufHeight, nFormat, nType, pData ) );
+    SAL_INFO( "vcl.opengl", "Created texture " << mpTexture->Id() );
 
     if( bAllocated )
         delete pData;
@@ -412,6 +417,8 @@ bool OpenGLSalBitmap::ReadTexture()
     GLuint nFramebufferId, nRenderbufferDepthId, nRenderbufferColorId;
     sal_uInt8* pData = maUserBuffer.get();
 
+    SAL_INFO( "vcl.opengl", "::ReadTexture" );
+
     // TODO Check mnTexWidth and mnTexHeight
 
     mpContext->makeCurrent();
diff --git a/vcl/opengl/texture.cxx b/vcl/opengl/texture.cxx
index 2770c20a5519..0c8dc1d69b8e 100644
--- a/vcl/opengl/texture.cxx
+++ b/vcl/opengl/texture.cxx
@@ -95,6 +95,16 @@ GLuint OpenGLTexture::Id() const
     return mnTexture;
 }
 
+int OpenGLTexture::GetWidth() const
+{
+    return mnWidth;
+}
+
+int OpenGLTexture::GetHeight() const
+{
+    return mnHeight;
+}
+
 GLenum OpenGLTexture::GetFilter() const
 {
     return mnFilter;
diff --git a/vcl/opengl/x11/gdiimpl.cxx b/vcl/opengl/x11/gdiimpl.cxx
index 353ec7649f39..6e803bd21acd 100644
--- a/vcl/opengl/x11/gdiimpl.cxx
+++ b/vcl/opengl/x11/gdiimpl.cxx
@@ -64,12 +64,14 @@ void X11OpenGLSalGraphicsImpl::Init()
     {
         Window aWin = dynamic_cast<X11WindowProvider*>(mrParent.m_pFrame)->GetX11Window();
         maContext.init( mrParent.GetXDisplay(), aWin, mrParent.m_nXScreen.getXScreen());
+        SetOffscreen( false );
     }
     else if( mrParent.m_pVDev )
     {
         maContext.init( mrParent.GetXDisplay(), mrParent.m_pVDev->GetDrawable(),
                         mrParent.m_pVDev->GetWidth(), mrParent.m_pVDev->GetHeight(),
                         mrParent.m_nXScreen.getXScreen() );
+        SetOffscreen( true );
     }
     else
     {