vcl: Reduce OpenGLX11CairoTextRender surface area to size of text bounds

With this patch I get the text boundary and use it to reduce the size
of the surface to this area. However, this is mainly needed for
OpenGLX11CairoTextRender, which creates a surface image and uses this
for OpenGL rendering.

Change-Id: Icffc19bed89aaa2ff84ae845d274258a6fca27da

5 files changed, 53 insertions, 10 deletions

diff --git a/vcl/unx/generic/gdi/cairotextrender.cxx b/vcl/unx/generic/gdi/cairotextrender.cxx
index 7b0438ea49bf..1ad59365e0af 100644
--- a/vcl/unx/generic/gdi/cairotextrender.cxx
+++ b/vcl/unx/generic/gdi/cairotextrender.cxx
@@ -204,7 +204,7 @@ void CairoTextRender::DrawServerFontLayout( const ServerFontLayout& rLayout )
     if (cairo_glyphs.empty())
         return;
 
-    cairo_surface_t *surface = getCairoSurface();
+    cairo_surface_t *surface = getCairoSurface( rLayout );
 
     DBG_ASSERT( surface!=NULL, "no cairo surface for text" );
     if( !surface )
diff --git a/vcl/unx/generic/gdi/openglx11cairotextrender.cxx b/vcl/unx/generic/gdi/openglx11cairotextrender.cxx
index 64bf196ef54c..67024bf0f561 100644
--- a/vcl/unx/generic/gdi/openglx11cairotextrender.cxx
+++ b/vcl/unx/generic/gdi/openglx11cairotextrender.cxx
@@ -20,23 +20,64 @@ OpenGLX11CairoTextRender::OpenGLX11CairoTextRender(bool bPrinter, X11SalGraphics
 {
 }
 
-cairo_surface_t* OpenGLX11CairoTextRender::getCairoSurface()
+cairo_surface_t* OpenGLX11CairoTextRender::getCairoSurface( const ServerFontLayout& rLayout )
 {
     // static size_t id = 0;
     // OString aFileName = OString("/tmp/libo_logs/text_rendering") + OString::number(id++) + OString(".svg");
     // cairo_surface_t* surface = cairo_svg_surface_create(aFileName.getStr(), GetWidth(), GetHeight());
     cairo_surface_t* surface = NULL;
+    Rectangle aTextBoundRect;
     OpenGLSalGraphicsImpl *pImpl = dynamic_cast< OpenGLSalGraphicsImpl* >(mrParent.GetImpl());
-    if( pImpl )
+
+    if (pImpl)
     {
         Rectangle aClipRect = pImpl->getClipRegion().GetBoundRect();
-        if( aClipRect.GetWidth() == 0 || aClipRect.GetHeight() == 0 )
+
+        // no clipping area, we need to take the whole area
+        if ( aClipRect.IsEmpty() )
+        {
+            aClipRect.setWidth(GetWidth());
+            aClipRect.setHeight(GetHeight());
+        }
+
+        if (!rLayout.GetOrientation() )
+        {
+            // GetBoundRect can fail!
+            if ( rLayout.GetBoundRect(mrParent, aTextBoundRect) )
+            {
+                // we need to take into account SalLayout's drawing offset
+                int nOffsetX = rLayout.DrawOffset().X() - rLayout.DrawBase().X();
+                int nOffsetY = rLayout.DrawOffset().Y() - rLayout.DrawBase().Y();
+
+                aTextBoundRect.Left() += nOffsetX;
+                aTextBoundRect.Top() += nOffsetY;
+
+                aTextBoundRect = aTextBoundRect.Intersection(aClipRect);
+            }
+            else
+            {
+                SAL_WARN("vcl.layout", "GetBoundRect() failed");
+            }
+        }
+        else
         {
-            aClipRect.setWidth( GetWidth() );
-            aClipRect.setHeight( GetHeight() );
+            aTextBoundRect = aClipRect;
         }
-        surface = cairo_image_surface_create( CAIRO_FORMAT_ARGB32, aClipRect.GetWidth(), aClipRect.GetHeight() );
     }
+    else
+    {
+        SAL_WARN("vcl.opengl", "No OpenGLSalGraphicsImpl!");
+        return NULL;
+    }
+
+
+    double nDX=0, nDY=0;
+    getSurfaceOffset(nDX, nDY);
+
+    // add cairo surface offsets to work out surface width and height
+    surface = cairo_image_surface_create( CAIRO_FORMAT_ARGB32, aTextBoundRect.GetWidth() + nDX,
+                                                               aTextBoundRect.GetHeight() + nDY );
+
     return surface;
 }
 
diff --git a/vcl/unx/generic/gdi/openglx11cairotextrender.hxx b/vcl/unx/generic/gdi/openglx11cairotextrender.hxx
index 171949651635..4f8a0558a3eb 100644
--- a/vcl/unx/generic/gdi/openglx11cairotextrender.hxx
+++ b/vcl/unx/generic/gdi/openglx11cairotextrender.hxx
@@ -17,7 +17,7 @@ class OpenGLX11CairoTextRender : public X11CairoTextRender
 public:
     OpenGLX11CairoTextRender(bool bPrinter, X11SalGraphics& rParent);
 
-    virtual cairo_surface_t* getCairoSurface() SAL_OVERRIDE;
+    virtual cairo_surface_t* getCairoSurface( const ServerFontLayout& rLayout ) SAL_OVERRIDE;
     virtual void getSurfaceOffset(double& nDX, double& nDY) SAL_OVERRIDE;
     virtual void drawSurface(cairo_t* cr) SAL_OVERRIDE;
 };
diff --git a/vcl/unx/generic/gdi/x11cairotextrender.cxx b/vcl/unx/generic/gdi/x11cairotextrender.cxx
index f3aa47d07800..2519816298a0 100644
--- a/vcl/unx/generic/gdi/x11cairotextrender.cxx
+++ b/vcl/unx/generic/gdi/x11cairotextrender.cxx
@@ -53,7 +53,8 @@ GlyphCache& X11CairoTextRender::getPlatformGlyphCache()
     return X11GlyphCache::GetInstance();
 }
 
-cairo_surface_t* X11CairoTextRender::getCairoSurface()
+
+cairo_surface_t* X11CairoTextRender::getCairoSurface( const ServerFontLayout& )
 {
     // find a XRenderPictFormat compatible with the Drawable
     XRenderPictFormat* pVisualFormat = mrParent.GetXRenderFormat();
diff --git a/vcl/unx/generic/gdi/x11cairotextrender.hxx b/vcl/unx/generic/gdi/x11cairotextrender.hxx
index 1449b3aa0dc5..57c85696e0a6 100644
--- a/vcl/unx/generic/gdi/x11cairotextrender.hxx
+++ b/vcl/unx/generic/gdi/x11cairotextrender.hxx
@@ -21,6 +21,7 @@
 #define INCLUDED_VCL_UNX_GENERIC_GDI_X11CAIROTEXTRENDER_HXX value
 
 #include "cairotextrender.hxx"
+#include "generic/glyphcache.hxx"
 
 #include "unx/saldata.hxx"
 #include "unx/saldisp.hxx"
@@ -40,7 +41,7 @@ public:
     X11CairoTextRender(bool bPrinter, X11SalGraphics& rParent);
 
     virtual GlyphCache& getPlatformGlyphCache() SAL_OVERRIDE;
-    virtual cairo_surface_t* getCairoSurface() SAL_OVERRIDE;
+    virtual cairo_surface_t* getCairoSurface( const ServerFontLayout &rLayout ) SAL_OVERRIDE;
     virtual void getSurfaceOffset(double& nDX, double& nDY) SAL_OVERRIDE;
     virtual void clipRegion(cairo_t* cr) SAL_OVERRIDE;
     virtual void drawSurface(cairo_t* cr) SAL_OVERRIDE;