Added a layer compositor for the Cairo backend.

common/CMakeLists.txt

@@ -50,6 +50,7 @@ set(GAL_SRCS
 
     # Cairo GAL
     gal/cairo/cairo_gal.cpp
+    gal/cairo/cairo_compositor.cpp
     )
 
 add_library(gal STATIC ${GAL_SRCS})

common/gal/cairo/cairo_compositor.cpp

+/*i
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2013 CERN
+ * @author Maciej Suminski <maciej.suminski@cern.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http:O//www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/**
+ * @file cairo_compositor.cpp
+ * @brief Class that handles multitarget rendering (ie. to different textures/surfaces) and
+ * later compositing into a single image (Cairo flavour).
+ */
+
+#include <gal/cairo/cairo_compositor.h>
+#include <wx/log.h>
+
+using namespace KiGfx;
+
+CAIRO_COMPOSITOR::CAIRO_COMPOSITOR( cairo_t** aMainContext ) :
+     m_current( 0 ), m_currentContext( aMainContext ), m_mainContext( *aMainContext )
+{
+    // Obtain the transformation matrix used in the main context
+    cairo_get_matrix( m_mainContext, &m_matrix );
+}
+
+
+CAIRO_COMPOSITOR::~CAIRO_COMPOSITOR()
+{
+    clean();
+}
+
+
+void CAIRO_COMPOSITOR::Initialize()
+{
+    // Nothing has to be done
+}
+
+
+void CAIRO_COMPOSITOR::Resize( unsigned int aWidth, unsigned int aHeight )
+{
+    clean();
+
+    m_width  = aWidth;
+    m_height = aHeight;
+
+    m_stride     = cairo_format_stride_for_width( CAIRO_FORMAT_ARGB32, m_width );
+    m_bufferSize = m_stride * m_height;
+}
+
+
+unsigned int CAIRO_COMPOSITOR::GetBuffer()
+{
+    // Pixel storage
+    BitmapPtr bitmap( new unsigned int[m_bufferSize] );
+
+    // Create the Cairo surface
+    cairo_surface_t* surface = cairo_image_surface_create_for_data(
+                                                        (unsigned char*) bitmap.get(),
+                                                        CAIRO_FORMAT_ARGB32, m_width,
+                                                        m_height, m_stride );
+    cairo_t* context = cairo_create( surface );
+    #ifdef __WXDEBUG__
+        cairo_status_t status = cairo_status( context );
+        wxASSERT_MSG( status == CAIRO_STATUS_SUCCESS, "Cairo context creation error" );
+    #endif /* __WXDEBUG__ */
+
+    // Set default settings for the buffer
+    cairo_set_antialias( context, CAIRO_ANTIALIAS_SUBPIXEL );
+    cairo_set_line_join( context, CAIRO_LINE_JOIN_ROUND );
+    cairo_set_line_cap( context, CAIRO_LINE_CAP_ROUND );
+
+    // Use the same transformation matrix as the main context
+    cairo_set_matrix( context, &m_matrix );
+
+    // Store the new buffer
+    CAIRO_BUFFER buffer = { context, surface, bitmap };
+    m_buffers.push_back( buffer );
+
+    return usedBuffers();
+}
+
+
+void CAIRO_COMPOSITOR::SetBuffer( unsigned int aBufferHandle )
+{
+    if( aBufferHandle <= usedBuffers() )
+    {
+        m_current = aBufferHandle - 1;
+        *m_currentContext = m_buffers[m_current].context;
+    }
+#ifdef __WXDEBUG__
+    else
+        wxLogDebug( wxT( "Tried to use a not existing buffer" ) );
+#endif
+}
+
+
+void CAIRO_COMPOSITOR::ClearBuffer()
+{
+    // Reset the transformation matrix, so it is possible to composite images using
+    // screen coordinates instead of world coordinates
+    cairo_identity_matrix( m_buffers[m_current].context );
+
+    cairo_set_source_rgba( m_buffers[m_current].context, 0.0, 0.0, 0.0, 0.0 );
+    cairo_rectangle( m_buffers[m_current].context, 0.0, 0.0, m_width, m_height );
+    cairo_fill( m_buffers[m_current].context );
+
+    // Restore the transformation matrix
+    cairo_set_matrix( m_buffers[m_current].context, &m_matrix );
+}
+
+
+void CAIRO_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle )
+{
+    if( aBufferHandle <= usedBuffers() )
+    {
+        // Reset the transformation matrix, so it is possible to composite images using
+        // screen coordinates instead of world coordinates
+        cairo_identity_matrix( m_mainContext );
+
+        cairo_set_source_surface( m_mainContext, m_buffers[aBufferHandle - 1].surface, 0.0, 0.0 );
+        cairo_paint( m_mainContext );
+
+        // Restore the transformation matrix
+        cairo_set_matrix( m_mainContext, &m_matrix );
+    }
+#ifdef __WXDEBUG__
+    else
+        wxLogDebug( wxT( "Tried to use a not existing buffer" ) );
+#endif
+}
+
+
+void CAIRO_COMPOSITOR::clean()
+{
+    CAIRO_BUFFERS::const_iterator it;
+
+    for( it = m_buffers.begin(); it != m_buffers.end(); ++it )
+    {
+        cairo_destroy( it->context );
+        cairo_surface_destroy( it->surface );
+    }
+
+    m_buffers.clear();
+}

include/gal/cairo/cairo_compositor.h

+/*
+ * This program source code file is part of KiCad, a free EDA CAD application.
+ *
+ * Copyright (C) 2013 CERN
+ * @author Maciej Suminski <maciej.suminski@cern.ch>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, you may find one here:
+ * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
+ * or you may search the http://www.gnu.org website for the version 2 license,
+ * or you may write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
+ */
+
+/**
+ * @file cairo_compositor.h
+ * @brief Class that handles multitarget rendering (ie. to different textures/surfaces) and
+ * later compositing into a single image (Cairo flavour).
+ */
+
+#ifndef CAIRO_COMPOSITOR_H_
+#define CAIRO_COMPOSITOR_H_
+
+#include <gal/compositor.h>
+#include <cairo.h>
+#include <boost/smart_ptr/shared_array.hpp>
+#include <deque>
+
+namespace KiGfx
+{
+
+class CAIRO_COMPOSITOR : public COMPOSITOR
+{
+public:
+    CAIRO_COMPOSITOR( cairo_t** aMainContext );
+    virtual ~CAIRO_COMPOSITOR();
+
+    /// @copydoc COMPOSITOR::Initialize()
+    virtual void Initialize();
+
+    /// @copydoc COMPOSITOR::Resize()
+    virtual void Resize( unsigned int aWidth, unsigned int aHeight );
+
+    /// @copydoc COMPOSITOR::GetBuffer()
+    virtual unsigned int GetBuffer();
+
+    /// @copydoc COMPOSITOR::SetBuffer()
+    virtual void SetBuffer( unsigned int aBufferHandle );
+
+    /// @copydoc COMPOSITOR::ClearBuffer()
+    virtual void ClearBuffer();
+
+    /// @copydoc COMPOSITOR::DrawBuffer()
+    virtual void DrawBuffer( unsigned int aBufferHandle );
+
+protected:
+    typedef boost::shared_array<unsigned int> BitmapPtr;
+    typedef struct
+    {
+        cairo_t* context;                   ///< Main texture handle
+        cairo_surface_t* surface;           ///< Point to which an image from texture is attached
+        BitmapPtr bitmap;                   ///< Pixel storage
+    } CAIRO_BUFFER;
+
+    unsigned int                m_current;                ///< Currently used buffer handle
+    typedef std::deque<CAIRO_BUFFER> CAIRO_BUFFERS;
+
+    /// Pointer to the current context, so it can be changed
+    cairo_t**                   m_currentContext;
+
+    /// Rendering target used for compositing (the main display)
+    cairo_t*                    m_mainContext;
+
+    /// Transformation matrix
+    cairo_matrix_t              m_matrix;
+
+    /// Stores information about initialized buffers
+    CAIRO_BUFFERS               m_buffers;
+
+    unsigned int m_stride;              ///< Stride to use given the desired format and width
+    unsigned int m_bufferSize;          ///< Amount of memory needed to store a buffer
+
+    /**
+     * Function clean()
+     * performs freeing of resources.
+     */
+    void clean();
+
+    /// Returns number of currently used buffers
+    unsigned int usedBuffers()
+    {
+        return m_buffers.size();
+    }
+};
+
+} // namespace KiGfx
+
+#endif /* COMPOSITOR_H_ */

include/gal/cairo/cairo_gal.h

@@ -33,7 +33,7 @@
 #include <cairo.h>
 
 #include <gal/graphics_abstraction_layer.h>
-
+#include <boost/smart_ptr/shared_ptr.hpp>
 
 #if defined(__WXMSW__)
 #define SCREEN_DEPTH 24
@@ -62,6 +62,8 @@
  */
 namespace KiGfx
 {
+class CAIRO_COMPOSITOR;
+
 class CAIRO_GAL : public GAL, public wxWindow
 {
 public:
@@ -81,7 +83,7 @@ public:
      * @param aName is the name of this window for use by wxWindow::FindWindowByName()
      */
     CAIRO_GAL( wxWindow* aParent, wxEvtHandler* aMouseListener = NULL,
-               wxEvtHandler* aPaintListener = NULL, const wxString& aName = wxT("CairoCanvas") );
+               wxEvtHandler* aPaintListener = NULL, const wxString& aName = wxT( "CairoCanvas" ) );
 
     virtual ~CAIRO_GAL();
 
@@ -299,11 +301,15 @@ private:
     /// Super class definition
     typedef GAL super;
 
+    // Compositing variables
+    boost::shared_ptr<CAIRO_COMPOSITOR> compositor; ///< Object for layers compositing
+    unsigned int mainBuffer;                        ///< Handle to the main buffer
+    unsigned int overlayBuffer;                     ///< Handle to the overlay buffer
+
     // Variables related to wxWidgets
     wxWindow*                   parentWindow;       ///< Parent window
     wxEvtHandler*               mouseListener;      ///< Mouse listener
     wxEvtHandler*               paintListener;      ///< Paint listener
-    wxRect                      clientRectangle;    ///< Area definition of the surface
     unsigned int                bufferSize;         ///< Size of buffers cairoOutput, bitmapBuffers
     unsigned char*              wxOutput;           ///< wxImage comaptible buffer
 
@@ -315,11 +321,6 @@ private:
     wxBitmap*                   cursorPixelsSaved;      ///< Saved cursor pixels
     int                         cursorSize;             ///< Cursor size
 
-    // Variables for the grouping function
-    int                         actualGroupIndex;   ///< The index of the actual group
-    bool                        isGrouping;         ///< Is grouping enabled ?
-    bool                        isElementAdded;     ///< Was an graphic element added ?
-
     /// Maximum number of arguments for one command
     static const int MAX_CAIRO_ARGUMENTS = 6;
 
@@ -352,15 +353,19 @@ private:
         cairo_path_t* cairoPath;                    ///< Pointer to a Cairo path
     } GroupElement;
 
+    // Variables for the grouping function
+    bool                        isGrouping;         ///< Is grouping enabled ?
+    bool                        isElementAdded;     ///< Was an graphic element added ?
     typedef std::deque<GroupElement> Group;         ///< A graphic group type definition
-    std::map<int, Group> groups;                    ///< List of graphic groups
-    unsigned int groupCounter;                      ///< Counter used for generating keys for groups
-    Group* currentGroup;                            ///< Currently used group
+    std::map<int, Group>        groups;             ///< List of graphic groups
+    unsigned int                groupCounter;       ///< Counter used for generating keys for groups
+    Group*                      currentGroup;       ///< Currently used group
 
     // Variables related to Cairo <-> wxWidgets
     cairo_matrix_t      cairoWorldScreenMatrix; ///< Cairo world to screen transformation matrix
-    cairo_t*            cairoImage;             ///< Cairo image
-    cairo_surface_t*    cairoSurface;           ///< Cairo surface
+    cairo_t*            currentContext;         ///< Currently used Cairo context for drawing
+    cairo_t*            context;                ///< Cairo image
+    cairo_surface_t*    surface;                ///< Cairo surface
     unsigned int*       bitmapBuffer;           ///< Storage of the cairo image
     unsigned int*       bitmapBufferBackup;     ///< Backup storage of the cairo image
     int                 stride;                 ///< Stride value for Cairo
@@ -400,15 +405,21 @@ private:
     /// Prepare Cairo surfaces for drawing
     void initSurface();
 
-    // Destroy Cairo surfaces when are not needed anymore
+    /// Destroy Cairo surfaces when are not needed anymore
     void deinitSurface();
 
+    /// Prepare the compositor
+    void setCompositor();
+
     /**
      * @brief Returns a valid key that can be used as a new group number.
      *
      * @return An unique group number that is not used by any other group.
      */
     unsigned int getNewGroupNumber();
+
+    /// Format used to store pixels
+    static const cairo_format_t GAL_FORMAT = CAIRO_FORMAT_RGB24;
 };
 } // namespace KiGfx