OpenGL multitarget rendering (compositing).

common/CMakeLists.txt

@@ -29,11 +29,15 @@ add_custom_target(
 )
 
 set(GAL_SRCS
+    # Common part
     drawpanel_gal.cpp
     painter.cpp
     gal/graphics_abstraction_layer.cpp
     gal/stroke_font.cpp
     gal/color4d.cpp
+    view/wx_view_controls.cpp
+
+    # OpenGL GAL
     gal/opengl/opengl_gal.cpp
     gal/opengl/shader.cpp
     gal/opengl/vertex_item.cpp
@@ -42,8 +46,10 @@ set(GAL_SRCS
     gal/opengl/noncached_container.cpp
     gal/opengl/vertex_manager.cpp
     gal/opengl/gpu_manager.cpp
+    gal/opengl/opengl_compositor.cpp
+
+    # Cairo GAL
     gal/cairo/cairo_gal.cpp
-    view/wx_view_controls.cpp
     )
 
 add_library(gal STATIC ${GAL_SRCS})

common/gal/cairo/cairo_gal.cpp

@@ -280,6 +280,12 @@ void CAIRO_GAL::RestoreScreen()
 }
 
 
+void CAIRO_GAL::SetTarget( RenderTarget aTarget )
+{
+    wxASSERT_MSG( false, wxT( "Not implemented yet" ) );
+}
+
+
 void CAIRO_GAL::DrawLine( const VECTOR2D& aStartPoint, const VECTOR2D& aEndPoint )
 {
     cairo_move_to( cairoImage, aStartPoint.x, aStartPoint.y );

common/gal/graphics_abstraction_layer.cpp

@@ -62,6 +62,8 @@ void GAL::DrawGrid()
     if( !gridVisibility )
         return;
 
+    SetTarget( TARGET_NONCACHED );
+
     // The grid consists of lines
     // For the drawing the start points, end points and increments have to be calculated in world coordinates
     VECTOR2D    screenStartPoint( 0, 0 );

common/gal/opengl/gpu_manager.cpp

@@ -77,9 +77,11 @@ void GPU_MANAGER::SetShader( SHADER& aShader )
 
 // Cached manager
 GPU_CACHED_MANAGER::GPU_CACHED_MANAGER( VERTEX_CONTAINER* aContainer ) :
-    GPU_MANAGER( aContainer ), m_buffersInitialized( false ), m_indicesPtr( NULL ),
+    GPU_MANAGER( aContainer ), m_buffersInitialized( false ),
     m_indicesSize( 0 )
 {
+    // Allocate the biggest possible buffer for indices
+    m_indices.reset( new GLuint[aContainer->GetSize()] );
 }
 
 
@@ -252,7 +254,6 @@ void GPU_NONCACHED_MANAGER::EndDrawing()
     VERTEX*  vertices       = m_container->GetAllVertices();
     GLfloat* coordinates    = (GLfloat*) ( vertices );
     GLubyte* colors         = (GLubyte*) ( vertices ) + ColorOffset;
-    GLfloat* shaders        = (GLfloat*) ( vertices ) + ShaderOffset / sizeof(GLfloat);
 
     // Prepare buffers
     glEnableClientState( GL_VERTEX_ARRAY );
@@ -263,6 +264,8 @@ void GPU_NONCACHED_MANAGER::EndDrawing()
 
     if( m_shader != NULL )    // Use shader if applicable
     {
+        GLfloat* shaders = (GLfloat*) ( vertices ) + ShaderOffset / sizeof(GLfloat);
+
         m_shader->Use();
         glEnableVertexAttribArray( m_shaderAttrib );
         glVertexAttribPointer( m_shaderAttrib, ShaderStride, GL_FLOAT, GL_FALSE,

common/gal/opengl/opengl_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 opengl_compositor.cpp
+ * @brief Class that handles multitarget rendering (ie. to different textures/surfaces) and
+ * later compositing into a single image (OpenGL flavour).
+ */
+
+#include <gal/opengl/opengl_compositor.h>
+#include <wx/log.h>
+
+using namespace KiGfx;
+
+OPENGL_COMPOSITOR::OPENGL_COMPOSITOR() :
+    m_initialized( false ), m_current( 0 )
+{
+}
+
+
+OPENGL_COMPOSITOR::~OPENGL_COMPOSITOR()
+{
+    if( m_initialized )
+        clean();
+}
+
+
+void OPENGL_COMPOSITOR::Initialize()
+{
+    if( m_initialized )
+        return;
+
+    // Get the maximum number of buffers
+    glGetIntegerv( GL_MAX_COLOR_ATTACHMENTS, (GLint*) &m_maxBuffers );
+
+    // We need framebuffer objects for drawing the screen contents
+    // Generate framebuffer and a depth buffer
+    glGenFramebuffers( 1, &m_framebuffer );
+    glBindFramebuffer( GL_FRAMEBUFFER, m_framebuffer );
+    m_currentFbo = m_framebuffer;
+
+    // Allocate memory for the depth buffer
+    // Attach the depth buffer to the framebuffer
+    glGenRenderbuffers( 1, &m_depthBuffer );
+    glBindRenderbuffer( GL_RENDERBUFFER, m_depthBuffer );
+
+    // Use here a size of 24 bits for the depth buffer, 8 bits for the stencil buffer
+    // this is required later for anti-aliasing
+    glRenderbufferStorage( GL_RENDERBUFFER, GL_DEPTH_STENCIL, m_width, m_height );
+    glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+                               GL_RENDERBUFFER, m_depthBuffer );
+    glFramebufferRenderbuffer( GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT,
+                               GL_RENDERBUFFER, m_depthBuffer );
+
+    // Check the status, exit if the framebuffer can't be created
+    GLenum status = glCheckFramebufferStatus( GL_FRAMEBUFFER );
+
+    if( status != GL_FRAMEBUFFER_COMPLETE )
+    {
+        wxLogFatalError( wxT( "Cannot create the framebuffer." ) );
+    }
+
+    // Unbind the framebuffer, so by default all the rendering goes directly to the display
+    glBindFramebuffer( GL_FRAMEBUFFER, 0 );
+    m_currentFbo = 0;
+
+    m_initialized = true;
+}
+
+
+void OPENGL_COMPOSITOR::Resize( unsigned int aWidth, unsigned int aHeight )
+{
+    if( m_initialized )
+        clean();
+
+    m_width  = aWidth;
+    m_height = aHeight;
+}
+
+
+unsigned int OPENGL_COMPOSITOR::GetBuffer()
+{
+    wxASSERT( m_initialized );
+
+    if( m_buffers.size() < m_maxBuffers )
+    {
+        // GL_COLOR_ATTACHMENTn are consecutive integers
+        GLuint attachmentPoint = GL_COLOR_ATTACHMENT0 + usedBuffers();
+        GLuint textureTarget;
+
+        // Generate the texture for the pixel storage
+        glGenTextures( 1, &textureTarget );
+        glBindTexture( GL_TEXTURE_2D, textureTarget );
+
+        // Set texture parameters
+        glTexImage2D( GL_TEXTURE_2D, 0, GL_RGBA, m_width, m_height, 0, GL_RGBA,
+                      GL_UNSIGNED_BYTE, NULL );
+        glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
+        glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
+
+        // Bind the texture to the specific attachment point, clear and rebind the screen
+        glBindFramebuffer( GL_FRAMEBUFFER, m_framebuffer );
+        m_currentFbo = m_framebuffer;
+        glFramebufferTexture2D( GL_FRAMEBUFFER, attachmentPoint, GL_TEXTURE_2D, textureTarget, 0 );
+        ClearBuffer();
+        glBindFramebuffer( GL_FRAMEBUFFER, 0 );
+        m_currentFbo = 0;
+
+        // Store the new buffer
+        BUFFER_ITEM buffer = { textureTarget, attachmentPoint };
+        m_buffers.push_back( buffer );
+
+        return usedBuffers();
+    }
+
+    // Unfortunately we have no more buffers left
+    return 0;
+}
+
+
+void OPENGL_COMPOSITOR::SetBuffer( unsigned int aBufferHandle )
+{
+    if( aBufferHandle <= usedBuffers() )
+    {
+        // Change the rendering destination to the selected attachment point
+        if( m_currentFbo != m_framebuffer )
+        {
+            glBindFramebuffer( GL_FRAMEBUFFER, m_framebuffer );
+            m_currentFbo = m_framebuffer;
+        }
+
+        if( m_current != aBufferHandle - 1 )
+        {
+            glDrawBuffer( m_buffers[m_current].attachmentPoint );
+            m_current = aBufferHandle - 1;
+        }
+    }
+}
+
+
+void OPENGL_COMPOSITOR::ClearBuffer()
+{
+    wxASSERT( m_initialized );
+
+    glClearColor( 0.0f, 0.0f, 0.0f, 0.0f );
+    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+}
+
+
+void OPENGL_COMPOSITOR::BlitBuffer( unsigned int aBufferHandle )
+{
+    wxASSERT( m_initialized );
+
+    wxASSERT_MSG( false, wxT( "Not implemented yet" ) );
+}
+
+
+void OPENGL_COMPOSITOR::DrawBuffer( unsigned int aBufferHandle, double aDepth )
+{
+    wxASSERT( m_initialized );
+
+    // Switch to the main framebuffer and blit the scene
+    glBindFramebuffer( GL_FRAMEBUFFER, 0 );
+    m_currentFbo = 0;
+
+    // Depth test has to be disabled to make transparency working
+    glDisable( GL_DEPTH_TEST );
+    glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA );
+
+    // Enable texturing and bind the main texture
+    glEnable( GL_TEXTURE_2D );
+    glBindTexture( GL_TEXTURE_2D, m_buffers[aBufferHandle - 1].textureTarget );
+
+    // Draw a full screen quad with the texture
+    glMatrixMode( GL_MODELVIEW );
+    glPushMatrix();
+    glLoadIdentity();
+    glMatrixMode( GL_PROJECTION );
+    glPushMatrix();
+    glLoadIdentity();
+
+    glBegin( GL_TRIANGLES );
+    glTexCoord2f( 0.0f,  1.0f );
+    glVertex3f(  -1.0f, -1.0f, aDepth );
+    glTexCoord2f( 1.0f,  1.0f );
+    glVertex3f(   1.0f, -1.0f, aDepth );
+    glTexCoord2f( 1.0f,  0.0f );
+    glVertex3f(   1.0f,  1.0f, aDepth );
+
+    glTexCoord2f( 0.0f,  1.0f );
+    glVertex3f(  -1.0f, -1.0f, aDepth );
+    glTexCoord2f( 1.0f,  0.0f );
+    glVertex3f(   1.0f,  1.0f, aDepth );
+    glTexCoord2f( 0.0f,  0.0f );
+    glVertex3f(  -1.0f,  1.0f, aDepth );
+    glEnd();
+
+    glPopMatrix();
+    glMatrixMode( GL_MODELVIEW );
+    glPopMatrix();
+}
+
+
+void OPENGL_COMPOSITOR::clean()
+{
+    wxASSERT( m_initialized );
+
+    glDeleteFramebuffers( 1, &m_framebuffer );
+    glDeleteRenderbuffers( 1, &m_depthBuffer );
+
+    Buffers::const_iterator it;
+    for( it = m_buffers.begin(); it != m_buffers.end(); ++it )
+    {
+        glDeleteTextures( 1, &it->textureTarget );
+    }
+    m_buffers.clear();
+
+    m_initialized = false;
+}
+
+GLuint OPENGL_COMPOSITOR::m_currentFbo = 0;

common/view/view.cpp

@@ -48,9 +48,9 @@ void VIEW::AddLayer( int aLayer, bool aDisplayOnly )
         m_layers[aLayer].items          = new VIEW_RTREE();
         m_layers[aLayer].renderingOrder = aLayer;
         m_layers[aLayer].enabled        = true;
-        m_layers[aLayer].cached         = true;
         m_layers[aLayer].isDirty        = false;
         m_layers[aLayer].displayOnly    = aDisplayOnly;
+        m_layers[aLayer].target         = TARGET_CACHED;
     }
 
     sortLayers();
@@ -136,7 +136,7 @@ int VIEW::Query( const BOX2I& aRect, std::vector<LayerItemPair>& aResult )
 
 VIEW::VIEW( bool aIsDynamic ) :
     m_enableOrderModifier( false ),
-    m_scale ( 1.0 ),
+    m_scale( 1.0 ),
     m_painter( NULL ),
     m_gal( NULL ),
     m_dynamic( aIsDynamic )
@@ -321,7 +321,7 @@ struct VIEW::updateItemsColor
 void VIEW::UpdateLayerColor( int aLayer )
 {
     // There is no point in updating non-cached layers
-    if( !m_layers[aLayer].cached )
+    if( m_layers[aLayer].target != TARGET_CACHED )
         return;
 
     BOX2I r;
@@ -344,7 +344,7 @@ void VIEW::UpdateAllLayersColor()
         VIEW_LAYER* l = &( ( *i ).second );
 
         // There is no point in updating non-cached layers
-        if( !m_layers[l->id].cached )
+        if( l->target != TARGET_CACHED )
             continue;
 
         updateItemsColor visitor( l->id, m_painter, m_gal );
@@ -376,7 +376,7 @@ struct VIEW::changeItemsDepth
 void VIEW::ChangeLayerDepth( int aLayer, int aDepth )
 {
     // There is no point in updating non-cached layers
-    if( !m_layers[aLayer].cached )
+    if( m_layers[aLayer].target != TARGET_CACHED )
         return;
 
     BOX2I r;
@@ -483,7 +483,7 @@ struct VIEW::drawItem
         if( !drawCondition )
             return;
 
-        if( currentLayer->cached )
+        if( currentLayer->target == TARGET_CACHED )
         {
             // Draw using cached information or create one
             int group = aItem->getGroup( currentLayer->id );
@@ -521,6 +521,7 @@ void VIEW::redrawRect( const BOX2I& aRect )
         {
             drawItem drawFunc( this, l );
 
+            m_gal->SetTarget( l->target );
             m_gal->SetLayerDepth( l->renderingOrder );
             l->items->Query( aRect, drawFunc );
             l->isDirty = false;
@@ -709,8 +710,10 @@ void VIEW::RecacheAllItems( bool aImmediately )
     {
         VIEW_LAYER* l = & ( ( *i ).second );
 
-        if( l->cached )
+        // Obviously, there is only one cached target that has to be recomputed
+        if( l->target == TARGET_CACHED )
         {
+            m_gal->SetTarget( l->target );
             m_gal->SetLayerDepth( l->renderingOrder );
             recacheLayer visitor( this, m_gal, l->id, aImmediately );
             l->items->Query( r, visitor );

include/gal/cairo/cairo_gal.h

@@ -252,6 +252,9 @@ public:
     /// @copydoc GAL::RestoreScreen()
     virtual void RestoreScreen();
 
+    /// @copydoc GAL::SetTarget()
+    virtual void SetTarget( RenderTarget aTarget );
+
     // -------
     // Cursor
     // -------

include/gal/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 compositor.h
+ * @brief Class that handles multitarget rendering (ie. to different textures/surfaces) and
+ * later compositing into a single image.
+ */
+
+#ifndef COMPOSITOR_H_
+#define COMPOSITOR_H_
+
+namespace KiGfx
+{
+
+class COMPOSITOR
+{
+public:
+    virtual ~COMPOSITOR()
+    {
+    }
+
+    /**
+     * Function Reset()
+     * performs primary initialiation, necessary to use the object.
+     */
+    virtual void Initialize() = 0;
+
+    /**
+     * Function Resize()
+     * clears the state of COMPOSITOR, so it has to be reinitialized again with the new dimensions.
+     *
+     * @param aWidth is the framebuffer width (in pixels).
+     * @param aHeight is the framebuffer height (in pixels).
+     */
+    virtual void Resize( unsigned int aWidth, unsigned int aHeight ) = 0;
+
+    /**
+     * Function GetBuffer()
+     * prepares a new buffer that may be used as a rendering target.
+     *
+     * @return is the handle of the buffer. In case of failure 0 (zero) is returned as the handle.
+     */
+    virtual unsigned int GetBuffer() = 0;
+
+    /**
+     * Function SetBuffer()
+     * sets the selected buffer as the rendering target. All the following drawing functions are
+     * going to be rendered in the selected buffer.
+     *
+     * @param aBufferHandle is the handle of the buffer or 0 in case of rendering directly to the
+     * display.
+     */
+    virtual void SetBuffer( unsigned int aBufferHandle ) = 0;
+
+    /**
+     * Function ClearBuffer()
+     * clears the selected buffer (set by the SetBuffer() function).
+     */
+    virtual void ClearBuffer() = 0;
+
+    /**
+     * Function BlitBuffer()
+     * pastes the content of the buffer to the current buffer (set by SetBuffer() function).
+     *
+     * @param aBufferHandle is the handle to the buffer that is going to be pasted.
+     */
+   virtual void BlitBuffer( unsigned int aBufferHandle ) = 0;
+
+    /**
+     * Function DrawBuffer()
+     * draws the selected buffer on the screen.
+     *
+     * @param aBufferHandle is the handle of the buffer to be drawn.
+     * @param aDepth is the depth on which the buffer should be drawn. // TODO mention if higher depth value means close to the screen or is it opposite
+     */
+    virtual void DrawBuffer( unsigned int aBufferHandle, double aDepth ) = 0;
+
+protected:
+    unsigned int m_width;           ///< Width of the buffer (in pixels)
+    unsigned int m_height;          ///< Height of the buffer (in pixels)
+};
+
+} // namespace KiGfx
+
+#endif /* COMPOSITOR_H_ */

include/gal/definitions.h

@@ -31,4 +31,17 @@
 #define SWAP( varA, condition, varB ) if( varA condition varB ) { double tmp = varA; varA = varB; \
                                                                   varB = tmp; }
 
+namespace KiGfx
+{
+    /**
+     * RenderTarget: Possible rendering targets
+     */
+    enum RenderTarget
+    {
+        TARGET_CACHED,      ///< Main rendering target (cached)
+        TARGET_NONCACHED,   ///< Auxiliary rendering target (noncached)
+        TARGET_OVERLAY      ///< Items that may change while the view stays the same (noncached)
+    };
+}
+
 #endif /* DEFINITIONS_H_ */

include/gal/graphics_abstraction_layer.h

@@ -35,6 +35,7 @@
 #include <math/matrix3x3.h>
 
 #include <gal/color4d.h>
+#include <gal/definitions.h>
 #include <gal/stroke_font.h>
 #include <newstroke_font.h>
 
@@ -546,16 +547,27 @@ public:
         return worldScale;
     }
 
+    // ---------------------------
+    // Buffer manipulation methods
+    // ---------------------------
+
     /**
      * @brief Save the screen contents.
      */
     virtual void SaveScreen() = 0;
 
     /**
-     * @brief Save the screen contents.
+     * @brief Restore the screen contents.
      */
     virtual void RestoreScreen() = 0;
 
+    /**
+     * @brief Sets the target for rendering.
+     *
+     * @param aTarget is the new target for rendering.
+     */
+    virtual void SetTarget( RenderTarget aTarget ) = 0;
+
     // -------------
     // Grid methods
     // -------------

include/gal/opengl/opengl_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 opengl_compositor.h
+ * @brief Class that handles multitarget rendering (ie. to different textures/surfaces) and
+ * later compositing into a single image (OpenGL flavour).
+ */
+
+#ifndef OPENGL_COMPOSITOR_H_
+#define OPENGL_COMPOSITOR_H_
+
+#include <gal/compositor.h>
+#include <GL/glew.h>
+#include <vector>
+
+namespace KiGfx
+{
+
+class OPENGL_COMPOSITOR : public COMPOSITOR
+{
+public:
+    OPENGL_COMPOSITOR();
+    virtual ~OPENGL_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::BlitBuffer()
+    virtual void BlitBuffer( unsigned int aBufferHandle );
+
+    ///< @copydoc COMPOSITOR::DrawBuffer()
+    virtual void DrawBuffer( unsigned int aBufferHandle, double aDepth );
+
+protected:
+    typedef struct
+    {
+        GLuint textureTarget;                ///< Main texture handle
+        GLuint attachmentPoint;
+    } BUFFER_ITEM;
+
+    bool                        m_initialized;
+    unsigned int                m_current;
+    GLuint                      m_framebuffer;            ///< Main FBO handle
+    GLuint                      m_depthBuffer;            ///< Depth buffer handle
+    unsigned int                m_maxBuffers;             ///< Maximal amount of buffers
+    typedef std::vector<BUFFER_ITEM> Buffers;
+    Buffers                     m_buffers;
+
+    /// Store the currently used FBO name in case there was more than one compositor used
+    static GLuint               m_currentFbo;
+
+    /**
+     * Function clean()
+     * performs freeing of resources.
+     */
+    void clean();
+
+    ///< Returns number of used buffers
+    unsigned int usedBuffers()
+    {
+        return m_buffers.size();
+    }
+};
+
+} // namespace KiGfx
+
+#endif /* COMPOSITOR_H_ */

include/gal/opengl/opengl_gal.h

@@ -35,6 +35,7 @@
 #include <gal/opengl/vertex_manager.h>
 #include <gal/opengl/vertex_item.h>
 #include <gal/opengl/noncached_container.h>
+#include <gal/opengl/opengl_compositor.h>
 
 #include <wx/wx.h>
 #include <wx/glcanvas.h>
@@ -268,6 +269,9 @@ public:
     /// @copydoc GAL::RestoreScreen()
     virtual void RestoreScreen();
 
+    /// @copydoc GAL::SetTarget()
+    virtual void SetTarget( RenderTarget aTarget );
+
     // -------
     // Cursor
     // -------
@@ -328,7 +332,7 @@ private:
     wxEvtHandler*   mouseListener;
     wxEvtHandler*   paintListener;
 
-    // VBO buffered vertices for faster circle & semicircle drawing
+    // Precomputed vertices for faster circle & semicircle drawing
     NONCACHED_CONTAINER   circleContainer;        ///< Container for storing circle vertices
 
     // Vertex buffer objects related fields
@@ -338,6 +342,12 @@ private:
     VERTEX_MANAGER*       currentManager;         ///< Currently used VERTEX_MANAGER (for storing VERTEX_ITEMs)
     VERTEX_MANAGER        cachedManager;          ///< Container for storing cached VERTEX_ITEMs
     VERTEX_MANAGER        nonCachedManager;       ///< Container for storing non-cached VERTEX_ITEMs
+    VERTEX_MANAGER        overlayManager;         ///< Container for storing overlaid VERTEX_ITEMs
+
+    // Framebuffer & compositing
+    OPENGL_COMPOSITOR     compositor;             ///< Handles multiple rendering targets
+    unsigned int          mainBuffer;             ///< Main rendering target
+    unsigned int          overlayBuffer;          ///< Auxiliary rendering target (for menus etc.)
 
     // Polygon tesselation
     GLUtesselator*         tesselator;            ///< Pointer to the tesselator
@@ -350,20 +360,11 @@ private:
     int             cursorSize;             ///< Size of the cursor in pixels
     GLubyte*        cursorShape;            ///< Cursor pixel storage
     GLubyte*        cursorSave;             ///< Saved cursor pixels
-    bool            isDeleteSavedPixels;    ///< Flag for deleting saved pixels
     VECTOR2D        savedCursorPosition;    ///< Last saved cursor position
 
-    // Frame buffer
-    GLuint          frameBuffer;            ///< Main FBO handle
-    GLuint          depthBuffer;            ///< Depth buffer handle
-    GLuint          texture;                ///< Main texture handle
-    GLuint          frameBufferBackup;      ///< Backup FBO handle
-    GLuint          depthBufferBackup;      ///< Backup depth buffer handle
-    GLuint          textureBackup;          ///< Backup texture handle
-
     // Internal flags
     bool            isGlewInitialized;          ///< Is GLEW initialized?
-    bool            isFrameBufferInitialized;   ///< Are the frame buffers initialized?
+    bool            isFramebufferInitialized;   ///< Are the framebuffers initialized?
     bool            isShaderInitialized;        ///< Was the shader initialized?
     bool            isUseShader;                ///< Should the shaders be used?
     bool            isGrouping;                 ///< Was a group started?
@@ -434,34 +435,6 @@ private:
      */
     void initCursor( int aCursorSize );
 
-    /**
-     * @brief Blit the main texture to the screen.
-     *
-     * @param aIsClearFrameBuffer if true, the frame buffer is cleared as well.
-     */
-    void blitMainTexture( bool aIsClearFrameBuffer );
-
-    /// @brief Initialize the frame buffers for main contents and backup storage.
-    void initFrameBuffers();
-
-    /**
-     * @brief Generate a frame buffer for the screen contents.
-     *
-     * @param aFrameBuffer is the pointer to the frame buffer handle.
-     * @param aDepthBuffer is the pointer to the depth buffer handle.
-     * @param aTexture is the pointer to the texture handle.
-     */
-    void generateFrameBuffer( GLuint* aFrameBuffer, GLuint* aDepthBuffer, GLuint* aTexture );
-
-    /**
-     * @brief Delete the frame buffer for the screen contents.
-     *
-     * @param aFrameBuffer is the pointer to the frame buffer handle.
-     * @param aDepthBuffer is the pointer to the depth buffer handle.
-     * @param aTexture is the pointer to the texture handle.
-     */
-    void deleteFrameBuffer( GLuint* aFrameBuffer, GLuint* aDepthBuffer, GLuint* aTexture );
-
     /**
      * @brief Draw a quad for the line.
      *

include/gal/opengl/vertex_common.h

@@ -43,7 +43,7 @@ enum SHADER_TYPE
     SHADER_STROKED_CIRCLE,
 };
 
-typedef struct VERTEX
+typedef struct
 {
     GLfloat x, y, z;        // Coordinates
     GLubyte r, g, b, a;     // Color

include/gal/opengl/vertex_container.h

@@ -34,7 +34,6 @@
 
 namespace KiGfx
 {
-class VERTEX;
 class VERTEX_ITEM;
 class SHADER;
 

include/view/view.h

@@ -30,6 +30,7 @@
 #include <boost/unordered/unordered_map.hpp>
 
 #include <math/box2.h>
+#include <gal/definitions.h>
 
 namespace KiGfx
 {
@@ -258,14 +259,14 @@ public:
     }
 
     /**
-     * Function SetLayerCached()
-     * Turns on or off the cached parameter of a particular layer.
-     * @param aLayer: the layer
-     * @param aCached: the new parameter value
+     * Function SetLayerTarget()
+     * Changes the rendering target for a particular layer.
+     * @param aLayer is the layer.
+     * @param aTarget is the rendering target.
      */
-    inline void SetLayerCached( int aLayer, bool aCached = true )
+    inline void SetLayerTarget( int aLayer, RenderTarget aTarget )
     {
-        m_layers[aLayer].cached = aCached;
+        m_layers[aLayer].target = aTarget;
     }
 
     /**
@@ -367,14 +368,13 @@ private:
         bool                    enabled;         ///* is the layer to be rendered?
         bool                    isDirty;         ///* does it contain any dirty items (updated since last redraw)
         bool                    displayOnly;     ///* is the layer display only?
-        bool                    cached;          ///* items on non-cached layers are displayed in
-                                                 ///* immediate mode
         VIEW_RTREE*             items;           ///* R-tree indexing all items on this layer.
         std::vector<VIEW_ITEM*> dirtyItems;      ///* set of dirty items collected since last redraw
         int                     renderingOrder;  ///* rendering order of this layer
         int                     id;              ///* layer ID
         BOX2I                   extents;         ///* sum of bboxes of all items on the layer
         BOX2I                   dirtyExtents;    ///* sum of bboxes of all dirty items on the layer
+        RenderTarget            target;          ///* where the layer should be rendered
     };
 
     // Convenience typedefs

pcbnew/basepcbframe.cpp

@@ -207,7 +207,7 @@ void PCB_BASE_FRAME::SetBoard( BOARD* aBoard )
         // so there is no point in caching them
         for( LAYER_NUM layer = FIRST_NETNAME_LAYER; layer <= LAST_NETNAME_LAYER; ++layer )
         {
-             view->SetLayerCached( layer, false );
+             view->SetLayerTarget( layer, KiGfx::TARGET_NONCACHED );
         }
 
         // Load layer & elements visibility settings