Changes: Add a depth buffer attachment to the framebuffer object so we can

take advantage of GPU depth test to properly render Z-order of off-screen items
irrespective of item ordering. Fix naming conflict with MWindowPropertyCache::windowGroup().

4 files changed, 19 insertions, 8 deletions

diff --git a/src/mcompositescene.cpp b/src/mcompositescene.cpp
index 593e075..b0d6c23 100644
--- a/src/mcompositescene.cpp
+++ b/src/mcompositescene.cpp
@@ -127,7 +127,7 @@ void MCompositeScene::drawItems(QPainter *painter, int numItems, QGraphicsItem *
         if (!cw->isWindowTransitioning()
             && !cw->propertyCache()->hasAlpha() 
             && cw->opacity() == 1.0
-            && !cw->windowGroup()) // window is renderered off-screen)
+            && !cw->group()) // window is not renderered off-screen)
             visible -= r;
     }
     if (size > 0) {
diff --git a/src/mcompositewindow.cpp b/src/mcompositewindow.cpp
index 40af5de..3055f8c 100644
--- a/src/mcompositewindow.cpp
+++ b/src/mcompositewindow.cpp
@@ -794,7 +794,7 @@ bool MCompositeWindow::isMapped() const
     return pc ? pc->isMapped() : false;
 }
 
-MCompositeWindowGroup* MCompositeWindow::windowGroup() const
+MCompositeWindowGroup* MCompositeWindow::group() const
 {
     return renderer()->current_window_group;
 }
diff --git a/src/mcompositewindow.h b/src/mcompositewindow.h
index a7b480c..f13fcce 100644
--- a/src/mcompositewindow.h
+++ b/src/mcompositewindow.h
@@ -309,7 +309,7 @@ public:
      *  Returns a pointer to this window's group if it belongs to a group and 0
      * if 0 if not a member
      */
-    MCompositeWindowGroup* windowGroup() const;
+    MCompositeWindowGroup* group() const;
     
     /*! Disabled alpha-blending for a dim-effect instead */
     void setDimmedEffect(bool dimmed) { dimmed_effect = dimmed; }
diff --git a/src/mcompositewindowgroup.cpp b/src/mcompositewindowgroup.cpp
index 27aa61f..93bad80 100644
--- a/src/mcompositewindowgroup.cpp
+++ b/src/mcompositewindowgroup.cpp
@@ -48,8 +48,10 @@
 
 #ifdef GLES2_VERSION
 #define FORMAT GL_RGBA
+#define DEPTH GL_DEPTH_COMPONENT16
 #else
 #define FORMAT GL_RGBA8
+#define DEPTH GL_DEPTH_COMPONENT
 #endif
 
 class MCompositeWindowGroupPrivate
@@ -59,14 +61,15 @@ public:
         :main_window(mainWindow),
          texture(0),
          fbo(0),
+         depth_buffer(0),
          valid(false),
          renderer(new MTexturePixmapPrivate(0, mainWindow))            
-    {
-       
+    {       
     }
     MTexturePixmapItem* main_window;
     GLuint texture;
     GLuint fbo;
+    GLuint depth_buffer;
     
     bool valid;
     QList<MTexturePixmapItem*> item_groups;
@@ -88,7 +91,7 @@ MCompositeWindowGroup::MCompositeWindowGroup(MTexturePixmapItem* mainWindow)
     connect(mainWindow, SIGNAL(destroyed()), SLOT(deleteLater()));
     init();
     updateWindowPixmap();
-    setZValue(mainWindow->zValue() - 1);
+    setZValue(mainWindow->zValue());
     stackBefore(mainWindow);
 }
 
@@ -126,9 +129,9 @@ void MCompositeWindowGroup::init()
         return;
     }
     d->renderer->current_window_group = this;
-
-    // no renderbuffer because we dont need the stencil and depthbuffer attachment
+    
     glGenFramebuffers(1, &d->fbo);
+    glGenRenderbuffers(1, &d->depth_buffer);
     glBindFramebuffer(GL_RENDERBUFFER, d->fbo);
     
     glGenTextures(1, &d->texture);
@@ -139,9 +142,17 @@ void MCompositeWindowGroup::init()
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     
+    glBindRenderbuffer(GL_RENDERBUFFER, d->depth_buffer);
+    glRenderbufferStorage(GL_RENDERBUFFER, DEPTH, 
+                          d->main_window->boundingRect().width(), 
+                          d->main_window->boundingRect().height());
+
     glBindFramebuffer(GL_FRAMEBUFFER, d->fbo);
     glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0,
                            GL_TEXTURE_2D, d->texture, 0);
+
+    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT,
+                              GL_RENDERBUFFER, d->depth_buffer);
     
     glBindTexture(GL_TEXTURE_2D, d->texture);
     glTexImage2D(GL_TEXTURE_2D, 0, FORMAT,