Support having multiple rendertarget-using effects active at once

svn path=/branches/work/kwin_composite/; revision=656210

effects.cpp

@@ -16,6 +16,7 @@ License. See the file "COPYING" for the exact licensing terms.
 #include "scene_xrender.h"
 #include "scene_opengl.h"
 #include "workspace.h"
+#include "kwinglutils.h"
 
 #include <QFile>
 
@@ -393,6 +394,27 @@ EffectWindow* EffectsHandlerImpl::currentTabBoxWindow() const
     return NULL;
     }
 
+void EffectsHandlerImpl::pushRenderTarget(GLRenderTarget* target)
+{
+#ifdef HAVE_OPENGL
+    target->enable();
+    render_targets.push(target);
+#endif
+}
+
+GLRenderTarget* EffectsHandlerImpl::popRenderTarget()
+{
+#ifdef HAVE_OPENGL
+    GLRenderTarget* ret = render_targets.pop();
+    ret->disable();
+    if( !render_targets.isEmpty() )
+        render_targets.top()->enable();
+    return ret;
+#else
+    return 0;
+#endif
+}
+
 void EffectsHandlerImpl::addRepaintFull()
     {
     Workspace::self()->addRepaintFull();

effects.h

@@ -15,6 +15,8 @@ License. See the file "COPYING" for the exact licensing terms.
 
 #include "scene.h"
 
+#include <QStack>
+
 
 
 namespace KWin
@@ -60,6 +62,9 @@ class EffectsHandlerImpl : public EffectsHandler
         virtual int currentTabBoxDesktop() const;
         virtual EffectWindow* currentTabBoxWindow() const;
 
+        virtual void pushRenderTarget(GLRenderTarget* target);
+        virtual GLRenderTarget* popRenderTarget();
+
         virtual void addRepaintFull();
         virtual void addRepaint( const QRect& r );
         virtual void addRepaint( int x, int y, int w, int h );
@@ -107,6 +112,7 @@ class EffectsHandlerImpl : public EffectsHandler
     protected:
         KLibrary* findEffectLibrary( const QString& effectname );
         Effect* keyboard_grab_effect;
+        QStack<GLRenderTarget*> render_targets;
 };
 
 class EffectWindowImpl : public EffectWindow

effects/demo_liquid.cpp

@@ -17,6 +17,7 @@ License. See the file "COPYING" for the exact licensing terms.
 #include <KStandardDirs>
 
 #include <kdebug.h>
+#include <assert.h>
 
 
 namespace KWin
@@ -79,7 +80,7 @@ void LiquidEffect::prePaintScreen( int* mask, QRegion* region, int time )
         {
         *mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
         // Start rendering to texture
-        mRenderTarget->enable();
+        effects->pushRenderTarget(mRenderTarget);
         }
 
     effects->prePaintScreen(mask, region, time);
@@ -93,7 +94,7 @@ void LiquidEffect::postPaintScreen()
     if(mValid)
         {
         // Disable render texture
-        mRenderTarget->disable();
+        assert( effects->popRenderTarget() == mRenderTarget );
         mTexture->bind();
 
         // Use the shader

effects/test_fbo.cpp

@@ -13,6 +13,7 @@ License. See the file "COPYING" for the exact licensing terms.
 
 #include <kwinglutils.h>
 
+#include <assert.h>
 
 namespace KWin
 {
@@ -47,7 +48,7 @@ void TestFBOEffect::prePaintScreen( int* mask, QRegion* region, int time )
         {
         *mask |= PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS;
         // Start rendering to texture
-        mRenderTarget->enable();
+        effects->pushRenderTarget(mRenderTarget);
         }
 
     effects->prePaintScreen(mask, region, time);
@@ -61,7 +62,7 @@ void TestFBOEffect::postPaintScreen()
     if(mValid)
         {
         // Disable render texture
-        mRenderTarget->disable();
+        assert( effects->popRenderTarget() == mRenderTarget );
         mTexture->bind();
 
         // Render fullscreen quad with screen contents

lib/kwineffects.h

@@ -36,6 +36,7 @@ class EffectWindow;
 class EffectWindowGroup;
 class Effect;
 class Vertex;
+class GLRenderTarget;
 
 typedef QPair< QString, Effect* > EffectPair;
 typedef QPair< Effect*, Window > InputWindowPair;
@@ -208,6 +209,9 @@ class KWIN_EXPORT EffectsHandler
         virtual int currentTabBoxDesktop() const = 0;
         virtual EffectWindow* currentTabBoxWindow() const = 0;
 
+        virtual void pushRenderTarget(GLRenderTarget* target) = 0;
+        virtual GLRenderTarget* popRenderTarget() = 0;
+
         // Repaints the entire workspace
         virtual void addRepaintFull() = 0;
         virtual void addRepaint( const QRect& r ) = 0;