diff --git a/effects/coverswitch/coverswitch.cpp b/effects/coverswitch/coverswitch.cpp
index 56c1a8df93..022a494c85 100644
--- a/effects/coverswitch/coverswitch.cpp
+++ b/effects/coverswitch/coverswitch.cpp
@@ -139,61 +139,6 @@ void CoverSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& d
     effects->paintScreen(mask, region, data);
 
     if (mActivated || stop || stopRequested) {
-        QMatrix4x4 origProjection;
-        QMatrix4x4 origModelview;
-        ShaderManager *shaderManager = ShaderManager::instance();
-        if (effects->numScreens() > 1) {
-            // unfortunatelly we have to change the projection matrix in dual screen mode
-            QRect fullRect = effects->clientArea(FullArea, activeScreen, effects->currentDesktop());
-            float fovy = 60.0f;
-            float aspect = 1.0f;
-            float zNear = 0.1f;
-            float zFar = 100.0f;
-            float ymax = zNear * tan(fovy  * M_PI / 360.0f);
-            float ymin = -ymax;
-            float xmin =  ymin * aspect;
-            float xmax = ymax * aspect;
-            float xTranslate = 0.0;
-            float yTranslate = 0.0;
-            float xminFactor = 1.0;
-            float xmaxFactor = 1.0;
-            float yminFactor = 1.0;
-            float ymaxFactor = 1.0;
-            if (area.x() == 0 && area.width() != fullRect.width()) {
-                // horizontal layout: left screen
-                xminFactor = (float)area.width() / (float)fullRect.width();
-                xmaxFactor = ((float)fullRect.width() - (float)area.width() * 0.5f) / ((float)fullRect.width() * 0.5f);
-                xTranslate = (float)fullRect.width() * 0.5f - (float)area.width() * 0.5f;
-            }
-            if (area.x() != 0 && area.width() != fullRect.width()) {
-                // horizontal layout: right screen
-                xminFactor = ((float)fullRect.width() - (float)area.width() * 0.5f) / ((float)fullRect.width() * 0.5f);
-                xmaxFactor = (float)area.width() / (float)fullRect.width();
-                xTranslate = (float)fullRect.width() * 0.5f - (float)area.width() * 0.5f;
-            }
-            if (area.y() == 0 && area.height() != fullRect.height()) {
-                // vertical layout: top screen
-                yminFactor = ((float)fullRect.height() - (float)area.height() * 0.5f) / ((float)fullRect.height() * 0.5f);
-                ymaxFactor = (float)area.height() / (float)fullRect.height();
-                yTranslate = (float)fullRect.height() * 0.5f - (float)area.height() * 0.5f;
-            }
-            if (area.y() != 0 && area.height() != fullRect.height()) {
-                // vertical layout: bottom screen
-                yminFactor = (float)area.height() / (float)fullRect.height();
-                ymaxFactor = ((float)fullRect.height() - (float)area.height() * 0.5f) / ((float)fullRect.height() * 0.5f);
-                yTranslate = (float)fullRect.height() * 0.5f - (float)area.height() * 0.5f;
-            }
-            QMatrix4x4 projection;
-            projection.frustum(xmin * xminFactor, xmax * xmaxFactor, ymin * yminFactor, ymax * ymaxFactor, zNear, zFar);
-            QMatrix4x4 modelview;
-            modelview.translate(xTranslate, yTranslate, 0.0);
-            GLShader *shader = shaderManager->pushShader(ShaderManager::GenericShader);
-            origProjection = shader->getUniformMatrix4x4("projection");
-            origModelview = shader->getUniformMatrix4x4("modelview");
-            shader->setUniform("projection", projection);
-            shader->setUniform("modelview", origModelview * modelview);
-            shaderManager->popShader();
-        }
 
         QList< EffectWindow* > tempList = currentWindowList;
         int index = tempList.indexOf(selected_window);
@@ -296,7 +241,7 @@ void CoverSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& d
             glEnable(GL_SCISSOR_TEST);
 
             if (m_reflectionShader && m_reflectionShader->isValid()) {
-                shaderManager->pushShader(m_reflectionShader);
+                ShaderManager::instance()->pushShader(m_reflectionShader);
                 QMatrix4x4 windowTransformation;
                 windowTransformation.translate(area.x() + area.width() * 0.5f, 0.0, 0.0);
                 m_reflectionShader->setUniform("windowTransformation", windowTransformation);
@@ -324,20 +269,13 @@ void CoverSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& d
                 vbo->setData(6, 3, verts.data(), texcoords.data());
                 vbo->render(GL_TRIANGLES);
 
-                shaderManager->popShader();
+                ShaderManager::instance()->popShader();
             }
             glDisable(GL_SCISSOR_TEST);
             glDisable(GL_BLEND);
         }
         paintScene(frontWindow, leftWindows, rightWindows);
 
-        if (effects->numScreens() > 1) {
-            GLShader *shader = shaderManager->pushShader(ShaderManager::GenericShader);
-            shader->setUniform("projection", origProjection);
-            shader->setUniform("modelview", origModelview);
-            shaderManager->popShader();
-        }
-
         // Render the caption frame
         if (windowTitle) {
             double opacity = 1.0;
@@ -518,6 +456,62 @@ void CoverSwitchEffect::slotTabBoxAdded(int mode)
                     }
                 }
 
+                if (effects->numScreens() > 1) {
+                    // unfortunatelly we have to change the projection matrix in dual screen mode
+                    // code is adapted from SceneOpenGL2::createProjectionMatrix()
+                    QRect fullRect = effects->clientArea(FullArea, activeScreen, effects->currentDesktop());
+                    float fovy = 60.0f;
+                    float aspect = 1.0f;
+                    float zNear = 0.1f;
+                    float zFar = 100.0f;
+
+                    float ymax = zNear * std::tan(fovy * M_PI / 360.0f);
+                    float ymin = -ymax;
+                    float xmin =  ymin * aspect;
+                    float xmax = ymax * aspect;
+
+                    if (area.width() != fullRect.width()) {
+                        if (area.x() == 0) {
+                            // horizontal layout: left screen
+                            xmin *= (float)area.width() / (float)fullRect.width();
+                            xmax *= (fullRect.width() - 0.5f * area.width()) / (0.5f * fullRect.width());
+                        } else {
+                            // horizontal layout: right screen
+                            xmin *= (fullRect.width() - 0.5f * area.width()) / (0.5f * fullRect.width());
+                            xmax *= (float)area.width() / (float)fullRect.width();
+                        }
+                    }
+                    if (area.height() != fullRect.height()) {
+                        if (area.y() == 0) {
+                            // vertical layout: top screen
+                            ymin *= (fullRect.height() - 0.5f * area.height()) / (0.5f * fullRect.height());
+                            ymax *= (float)area.height() / (float)fullRect.height();
+                        } else {
+                            // vertical layout: bottom screen
+                            ymin *= (float)area.height() / (float)fullRect.height();
+                            ymax *= (fullRect.height() - 0.5f * area.height()) / (0.5f * fullRect.height());
+                        }
+                    }
+
+                    m_projectionMatrix = QMatrix4x4();
+                    m_projectionMatrix.frustum(xmin, xmax, ymin, ymax, zNear, zFar);
+
+                    const float scaleFactor = 1.1f / zNear;
+
+                    // Create a second matrix that transforms screen coordinates
+                    // to world coordinates.
+                    QMatrix4x4 matrix;
+                    matrix.translate(xmin * scaleFactor, ymax * scaleFactor, -1.1);
+                    matrix.scale( (xmax - xmin) * scaleFactor / fullRect.width(),
+                                -(ymax - ymin) * scaleFactor / fullRect.height(),
+                                0.001);
+                    // Combine the matrices
+                    m_projectionMatrix *= matrix;
+
+                    m_modelviewMatrix = QMatrix4x4();
+                    m_modelviewMatrix.translate(area.x(), area.y(), 0.0);
+                }
+
                 // Setup caption frame geometry
                 if (windowTitle) {
                     QRect frameRect = QRect(area.width() * 0.25f + area.x(),
@@ -715,6 +709,10 @@ void CoverSwitchEffect::paintFrontWindow(EffectWindow* frontWindow, int width, i
         return;
     bool specialHandlingForward = false;
     WindowPaintData data(frontWindow);
+    if (effects->numScreens() > 1) {
+        data.setProjectionMatrix(m_projectionMatrix);
+        data.setModelViewMatrix(m_modelviewMatrix);
+    }
     data.setXTranslation(area.width() * 0.5 - frontWindow->geometry().x() - frontWindow->geometry().width() * 0.5);
     if (leftWindows == 0) {
         leftWindows = 1;
@@ -773,6 +771,10 @@ void CoverSwitchEffect::paintWindows(const EffectWindowList& windows, bool left,
     // has to appear on this side after half of the time
     if (animation && timeLine.currentValue() >= 0.5 && additionalWindow != NULL) {
         WindowPaintData data(additionalWindow);
+        if (effects->numScreens() > 1) {
+            data.setProjectionMatrix(m_projectionMatrix);
+            data.setModelViewMatrix(m_modelviewMatrix);
+        }
         data.setRotationAxis(Qt::YAxis);
         data.setRotationAngle(angle * rotateFactor);
         if (left) {
@@ -793,6 +795,10 @@ void CoverSwitchEffect::paintWindows(const EffectWindowList& windows, bool left,
             continue;
         }
         WindowPaintData data(window);
+        if (effects->numScreens() > 1) {
+            data.setProjectionMatrix(m_projectionMatrix);
+            data.setModelViewMatrix(m_modelviewMatrix);
+        }
         data.setRotationAxis(Qt::YAxis);
         data.setRotationAngle(angle);
         if (left)
diff --git a/effects/coverswitch/coverswitch.h b/effects/coverswitch/coverswitch.h
index 17307e4e49..b058db4d4d 100644
--- a/effects/coverswitch/coverswitch.h
+++ b/effects/coverswitch/coverswitch.h
@@ -157,6 +157,8 @@ private:
     bool secondaryTabBox;
 
     GLShader *m_reflectionShader;
+    QMatrix4x4 m_projectionMatrix;
+    QMatrix4x4 m_modelviewMatrix;
 };
 
 } // namespace
diff --git a/effects/flipswitch/flipswitch.cpp b/effects/flipswitch/flipswitch.cpp
index cdd57896fc..fd39b5032e 100644
--- a/effects/flipswitch/flipswitch.cpp
+++ b/effects/flipswitch/flipswitch.cpp
@@ -192,62 +192,6 @@ void FlipSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& da
             }
         }
 
-        // multiscreen part taken from coverswitch.cpp
-        // TODO: move to kwinglutils
-        QMatrix4x4 origProjection;
-        QMatrix4x4 origModelview;
-        if (effects->numScreens() > 1) {
-            // unfortunatelly we have to change the projection matrix in dual screen mode
-            QRect fullRect = effects->clientArea(FullArea, effects->activeScreen(), effects->currentDesktop());
-            float fovy = 60.0f;
-            float aspect = 1.0f;
-            float zNear = 0.1f;
-            float zFar = 100.0f;
-            float ymax = zNear * tan(fovy  * M_PI / 360.0f);
-            float ymin = -ymax;
-            float xmin =  ymin * aspect;
-            float xmax = ymax * aspect;
-            float xTranslate = 0.0;
-            float yTranslate = 0.0;
-            float xminFactor = 1.0;
-            float xmaxFactor = 1.0;
-            float yminFactor = 1.0;
-            float ymaxFactor = 1.0;
-            if (m_screenArea.x() == 0 && m_screenArea.width() != fullRect.width()) {
-                // horizontal layout: left screen
-                xminFactor = (float)m_screenArea.width() / (float)fullRect.width();
-                xmaxFactor = ((float)fullRect.width() - (float)m_screenArea.width() * 0.5f) / ((float)fullRect.width() * 0.5f);
-                xTranslate = (float)fullRect.width() * 0.5f - (float)m_screenArea.width() * 0.5f;
-            }
-            if (m_screenArea.x() != 0 && m_screenArea.width() != fullRect.width()) {
-                // horizontal layout: right screen
-                xminFactor = ((float)fullRect.width() - (float)m_screenArea.width() * 0.5f) / ((float)fullRect.width() * 0.5f);
-                xmaxFactor = (float)m_screenArea.width() / (float)fullRect.width();
-                xTranslate = (float)fullRect.width() * 0.5f - (float)m_screenArea.width() * 0.5f;
-            }
-            if (m_screenArea.y() == 0 && m_screenArea.height() != fullRect.height()) {
-                // vertical layout: top screen
-                yminFactor = ((float)fullRect.height() - (float)m_screenArea.height() * 0.5f) / ((float)fullRect.height() * 0.5f);
-                ymaxFactor = (float)m_screenArea.height() / (float)fullRect.height();
-                yTranslate = (float)fullRect.height() * 0.5f - (float)m_screenArea.height() * 0.5f;
-            }
-            if (m_screenArea.y() != 0 && m_screenArea.height() != fullRect.height()) {
-                // vertical layout: bottom screen
-                yminFactor = (float)m_screenArea.height() / (float)fullRect.height();
-                ymaxFactor = ((float)fullRect.height() - (float)m_screenArea.height() * 0.5f) / ((float)fullRect.height() * 0.5f);
-                yTranslate = (float)fullRect.height() * 0.5f - (float)m_screenArea.height() * 0.5f;
-            }
-            QMatrix4x4 projection;
-            projection.frustum(xmin * xminFactor, xmax * xmaxFactor, ymin * yminFactor, ymax * ymaxFactor, zNear, zFar);
-            QMatrix4x4 modelview;
-            modelview.translate(xTranslate, yTranslate, 0.0);
-            ShaderBinder binder(ShaderManager::GenericShader);
-            GLShader *shader = binder.shader();
-            origProjection = shader->getUniformMatrix4x4("projection");
-            origModelview = shader->getUniformMatrix4x4("modelview");
-            shader->setUniform("projection", projection);
-            shader->setUniform("modelview", origModelview * modelview);
-        }
 
         int winMask = PAINT_WINDOW_TRANSFORMED | PAINT_WINDOW_TRANSLUCENT;
         // fade in/out one window at the end of the stack during animation
@@ -255,6 +199,10 @@ void FlipSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& da
             EffectWindow* w = m_flipOrderedWindows.last();
             if (ItemInfo *info = m_windows.value(w,0)) {
                 WindowPaintData data(w);
+                if (effects->numScreens() > 1) {
+                    data.setProjectionMatrix(m_projectionMatrix);
+                    data.setModelViewMatrix(m_modelviewMatrix);
+                }
                 data.setRotationAxis(Qt::YAxis);
                 data.setRotationAngle(m_angle * m_startStopTimeLine.currentValue());
                 data.setOpacity(info->opacity);
@@ -286,6 +234,10 @@ void FlipSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& da
             if (!info)
                 continue;
             WindowPaintData data(w);
+            if (effects->numScreens() > 1) {
+                data.setProjectionMatrix(m_projectionMatrix);
+                data.setModelViewMatrix(m_modelviewMatrix);
+            }
             data.setRotationAxis(Qt::YAxis);
             data.setRotationAngle(m_angle * m_startStopTimeLine.currentValue());
             data.setOpacity(info->opacity);
@@ -342,13 +294,6 @@ void FlipSwitchEffect::paintScreen(int mask, QRegion region, ScreenPaintData& da
             effects->drawWindow(w, winMask, infiniteRegion(), data);
         }
 
-        if (effects->numScreens() > 1) {
-            ShaderBinder binder(ShaderManager::GenericShader);
-            GLShader *shader = binder.shader();
-            shader->setUniform("projection", origProjection);
-            shader->setUniform("modelview", origModelview);
-        }
-
         if (m_windowTitle) {
             // Render the caption frame
             if (m_animation) {
@@ -581,6 +526,62 @@ void FlipSwitchEffect::setActive(bool activate, FlipSwitchMode mode)
         m_activeScreen = effects->activeScreen();
         m_screenArea = effects->clientArea(ScreenArea, m_activeScreen, effects->currentDesktop());
 
+        if (effects->numScreens() > 1) {
+            // unfortunatelly we have to change the projection matrix in dual screen mode
+            // code is copied from Coverswitch
+            QRect fullRect = effects->clientArea(FullArea, m_activeScreen, effects->currentDesktop());
+            float fovy = 60.0f;
+            float aspect = 1.0f;
+            float zNear = 0.1f;
+            float zFar = 100.0f;
+
+            float ymax = zNear * std::tan(fovy * M_PI / 360.0f);
+            float ymin = -ymax;
+            float xmin =  ymin * aspect;
+            float xmax = ymax * aspect;
+
+            if (m_screenArea.width() != fullRect.width()) {
+                if (m_screenArea.x() == 0) {
+                    // horizontal layout: left screen
+                    xmin *= (float)m_screenArea.width() / (float)fullRect.width();
+                    xmax *= (fullRect.width() - 0.5f * m_screenArea.width()) / (0.5f * fullRect.width());
+                } else {
+                    // horizontal layout: right screen
+                    xmin *= (fullRect.width() - 0.5f * m_screenArea.width()) / (0.5f * fullRect.width());
+                    xmax *= (float)m_screenArea.width() / (float)fullRect.width();
+                }
+            }
+            if (m_screenArea.height() != fullRect.height()) {
+                if (m_screenArea.y() == 0) {
+                    // vertical layout: top screen
+                    ymin *= (fullRect.height() - 0.5f * m_screenArea.height()) / (0.5f * fullRect.height());
+                    ymax *= (float)m_screenArea.height() / (float)fullRect.height();
+                } else {
+                    // vertical layout: bottom screen
+                    ymin *= (float)m_screenArea.height() / (float)fullRect.height();
+                    ymax *= (fullRect.height() - 0.5f * m_screenArea.height()) / (0.5f * fullRect.height());
+                }
+            }
+
+            m_projectionMatrix = QMatrix4x4();
+            m_projectionMatrix.frustum(xmin, xmax, ymin, ymax, zNear, zFar);
+
+            const float scaleFactor = 1.1f / zNear;
+
+            // Create a second matrix that transforms screen coordinates
+            // to world coordinates.
+            QMatrix4x4 matrix;
+            matrix.translate(xmin * scaleFactor, ymax * scaleFactor, -1.1);
+            matrix.scale( (xmax - xmin) * scaleFactor / fullRect.width(),
+                        -(ymax - ymin) * scaleFactor / fullRect.height(),
+                        0.001);
+            // Combine the matrices
+            m_projectionMatrix *= matrix;
+
+            m_modelviewMatrix = QMatrix4x4();
+            m_modelviewMatrix.translate(m_screenArea.x(), m_screenArea.y(), 0.0);
+        }
+
         if (m_stop) {
             // effect is still closing from last usage
             m_stop = false;
diff --git a/effects/flipswitch/flipswitch.h b/effects/flipswitch/flipswitch.h
index 058e6b3835..859f30c65f 100644
--- a/effects/flipswitch/flipswitch.h
+++ b/effects/flipswitch/flipswitch.h
@@ -22,6 +22,7 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #define KWIN_FLIPSWITCH_H
 
 #include <kwineffects.h>
+#include <QMatrix4x4>
 #include <QQueue>
 #include <QTimeLine>
 
@@ -133,6 +134,8 @@ private:
     QFont m_captionFont;
     EffectWindowList m_flipOrderedWindows;
     QHash< const EffectWindow*, ItemInfo* > m_windows;
+    QMatrix4x4 m_projectionMatrix;
+    QMatrix4x4 m_modelviewMatrix;
     // options
     bool m_tabbox;
     bool m_tabboxAlternative;