diff --git a/autotests/test_screen_paint_data.cpp b/autotests/test_screen_paint_data.cpp
--- a/autotests/test_screen_paint_data.cpp
+++ b/autotests/test_screen_paint_data.cpp
@@ -20,6 +20,7 @@
 
 #include <kwineffects.h>
 
+#include <QMatrix4x4>
 #include <QtGui/QVector2D>
 #include <QVector3D>
 
@@ -57,11 +58,12 @@
     QCOMPARE(data.rotationAngle(), 0.0);
     QCOMPARE(data.rotationOrigin(), QVector3D());
     QCOMPARE(data.rotationAxis(), QVector3D(0.0, 0.0, 1.0));
+    QCOMPARE(data.outputGeometry(), QRect());
 }
 
 void TestScreenPaintData::testCopyCtor()
 {
-    ScreenPaintData data;
+    ScreenPaintData data(QMatrix4x4(), QRect(10, 20, 30, 40));
     ScreenPaintData data2(data);
     // no value had been changed
     QCOMPARE(data2.xScale(), 1.0);
@@ -74,6 +76,7 @@
     QCOMPARE(data2.rotationAngle(), 0.0);
     QCOMPARE(data2.rotationOrigin(), QVector3D());
     QCOMPARE(data2.rotationAxis(), QVector3D(0.0, 0.0, 1.0));
+    QCOMPARE(data2.outputGeometry(), QRect(10, 20, 30, 40));
 
     data2.setScale(QVector3D(0.5, 2.0, 3.0));
     data2.translate(0.5, 2.0, 3.0);
@@ -97,13 +100,14 @@
 void TestScreenPaintData::testAssignmentOperator()
 {
     ScreenPaintData data;
-    ScreenPaintData data2;
+    ScreenPaintData data2(QMatrix4x4(), QRect(10, 20, 30, 40));
 
     data2.setScale(QVector3D(0.5, 2.0, 3.0));
     data2.translate(0.5, 2.0, 3.0);
     data2.setRotationAngle(45.0);
     data2.setRotationOrigin(QVector3D(1.0, 2.0, 3.0));
     data2.setRotationAxis(QVector3D(1.0, 1.0, 0.0));
+    QCOMPARE(data2.outputGeometry(), QRect(10, 20, 30, 40));
 
     data = data2;
     // data and data2 should be the same
@@ -117,6 +121,7 @@
     QCOMPARE(data.rotationAngle(), 45.0);
     QCOMPARE(data.rotationOrigin(), QVector3D(1.0, 2.0, 3.0));
     QCOMPARE(data.rotationAxis(), QVector3D(1.0, 1.0, 0.0));
+    QCOMPARE(data.outputGeometry(), QRect(10, 20, 30, 40));
     // data 2
     QCOMPARE(data2.xScale(), 0.5);
     QCOMPARE(data2.yScale(), 2.0);
diff --git a/libkwineffects/kwineffects.h b/libkwineffects/kwineffects.h
--- a/libkwineffects/kwineffects.h
+++ b/libkwineffects/kwineffects.h
@@ -2547,7 +2547,7 @@
 {
 public:
     ScreenPaintData();
-    ScreenPaintData(const QMatrix4x4 &projectionMatrix);
+    ScreenPaintData(const QMatrix4x4 &projectionMatrix, const QRect &outputGeometry = QRect());
     ScreenPaintData(const ScreenPaintData &other);
     virtual ~ScreenPaintData();
     /**
@@ -2599,6 +2599,16 @@
      * @since 5.6
      **/
     QMatrix4x4 projectionMatrix() const;
+
+    /**
+     * The geometry of the currently rendered output.
+     * Only set for per-output rendering (e.g. Wayland).
+     *
+     * This geometry can be used as a hint about the native window the OpenGL context
+     * is bound. OpenGL calls need to be translated to this geometry.
+     * @since 5.9
+     **/
+    QRect outputGeometry() const;
 private:
     class Private;
     QScopedPointer<Private> d;
diff --git a/libkwineffects/kwineffects.cpp b/libkwineffects/kwineffects.cpp
--- a/libkwineffects/kwineffects.cpp
+++ b/libkwineffects/kwineffects.cpp
@@ -435,19 +435,21 @@
 {
 public:
     QMatrix4x4 projectionMatrix;
+    QRect outputGeometry;
 };
 
 ScreenPaintData::ScreenPaintData()
     : PaintData()
     , d(new Private())
 {
 }
 
-ScreenPaintData::ScreenPaintData(const QMatrix4x4 &projectionMatrix)
+ScreenPaintData::ScreenPaintData(const QMatrix4x4 &projectionMatrix, const QRect &outputGeometry)
     : PaintData()
     , d(new Private())
 {
     d->projectionMatrix = projectionMatrix;
+    d->outputGeometry = outputGeometry;
 }
 
 ScreenPaintData::~ScreenPaintData() = default;
@@ -464,6 +466,7 @@
     setRotationAxis(other.rotationAxis());
     setRotationAngle(other.rotationAngle());
     d->projectionMatrix = other.d->projectionMatrix;
+    d->outputGeometry = other.d->outputGeometry;
 }
 
 ScreenPaintData &ScreenPaintData::operator=(const ScreenPaintData &rhs)
@@ -478,6 +481,7 @@
     setRotationAxis(rhs.rotationAxis());
     setRotationAngle(rhs.rotationAngle());
     d->projectionMatrix = rhs.d->projectionMatrix;
+    d->outputGeometry = rhs.d->outputGeometry;
     return *this;
 }
 
@@ -530,6 +534,11 @@
     return d->projectionMatrix;
 }
 
+QRect ScreenPaintData::outputGeometry() const
+{
+    return d->outputGeometry;
+}
+
 //****************************************
 // Effect
 //****************************************
diff --git a/scene.h b/scene.h
--- a/scene.h
+++ b/scene.h
@@ -173,7 +173,7 @@
     void clearStackingOrder();
     // shared implementation, starts painting the screen
     void paintScreen(int *mask, const QRegion &damage, const QRegion &repaint,
-                     QRegion *updateRegion, QRegion *validRegion, const QMatrix4x4 &projection = QMatrix4x4());
+                     QRegion *updateRegion, QRegion *validRegion, const QMatrix4x4 &projection = QMatrix4x4(), const QRect &outputGeometry = QRect());
     friend class EffectsHandlerImpl;
     // called after all effects had their paintScreen() called
     void finalPaintScreen(int mask, QRegion region, ScreenPaintData& data);
diff --git a/scene.cpp b/scene.cpp
--- a/scene.cpp
+++ b/scene.cpp
@@ -107,7 +107,7 @@
 
 // returns mask and possibly modified region
 void Scene::paintScreen(int* mask, const QRegion &damage, const QRegion &repaint,
-                        QRegion *updateRegion, QRegion *validRegion, const QMatrix4x4 &projection)
+                        QRegion *updateRegion, QRegion *validRegion, const QMatrix4x4 &projection, const QRect &outputGeometry)
 {
     const QSize &screenSize = screens()->size();
     const QRegion displayRegion(0, 0, screenSize.width(), screenSize.height());
@@ -147,7 +147,7 @@
         paintBackground(region);
     }
 
-    ScreenPaintData data(projection);
+    ScreenPaintData data(projection, outputGeometry);
     effects->paintScreen(*mask, region, data);
 
     foreach (Window *w, stacking_order) {
diff --git a/scene_opengl.cpp b/scene_opengl.cpp
--- a/scene_opengl.cpp
+++ b/scene_opengl.cpp
@@ -710,7 +710,7 @@
 
             int mask = 0;
             updateProjectionMatrix();
-            paintScreen(&mask, damage.intersected(geo), repaint, &update, &valid, projectionMatrix());   // call generic implementation
+            paintScreen(&mask, damage.intersected(geo), repaint, &update, &valid, projectionMatrix(), geo);   // call generic implementation
 
             GLVertexBuffer::streamingBuffer()->endOfFrame();