diff --git a/doc/platform.dox b/doc/platform.dox
index 92574996b..fe4f82af3 100644
--- a/doc/platform.dox
+++ b/doc/platform.dox
@@ -47,10 +47,9 @@ Windowed applications provide a window and keyboard and mouse handling. The
 most basic toolkit (and toolkit packaged for most systems) is GLUT, which is
 implemented in @ref Platform::GlutApplication. As said above, the usage is
 similar for all toolkits, you must provide one-argument constructor and
-implement at least @ref GlutApplication::viewportEvent() "viewportEvent()" and
-@ref GlutApplication::drawEvent() "drawEvent()". The class can be then used
-directly in `main()`, but for convenience and portability it's better to use
-@ref MAGNUM_GLUTAPPLICATION_MAIN() macro.
+implement at least @ref GlutApplication::drawEvent() "drawEvent()" function.
+The class can be then used directly in `main()`, but for convenience and
+portability it's better to use @ref MAGNUM_GLUTAPPLICATION_MAIN() macro.
 
 To simplify the porting, the library provides `Platform::Application` typedef
 and `MAGNUM_APPLICATION_MAIN()` macro (but only if only one application header
@@ -78,7 +77,6 @@ class MyApplication: public Platform::Application {
         MyApplication(const Arguments& arguments);
 
     private:
-        void viewportEvent(const Vector2i& viewport) override;
         void drawEvent() override;
 };
 
@@ -87,11 +85,6 @@ MyApplication::MyApplication(const Arguments& arguments): Platform::Application(
     Renderer::setClearColor({0.0f, 0.0f, 0.4f});
 }
 
-void MyApplication::viewportEvent(const Vector2i& size) {
-    // Resize the framebuffer to new window size
-    defaultFramebuffer.setViewport({{}, size});
-}
-
 void MyApplication::drawEvent() {
     // Clear the window
     defaultFramebuffer.clear(DefaultFramebuffer::Clear::Color);
@@ -104,6 +97,28 @@ void MyApplication::drawEvent() {
 MAGNUM_APPLICATION_MAIN(MyApplication)
 @endcode
 
+@subsection platform-windowed-viewport Responding to viewport size changes
+
+By default the application doesn't respond to window size changes in any way,
+as the window has fixed size in most cases. To respond to size change for
+example by resizing the default framebuffer, you need to reimplement
+@ref GlutApplication::viewportEvent() "viewportEvent()" function and pass the
+new size to the framebuffer:
+@code
+class MyApplication: public Platform::Application {
+    // ...
+
+    private:
+        void viewportEvent(const Vector2i& size) override;
+};
+
+// ...
+
+void MyApplication::viewportEvent(const Vector2i& size) {
+    defaultFramebuffer.setViewport({{}, size});
+}
+@endcode
+
 @section platform-windowless Windowless applications
 
 Windowless applications provide just a context for ofscreen rendering or
diff --git a/src/Platform/AbstractXApplication.cpp b/src/Platform/AbstractXApplication.cpp
index b01fbddd9..20c33d53b 100644
--- a/src/Platform/AbstractXApplication.cpp
+++ b/src/Platform/AbstractXApplication.cpp
@@ -169,6 +169,7 @@ int AbstractXApplication::exec() {
     return 0;
 }
 
+void AbstractXApplication::viewportEvent(const Vector2i&) {}
 void AbstractXApplication::keyPressEvent(KeyEvent&) {}
 void AbstractXApplication::keyReleaseEvent(KeyEvent&) {}
 void AbstractXApplication::mousePressEvent(MouseEvent&) {}
diff --git a/src/Platform/AbstractXApplication.h b/src/Platform/AbstractXApplication.h
index b1cd8c867..653a24092 100644
--- a/src/Platform/AbstractXApplication.h
+++ b/src/Platform/AbstractXApplication.h
@@ -125,7 +125,7 @@ class AbstractXApplication {
     private:
     #endif
         /** @copydoc Sdl2Application::viewportEvent() */
-        virtual void viewportEvent(const Vector2i& size) = 0;
+        virtual void viewportEvent(const Vector2i& size);
 
         /** @copydoc Sdl2Application::drawEvent() */
         virtual void drawEvent() = 0;
diff --git a/src/Platform/GlutApplication.cpp b/src/Platform/GlutApplication.cpp
index cce9242c0..f1e178d8a 100644
--- a/src/Platform/GlutApplication.cpp
+++ b/src/Platform/GlutApplication.cpp
@@ -111,6 +111,7 @@ void GlutApplication::staticMouseMoveEvent(int x, int y) {
     instance->mouseMoveEvent(e);
 }
 
+void GlutApplication::viewportEvent(const Vector2i&) {}
 void GlutApplication::keyPressEvent(KeyEvent&) {}
 void GlutApplication::keyReleaseEvent(KeyEvent&) {}
 void GlutApplication::mousePressEvent(MouseEvent&) {}
diff --git a/src/Platform/GlutApplication.h b/src/Platform/GlutApplication.h
index e7267abe7..8e7391078 100644
--- a/src/Platform/GlutApplication.h
+++ b/src/Platform/GlutApplication.h
@@ -58,13 +58,14 @@ in CMake, add `${MAGNUM_GLUTAPPLICATION_INCLUDE_DIRS}` to include path and link
 to `${MAGNUM_GLUTAPPLICATION_LIBRARIES}`. If no other application is requested,
 you can also use generic `${MAGNUM_APPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_APPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section GlutApplication-usage Usage
 
-You need to implement at least @ref drawEvent() and @ref viewportEvent() to be
-able to draw on the screen. The subclass can be then used directly in `main()`
--- see convenience macro @ref MAGNUM_GLUTAPPLICATION_MAIN().
+You need to implement at least @ref drawEvent() to be able to draw on the
+screen. The subclass can be then used directly in `main()` -- see convenience
+macro @ref MAGNUM_GLUTAPPLICATION_MAIN(). See @ref platform for more
+information.
 @code
 class MyApplication: public Platform::GlutApplication {
     // implement required methods...
@@ -151,7 +152,7 @@ class GlutApplication {
     private:
     #endif
         /** @copydoc Sdl2Application::viewportEvent() */
-        virtual void viewportEvent(const Vector2i& size) = 0;
+        virtual void viewportEvent(const Vector2i& size);
 
         /** @copydoc Sdl2Application::drawEvent() */
         virtual void drawEvent() = 0;
diff --git a/src/Platform/GlxApplication.h b/src/Platform/GlxApplication.h
index a0042304b..66fa3e4a4 100644
--- a/src/Platform/GlxApplication.h
+++ b/src/Platform/GlxApplication.h
@@ -46,13 +46,14 @@ CMake. To use it, you need to request `%GlxApplication` component in CMake, add
 `${MAGNUM_GLXAPPLICATION_LIBRARIES}`. If no other application is requested, you
 can also use generic `${MAGNUM_APPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_APPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section GlxApplication-usage Usage
 
-You need to implement at least @ref drawEvent() and @ref viewportEvent() to be
-able to draw on the screen. The subclass can be then used directly in `main()`
--- see convenience macro @ref MAGNUM_GLXAPPLICATION_MAIN().
+You need to implement at least @ref drawEvent() to be able to draw on the
+screen. The subclass can be then used directly in `main()` -- see convenience
+macro @ref MAGNUM_GLXAPPLICATION_MAIN(). See @ref platform for more
+information.
 @code
 class MyApplication: public Platform::GlxApplication {
     // implement required methods...
diff --git a/src/Platform/NaClApplication.cpp b/src/Platform/NaClApplication.cpp
index bdb34e5e6..4e8385543 100644
--- a/src/Platform/NaClApplication.cpp
+++ b/src/Platform/NaClApplication.cpp
@@ -251,6 +251,7 @@ void NaClApplication::mouseLockCallback(void* applicationInstance, std::int32_t)
     instance->flags |= Flag::MouseLocked;
 }
 
+void NaClApplication::viewportEvent(const Vector2i&) {}
 void NaClApplication::keyPressEvent(KeyEvent&) {}
 void NaClApplication::keyReleaseEvent(KeyEvent&) {}
 void NaClApplication::mousePressEvent(MouseEvent&) {}
diff --git a/src/Platform/NaClApplication.h b/src/Platform/NaClApplication.h
index 0c9203f03..0377f76b8 100644
--- a/src/Platform/NaClApplication.h
+++ b/src/Platform/NaClApplication.h
@@ -63,13 +63,14 @@ to request `%NaClApplication` component in CMake, add
 `${MAGNUM_NACLAPPLICATION_LIBRARIES}`. If no other application is requested,
 you can also use generic `${MAGNUM_APPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_APPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section NaClApplication-usage Usage
 
-You need to implement at least @ref drawEvent() and @ref viewportEvent() to be
-able to draw on the screen. The subclass must be then registered to NaCl API
-using @ref MAGNUM_NACLAPPLICATION_MAIN() macro.
+You need to implement at least @ref drawEvent() to be able to draw on the
+screen. The subclass must be then registered to NaCl API using
+@ref MAGNUM_NACLAPPLICATION_MAIN() macro. See @ref platform for more
+information.
 @code
 class MyApplication: public Platform::NaClApplication {
     // implement required methods...
@@ -218,7 +219,7 @@ class NaClApplication: public pp::Instance, public pp::Graphics3DClient, public
     private:
     #endif
         /** @copydoc Sdl2Application::viewportEvent() */
-        virtual void viewportEvent(const Vector2i& size) = 0;
+        virtual void viewportEvent(const Vector2i& size);
 
         /** @copydoc Sdl2Application::drawEvent() */
         virtual void drawEvent() = 0;
diff --git a/src/Platform/ScreenedApplication.h b/src/Platform/ScreenedApplication.h
index 2836a63b1..fc7e0a468 100644
--- a/src/Platform/ScreenedApplication.h
+++ b/src/Platform/ScreenedApplication.h
@@ -170,15 +170,11 @@ template<class Application> class BasicScreenedApplication: public Application,
          * @brief Global viewport event
          *
          * Called when window size changes, *before* all screens'
-         * @ref BasicScreen::viewportEvent() "viewportEvent()". You should at
-         * least pass the new size to @ref DefaultFramebuffer::setViewport().
-         *
-         * Note that this function might not get called at all if the window
-         * size doesn't change. You are responsible for configuring the initial
-         * state yourself, viewport of default framebuffer can be retrieved
-         * from @ref DefaultFramebuffer::viewport().
+         * @ref BasicScreen::viewportEvent() "viewportEvent()". Default
+         * implementation does nothing. See @ref Sdl2Application::viewportEvent() "*Application::viewportEvent()"
+         * for more information.
          */
-        virtual void globalViewportEvent(const Vector2i& size) = 0;
+        virtual void globalViewportEvent(const Vector2i& size);
 
         /**
          * @brief Draw event
diff --git a/src/Platform/ScreenedApplication.hpp b/src/Platform/ScreenedApplication.hpp
index 2063c51fb..1a27d2269 100644
--- a/src/Platform/ScreenedApplication.hpp
+++ b/src/Platform/ScreenedApplication.hpp
@@ -72,6 +72,8 @@ template<class Application> BasicScreenedApplication<Application>& BasicScreened
     return *this;
 }
 
+template<class Application> void BasicScreenedApplication<Application>::globalViewportEvent(const Vector2i&) {}
+
 template<class Application> void BasicScreenedApplication<Application>::viewportEvent(const Vector2i& size) {
     /* Call viewport event after all other (because of framebuffer resizing) */
     globalViewportEvent(size);
diff --git a/src/Platform/Sdl2Application.cpp b/src/Platform/Sdl2Application.cpp
index 2f5b7785a..417daa0e4 100644
--- a/src/Platform/Sdl2Application.cpp
+++ b/src/Platform/Sdl2Application.cpp
@@ -244,6 +244,7 @@ void Sdl2Application::setMouseLocked(bool enabled) {
     #endif
 }
 
+void Sdl2Application::viewportEvent(const Vector2i&) {}
 void Sdl2Application::keyPressEvent(KeyEvent&) {}
 void Sdl2Application::keyReleaseEvent(KeyEvent&) {}
 void Sdl2Application::mousePressEvent(MouseEvent&) {}
diff --git a/src/Platform/Sdl2Application.h b/src/Platform/Sdl2Application.h
index 7df1cbf30..073ea799b 100644
--- a/src/Platform/Sdl2Application.h
+++ b/src/Platform/Sdl2Application.h
@@ -64,13 +64,14 @@ to find SDL2), request `%Sdl2Application` component in CMake, add
 `${MAGNUM_SDL2APPLICATION_LIBRARIES}`. If no other application is requested,
 you can also use generic `${MAGNUM_APPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_APPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section Sdl2Application-usage Usage
 
-You need to implement at least @ref drawEvent() and @ref viewportEvent() to be
-able to draw on the screen. The subclass can be then used directly in `main()`
--- see convenience macro @ref MAGNUM_SDL2APPLICATION_MAIN().
+You need to implement at least @ref drawEvent() to be able to draw on the
+screen. The subclass can be then used directly in `main()` -- see convenience
+macro @ref MAGNUM_SDL2APPLICATION_MAIN(). See @ref platform for more
+information.
 @code
 class MyApplication: public Platform::Sdl2Application {
     // implement required methods...
@@ -235,16 +236,19 @@ class Sdl2Application {
         /**
          * @brief Viewport event
          *
-         * Called when window size changes. You should pass the new size to
-         * @ref DefaultFramebuffer::setViewport() and possibly elsewhere
-         * (cameras, other framebuffers...).
+         * Called when window size changes. The default implementation does
+         * nothing, if you want to respond to size changes, you should pass the
+         * new size to @ref DefaultFramebuffer::setViewport() and possibly
+         * elsewhere (to @ref SceneGraph::AbstractCamera::setViewport() "SceneGraph::Camera*D::setViewport()",
+         * other framebuffers...).
          *
          * Note that this function might not get called at all if the window
-         * size doesn't change. You are responsible for configuring the initial
-         * state yourself, viewport of default framebuffer can be retrieved
-         * from @ref DefaultFramebuffer::viewport().
+         * size doesn't change. You should configure the initial state of your
+         * cameras, framebuffers etc. in application constructor rather than
+         * relying on this function to be called. Viewport of default
+         * framebuffer can be retrieved via @ref DefaultFramebuffer::viewport().
          */
-        virtual void viewportEvent(const Vector2i& size) = 0;
+        virtual void viewportEvent(const Vector2i& size);
 
         /**
          * @brief Draw event
diff --git a/src/Platform/WindowlessGlxApplication.h b/src/Platform/WindowlessGlxApplication.h
index 3b531f85e..dd5ec4193 100644
--- a/src/Platform/WindowlessGlxApplication.h
+++ b/src/Platform/WindowlessGlxApplication.h
@@ -56,12 +56,13 @@ include path and link to `${MAGNUM_WINDOWLESSGLXAPPLICATION_LIBRARIES}`. If no
 other windowless application is requested, you can also use generic
 `${MAGNUM_WINDOWLESSAPPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_WINDOWLESSAPPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section WindowlessGlxApplication-usage Usage
 
 Place your code into @ref exec(). The subclass can be then used directly in
 `main()` -- see convenience macro @ref MAGNUM_WINDOWLESSGLXAPPLICATION_MAIN().
+See @ref platform for more information.
 @code
 class MyApplication: public Platform::WindowlessGlxApplication {
     // implement required methods...
diff --git a/src/Platform/WindowlessNaClApplication.h b/src/Platform/WindowlessNaClApplication.h
index 277b82111..a6f2a55ef 100644
--- a/src/Platform/WindowlessNaClApplication.h
+++ b/src/Platform/WindowlessNaClApplication.h
@@ -60,12 +60,13 @@ you need to request `%WindowlessNaClApplication` component in CMake, add
 application is requested, you can also use generic
 `${MAGNUM_WINDOWLESSAPPLICATION_INCLUDE_DIRS}` and
 `${MAGNUM_WINDOWLESSAPPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section WindowlessNaClApplication-usage Usage
 
 Place your code into @ref exec(). The subclass must be then registered to NaCl
-API using @ref MAGNUM_WINDOWLESSNACLAPPLICATION_MAIN() macro.
+API using @ref MAGNUM_WINDOWLESSNACLAPPLICATION_MAIN() macro. See @ref platform
+for more information.
 @code
 class MyApplication: public Platform::WindowlessNaClApplication {
     // implement required methods...
diff --git a/src/Platform/XEglApplication.h b/src/Platform/XEglApplication.h
index dc7aae7f2..67f75d4d6 100644
--- a/src/Platform/XEglApplication.h
+++ b/src/Platform/XEglApplication.h
@@ -47,13 +47,14 @@ request `%XEglApplication` component in CMake, add `${MAGNUM_XEGLAPPLICATION_INC
 to include path and link to `${MAGNUM_XEGLAPPLICATION_LIBRARIES}`.  If no other
 application is requested, you can also use generic `${MAGNUM_APPLICATION_INCLUDE_DIRS}`
 and `${MAGNUM_APPLICATION_LIBRARIES}` aliases to simplify porting. See
-@ref building, @ref cmake and @ref platform for more information.
+@ref building and @ref cmake for more information.
 
 @section XEglApplication-usage Usage
 
-You need to implement at least @ref drawEvent() and @ref viewportEvent() to be
-able to draw on the screen.  The subclass can be then used directly in `main()`
--- see convenience macro @ref MAGNUM_XEGLAPPLICATION_MAIN().
+You need to implement at least @ref drawEvent() to be able to draw on the
+screen.  The subclass can be then used directly in `main()` -- see convenience
+macro @ref MAGNUM_XEGLAPPLICATION_MAIN(). See @ref platform for more
+information.
 @code
 class MyApplication: public Platform::XEglApplication {
     // implement required methods...