Platform: respect DPI in setMin/MaxWindowSize().

I hope this doesn't break someone's use case.

doc/changelog.dox

@@ -101,6 +101,9 @@ See also:
 -   @ref Platform::Sdl2Application::viewportEvent() gets properly fired also
     when window size changes programmatically (such as through
     @ref Platform::Sdl2Application::setMinWindowSize() "setMinWindowSize()")
+-   @ref Platform::GlfwApplication::setMinWindowSize() /
+    @ref Platform::GlfwApplication::setMaxWindowSize() and equivalent APIs in
+    @ref Platform::Sdl2Application now correctly take DPI scaling into account
 -   The @ref Primitives::cylinderSolid() and @ref Primitives::coneSolid()
     primitives were missing a face when both caps and texture coordinates were
     enabled (see [mosra/magnum#386](https://github.com/mosra/magnum/issues/386))
@@ -122,6 +125,11 @@ See also:
     @ref Animation library was changed to allow mutable access to the keys &
     values it references. Existing code needs to be changed to say
     @cpp TrackView<const K, const V> @ce instead of @cpp TrackView<K, V> @ce.
+-   @ref Platform::GlfwApplication::setMinWindowSize() /
+    @ref Platform::GlfwApplication::setMaxWindowSize() and equivalent APIs in
+    @ref Platform::Sdl2Application now premultiply the value with
+    @ref Platform::GlfwApplication::dpiScaling() "dpiScaling()" to work
+    independently on display DPI. This might break existing uses.
 
 @subsection changelog-latest-documentation Documentation
 

src/Magnum/Platform/GlfwApplication.cpp

@@ -588,15 +588,17 @@ Vector2i GlfwApplication::windowSize() const {
 void GlfwApplication::setMinWindowSize(const Vector2i& size) {
     CORRADE_ASSERT(_window, "Platform::GlfwApplication::setMinWindowSize(): no window opened", );
 
-    glfwSetWindowSizeLimits(_window, size.x(), size.y(), _maxWindowSize.x(), _maxWindowSize.y());
-    _minWindowSize = size;
+    const Vector2i newSize = _dpiScaling*size;
+    glfwSetWindowSizeLimits(_window, newSize.x(), newSize.y(), _maxWindowSize.x(), _maxWindowSize.y());
+    _minWindowSize = newSize;
 }
 
 void GlfwApplication::setMaxWindowSize(const Vector2i& size) {
     CORRADE_ASSERT(_window, "Platform::GlfwApplication::setMaxWindowSize(): no window opened", );
 
-    glfwSetWindowSizeLimits(_window, _minWindowSize.x(), _minWindowSize.y(), size.x(), size.y());
-    _maxWindowSize = size;
+    const Vector2i newSize = _dpiScaling*size;
+    glfwSetWindowSizeLimits(_window, _minWindowSize.x(), _minWindowSize.y(), newSize.x(), newSize.y());
+    _maxWindowSize = newSize;
 }
 #endif
 

src/Magnum/Platform/GlfwApplication.h

@@ -360,8 +360,9 @@ class GlfwApplication {
          * @param size    The minimum size, in screen coordinates
          *
          * If a value is set to @cpp -1 @ce, it will disable/remove the
-         * corresponding limit.
-         *
+         * corresponding limit. To make the sizing work independently of the
+         * display DPI, @p size is internally multiplied with @ref dpiScaling()
+         * before getting applied.
          * @note Supported since GLFW 3.2.
          */
         void setMinWindowSize(const Vector2i& size = {-1, -1});
@@ -371,8 +372,9 @@ class GlfwApplication {
          * @param size    The maximum size, in screen coordinates
          *
          * If a value is set to @cpp -1 @ce, it will disable/remove the
-         * corresponding limit.
-         *
+         * corresponding limit. To make the sizing work independently of the
+         * display DPI, @p size is internally multiplied with @ref dpiScaling()
+         * before getting applied.
          * @note Supported since GLFW 3.2.
          */
         void setMaxWindowSize(const Vector2i& size = {-1, -1});

src/Magnum/Platform/Sdl2Application.cpp

@@ -612,12 +612,16 @@ Vector2i Sdl2Application::windowSize() const {
 #ifndef CORRADE_TARGET_EMSCRIPTEN
 void Sdl2Application::setMinWindowSize(const Vector2i& size) {
     CORRADE_ASSERT(_window, "Platform::Sdl2Application::setMinWindowSize(): no window opened", );
-    SDL_SetWindowMinimumSize(_window, size.x(), size.y());
+
+    const Vector2i newSize = _dpiScaling*size;
+    SDL_SetWindowMinimumSize(_window, newSize.x(), newSize.y());
 }
 
 void Sdl2Application::setMaxWindowSize(const Vector2i& size) {
     CORRADE_ASSERT(_window, "Platform::Sdl2Application::setMaxWindowSize(): no window opened", );
-    SDL_SetWindowMaximumSize(_window, size.x(), size.y());
+
+    const Vector2i newSize = _dpiScaling*size;
+    SDL_SetWindowMaximumSize(_window, newSize.x(), newSize.y());
 }
 #endif
 

src/Magnum/Platform/Sdl2Application.h

@@ -634,8 +634,9 @@ class Sdl2Application {
          * @param size    The minimum size, in screen coordinates
          *
          * Note that, unlike in @ref GlfwApplication, SDL2 doesn't have a way
-         * to disable/remove a size limit.
-         *
+         * to disable/remove a size limit. To make the sizing work
+         * independently of the display DPI, @p size is internally multiplied
+         * with @ref dpiScaling() before getting applied.
          * @note Not available in @ref CORRADE_TARGET_EMSCRIPTEN "Emscripten".
          */
         void setMinWindowSize(const Vector2i& size);
@@ -645,8 +646,9 @@ class Sdl2Application {
          * @param size    The maximum size, in screen coordinates
          *
          * Note that, unlike in @ref GlfwApplication, SDL2 doesn't have a way
-         * to disable/remove a size limit.
-         *
+         * to disable/remove a size limit. To make the sizing work
+         * independently of the display DPI, @p size is internally multiplied
+         * with @ref dpiScaling() before getting applied.
          * @note Not available in @ref CORRADE_TARGET_EMSCRIPTEN "Emscripten".
          */
         void setMaxWindowSize(const Vector2i& size);