Platform: lazy-load modifiers in GlfwApplication mouse move/scroll event.

No need to fetch them every time. Doing it similarly to Sdl2Application.

doc/changelog.dox

@@ -91,6 +91,8 @@ See also:
     well, see @ref opengl-workarounds for more information.
 -   @ref Platform::GlfwApplication no longer stores a needless global window
     pointer
+-   @ref Platform::GlfwApplication now loads modifiers for mouse move and mouse
+    scroll events lazily, only when needed
 
 @subsubsection changelog-latest-changes-shaders Shaders library
 
@@ -129,6 +131,9 @@ See also:
     @ref GL::Framebuffer::clearColor(), @ref GL::Framebuffer::clearDepth(),
     @ref GL::Framebuffer::clearStencil() and @ref GL::Framebuffer::clearDepthStencil()
     were binding the framebuffer for drawing, which was completely unnecessary
+-   @ref Platform::GlfwApplication::InputEvent::Modifier::Super is properly
+    reported for both left and right modifier (Windows/⌘) key instead of just
+    the right one
 
 @subsection changelog-latest-docs Documentation
 

src/Magnum/Platform/GlfwApplication.cpp

@@ -148,6 +148,31 @@ bool GlfwApplication::tryCreate(const Configuration& configuration) {
     return true;
 }
 
+namespace {
+
+GlfwApplication::InputEvent::Modifiers currentGlfwModifiers(GLFWwindow* window) {
+    static_assert(GLFW_PRESS == true && GLFW_RELEASE == false,
+        "GLFW press and release constants do not correspond to bool values");
+
+    GlfwApplication::InputEvent::Modifiers mods;
+    if(glfwGetKey(window, GLFW_KEY_LEFT_SHIFT) ||
+       glfwGetKey(window, GLFW_KEY_RIGHT_SHIFT))
+        mods |= GlfwApplication::InputEvent::Modifier::Shift;
+    if(glfwGetKey(window, GLFW_KEY_LEFT_CONTROL) ||
+       glfwGetKey(window, GLFW_KEY_RIGHT_CONTROL))
+        mods |= GlfwApplication::InputEvent::Modifier::Ctrl;
+    if(glfwGetKey(window, GLFW_KEY_LEFT_ALT) ||
+       glfwGetKey(window, GLFW_KEY_RIGHT_ALT))
+        mods |= GlfwApplication::InputEvent::Modifier::Alt;
+    if(glfwGetKey(window, GLFW_KEY_LEFT_SUPER) ||
+       glfwGetKey(window, GLFW_KEY_RIGHT_SUPER))
+        mods |= GlfwApplication::InputEvent::Modifier::Super;
+
+    return mods;
+}
+
+}
+
 #ifdef MAGNUM_TARGET_GL
 bool GlfwApplication::tryCreate(const Configuration& configuration, const GLConfiguration&
     #ifndef MAGNUM_BUILD_DEPRECATED
@@ -370,9 +395,14 @@ void GlfwApplication::staticKeyEvent(GLFWwindow* const window, const int key, in
     }
 }
 
-void GlfwApplication::staticMouseMoveEvent(GLFWwindow* window, double x, double y) {
-    MouseMoveEvent e{Vector2i{Int(x), Int(y)}, KeyEvent::getCurrentGlfwModifiers(window)};
-    static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window))->mouseMoveEvent(e);
+auto GlfwApplication::MouseMoveEvent::modifiers() -> Modifiers {
+    if(!_modifiers) _modifiers = currentGlfwModifiers(_window);
+    return *_modifiers;
+}
+
+auto GlfwApplication::MouseScrollEvent::modifiers() -> Modifiers {
+    if(!_modifiers) _modifiers = currentGlfwModifiers(_window);
+    return *_modifiers;
 }
 
 void GlfwApplication::staticMouseEvent(GLFWwindow* window, int button, int action, int mods) {
@@ -389,10 +419,15 @@ void GlfwApplication::staticMouseEvent(GLFWwindow* window, int button, int actio
     } /* we don't handle GLFW_REPEAT */
 }
 
+void GlfwApplication::staticMouseMoveEvent(GLFWwindow* window, double x, double y) {
+    MouseMoveEvent e{window, Vector2i{Int(x), Int(y)}};
+    static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window))->mouseMoveEvent(e);
+}
+
 void GlfwApplication::staticMouseScrollEvent(GLFWwindow* window, double xoffset, double yoffset) {
     const auto instance = static_cast<GlfwApplication*>(glfwGetWindowUserPointer(window));
 
-    MouseScrollEvent e(Vector2{Float(xoffset), Float(yoffset)}, KeyEvent::getCurrentGlfwModifiers(window));
+    MouseScrollEvent e(window, Vector2{Float(xoffset), Float(yoffset)});
     instance->mouseScrollEvent(e);
 
     #ifdef MAGNUM_BUILD_DEPRECATED
@@ -401,7 +436,7 @@ void GlfwApplication::staticMouseScrollEvent(GLFWwindow* window, double xoffset,
         #pragma GCC diagnostic push
         #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         #endif
-        MouseEvent e1((yoffset > 0.0) ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {}, KeyEvent::getCurrentGlfwModifiers(window));
+        MouseEvent e1((yoffset > 0.0) ? MouseEvent::Button::WheelUp : MouseEvent::Button::WheelDown, {}, currentGlfwModifiers(window));
         #ifdef __GNUC__
         #pragma GCC diagnostic pop
         #endif
@@ -425,23 +460,6 @@ void GlfwApplication::staticErrorCallback(int, const char* description) {
     Error() << description;
 }
 
-auto GlfwApplication::KeyEvent::getCurrentGlfwModifiers(GLFWwindow* window) -> Modifiers {
-    static_assert(GLFW_PRESS == true && GLFW_RELEASE == false,
-        "GLFW press and release constants do not correspond to bool values");
-
-    Modifiers mods;
-    if(glfwGetKey(window, Int(Key::LeftShift)) || glfwGetKey(window, Int(Key::RightShift)))
-        mods |= Modifier::Shift;
-    if(glfwGetKey(window, Int(Key::LeftAlt)) || glfwGetKey(window, Int(Key::RightAlt)))
-        mods |= Modifier::Alt;
-    if(glfwGetKey(window, Int(Key::LeftCtrl)) || glfwGetKey(window, Int(Key::RightCtrl)))
-        mods |= Modifier::Ctrl;
-    if(glfwGetKey(window, Int(Key::RightSuper)))
-        mods |= Modifier::Super;
-
-    return mods;
-}
-
 void GlfwApplication::viewportEvent(const Vector2i&) {}
 void GlfwApplication::keyPressEvent(KeyEvent&) {}
 void GlfwApplication::keyReleaseEvent(KeyEvent&) {}

src/Magnum/Platform/GlfwApplication.h

@@ -33,6 +33,7 @@
 #include <memory>
 #include <string>
 #include <Corrade/Containers/ArrayView.h>
+#include <Corrade/Containers/Optional.h>
 
 #include "Magnum/Magnum.h"
 #include "Magnum/Tags.h"
@@ -1116,8 +1117,6 @@ class GlfwApplication::KeyEvent: public GlfwApplication::InputEvent {
         constexpr bool isRepeated() const { return _repeated; }
 
     private:
-        static Modifiers getCurrentGlfwModifiers(GLFWwindow* window);
-
         constexpr KeyEvent(Key key, Modifiers modifiers, bool repeated): _key{key}, _modifiers{modifiers}, _repeated{repeated} {}
 
         const Key _key;
@@ -1195,16 +1194,21 @@ class GlfwApplication::MouseMoveEvent: public GlfwApplication::InputEvent {
 
     public:
         /** @brief Position */
-        constexpr Vector2i position() const { return _position; }
+        Vector2i position() const { return _position; }
 
-        /** @brief Modifiers */
-        constexpr Modifiers modifiers() const { return _modifiers; }
+        /**
+         * @brief Modifiers
+         *
+         * Lazily populated on first request.
+         */
+        Modifiers modifiers();
 
     private:
-        constexpr MouseMoveEvent(const Vector2i& position, Modifiers modifiers): _position(position), _modifiers(modifiers) {}
+        explicit MouseMoveEvent(GLFWwindow* window, const Vector2i& position): _window{window}, _position{position} {}
 
+        GLFWwindow* _window;
         const Vector2i _position;
-        const Modifiers _modifiers;
+        Containers::Optional<Modifiers> _modifiers;
 };
 
 /**
@@ -1217,16 +1221,21 @@ class GlfwApplication::MouseScrollEvent: public GlfwApplication::InputEvent {
 
     public:
         /** @brief Scroll offset */
-        constexpr Vector2 offset() const { return _offset; }
+        Vector2 offset() const { return _offset; }
 
-        /** @brief Modifiers */
-        constexpr Modifiers modifiers() const { return _modifiers; }
+        /**
+         * @brief Modifiers
+         *
+         * Lazily populated on first request.
+         */
+        Modifiers modifiers();
 
     private:
-        constexpr MouseScrollEvent(const Vector2& offset, Modifiers modifiers): _offset(offset), _modifiers(modifiers) {}
+        explicit MouseScrollEvent(GLFWwindow* window, const Vector2& offset): _window{window}, _offset{offset} {}
 
+        GLFWwindow* _window;
         const Vector2 _offset;
-        const Modifiers _modifiers;
+        Containers::Optional<Modifiers> _modifiers;
 };
 
 /**