From 47ade4ef5329bd62fc2ce40cf78b0c589b2e141a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Vladim=C3=ADr=20Vondru=C5=A1?= <mosra@centrum.cz>
Date: Sat, 25 Aug 2018 19:15:09 +0200
Subject: [PATCH] Platform: make it possible to get scroll position in Glfw and
 Sdl2App.

---
 doc/changelog.dox                       |  2 ++
 src/Magnum/Platform/GlfwApplication.cpp | 10 ++++++++++
 src/Magnum/Platform/GlfwApplication.h   |  8 ++++++++
 src/Magnum/Platform/Sdl2Application.cpp |  7 +++++++
 src/Magnum/Platform/Sdl2Application.h   | 11 ++++++++++-
 5 files changed, 37 insertions(+), 1 deletion(-)

diff --git a/doc/changelog.dox b/doc/changelog.dox
index 5c893bf37..957206ec2 100644
--- a/doc/changelog.dox
+++ b/doc/changelog.dox
@@ -98,6 +98,8 @@ See also:
     @ref Platform::Sdl2Application::setContainerCssClass()
 -   Implemented @ref Platform::GlfwApplication::MouseMoveEvent::buttons() for
     feature parity with @ref Platform::Sdl2Application
+-   Added @ref Platform::Sdl2Application::MouseScrollEvent::position() and
+    @ref Platform::GlfwApplication::MouseScrollEvent::position()
 -   Added @ref Platform::Sdl2Application::GLConfiguration::setColorBufferSize() "GLConfiguration::setColorBufferSize()",
     @ref Platform::Sdl2Application::GLConfiguration::setDepthBufferSize() "GLConfiguration::setDepthBufferSize()",
     @ref Platform::Sdl2Application::GLConfiguration::setStencilBufferSize() "GLConfiguration::setStencilBufferSize()",
diff --git a/src/Magnum/Platform/GlfwApplication.cpp b/src/Magnum/Platform/GlfwApplication.cpp
index f3b33d5a6..0ce6f6b98 100644
--- a/src/Magnum/Platform/GlfwApplication.cpp
+++ b/src/Magnum/Platform/GlfwApplication.cpp
@@ -465,6 +465,16 @@ auto GlfwApplication::MouseMoveEvent::modifiers() -> Modifiers {
     return *_modifiers;
 }
 
+Vector2i GlfwApplication::MouseScrollEvent::position() {
+    if(!_position) {
+        Vector2d position;
+        glfwGetCursorPos(_window, &position.x(), &position.y());
+        _position = Vector2i{position};
+    }
+
+    return *_position;
+}
+
 auto GlfwApplication::MouseScrollEvent::modifiers() -> Modifiers {
     if(!_modifiers) _modifiers = currentGlfwModifiers(_window);
     return *_modifiers;
diff --git a/src/Magnum/Platform/GlfwApplication.h b/src/Magnum/Platform/GlfwApplication.h
index 816c94da8..29fd9d294 100644
--- a/src/Magnum/Platform/GlfwApplication.h
+++ b/src/Magnum/Platform/GlfwApplication.h
@@ -1342,6 +1342,13 @@ class GlfwApplication::MouseScrollEvent: public GlfwApplication::InputEvent {
         /** @brief Scroll offset */
         Vector2 offset() const { return _offset; }
 
+        /**
+         * @brief Position
+         *
+         * Lazily populated on first request.
+         */
+        Vector2i position();
+
         /**
          * @brief Modifiers
          *
@@ -1354,6 +1361,7 @@ class GlfwApplication::MouseScrollEvent: public GlfwApplication::InputEvent {
 
         GLFWwindow* _window;
         const Vector2 _offset;
+        Containers::Optional<Vector2i> _position;
         Containers::Optional<Modifiers> _modifiers;
 };
 
diff --git a/src/Magnum/Platform/Sdl2Application.cpp b/src/Magnum/Platform/Sdl2Application.cpp
index e6cf7ecc5..c1220144e 100644
--- a/src/Magnum/Platform/Sdl2Application.cpp
+++ b/src/Magnum/Platform/Sdl2Application.cpp
@@ -879,6 +879,13 @@ Sdl2Application::InputEvent::Modifiers Sdl2Application::MouseMoveEvent::modifier
     return _modifiers = fixedModifiers(Uint16(SDL_GetModState()));
 }
 
+Vector2i Sdl2Application::MouseScrollEvent::position() {
+    if(_positionLoaded) return _position;
+    _positionLoaded = true;
+    SDL_GetMouseState(&_position.x(), &_position.y());
+    return _position;
+}
+
 Sdl2Application::InputEvent::Modifiers Sdl2Application::MouseScrollEvent::modifiers() {
     if(_modifiersLoaded) return _modifiers;
     _modifiersLoaded = true;
diff --git a/src/Magnum/Platform/Sdl2Application.h b/src/Magnum/Platform/Sdl2Application.h
index 229513578..2c316aa4e 100644
--- a/src/Magnum/Platform/Sdl2Application.h
+++ b/src/Magnum/Platform/Sdl2Application.h
@@ -2035,6 +2035,13 @@ class Sdl2Application::MouseScrollEvent: public Sdl2Application::InputEvent {
         /** @brief Scroll offset */
         Vector2 offset() const { return _offset; }
 
+        /**
+         * @brief Position
+         *
+         * Lazily populated on first request.
+         */
+        Vector2i position();
+
         /**
          * @brief Modifiers
          *
@@ -2043,10 +2050,12 @@ class Sdl2Application::MouseScrollEvent: public Sdl2Application::InputEvent {
         Modifiers modifiers();
 
     private:
-        explicit MouseScrollEvent(const Vector2& offset): _offset{offset}, _modifiersLoaded{false} {}
+        explicit MouseScrollEvent(const Vector2& offset): _offset{offset}, _positionLoaded{false}, _modifiersLoaded{false} {}
 
         const Vector2 _offset;
+        bool _positionLoaded;
         bool _modifiersLoaded;
+        Vector2i _position;
         Modifiers _modifiers;
 };