Add mouse drag support to input manager

Camera can now be panned using MMB click & drag
ajweeks · Nov 8, 2017 · f1904b8 · f1904b8
1 parent b136280
commit f1904b8
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Showing 4 changed files with 60 additions and 23 deletions.
diff --git a/FlexEngine/include/FreeCamera.hpp b/FlexEngine/include/FreeCamera.hpp
@@ -64,16 +64,18 @@ namespace flex
 		float m_ZFar;
 
 		glm::vec3 m_Position;
+		glm::vec3 m_DragStartPosition;
 
 		float m_Yaw;
 		float m_Pitch;
 		glm::vec3 m_Forward;
 		glm::vec3 m_Up;
 		glm::vec3 m_Right;
 
-		float m_MoveSpeed;
-		float m_ScrollDollySpeed;
-		float m_DragDollySpeed;
+		float m_MoveSpeed; // Keyboard
+		float m_PanSpeed; // MMB
+		float m_DragDollySpeed; // RMB
+		float m_ScrollDollySpeed; // Scroll wheel
 		float m_MoveSpeedFastMultiplier;
 		float m_MoveSpeedSlowMultiplier;
 		float m_RotationSpeed;

diff --git a/FlexEngine/include/InputManager.hpp b/FlexEngine/include/InputManager.hpp
@@ -180,6 +180,12 @@ namespace flex
 			int down; // A count of how many frames this key has been down for (0 means not down)
 		};
 
+		struct MouseDrag
+		{
+			glm::vec2 startLocation;
+			glm::vec2 endLocation;
+		};
+
 		InputManager();
 		~InputManager();
 
@@ -191,18 +197,20 @@ namespace flex
 		bool GetKeyPressed(KeyCode keyCode) const;
 
 		void CursorPosCallback(double x, double y);
-		void MouseButtonCallback(const GameContext& gameContext, MouseButton button, Action action, int mods);
+		void MouseButtonCallback(const GameContext& gameContext, MouseButton mouseButton, Action action, int mods);
 		void ScrollCallback(double xOffset, double yOffset);
 		void KeyCallback(KeyCode keycode, Action action, int mods);
 		void CharCallback(unsigned int character);
 
 		void SetMousePosition(glm::vec2 mousePos, bool updatePreviousPos = true);
 		glm::vec2 GetMousePosition() const;
 		glm::vec2 GetMouseMovement() const;
-		int GetMouseButtonDown(MouseButton button) const;
-		bool GetMouseButtonClicked(MouseButton button) const;
+		int GetMouseButtonDown(MouseButton mouseButton) const;
+		bool GetMouseButtonClicked(MouseButton mouseButton) const;
 		float GetVerticalScrollDistance() const;
 
+		glm::vec2 GetMouseDragDistance(MouseButton mouseButton);
+
 		void ClearAllInputs(const GameContext& gameContext);
 		void ClearMouseInput(const GameContext& gameContext);
 		void ClearKeyboadInput(const GameContext& gameContext);
@@ -212,6 +220,7 @@ namespace flex
 
 		static const int MOUSE_BUTTON_COUNT = (int)MouseButton::_NONE;
 		Key m_MouseButtons[MOUSE_BUTTON_COUNT];
+		MouseDrag m_MouseButtonDrags[MOUSE_BUTTON_COUNT];
 		glm::vec2 m_MousePosition;
 		glm::vec2 m_PrevMousePosition;
 		float m_ScrollXOffset;

diff --git a/FlexEngine/src/FreeCamera.cpp b/FlexEngine/src/FreeCamera.cpp
@@ -15,10 +15,11 @@ namespace flex
 		m_FOV(FOV), m_ZNear(zNear), m_ZFar(zFar),
 		m_Position(glm::vec3(0.0f)),
 		m_MoveSpeed(50.0f),
+		m_PanSpeed(10.0f),
+		m_DragDollySpeed(0.1f),
+		m_ScrollDollySpeed(2.0f),
 		m_MoveSpeedFastMultiplier(3.5f),
 		m_MoveSpeedSlowMultiplier(0.05f),
-		m_ScrollDollySpeed(2.0f),
-		m_DragDollySpeed(0.1f),
 		m_RotationSpeed(0.0011f),
 		m_View(glm::mat4(0.0f)),
 		m_Proj(glm::mat4(0.0f)),
@@ -90,6 +91,18 @@ namespace flex
 			translation -= m_Up;
 		}
 
+		if (gameContext.inputManager->GetMouseButtonClicked(InputManager::MouseButton::MIDDLE))
+		{
+			m_DragStartPosition = m_Position;
+		}
+		else if (gameContext.inputManager->GetMouseButtonDown(InputManager::MouseButton::MIDDLE))
+		{
+			glm::vec2 dragDist = gameContext.inputManager->GetMouseDragDistance(InputManager::MouseButton::MIDDLE);
+			glm::vec2 frameBufferSize = (glm::vec2)gameContext.window->GetFrameBufferSize();
+			glm::vec2 normDragDist = dragDist / frameBufferSize;
+			m_Position = (m_DragStartPosition + (normDragDist.x * m_Right + normDragDist.y * m_Up) * m_PanSpeed);
+		}
+
 		float scrollDistance = gameContext.inputManager->GetVerticalScrollDistance();
 		if (scrollDistance != 0.0f)
 		{
@@ -112,7 +125,9 @@ namespace flex
 			speedMultiplier = m_MoveSpeedSlowMultiplier;
 		}
 
-		Translate(translation * m_MoveSpeed * speedMultiplier * gameContext.deltaTime);
+		glm::vec3 finalTranslation = translation * m_MoveSpeed * speedMultiplier * gameContext.deltaTime;
+		Translate(finalTranslation);
+		m_DragStartPosition += finalTranslation;
 
 		RecalculateViewProjection(gameContext);
 	}

diff --git a/FlexEngine/src/InputManager.cpp b/FlexEngine/src/InputManager.cpp
@@ -57,6 +57,7 @@ namespace flex
 			if (m_MouseButtons[i].down > 0)
 			{
 				++m_MouseButtons[i].down;
+				m_MouseButtonDrags[i].endLocation = m_MousePosition;
 			}
 		}
 	}
@@ -105,25 +106,28 @@ namespace flex
 		io.MousePos = m_MousePosition;
 	}
 
-	void InputManager::MouseButtonCallback(const GameContext& gameContext, MouseButton button, Action action, int mods)
+	void InputManager::MouseButtonCallback(const GameContext& gameContext, MouseButton mouseButton, Action action, int mods)
 	{
 		UNREFERENCED_PARAMETER(gameContext);
 		UNREFERENCED_PARAMETER(mods);
 
-		assert((int)button < MOUSE_BUTTON_COUNT);
+		assert((int)mouseButton < MOUSE_BUTTON_COUNT);
 
 		if (action == Action::PRESS)
 		{
-			++m_MouseButtons[(int)button].down;
-
+			++m_MouseButtons[(int)mouseButton].down;
+			m_MouseButtonDrags[(int)mouseButton].startLocation = m_MousePosition;
+			m_MouseButtonDrags[(int)mouseButton].endLocation = m_MousePosition;
 			//if (button == MouseButton::LEFT)
 			//{
 			//	gameContext.window->SetCursorMode(Window::CursorMode::HIDDEN);
 			//}
 		}
-		else
+		else if (action == Action::RELEASE)
 		{
-			m_MouseButtons[(int)button].down = 0;
+			m_MouseButtons[(int)mouseButton].down = 0;
+			m_MouseButtonDrags[(int)mouseButton].startLocation = m_MousePosition;
+			m_MouseButtonDrags[(int)mouseButton].endLocation = m_MousePosition;
 
 			//if (button == MouseButton::LEFT)
 			//{
@@ -132,8 +136,8 @@ namespace flex
 		}
 
 		ImGuiIO& io = ImGui::GetIO();
-		io.MouseDown[(int)button] = m_MouseButtons[(int)button].down > 0;
-		io.MouseClicked[(int)button] = m_MouseButtons[(int)button].down == 1;
+		io.MouseDown[(int)mouseButton] = m_MouseButtons[(int)mouseButton].down > 0;
+		io.MouseClicked[(int)mouseButton] = m_MouseButtons[(int)mouseButton].down == 1;
 	}
 
 	void InputManager::ScrollCallback(double xOffset, double yOffset)
@@ -197,25 +201,32 @@ namespace flex
 		return m_MousePosition - m_PrevMousePosition;
 	}
 
-	int InputManager::GetMouseButtonDown(MouseButton button) const
+	int InputManager::GetMouseButtonDown(MouseButton mouseButton) const
 	{
-		assert((int)button >= 0 && (int)button <= MOUSE_BUTTON_COUNT - 1);
+		assert((int)mouseButton >= 0 && (int)mouseButton <= MOUSE_BUTTON_COUNT - 1);
 
-		return m_MouseButtons[(int)button].down;
+		return m_MouseButtons[(int)mouseButton].down;
 	}
 
-	bool InputManager::GetMouseButtonClicked(MouseButton button) const
+	bool InputManager::GetMouseButtonClicked(MouseButton mouseButton) const
 	{
-		assert((int)button >= 0 && (int)button <= MOUSE_BUTTON_COUNT - 1);
+		assert((int)mouseButton >= 0 && (int)mouseButton <= MOUSE_BUTTON_COUNT - 1);
 
-		return m_MouseButtons[(int)button].down == 1;
+		return (m_MouseButtons[(int)mouseButton].down == 1);
 	}
 
 	float InputManager::GetVerticalScrollDistance() const
 	{
 		return m_ScrollYOffset;
 	}
 
+	glm::vec2 InputManager::GetMouseDragDistance(MouseButton mouseButton)
+	{
+		assert((int)mouseButton >= 0 && (int)mouseButton <= MOUSE_BUTTON_COUNT - 1);
+
+		return (m_MouseButtonDrags[(int)mouseButton].endLocation - m_MouseButtonDrags[(int)mouseButton].startLocation);
+	}
+
 	void InputManager::ClearAllInputs(const GameContext& gameContext)
 	{
 		ClearMouseInput(gameContext);