feat: add firstpersoncontroller

destrum/src/Input/InputManager.cpp

@@ -46,11 +46,11 @@ void InputManager::BeginFrame() {
 
     m_textInput.clear();
 
-    // Update mouse delta based on last known position
-    m_mouseDX = m_mouseX - m_prevMouseX;
-    m_mouseDY = m_mouseY - m_prevMouseY;
-    m_prevMouseX = m_mouseX;
-    m_prevMouseY = m_mouseY;
+    // Relative mouse accumulators are filled during SDL event processing
+    // and consumed by game code each frame. Reset them here (before events
+    // are processed) so this frame accumulates fresh deltas.
+    m_mouseRelDX = 0;
+    m_mouseRelDY = 0;
 
     // Clear controller "edge" sets + snapshot axes
     for (auto& [id, pad]: m_pads) {
@@ -60,6 +60,12 @@ void InputManager::BeginFrame() {
     }
 }
 
+void InputManager::SetMouseCaptured(bool captured) {
+    if (captured == m_MouseCaptured) return;
+    m_MouseCaptured = captured;
+    SDL_SetRelativeMouseMode(captured ? SDL_TRUE : SDL_FALSE);
+}
+
 void InputManager::AddController(int deviceIndex) {
     if (!SDL_IsGameController(deviceIndex)) return;
 
@@ -134,6 +140,8 @@ bool InputManager::ProcessEvent(const SDL_Event& e) {
         case SDL_MOUSEMOTION: {
             m_mouseX = e.motion.x;
             m_mouseY = e.motion.y;
+            m_mouseRelDX += e.motion.xrel;
+            m_mouseRelDY += e.motion.yrel;
         }
         break;