feat: add interactable component and test button

lightkeeper/src/Lightkeeper.cpp

@@ -2,9 +2,11 @@
 
 #include <destrum/Components/CameraComponent.h>
 #include <destrum/FS/AssetFS.h>
+#include <destrum/Graphics/Managers/Renderer2D.h>
 #include <destrum/Scene/Scene.h>
 
 #include <components/FirstPersonController.h>
+#include <components/Interactable.h>
 #include <components/GameComponentRegistry.h>
 
 LightKeeper::LightKeeper() : App()
@@ -69,6 +71,29 @@ void LightKeeper::customUpdate(float dt)
     updateDebugUi();
 }
 
+void LightKeeper::drawCrosshair()
+{
+    if (!isPlayerViewActive()) {
+        return;
+    }
+
+    const bool focused = mainScene.playerController->GetFocusedInteractable() != nullptr;
+    const glm::vec4 color = focused ? glm::vec4{1.0f, 0.8f, 0.25f, 1.0f} : glm::vec4{1.0f, 1.0f, 1.0f, 0.8f};
+    const float armLength = focused ? 16.0f : 10.0f;
+    constexpr float thickness = 2.0f;
+
+    const VkExtent3D extent = renderer.getDrawImage().extent;
+    const glm::vec2 center{static_cast<float>(extent.width) * 0.5f, static_cast<float>(extent.height) * 0.5f};
+
+    auto& renderer2D = Renderer2D::GetInstance();
+    const float halfArm = armLength * 0.5f;
+    renderer2D.DrawLine(center - glm::vec2{halfArm, 0.0f}, center + glm::vec2{halfArm, 0.0f}, thickness, color);
+    renderer2D.DrawLine(center - glm::vec2{0.0f, halfArm}, center + glm::vec2{0.0f, halfArm}, thickness, color);
+    if (focused) {
+        renderer2D.DrawEllipseOutline(center, glm::vec2{14.0f}, thickness, color);
+    }
+}
+
 bool LightKeeper::isPlayerViewActive() const
 {
     return mainScene.playerController != nullptr && mainScene.playerController->IsMouseCaptured();
@@ -92,8 +117,8 @@ void LightKeeper::customDraw()
 
     renderer.beginDrawing(gfxDevice);
     submitDebugDraws();
+    drawCrosshair();
 
-    // The player camera is placed here, after the fixed steps, so it can be interpolated between them
     if (isPlayerViewActive())
     {
         camera.SetRotation(mainScene.playerController->GetYaw(), mainScene.playerController->GetPitch());