Implement VCanvas and Update TextElem

- Text now requires a font and is able to take an individual scale
- Container requires &ref for Elements to make sure they always exist
- SetViewport now sets the canvas as well
- SetBaseViewport Sets the Virtual Canvas Size
- Layout Now requires a Drawlist reference in Render function
- main.cpp: updated the template

include/pd/ultra/elems/element.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <functional>
 #include <pd/lithium/lithium.hpp>
 #include <pd/ultra/flags.hpp>
 
@@ -7,6 +8,7 @@ namespace PD {
 namespace Ultra {
 class Canvas;
 class Container;
+using EventFunc = std::function<void()>;
 class PD_API ElementBase {
  public:
   ElementBase() {}
@@ -17,24 +19,36 @@ class PD_API ElementBase {
    * Reset Function (for PD::Pool::FastReset)
    */
   virtual void Reset() {}
-  void Update();
+  virtual void Update();
 
   void SetAlignment(UltraAlignment a) { pAlignment = a; }
   void SetPosition(const PD::fvec2& pos) { pPos = pos; }
   void SetPosition(float x, float y) { pPos = PD::fvec2(x, y); }
   void SetSize(const PD::fvec2& size) { pSize = size; }
   void SetSize(float w, float h) { pSize = PD::fvec2(w, h); }
+  /**
+   * Executed every frame
+   * Elemnents can override / discard this func
+   */
+  virtual void OnHover(EventFunc func) { pHover = func; }
+  /**
+   * Executrd on KeyUp event
+   * Elemnents can override / discard this func
+   */
+  virtual void OnPress(EventFunc func) { pPress = func; }
 
  protected:
   friend class Container;
   void SetParent(Container* c) { pParent = c; }
   bool RevisionUpdate(PD::u32 req);
-  Container* pParent;
+  Container* pParent = nullptr;
   PD::u32 pCanvasRev = 0;
   UltraAlignment pAlignment = 0;
   PD::fvec2 pPos;
   PD::fvec2 pSize;
   PD::Li::Rect pRenderspace;
+  EventFunc pHover = nullptr;
+  EventFunc pPress = nullptr;
 };
 }  // namespace Ultra
 }  // namespace PD