Reimplement list sorting and Fix UI7 Layers

include/pd/lithium/command.hpp

@@ -132,10 +132,24 @@ class CmdPool {
       size_t idx = pPoolIdx++;
       *pPool[idx] = *p.GetCmd(i);
       pPool[idx]->Index = idx;
+      pPool[idx]->Layer += Layer;
     }
   }
 
+  void Sort() {
+    std::sort(begin(), end(),
+              [](const Command::Ref& a, const Command::Ref& b) -> bool {
+                if (a->Layer == b->Layer) {
+                  return a->Tex < b->Tex;
+                }
+                return a->Layer < b->Layer;
+              });
+  }
+
  private:
+  friend class DrawList;
+  Command::Ref* begin() { return &pPool[0]; }
+  Command::Ref* end() { return &pPool[pPoolIdx]; }
   std::vector<Command::Ref> pPool;
   u32 pPoolIdx = 0;
   int Layer = 0;

include/pd/lithium/drawlist.hpp

@@ -83,10 +83,10 @@ class PD_LITHIUM_API DrawList {
 
   Command::Ref GetNewCmd();
   void Clear();
-  void Layer(int l) { this->pLayer = l; }
-  int Layer() { return this->pLayer; }
-  void LayerUp() { this->pLayer++; }
-  void LayerDown() { this->pLayer--; }
+  void Layer(int l) { this->pPool.Layer = l; }
+  int Layer() { return this->pPool.Layer; }
+  void LayerUp() { this->pPool.Layer++; }
+  void LayerDown() { this->pPool.Layer--; }
 
   void SetFont(Font::Ref font) { pCurrentFont = font; }
   void SetFontScale(float scale) { pFontScale = scale; }
@@ -212,7 +212,6 @@ class PD_LITHIUM_API DrawList {
   /** Data Section */
 
   std::stack<fvec4> pClipRects;
-  int pLayer;
   float pFontScale = 0.7f;
   Font::Ref pCurrentFont;
   Texture::Ref CurrentTex;