started on sprite support

Renderer.cs

@@ -1,4 +1,5 @@
 using OpenTK.Graphics.OpenGL4;
+using OpenTK.Mathematics;
 using static System.Runtime.InteropServices.JavaScript.JSType;
 
 namespace Voxel
@@ -10,7 +11,6 @@ namespace Voxel
         private static bool _buffersDirty;
 
         private static Dictionary<(int, int), int> _chunkBufferSizes = new Dictionary<(int, int), int>();
-        private static List<ChunkMesh> _chunkMeshes = new List<ChunkMesh>();
         private static Shader _shader;
         private static readonly Texture _texture;
         private static World? _world;
@@ -53,6 +53,7 @@ namespace Voxel
             }
 
             RenderWorld();
+            RenderUi();
         }
 
         private static void UpdateAllChunksBuffer()
@@ -75,6 +76,32 @@ namespace Voxel
             }
         }
 
+        private static void RenderUi()
+        {
+            GL.Disable(EnableCap.DepthTest);
+            GL.Enable(EnableCap.Blend);
+            GL.BlendFunc(BlendingFactor.SrcAlpha, BlendingFactor.OneMinusSrcAlpha);
+
+            //_uiShader.Use();
+
+            //Matrix4 projection = Matrix4.CreateOrthographicOffCenter(
+            //    0, screenWidth, screenHeight, 0, -1, 1);
+            //_uiShader.SetMatrix4("projection", projection);
+
+            // Bind UI texture atlas
+            //_uiTexture.Bind();
+
+            // Draw all UI sprites (batch by texture for efficiency)
+            foreach (var sprite in _uiSprites)
+            {
+                sprite.Draw();
+            }
+
+            // Restore 3D settings
+            GL.Disable(EnableCap.Blend);
+            GL.Enable(EnableCap.DepthTest);
+        }
+
         private static void RenderWorld()
         {
             if (_world == null) return;

UISprite.cs

@@ -0,0 +1,17 @@
+using OpenTK.Mathematics;
+using System.Drawing;
+
+public class UISprite
+{
+    public Vector2 Position;  // Screen pixels (not normalized)
+    public Vector2 Size;      // Size in pixels
+    public Rectangle TextureRegion;  // Which part of atlas to use
+    public Color Tint = Color.White;
+    public float Rotation = 0f;
+    public Vector2 Origin = Vector2.Zero;  // Rotation/scale origin
+
+    public void Draw()
+    {
+        // Draw textured quad using TextureRegion coordinates
+    }
+}