Culling, rendering improvements and optimizations, block removing test.

Shader.cs

@@ -67,6 +67,17 @@ namespace Voxel
             GL.UniformMatrix4(location, false, ref matrix);
         }
 
+        public void SetInt(string name, int value)
+        {
+            int location = GL.GetUniformLocation(_handle, name);
+            if (location == -1)
+            {
+                Console.WriteLine($"Uniform '{name}' not found in shader.");
+                return;
+            }
+            GL.Uniform1(location, value);
+        }
+
         public void Use()
         {
             GL.UseProgram(_handle);