add platformer window infrastructure

Platformer/Util/Shader.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using OpenTK.Graphics.OpenGL4;
+
+namespace Platformer.Util
+{
+    public class Shader : GlObj
+    {
+        private static Dictionary<string, ShaderType> _shaderTypes = new Dictionary<string, ShaderType>()
+        {
+            [".vert"] = ShaderType.VertexShader,
+            [".frag"] = ShaderType.FragmentShader,
+            [".geom"] = ShaderType.GeometryShader,
+            [".comp"] = ShaderType.ComputeShader,
+        };
+
+        public Shader(ShaderType type) : base(GL.CreateShader(type))
+        {
+        }
+
+        public static Shader Compile(ShaderType type, string source)
+        {
+            var s = new Shader(type);
+            GL.ShaderSource(s, source);
+            GL.CompileShader(s);
+            return s;
+        }
+
+        public static Shader Compile(string filename)
+        {
+            var ext = Path.GetExtension(filename);
+
+            if (!_shaderTypes.ContainsKey(ext))
+                throw new InvalidOperationException($"Can't infer shader type for {filename}");
+
+            return Compile(_shaderTypes[ext], File.ReadAllText(filename));
+        }
+    }
+}