Shader.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Security.Permissions;
using System.Text;
using System.Threading.Tasks;

using OpenTK;
using OpenTK.Graphics.OpenGL;

namespace Core.OpenGLShader
{
    public class Shader : IDisposable
    {
        public Shader()
        {
        }

        public static string ComposeShaderCode(List<Tuple<string, string>> defines, string originalCode)
        {
            string defineString = "";
            if (defines != null)
            {
                foreach (var define in defines)
                {
                    defineString += $"#define {define.Item1} {define.Item2}\n";
                }
            }

            var codes = originalCode.Split(Environment.NewLine, StringSplitOptions.RemoveEmptyEntries);
            bool versionCodeExist = codes.Where(x => x.StartsWith("#version")).Count() > 0;
            
            string composedSourceCode = (versionCodeExist ? "" : VersionString) + defineString + originalCode;
            return composedSourceCode;
        }

        public void Dispose()
        {
            GL.DeleteShader(shaderObject);
            shaderObject = -1;
        }

        public bool CompileShader(string ShaderSourceCode)
        {
            string ShaderErrLog = "";
            bool bSuccess = CompileShader(ShaderSourceCode, out ShaderErrLog);

            if (bSuccess == false)
            {
                Console.WriteLine(ShaderErrLog);
            }

            return bSuccess;
        }

        public void CompileShader(string shaderSourceCode, List<Tuple<string, string>> defines)
        {
            string ShaderErrLog = "";
            bool bSuccess = CompileShader(shaderSourceCode, defines, out ShaderErrLog);

            if (bSuccess == false)
            {
                Console.WriteLine(ShaderErrLog);
            }
        }


        public bool CompileShader(string[] shaderSourceCodes, out string errorlog)
        {
            int [] LengthList = new int[shaderSourceCodes.Length];

            for (int i = 0; i < shaderSourceCodes.Length; ++i)
            {
                LengthList[i] = shaderSourceCodes[i].Length;
            }

            GL.ShaderSource(shaderObject, shaderSourceCodes.Length, shaderSourceCodes, LengthList);
            GL.CompileShader(shaderObject);

            errorlog = string.Empty;

            int nStatus;
            GL.GetShader(shaderObject, ShaderParameter.CompileStatus, out nStatus);

            if (nStatus != 1)
            {
                GL.GetShaderInfoLog(shaderObject, out errorlog);

                return false;
            }

            return true;
        }

        public bool CompileShader(string shaderSourceCode, List<Tuple<string, string>> defines, out string errorLog)
        {
            string modifiedSourceCode = ComposeShaderCode(defines, shaderSourceCode);

            GL.ShaderSource(shaderObject, modifiedSourceCode);
            GL.CompileShader(shaderObject);

            errorLog = string.Empty;

            int nStatus;
            GL.GetShader(shaderObject, ShaderParameter.CompileStatus, out nStatus);

            if (nStatus != 1)
            {
                GL.GetShaderInfoLog(shaderObject, out errorLog);
                return false;
            }

            return true;
        }

        public bool CompileShader(string shaderSourceCode, out string errorlog)
        {
            GL.ShaderSource(shaderObject, shaderSourceCode);
            GL.CompileShader(shaderObject);

            errorlog = string.Empty;

            int nStatus;
            GL.GetShader(shaderObject, ShaderParameter.CompileStatus, out nStatus);

            if (nStatus != 1)
            {
                GL.GetShaderInfoLog(shaderObject, out errorlog);

                return false;
            }

            return true;
        }

        public int ShaderObject 
        {
            get { return shaderObject; }

            protected set
            {
                shaderObject = value;
            }
        }

        private int shaderObject = -1;

        public static string VersionString = "#version 450 core\n";
    }
}