Renderer.cs

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using OpenTK.Graphics.OpenGL4;
using OpenTK.Windowing.Common;
using OpenTK.Windowing.Desktop;
using OpenTK.Mathematics;
namespace BioCore
{
    public class GLWindow : GameWindow
    {
        int vao, vbo;
        int shaderProgram;
 
        public GLWindow(GameWindowSettings gws, NativeWindowSettings nws)
            : base(gws, nws) {  }
 
        protected override void OnLoad()
        {
            base.OnLoad();
 
            GL.ClearColor(0f, 0f, 0f, 1f);
 
            CompileShaders();
            SetupGeometry();
            
        }
 
        protected override void OnResize(ResizeEventArgs e)
        {
            base.OnResize(e);
            GL.Viewport(0, 0, Size.X, Size.Y);
        }
 
        protected override void OnRenderFrame(FrameEventArgs args)
        {
            base.OnRenderFrame(args);
 
            GL.Clear(ClearBufferMask.ColorBufferBit);
 
            GL.UseProgram(shaderProgram);
            GL.BindVertexArray(vao);
            GL.DrawArrays(PrimitiveType.Triangles, 0, 3);
 
            SwapBuffers();
        }
 
        void SetupGeometry()
        {
            float[] vertices =
            {
             0f,  0.5f,
            -0.5f, -0.5f,
             0.5f, -0.5f
        };
 
            vao = GL.GenVertexArray();
            vbo = GL.GenBuffer();
 
            GL.BindVertexArray(vao);
            GL.BindBuffer(BufferTarget.ArrayBuffer, vbo);
            GL.BufferData(BufferTarget.ArrayBuffer, vertices.Length * sizeof(float), vertices, BufferUsageHint.StaticDraw);
 
            GL.VertexAttribPointer(0, 2, VertexAttribPointerType.Float, false, 2 * sizeof(float), 0);
            GL.EnableVertexAttribArray(0);
        }
 
        void CompileShaders()
        {
            string vertexShaderSource = @"
#version 330 core
layout (location = 0) in vec2 aPos;
void main()
{
    gl_Position = vec4(aPos.xy, 0.0, 1.0);
}";
 
            string fragmentShaderSource = @"
#version 330 core
out vec4 FragColor;
void main()
{
    FragColor = vec4(1,0,0,1);
}";
 
            int vs = GL.CreateShader(ShaderType.VertexShader);
            GL.ShaderSource(vs, vertexShaderSource);
            GL.CompileShader(vs);
 
            int fs = GL.CreateShader(ShaderType.FragmentShader);
            GL.ShaderSource(fs, fragmentShaderSource);
            GL.CompileShader(fs);
 
            shaderProgram = GL.CreateProgram();
            GL.AttachShader(shaderProgram, vs);
            GL.AttachShader(shaderProgram, fs);
            GL.LinkProgram(shaderProgram);
 
            GL.DeleteShader(vs);
            GL.DeleteShader(fs);
        }
    }
}