public void CreateDeviceResources()
{
vertexBufferSize = 100_000;
indexBufferSize = 20_000;
vao = Ogl.GenVertexArray("Dear IMGUI");
Ogl.BindVertexArray(vao);
vertexBuffer = Ogl.GenBuffer("Dear IMGUI - Vertex Buffer");
indexBuffer = Ogl.GenBuffer("Dear IMGUI - Index Buffer");
Ogl.BindBuffer(BufferTarget.ArrayBuffer, vertexBuffer);
Ogl.BufferData(BufferTarget.ArrayBuffer, vertexBufferSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
//Ogl.NamedBufferData(vertexBuffer, vertexBufferSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
Ogl.BindBuffer(BufferTarget.ElementArrayBuffer, indexBuffer);
Ogl.BufferData(BufferTarget.ElementArrayBuffer, indexBufferSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
//Ogl.NamedBufferData(indexBuffer, indexBufferSize, IntPtr.Zero, BufferUsageHint.DynamicDraw);
RecreateFontDeviceTexture();
Shader shader = Shader.CreateShaderWithProgram(imgui_vert, imgui_frag, "ImGUI Shader");
material = new Material(shader, fontTexture);
material.LoadMaterial();
Ogl.VertexArrayVertexBuffer(vao, 0, vertexBuffer, IntPtr.Zero, Unsafe.SizeOf <ImDrawVert>());
Ogl.VertexArrayElementBuffer(vao, indexBuffer);
Ogl.EnableVertexArrayAttrib(vao, 0);
Ogl.VertexArrayAttribBinding(vao, 0, 0);
Ogl.VertexArrayAttribFormat(vao, 0, 2, VertexAttribType.Float, false, 0);
Ogl.EnableVertexArrayAttrib(vao, 1);
Ogl.VertexArrayAttribBinding(vao, 1, 0);
Ogl.VertexArrayAttribFormat(vao, 1, 2, VertexAttribType.Float, false, 8);
Ogl.EnableVertexArrayAttrib(vao, 2);
Ogl.VertexArrayAttribBinding(vao, 2, 0);
Ogl.VertexArrayAttribFormat(vao, 2, 4, VertexAttribType.UnsignedByte, true, 16);
}