CSharpGL.Demos.KleinBottleModel.GetIndexBuffer C# (CSharp) Метод

        public IndexBuffer GetIndexBuffer()
        {
            if (this.indexBuffer == null)
            {
                int uCount = GetUCount(interval);
                int vCount = GetVCount(interval);
                int length = (uCount + 1) * vCount + (vCount + 1 + 1) * uCount;
                OneIndexBuffer buffer = CSharpGL.Buffer.Create(IndexBufferElementType.UInt, length, DrawMode.LineStrip, BufferUsage.StaticDraw);
                unsafe
                {
                    IntPtr pointer = buffer.MapBuffer(MapBufferAccess.WriteOnly);
                    var array = (uint*)pointer;
                    int index = 0;
                    // vertical lines.
                    for (int i = 0; i < vCount; i++)
                    {
                        for (int j = 0; j < uCount; j++)
                        {
                            array[index++] = (uint)(i + j * vCount);
                        }
                        array[index++] = uint.MaxValue;// primitive restart index.
                    }
                    // horizontal lines.
                    for (int i = 0; i < uCount; i++)
                    {
                        for (int j = 0; j < vCount; j++)
                        {
                            array[index++] = (uint)(j + i * vCount);
                        }
                        array[index++] = (uint)(0 + i * vCount);
                        array[index++] = uint.MaxValue;// primitive restart index.
                    }
                    buffer.UnmapBuffer();
                }
                this.indexBuffer = buffer;
            }

            return this.indexBuffer;
        }