1 files changed, 113 insertions, 0 deletions
diff --git a/Ryujinx.Graphics/Gal/OpenGL/OGLStreamBuffer.cs b/Ryujinx.Graphics/Gal/OpenGL/OGLStreamBuffer.cs
new file mode 100644
index 00000000..3d91b09f
--- /dev/null
+++ b/Ryujinx.Graphics/Gal/OpenGL/OGLStreamBuffer.cs
@@ -0,0 +1,113 @@
+using System;
+using OpenTK.Graphics.OpenGL;
+
+namespace Ryujinx.Graphics.Gal.OpenGL
+{
+    abstract class OGLStreamBuffer : IDisposable
+    {
+        public int Handle { get; protected set; }
+
+        public int Size { get; protected set; }
+
+        protected BufferTarget Target { get; private set; }
+
+        private bool Mapped = false;
+
+        public OGLStreamBuffer(BufferTarget Target, int MaxSize)
+        {
+            Handle = 0;
+            Mapped = false;
+
+            this.Target = Target;
+            this.Size = MaxSize;
+        }
+
+        public static OGLStreamBuffer Create(BufferTarget Target, int MaxSize)
+        {
+            //TODO: Query here for ARB_buffer_storage and use when available
+            return new SubDataBuffer(Target, MaxSize);
+        }
+
+        public byte[] Map(int Size)
+        {
+            if (Handle == 0 || Mapped || Size > this.Size)
+            {
+                throw new InvalidOperationException();
+            }
+
+            byte[] Memory = InternMap(Size);
+
+            Mapped = true;
+
+            return Memory;
+        }
+
+        public void Unmap(int UsedSize)
+        {
+            if (Handle == 0 || !Mapped)
+            {
+                throw new InvalidOperationException();
+            }
+
+            InternUnmap(UsedSize);
+
+            Mapped = false;
+        }
+
+        protected abstract byte[] InternMap(int Size);
+
+        protected abstract void InternUnmap(int UsedSize);
+
+        public void Dispose()
+        {
+            Dispose(true);
+        }
+
+        protected virtual void Dispose(bool Disposing)
+        {
+            if (Disposing && Handle != 0)
+            {
+                GL.DeleteBuffer(Handle);
+
+                Handle = 0;
+            }
+        }
+    }
+
+    class SubDataBuffer : OGLStreamBuffer
+    {
+        private byte[] Memory;
+
+        public SubDataBuffer(BufferTarget Target, int MaxSize)
+            : base(Target, MaxSize)
+        {
+            Memory = new byte[MaxSize];
+
+            GL.CreateBuffers(1, out int Handle);
+
+            GL.BindBuffer(Target, Handle);
+
+            GL.BufferData(Target, Size, IntPtr.Zero, BufferUsageHint.StreamDraw);
+
+            this.Handle = Handle;
+        }
+
+        protected override byte[] InternMap(int Size)
+        {
+            return Memory;
+        }
+
+        protected override void InternUnmap(int UsedSize)
+        {
+            GL.BindBuffer(Target, Handle);
+            
+            unsafe
+            {
+                fixed (byte* MemoryPtr = Memory)
+                {
+                    GL.BufferSubData(Target, IntPtr.Zero, UsedSize, (IntPtr)MemoryPtr);
+                }
+            }
+        }
+    }
+}
+\ No newline at end of file