I'm experiencing some CPU bottlenecks in my game(200 different vertex buffers, 4000 draw calls per scene, will be more in the future), so I decided to switch from VBO to bindless arrays.
I've been reading on the topic the past 2 days and I have a lot of questions as to why and how it does not work.
I'm running on Core i5 2500K Desktop, GeForce GTX 660 Ti. Drivers are from this year. Windows 7 64bit running on .Net 4.0 with a March 2012 OpenTK release.
First, when I try to Enable VertexAttribArrayUnifiedNv and check with GL.IsEnabled it returns false. I suppose this is the main culprit behind my problems.
This is how I make the buffer (only the positions for simplicity, will add the rest once this works)
GL.GenBuffers(1, out positionVboHandle); GL.BindBuffer(BufferTarget.ArrayBuffer, positionVboHandle); GL.BufferData<Vector3>(BufferTarget.ArrayBuffer, new IntPtr(verticesOGL.Length * Vector3.SizeInBytes), verticesOGL, BufferUsageHint.StaticDraw); GL.NV.GetBufferParameter((NvShaderBufferLoad)BufferTarget.ArrayBuffer, NvShaderBufferLoad.BufferGpuAddressNv, out bindlessPosition); GL.NV.MakeBufferResident((NvShaderBufferLoad)BufferTarget.ArrayBuffer, (NvShaderBufferLoad)All.ReadOnly);
and then I'm trying to render with
GL.Enable((EnableCap)All.VertexAttribArrayUnifiedNv); GL.NV.BufferAddressRange(NvVertexBufferUnifiedMemory.VertexArrayAddressNv/*VertexAttribArrayAddressNv*/, 0, pModel.bindlessPosition, new IntPtr(pModel.verticesOGL.Length * Vector3.SizeInBytes)); GL.BindAttribLocation(testShader.program, 0, "vertex_position"); GL.DrawArrays(BeginMode.Triangles, 0, pModel.verticesOGL.Length);
If I switch to BeginMode.Points I sometimes get in the shader (0,0,0) for the vertex input.
If I try to GL.EnableVertexAttribArray(0);
the program crashes on the GL.DrawArrays(..)
Maybe I'm not linking the attributes properly? I saw somewhere they use VertexFormatNV() but in OpenTK the parameters are different and I don't know what to put there.
Also I checked the 64-bit pointer GetBufferParameter throws and at first glance it seems legit. Each consecutive vertex array was places in the vicinity, though each pointer has lower values than the previous one.
I really hope someone can help me with this, or at least point me in the right direction as to where to work if the problem is from the wrapper itself.