/// <summary>
/// Updates a subset of the buffer object's data store.
/// </summary>
/// <typeparam name="T">The type of data in the data array.</typeparam>
/// <param name="vboID">The VBO whose buffer will be updated.</param>
/// <param name="target">Specifies the target buffer object. Must be ArrayBuffer, ElementArrayBuffer, PixelPackBuffer or PixelUnpackBuffer.</param>
/// <param name="data">The new data that will be copied to the data store.</param>
/// <param name="length">The size in bytes of the data store region being replaced.</param>
public static void BufferSubData <T>(uint vboID, BufferTarget target, T[] data, int length)
where T : struct
{
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
try
{
Gl.BindBuffer(target, vboID);
Gl.BufferSubData(target, IntPtr.Zero, (IntPtr)(Marshal.SizeOf(data[0]) * length), handle.AddrOfPinnedObject());
}
finally
{
handle.Free();
}
}
/// <summary>
/// Updates a subset of the buffer object's data store.
/// </summary>
/// <param name="data">The new data that will be copied to the data store.</param>
/// <param name="size">The size in bytes of the data store region being replaced.</param>
/// <param name="offset">The offset in bytes into the buffer object's data store where data replacement will begin.</param>
public void BufferSubData(T[] data, int size, int offset)
{
if (BufferTarget != OpenGL.BufferTarget.ArrayBuffer && BufferTarget != OpenGL.BufferTarget.ElementArrayBuffer &&
BufferTarget != OpenGL.BufferTarget.PixelPackBuffer && BufferTarget != OpenGL.BufferTarget.PixelUnpackBuffer)
{
throw new InvalidOperationException(string.Format("BufferSubData cannot be called with a BufferTarget of type {0}", BufferTarget.ToString()));
}
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
try
{
Gl.BindBuffer(this);
Gl.BufferSubData(BufferTarget, (IntPtr)offset, (IntPtr)size, handle.AddrOfPinnedObject());
}
finally
{
handle.Free();
}
}
/// <summary>
/// Actually create this BufferObject resources.
/// </summary>
/// <param name="ctx">
/// A <see cref="GraphicsContext"/> used for allocating resources.
/// </param>
/// <exception cref="ArgumentNullException">
/// Exception thrown if <paramref name="ctx"/> is null.
/// </exception>
/// <exception cref="ArgumentException">
/// Exception thrown if <paramref name="ctx"/> is not current on the calling thread.
/// </exception>
/// <exception cref="InvalidOperationException">
/// Exception thrown if this BufferObject has not client memory allocated and the hint is different from
/// <see cref="BufferObjectHint.StaticCpuDraw"/> or <see cref="BufferObjectHint.DynamicCpuDraw"/>.
/// </exception>
/// <exception cref="InvalidOperationException">
/// Exception thrown if this BufferObject is currently mapped.
/// </exception>
protected override void CreateObject(GraphicsContext ctx)
{
CheckCurrentContext(ctx);
if ((ClientBufferAddress == IntPtr.Zero) && ((Hint != BufferObjectHint.StaticCpuDraw) && (Hint != BufferObjectHint.DynamicCpuDraw)))
{
throw new InvalidOperationException("no client buffer");
}
// Determine the client buffer size
uint clientBufferSize = _ClientBufferSize;
if (ClientBufferAddress != IntPtr.Zero)
{
clientBufferSize = ClientBufferSize;
}
Debug.Assert(clientBufferSize > 0);
// Buffer must be bound
Bind(ctx);
if (ctx.Caps.GlExtensions.VertexBufferObject_ARB)
{
if (IsMapped)
{
throw new InvalidOperationException("mapped");
}
// Define buffer object (type, size and hints)
Gl.BufferData((int)BufferType, clientBufferSize, null, (int)Hint);
// Store GPU buffer size
_GpuBufferSize = clientBufferSize;
// Define buffer object contents
if (ClientBufferAddress != IntPtr.Zero)
{
// Provide buffer contents
Gl.BufferSubData(BufferType, IntPtr.Zero, _GpuBufferSize, ClientBufferAddress);
// Release memory, if it is not required anymore
if (_MemoryBufferAutoDispose)
{
ReleaseClientBuffer();
}
}
}
else
{
// Discard previous GPU buffer, if any
if (_GpuBuffer != null)
{
_GpuBuffer.Dispose();
}
if (ClientBufferAddress == IntPtr.Zero)
{
// Note: GPU buffer size specified by _ClientBufferSize
Debug.Assert(_ClientBufferSize > 0);
// Allocate simulated GPU buffer
_GpuBuffer = new AlignedMemoryBuffer(_ClientBufferSize, MinimumBufferAlignment);
}
else
{
// Let a virtual implementation decide how pass information from the client buffer and the "GPU" buffer
UploadClientBuffer();
}
// Store GPU buffer size
_GpuBufferSize = _GpuBuffer.Size;
}
// Reset requested client buffer size
_ClientBufferSize = 0;
}
