/// <inheritdoc/>
public override void SetDataAligned <T>(T[] data, Int32 dataOffset, Int32 dataCount, Int32 bufferOffset, out Int32 bufferSize, SetDataOptions options)
{
Contract.Require(data, nameof(data));
Contract.EnsureRange(dataCount > 0, nameof(dataCount));
Contract.EnsureRange(dataOffset >= 0 && dataOffset + dataCount <= data.Length, nameof(dataOffset));
Contract.EnsureRange(bufferOffset >= 0, nameof(bufferOffset));
Contract.Ensure(dataCount <= IndexCount, OpenGLStrings.DataTooLargeForBuffer);
var indexStride = GetElementSize();
bufferSize = indexStride * dataCount;
var handle = GCHandle.Alloc(data, GCHandleType.Pinned);
try
{
var caps = (OpenGLGraphicsCapabilities)Ultraviolet.GetGraphics().Capabilities;
if (caps.MinMapBufferAlignment > 0)
{
bufferSize = Math.Min(Math.Max(caps.MinMapBufferAlignment, MathUtil.FindNextPowerOfTwo(bufferSize)), SizeInBytes - bufferOffset);
}
using (OpenGLState.ScopedBindElementArrayBuffer(buffer))
{
var isPartialUpdate = (bufferOffset > 0 || bufferSize < SizeInBytes);
var isDiscarding = (options == SetDataOptions.Discard);
if (isDiscarding || !isPartialUpdate)
{
gl.NamedBufferData(buffer, gl.GL_ELEMENT_ARRAY_BUFFER, this.size, isPartialUpdate ? null : handle.AddrOfPinnedObject().ToPointer(), usage);
gl.ThrowIfError();
}
if (isPartialUpdate)
{
if (caps.MinMapBufferAlignment >= 0)
{
var bufferRangeAccess = gl.GL_MAP_WRITE_BIT | (options == SetDataOptions.NoOverwrite ? gl.GL_MAP_UNSYNCHRONIZED_BIT : 0);
var bufferRangePtr = (Byte *)gl.MapNamedBufferRange(buffer, gl.GL_ELEMENT_ARRAY_BUFFER,
(IntPtr)bufferOffset, (IntPtr)bufferSize, bufferRangeAccess);
gl.ThrowIfError();
var sourceRangePtr = (Byte *)handle.AddrOfPinnedObject() + (dataOffset * indexStride);
var sourceSizeInBytes = dataCount * indexStride;
for (int i = 0; i < sourceSizeInBytes; i++)
{
*bufferRangePtr++ = *sourceRangePtr++;
}
gl.UnmapNamedBuffer(buffer, gl.GL_ELEMENT_ARRAY_BUFFER);
gl.ThrowIfError();
}
else
{
gl.NamedBufferSubData(buffer, gl.GL_ELEMENT_ARRAY_BUFFER,
(IntPtr)bufferOffset, (IntPtr)bufferSize, (Byte *)handle.AddrOfPinnedObject().ToPointer() + (dataOffset * indexStride));
gl.ThrowIfError();
}
}
}
}
finally
{
handle.Free();
}
}
