/// <summary cref="DirectXBuffer.OnMap(DeviceContext)"/>
protected override unsafe IntPtr OnMap(DeviceContext context)
{
Debug.Assert(box.IsEmpty);
// Copy the texture into the staging texture
if (ViewFlags != DirectXViewFlags.WriteDiscard)
{
context.CopyResource(Texture, stagingTexture);
}
var mapMode = CPUDirectXAccelerator.ConvertToMapMode(ViewFlags);
box = context.MapSubresource(stagingTexture, 0, mapMode, MapFlags.None);
// Reserve enough space
var lengthInBytes = box.SlicePitch;
EnsureSpace(lengthInBytes);
if (ViewFlags != DirectXViewFlags.WriteDiscard)
{
// Copy the contents of the staging texture into the CPU-memory buffer
System.Buffer.MemoryCopy(
box.DataPointer.ToPointer(),
cpuMemory.NativePtr.ToPointer(),
lengthInBytes,
lengthInBytes);
}
return(cpuMemory.NativePtr);
}
/// <summary cref="DirectXBuffer.OnMap(DeviceContext)"/>
protected override unsafe IntPtr OnMap(DeviceContext context)
{
Debug.Assert(box.IsEmpty);
var mapMode = CPUDirectXAccelerator.ConvertToMapMode(ViewFlags);
// Copy the buffer to the staging buffer
if (ViewFlags != DirectXViewFlags.WriteDiscard)
{
context.CopyResource(Buffer, stagingBuffer);
}
box = context.MapSubresource(stagingBuffer, 0, mapMode, MapFlags.None);
// We have to copy the contents of the DX buffer into the CPU-memory buffer
if (ViewFlags != DirectXViewFlags.WriteDiscard)
{
System.Buffer.MemoryCopy(
box.DataPointer.ToPointer(),
cpuMemory.NativePtr.ToPointer(),
cpuMemory.LengthInBytes,
cpuMemory.LengthInBytes);
}
return(cpuMemory.NativePtr);
}