/// <summary>
/// Gets a copy of 3D texture data, specifying a mipmap level, source box, start index, and number of elements.
/// </summary>
/// <typeparam name="T">The type of the elements in the array.</typeparam>
/// <param name="level">Mipmap level.</param>
/// <param name="left">Position of the left side of the box on the x-axis.</param>
/// <param name="top">Position of the top of the box on the y-axis.</param>
/// <param name="right">Position of the right side of the box on the x-axis.</param>
/// <param name="bottom">Position of the bottom of the box on the y-axis.</param>
/// <param name="front">Position of the front of the box on the z-axis.</param>
/// <param name="back">Position of the back of the box on the z-axis.</param>
/// <param name="data">Array of data.</param>
/// <param name="startIndex">Index of the first element to get.</param>
/// <param name="elementCount">Number of elements to get.</param>
public void GetData <T>(
int level,
int left,
int top,
int right,
int bottom,
int front,
int back,
T[] data,
int startIndex,
int elementCount
) where T : struct
{
if (data == null || data.Length == 0)
{
throw new ArgumentException("data cannot be null");
}
if (data.Length < startIndex + elementCount)
{
throw new ArgumentException(
"The data passed has a length of " + data.Length.ToString() +
" but " + elementCount.ToString() + " pixels have been requested."
);
}
if ((left < 0 || left >= right) ||
(top < 0 || top >= bottom) ||
(front < 0 || front >= back))
{
throw new ArgumentException("Neither box size nor box position can be negative");
}
int elementSizeInBytes = Marshal.SizeOf(typeof(T));
ValidateGetDataFormat(Format, elementSizeInBytes);
GCHandle handle = GCHandle.Alloc(data, GCHandleType.Pinned);
FNA3D.FNA3D_GetTextureData3D(
GraphicsDevice.GLDevice,
texture,
left,
top,
front,
right - left,
bottom - top,
back - front,
level,
handle.AddrOfPinnedObject() + (startIndex * elementSizeInBytes),
elementCount * elementSizeInBytes
);
handle.Free();
}