Reads pixel data from a rectangular region of the surface into the specified buffer. The format to be used for pixels in the buffer is defined by the PixelFormat object and pixel format conversions will be performed as needed to store the data in the indicated format. The buffer is assumed to be positioned to the location where the first pixel data from the image pixel at location (x, y) will be stored. Pixel data for a row will be stored in adjacent locations within the buffer packed as tightly as possible for increasing X coordinates. Pixel data for adjacent rows will be stored offset from each other by the number of buffer data elements defined by scanlineStride.

Parameters:

<T>		the type of the buffer
x		the X coordinate of the rectangular region to read
y		the Y coordinate of the rectangular region to read
w		the width of the rectangular region to read
h		the height of the rectangular region to read
pixelformat		the PixelFormat object defining the format to store the pixels into buffer
buffer		a buffer of a type appropriate for the indicated PixelFormat object
scanlineStride		the distance between the pixel data for the start of one row of data in the buffer to the start of the next row of data.