Allocates a large-enough single-channel 8bpp bitmap and renders the
specified character/glyph at the specified scale into it, with
antialiasing. 0 is no coverage (transparent), 255 is fully covered (opaque).
*width & *height are filled out with the width & height of the bitmap,
which is stored left-to-right, top-to-bottom.
xoff/yoff are the offset it pixel space from the glyph origin to the top-left of the bitmap
Allocates a large-enough single-channel 8bpp bitmap and renders the specified character/glyph at the specified scale into it, with antialiasing. 0 is no coverage (transparent), 255 is fully covered (opaque). *width & *height are filled out with the width & height of the bitmap, which is stored left-to-right, top-to-bottom.
xoff/yoff are the offset it pixel space from the glyph origin to the top-left of the bitmap