Creates an image surface of the specified format and
dimensions. Initially the surface contents are set to 0.
(Specifically, within each pixel, each color or alpha channel
belonging to format will be 0. The contents of bits within a pixel,
but not belonging to the given format are undefined).
The format argument can be one of the following pixel
formats:
#CAIRO_FORMAT_ARGB32-
Each pixel is a 32-bit quantity, with alpha in the upper 8 bits, then
red, then green, then blue. The 32-bit quantities are stored native-endian.
Pre-multiplied alpha is used. (That is, 50% transparent red is $80800000,
not $80ff0000.)
#CAIRO_FORMAT_RGB24-
Each pixel is a 32-bit quantity, with the upper 8 bits unused. Red, green,
and blue are stored in the remaining 24 bits in that order.
#CAIRO_FORMAT_A8-
Each pixel is a 8-bit quantity holding an alpha value.
#CAIRO_FORMAT_A1-
Each pixel is a 1-bit quantity holding an alpha value. Pixels are packed
together into 32-bit quantities. The ordering of the bits matches the endianness
of the platform. On a big-endian machine, the first pixel is in the uppermost
bit, on a little-endian machine the first pixel is in the least-significant bit.
#CAIRO_FORMAT_RGB16_565-
Each pixel is a 16-bit quantity with red in the upper 5 bits, then green in the
middle 6 bits, and blue in the lower 5 bits.
#CAIRO_FORMAT_RGB30-
Like RGB24 but with 10bpc.
This function returns a handle to the newly created surface. The caller
owns the surface and should call csurface:Free() when done
with it.
This function always returns a valid handle, but it will return a
handle to a "nil" surface if an error such as out of memory
occurs. You can use csurface:Status() to check for this.