Legend:
Library
Module
Module type
Parameter
Class
Class type
Library
Module
Module type
Parameter
Class
Class type
The PNG functions allow reading PNG images into image surfaces, and writing any surface to a PNG file.
To create a new PNG file, start by creating an image surface, providing its format
(see Image.format
) and dimensions w
×h
with let surface = Cairo.Image.create format w h
. From this you can create a Cairo context to do your drawing: let cr =
Cairo.create surface
. Then, when you are done, call Cairo.PNG.write surface fname
to write the surface to the PNG file fname
.
val create : string -> Surface.t
create filename
creates a new image surface and initializes the contents to the given PNG file.
val create_from_stream : input:(string -> int -> unit) -> Surface.t
Creates a new image surface from PNG data read incrementally via the input
function. The input s l
function receives a string s
whose first l
bytes must be filled with PNG data. Any exception raised by input
is considered as a read error.
val write : Surface.t -> string -> unit
write surface filename
writes the contents of surface
to a new file filename
as a PNG image.
val write_to_stream : Surface.t -> (string -> unit) -> unit
Writes the image surface using the output
function.