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|
external rawget : string -> string
= "camltk_getimgdata"
external rawset : string -> string -> int -> int -> int -> int -> unit
= "camltk_setimgdata_bytecode" (* all int parameters MUST be positive *)
"camltk_setimgdata_native"
type t = {
pixmap_width : int;
pixmap_height: int;
pixmap_data: string
}
type pixel = string (* 3 chars *)
(* pixmap will be an abstract type *)
let width pix = pix.pixmap_width
let height pix = pix.pixmap_height
(* note: invalid size would have been caught by String.create, but we put
* it here for documentation purpose *)
let create w h =
if w < 0 || h < 0 then invalid_arg "invalid size"
else {
pixmap_width = w;
pixmap_height = h;
pixmap_data = String.create (w * h * 3);
}
(*
* operations on pixmaps
*)
let unsafe_copy pix_from pix_to =
String.unsafe_blit pix_from.pixmap_data 0
pix_to.pixmap_data 0
(String.length pix_from.pixmap_data)
(* We check only the length. w,h might be different... *)
let copy pix_from pix_to =
let l = String.length pix_from.pixmap_data in
if l <> String.length pix_to.pixmap_data then
raise (Invalid_argument "copy: incompatible length")
else unsafe_copy pix_from pix_to
(* Pixel operations *)
let unsafe_get_pixel pixmap x y =
let pos = (y * pixmap.pixmap_width + x) * 3 in
let r = String.create 3 in
String.unsafe_blit pixmap.pixmap_data pos r 0 3;
r
let unsafe_set_pixel pixmap x y pixel =
let pos = (y * pixmap.pixmap_width + x) * 3 in
String.unsafe_blit pixel 0 pixmap.pixmap_data pos 3
(* To get safe operations, we can either check x,y wrt [0,w[ and [0,h[
or rely on blit checking. We choose the first for clarity.
*)
let get_pixel pix x y =
if x < 0 || y < 0 || x >= pix.pixmap_width || y >= pix.pixmap_height
then invalid_arg "invalid pixel"
else unsafe_get_pixel pix x y
(* same check (pixel being abstract, it must be of good size *)
let set_pixel pix x y pixel =
if x < 0 || y < 0 || x >= pix.pixmap_width || y >= pix.pixmap_height
then invalid_arg "invalid pixel"
else unsafe_set_pixel pix x y pixel
(* black as default_color, if at all needed *)
let default_color = "\000\000\000"
(* Char.chr does range checking *)
let pixel r g b =
let s = String.create 3 in
s.[0] <- Char.chr r;
s.[1] <- Char.chr g;
s.[2] <- Char.chr b;
s
##ifdef CAMLTK
(* create pixmap from an existing image *)
let get photo =
match photo with
| PhotoImage s -> {
pixmap_width = CImagephoto.width photo;
pixmap_height = CImagephoto.height photo;
pixmap_data = rawget s;
}
(* copy a full pixmap into an image *)
let set photo pix =
match photo with
| PhotoImage s ->
rawset s pix.pixmap_data 0 0 pix.pixmap_width pix.pixmap_height
(* general blit of pixmap into image *)
let blit photo pix x y w h =
if x < 0 || y < 0 || w < 0 || h < 0 then invalid_arg "negative argument"
else match photo with
| PhotoImage s ->
rawset s pix.pixmap_data x y w h
(* get from a file *)
let from_file filename =
let img = CImagephoto.create [File filename] in
let pix = get img in
CImagephoto.delete img;
pix
##else
(* create pixmap from an existing image *)
let get photo =
match photo with
| `Photo s -> {
pixmap_width = Imagephoto.width photo;
pixmap_height = Imagephoto.height photo;
pixmap_data = rawget s;
}
(* copy a full pixmap into an image *)
let set photo pix =
match photo with
| `Photo s -> rawset s pix.pixmap_data 0 0 pix.pixmap_width pix.pixmap_height
(* general blit of pixmap into image *)
let blit photo pix x y w h =
if x < 0 || y < 0 || w < 0 || h < 0 then invalid_arg "negative argument"
else match photo with
| `Photo s -> rawset s pix.pixmap_data x y w h
(* get from a file *)
let from_file filename =
let img = Imagephoto.create ~file: filename () in
let pix = get img in
Imagephoto.delete img;
pix
##endif
|
