Source file imageBitmap.ml
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type t = bool array array
type bitmap = t
let create c width height : t = Array.init height (fun _ -> Array.make width c)
let create_white = create true
let create = create false
let make data : t = data
let init width height f =
make (Array.init height (fun j -> Array.init width (fun i -> f i j)))
let width (img : t) = if Array.length img = 0 then 0 else Array.length img.(0)
let height (img : t) = Array.length img
let get_pixel img i j = img.(j).(i)
let set_pixel img i j c = img.(j).(i) <- c
let fill img f =
for j = 0 to height img - 1 do
for i = 0 to width img - 1 do
set_pixel img i j (f i j)
done
done
let scale src tgt =
let ws = width src in
let wt = width tgt in
let hs = height src in
let ht = height tgt in
fill tgt (fun i j -> get_pixel src (i * ws / wt) (j * hs / ht))
let rescale p q img =
let img2 = create (width img * p / q) (height img * p / q) in
scale img img2;
img2
let blit src ?(x = 0) ?(y = 0) dst =
let width = min (width src) (width dst - x) in
let height = min (height src) (height dst - y) in
for j = 0 to height - 1 do
for i = 0 to width - 1 do
set_pixel dst (x + i) (y + j) (get_pixel src i j)
done
done
(** Bitmap fonts. *)
module Font = struct
module CharMap = Map.Make (struct
type t = char
let compare (c : t) (d : t) = Stdlib.compare c d
end)
(** A fixed-size font. *)
type nonrec t = {
map : t CharMap.t Lazy.t;
width : int; (** width of a char in pixels *)
height : int; (** height of a char in pixels *)
default : t; (** default displayed character when not supported *)
uppercase : bool; (** whether only uppercase caracters are supported *)
char_space : int;
line_space : int;
}
let height font = font.height
(** Our native font. *)
let native : t =
let prebitmap =
[
('A', [| " * "; "* *"; "***"; "* *"; "* *" |]);
('B', [| "** "; "* *"; "** "; "* *"; "** " |]);
('C', [| " **"; "* "; "* "; "* "; " **" |]);
('D', [| "** "; "* *"; "* *"; "* *"; "** " |]);
('E', [| "***"; "* "; "** "; "* "; "***" |]);
('F', [| "***"; "* "; "** "; "* "; "* " |]);
('G', [| " **"; "* "; "* *"; "* *"; " **" |]);
('H', [| "* *"; "* *"; "***"; "* *"; "* *" |]);
('I', [| " * "; " * "; " * "; " * "; " * " |]);
('J', [| " *"; " *"; " *"; "* *"; " * " |]);
('K', [| "* *"; "** "; "* "; "** "; "* *" |]);
('L', [| "* "; "* "; "* "; "* "; "***" |]);
('M', [| "* *"; "***"; "* *"; "* *"; "* *" |]);
('N', [| "* *"; "***"; "***"; "***"; "* *" |]);
('O', [| " * "; "* *"; "* *"; "* *"; " * " |]);
('P', [| "** "; "* *"; "** "; "* "; "* " |]);
('Q', [| " * "; "* *"; "* *"; "* *"; " **" |]);
('R', [| "** "; "* *"; "** "; "* *"; "* *" |]);
('S', [| " **"; "* "; " * "; " *"; "** " |]);
('T', [| "***"; " * "; " * "; " * "; " * " |]);
('U', [| "* *"; "* *"; "* *"; "* *"; "***" |]);
('V', [| "* *"; "* *"; "* *"; "* *"; " * " |]);
('W', [| "* *"; "* *"; "* *"; "***"; "* *" |]);
('X', [| "* *"; "* *"; " * "; "* *"; "* *" |]);
('Y', [| "* *"; "* *"; " * "; " * "; " * " |]);
('Z', [| "***"; " *"; " * "; "* "; "***" |]);
('0', [| " * "; "* *"; "* *"; "* *"; " * " |]);
('1', [| " * "; "** "; " * "; " * "; " * " |]);
('2', [| " * "; "* *"; " *"; " * "; "***" |]);
('3', [| "** "; " *"; " * "; " *"; "** " |]);
('4', [| " *"; " **"; "***"; " *"; " *" |]);
('5', [| "***"; "* "; "** "; " *"; "** " |]);
('6', [| " **"; "* "; "** "; "* *"; " * " |]);
('7', [| "***"; " *"; " * "; " * "; " * " |]);
('8', [| " * "; "* *"; " * "; "* *"; " * " |]);
('9', [| " * "; "* *"; " **"; " *"; " * " |]);
(' ', [| " "; " "; " "; " "; " " |]);
('.', [| " "; " "; " "; " "; " * " |]);
(',', [| " "; " "; " "; " * "; " * " |]);
('!', [| " * "; " * "; " * "; " "; " * " |]);
('?', [| " * "; "* *"; " **"; " * "; " * " |]);
('-', [| " "; " "; "***"; " "; " " |]);
('+', [| " "; " * "; "***"; " * "; " " |]);
('=', [| " "; "***"; " "; "***"; " " |]);
(':', [| " "; " * "; " "; " * "; " " |]);
('<', [| " *"; " * "; "* "; " * "; " *" |]);
('>', [| "* "; " * "; " *"; " * "; "* " |]);
]
in
let width = 3 in
let height = 5 in
let map =
Lazy.from_fun (fun () ->
List.fold_left
(fun f (c, b) ->
let bmp = init width height (fun i j -> b.(j).[i] <> ' ') in
CharMap.add c bmp f)
CharMap.empty prebitmap)
in
let default = create_white width height in
{
map;
width;
height;
default;
uppercase = true;
char_space = 1;
line_space = 2;
}
let render ?(font = native) ?size text =
let height = Option.value ~default:font.height size in
let text_height, text_width =
let h = ref 1 in
let max = ref 0 in
let cur = ref 0 in
for i = 0 to String.length text - 1 do
if text.[i] = '\n' then (
max := Stdlib.max !max !cur;
cur := 0;
incr h)
else incr cur
done;
max := Stdlib.max !max !cur;
(!h, !max)
in
let img =
let width =
(text_width * font.width) + ((text_width - 1) * font.char_space)
in
let height =
(text_height * font.height) + ((text_height - 1) * font.line_space)
in
let width = max width 0 in
let height = max height 0 in
create width height
in
let xoff = ref 0 in
let yoff = ref 0 in
for i = 0 to String.length text - 1 do
let c = text.[i] in
if c = '\n' then (
xoff := 0;
yoff := !yoff + font.height + font.line_space)
else (
let c = if font.uppercase then Char.uppercase_ascii c else c in
let c =
match CharMap.find_opt c (Lazy.force font.map) with
| Some c -> c
| None -> font.default
in
blit c ~x:!xoff ~y:!yoff img;
xoff := !xoff + font.width + font.char_space)
done;
rescale height font.height img
end