RosettaCodeData/Task/Bitmap-Write-a-PPM-file/ATS/bitmap-write-a-ppm-file-2.ats

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(*------------------------------------------------------------------*)
#define ATS_DYNLOADFLAG 0
#define ATS_PACKNAME "Rosetta_Code.bitmap_write_ppm_task"
#include "share/atspre_staload.hats"
staload "bitmap_task.sats"
(* You need to staload bitmap_task.dats, so the ATS compiler will have
access to its implementations of templates. But we staload it
anonymously, so the programmer will not have access. *)
staload _ = "bitmap_task.dats"
staload "bitmap_write_ppm_task.sats"
(*------------------------------------------------------------------*)
(* Realizing that MAXVAL, and how to represent depend on the
pixel type, we implement the template functions ONLY for pixels of
type rgb24. *)
(* We will implement raw PPM using "dump", and plain PPM using the
"get a pixel" square brackets. The latter method is simpler than
writing a different implementation of pixmap$pixels_dump<rgb24>,
and also helps us satisfy the stated requirements of the task.
("Dump" goes beyond what was asked for.) *)
implement
pixmap_write_ppm_raw_or_plain<rgb24> (outf, pix, plain) =
begin
fprintln! (outf, (if plain then "P3" else "P6") : string);
fprintln! (outf, width pix, " ", height pix);
fprintln! (outf, "255");
if ~plain then
dump<rgb24> (outf, pix)
else
let
val w = width pix and h = height pix
prval [w : int] EQINT () = eqint_make_guint w
prval [h : int] EQINT () = eqint_make_guint h
fun
loop {x, y : nat | x <= w; y <= h}
.<h - y, w - x>.
(pix : !pixmap (rgb24, w, h),
x : size_t x,
y : size_t y)
: void =
if y = h then
()
else if x = w then
loop (pix, i2sz 0, succ y)
else
let
val @(r, g, b) = rgb24_values pix[x, y]
in
fprintln! (outf, r, " ", g, " ", b);
loop (pix, succ x, y)
end
in
loop (pix, i2sz 0, i2sz 0);
true
end
end
implement
pixmap_write_ppm_raw<rgb24> (outf, pix) =
pixmap_write_ppm_raw_or_plain<rgb24> (outf, pix, false)
(*------------------------------------------------------------------*)
#ifdef BITMAP_WRITE_PPM_TASK_TEST #then
implement
main0 () =
let
val bgcolor = rgb24_make (217u, 217u, 214u)
and fgcolor1 = rgb24_make (210, 0, 0)
and fgcolor2 = rgb24_make (0, 150, 0)
and fgcolor3 = rgb24_make (0, 0, 220)
stadef w = 300
stadef h = 200
val w : size_t w = i2sz 300
and h : size_t h = i2sz 200
val @(pfgc | pix) = pixmap_make<rgb24> (w, h, bgcolor)
val () =
let
var x : Size_t
in
for* {x : nat | x <= w}
.<w - x>.
(x : size_t x) =>
(x := i2sz 0; x <> w; x := succ x)
begin
pix[x, i2sz 50] := fgcolor1;
pix[x, i2sz 100] := fgcolor2;
pix[x, i2sz 150] := fgcolor3
end
end
val outf_raw = fileref_open_exn ("image-raw.ppm", file_mode_w)
and outf_plain = fileref_open_exn ("image-plain.ppm", file_mode_w)
val success = pixmap_write_ppm<rgb24> (outf_raw, pix)
val () = assertloc success
val success = pixmap_write_ppm<rgb24> (outf_plain, pix, true)
val () = assertloc success
in
fileref_close outf_raw;
fileref_close outf_plain;
free (pfgc | pix)
end
#endif
(*------------------------------------------------------------------*)