Bitmap/Write a PPM file
< Bitmap
Bitmap/Write a PPM file
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
C
<C>#include <stdio.h>
void output_ppm(FILE *fd, image img) {
unsigned int n; fprintf(fd, "P6\n%d %d\n255\n", img->width, img->height); n = img->width * img->height; fwrite(img->buf, sizeof(pixel), n, fd); fflush(fd);
}</C>
Forth
: write-ppm { bmp fid -- } s" P6" fid write-line throw bmp bdim swap 0 <# bl hold #s #> fid write-file throw 0 <# #s #> fid write-line throw s" 255" fid write-line throw bmp bdata bmp bdim * pixels bounds do i 3 fid write-file throw pixel +loop ;
s" red.ppm" w/o create-file throw test over write-ppm close-file throw
OCaml
<ocaml>let output_ppm ~oc ~img:(_, r_channel, g_channel, b_channel) =
let width = Bigarray.Array2.dim1 r_channel and height = Bigarray.Array2.dim2 r_channel in Printf.fprintf oc "P6\n%d %d\n255\n" width height; for y = 0 to pred height do for x = 0 to pred width do output_char oc (char_of_int r_channel.{x,y}); output_char oc (char_of_int g_channel.{x,y}); output_char oc (char_of_int b_channel.{x,y}); done; done; output_char oc '\n'; flush oc;
- </ocaml>