add PPM reader

source/leela/main.rs

@@ -1,5 +1,5 @@
 use maraiah::{durandal::{err::*, file::*, image::*, sound::*},
-              marathon::{machdr, shp, snd, tga, wad, wav}};
+              marathon::{machdr, ppm, shp, snd, tga, wad, wav}};
 use std::{fs, io};
 
 fn make_tga(_opt: &Options, fname: &str, im: &impl Image) -> ResultS<()>
@@ -9,6 +9,13 @@ fn make_tga(_opt: &Options, fname: &str, im: &impl Image) -> ResultS<()>
    tga::write_tga(&mut out, im)
 }
 
+fn make_ppm(_opt: &Options, fname: &str, im: &impl Image) -> ResultS<()>
+{
+   let mut out = io::BufWriter::new(fs::File::create(fname)?);
+
+   ppm::write_ppm(&mut out, im)
+}
+
 fn make_yaml<T>(opt: &Options, data: &T) -> ResultS<()>
    where T: serde::Serialize + std::fmt::Debug
 {
@@ -111,6 +118,17 @@ fn process_snd(opt: &Options, b: &[u8]) -> ResultS<()>
    Ok(())
 }
 
+fn process_ppm(opt: &Options, b: &[u8]) -> ResultS<()>
+{
+   let im = ppm::read_ppm(b)?;
+
+   let fname = format!("{}/out.tga", opt.out_dir);
+   make_tga(opt, &fname, &im)?;
+
+   let fname = format!("{}/out.ppm", opt.out_dir);
+   make_ppm(opt, &fname, &im)
+}
+
 fn main() -> ResultS<()>
 {
    use argparse::*;
@@ -210,6 +228,7 @@ fn main() -> ResultS<()>
          "wad:" => process_wad(&opt, b),
          "shp:" => process_shp(&opt, b),
          "snd:" => process_snd(&opt, b),
+         "ppm:" => process_ppm(&opt, b),
          _      => Err(err_msg("invalid file type specified on commandline")),
       }?;
    }

source/marathon/ppm.rs

@@ -1,6 +1,6 @@
 //! Portable PixMap format images.
 
-use crate::durandal::{err::*, image::*};
+use crate::durandal::{err::*, fixed::FixedLong, image::*};
 use std::io;
 
 /// Writes a PPM file from an image.
@@ -24,4 +24,46 @@ pub fn write_ppm(out: &mut impl io::Write, im: &impl Image) -> ResultS<()>
    Ok(())
 }
 
+/// Reads a PPM file into an image.
+pub fn read_ppm(inp: &[u8]) -> ResultS<Image16>
+{
+   let mut it = inp.split(|&n| n == b'\n' || n == b'\r' || n == b' ');
+
+   if ok!(it.next(), "no magic number")? != b"P3" {
+      bail!("not P3 format");
+   }
+
+   let mut get_num = move || -> ResultS<u16> {
+      let st = loop {
+         match ok!(it.next(), "no more strings")? {
+            b"" => {}
+            st  => break st
+         }
+      };
+      let st = unsafe {std::str::from_utf8_unchecked(&st)};
+      let nu = u16::from_str_radix(st, 10)?;
+      Ok(nu)
+   };
+
+   let width  = get_num()?;
+   let height = get_num()?;
+   let depth  = i64::from(get_num()?);
+
+   let mut im = Image16::new(usize::from(width), usize::from(height));
+
+   for _ in 0..height * width {
+      let r = FixedLong::from_int(get_num()?.into());
+      let g = FixedLong::from_int(get_num()?.into());
+      let b = FixedLong::from_int(get_num()?.into());
+
+      let r = (r / depth * 65535).integ() as u16;
+      let g = (g / depth * 65535).integ() as u16;
+      let b = (b / depth * 65535).integ() as u16;
+
+      im.cr.push(Color16::new(r, g, b));
+   }
+
+   Ok(im)
+}
+
 // EOF