feat: adds --base64 option

Author: ynn

Cargo.lock

@@ -7,6 +7,7 @@ default-run = "piet_programming_language"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+base64 = "0.22.1"
 clap = { version = "4.5.48", features = ["derive"] }
 image = "0.25.8"
 itertools = "0.14.0"

Cargo.toml

@@ -58,9 +58,10 @@ Arguments:
 
 Options:
   -c, --codel-size <CODEL_SIZE>  Specifies the codel size (default: auto detect)
-      --fall-back-to-white       Treats unknown color as white instead of error
-      --fall-back-to-black       Treats unknown color as black instead of error
+      --fall-back-to-white       Treats unknown colors as white instead of error
+      --fall-back-to-black       Treats unknown colors as black instead of error
       --max-iter <MAX_ITER>      Terminates the program after this number of iterations
+      --base64                   Interprets <IMAGE_FILE> as a base64-encoded image instead of a file path
   -v, --verbose                  Enables debug output (path trace etc.)
   -h, --help                     Print help
   -V, --version                  Print version

README.md

@@ -23,6 +23,10 @@ pub struct Args {
     #[arg(long)]
     pub max_iter: Option<usize>,
 
+    /// Interprets <IMAGE_FILE> as a base64-encoded image instead of a file path
+    #[arg(long)]
+    pub base64: bool,
+
     /// Enables debug output (path trace etc.)
     #[arg(short, long)]
     pub verbose: bool,
@@ -54,6 +58,7 @@ mod tests {
             fall_back_to_white: false,
             fall_back_to_black: false,
             max_iter: None,
+            base64: false,
             verbose: false,
         };
         assert!(args.validate().is_ok());

src/args.rs

@@ -1,7 +1,7 @@
 use std::{
     error::Error,
     fmt::{self, Display},
-    path::Path,
+    io::{BufRead, Seek},
     rc::Rc,
 };
 
@@ -72,16 +72,13 @@ impl Display for Image {
 }
 
 impl Image {
-    pub fn new(
-        file: impl AsRef<Path>,
+    pub fn new<R: BufRead + Seek>(
+        reader: R,
         codel_size: Option<usize>,
         default_color: Option<Codel>,
     ) -> Result<Self, Box<dyn Error>> {
         let mut pixel_map = vec![];
-        if !file.as_ref().exists() {
-            return Err("file not found".into());
-        }
-        match ImageReader::open(file)?.decode()? {
+        match ImageReader::new(reader).with_guessed_format()?.decode()? {
             DynamicImage::ImageRgb8(img) => {
                 let height = img.height();
                 let width = img.width();

src/image.rs

@@ -9,8 +9,13 @@ pub mod interpreter;
 pub mod stdin;
 
 use std::error::Error;
+use std::fs;
+use std::io::{BufReader, Cursor};
 
+use base64::Engine;
+use base64::prelude::{BASE64_STANDARD, BASE64_STANDARD_NO_PAD};
 use codel::Codel;
+use itertools::Itertools;
 use rustc_hash::FxHashSet;
 
 use crate::args::Args;
@@ -35,7 +40,21 @@ pub fn run(args: &Args) -> Result<(), Box<dyn Error>> {
     } else {
         None
     };
-    let img = Image::new(&args.image_file, args.codel_size, default_color)?;
+
+    let image_content: Vec<u8> = if args.base64 {
+        let base64_encoded_image = args.image_file.split_whitespace().join(""); //`split_whitespace()` removes the wrapping newlines of GNU `base64` command.
+        if base64_encoded_image.len().is_multiple_of(4) {
+            BASE64_STANDARD.decode(&base64_encoded_image)?
+        } else {
+            BASE64_STANDARD_NO_PAD.decode(&base64_encoded_image)?
+        }
+    } else {
+        fs::read(&args.image_file)?
+    };
+
+    let reader = BufReader::new(Cursor::new(image_content));
+
+    let img = Image::new(reader, args.codel_size, default_color)?;
     debug_print(args.verbose, &format!("{}", img));
 
     if img.get_codel_at((0, 0)).is_black() {
@@ -167,6 +186,7 @@ mod tests {
             fall_back_to_white: true,
             fall_back_to_black: false,
             max_iter: None,
+            base64: false,
             verbose: false,
         };
         assert!(run(&args).is_ok());