From 2b9817080e5281b3a540b6ed878925227208fdc2 Mon Sep 17 00:00:00 2001
From: djairoh <ljxjah@mykolab.com>
Date: Wed, 8 Feb 2023 22:02:49 +0100
Subject: [PATCH] implemented braille support, including --threshold flag

---
 src/ascii_manipulation.rs | 52 ++++++++++++++++++++++++++++++---------
 src/cli.rs                |  5 ++++
 src/image_manipulation.rs | 10 ++++++--
 src/main.rs               |  4 +--
 4 files changed, 55 insertions(+), 16 deletions(-)

diff --git a/src/ascii_manipulation.rs b/src/ascii_manipulation.rs
index 6cf4cbf..70887ea 100644
--- a/src/ascii_manipulation.rs
+++ b/src/ascii_manipulation.rs
@@ -1,12 +1,13 @@
 use std::process::exit;
-use image::{DynamicImage, GenericImageView, Rgba};
+use image::{DynamicImage, GenericImageView, imageops, Rgba};
 use log::error;
 use crate::model_rgb_ascii::Ascii;
 
-fn get_color(pixel: (u32, u32, Rgba<u8>)) -> u8 {
-    let vec = pixel.2.0;
+const BRAILLE_TABLE: [[u8; 2]; 4] = [[1u8, 8u8], [2u8, 16u8], [4u8, 32u8], [64u8, 128u8]];
+
+fn get_color(pixel: Rgba<u8>) -> u8 {
     //luminosity method of getting lightness
-    (vec[0] as f32 * 0.3 + vec[1] as f32 * 0.59 + vec[2] as f32 * 0.11) as u8
+    (pixel[0] as f32 * 0.3 + pixel[1] as f32 * 0.59 + pixel[2] as f32 * 0.11) as u8
 }
 
 fn to_ascii(char_map: String, image: DynamicImage) -> Vec<Vec<Ascii>> {
@@ -15,8 +16,8 @@ fn to_ascii(char_map: String, image: DynamicImage) -> Vec<Vec<Ascii>> {
     let mut out: Vec<Vec<Ascii>> = Vec::new();
 
     for pixel in image.pixels() {
-        let ch = char_map.as_bytes()[((get_color(pixel) as f32-1.0)/255f32 * l) as usize];
-        //fixme: might break with non-ASCII char_map (ie braille chars, possibly)
+        let ch = char_map.as_bytes()[((get_color(pixel.2) as f32-1.0)/255f32 * l) as usize];
+        //fixme: might break with non-ASCII char_map
         str.push(Ascii::new(ch, pixel.2[0], pixel.2[1], pixel.2[2]));
 
         if pixel.0 == image.width()-1 {
@@ -35,15 +36,42 @@ pub fn to_complex_ascii(image: DynamicImage) -> Vec<Vec<Ascii>> {
     to_ascii(" .'`^\",:;Il!i><~+_-?][}{1)(|\\/tfjrxnuvczXYUJCLQ0OZmwqpdbkhao*#MW&8%B@$".to_owned(), image)
 }
 
-pub fn to_braille_ascii(image: DynamicImage) -> Vec<Vec<Ascii>> {
-    //todo: figure out braille symbols
-    vec![vec![Ascii::new(0, 0, 0, 0)]]
-}
-
 pub fn to_custom_ascii(char_map: String, image: DynamicImage) -> Vec<Vec<Ascii>> {
     if char_map.is_empty() {
         error!("Custom map can not be empty!");
         exit(1);
     }
     to_ascii(char_map, image)
-}
\ No newline at end of file
+}
+
+pub fn to_braille_ascii(mut image: DynamicImage, threshold: u8) -> Vec<Vec<Ascii>> {
+    let mut str: Vec<Ascii> = Vec::new();
+    let mut out: Vec<Vec<Ascii>> = Vec::new();
+
+    //you know your code is good when you have a quadruple nested for loop
+    for y in (0..image.height()).step_by(4) {
+        for x in (0..image.width()).step_by(2) {
+            let (mut r, mut g, mut b) = (0u16, 0u16, 0u16);
+            let mut braille_value: u32 = 10240;
+            for nx in 0..2 {
+                for ny in 0..4 {
+                    let pixel = image.get_pixel(x+nx, y+ny);
+                    r = r+pixel[0] as u16;
+                    g = g+pixel[1] as u16;
+                    b = b+pixel[2] as u16;
+                    if get_color(pixel) >= threshold {
+                        braille_value += BRAILLE_TABLE[ny as usize][nx as usize] as u32;
+                    }
+                }
+            }
+            str.push(Ascii { char: char::from_u32(braille_value).unwrap(), rgb: [(r/8) as u8, (g/8) as u8, (b/8) as u8] });
+            }
+        out.push(str);
+        str = Vec::new();
+    }
+    out
+}
+pub fn to_box_ascii(image: DynamicImage) -> Vec<Vec<Ascii>> {
+    //todo: this one
+    vec![vec![Ascii::new(0, 0, 0,0 )]]
+}
diff --git a/src/cli.rs b/src/cli.rs
index c311c8b..d8f2b6b 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -30,6 +30,11 @@ pub struct Cli {
     /// Takes priority over '--width'
     #[arg(short = 'f', long)]
     pub full: bool,
+    /// use a custom threshold when converting to braille
+    ///
+    /// default is 128
+    #[arg(default_value_t = 128, long)]
+    pub threshold: u8,
     /// use a custom character map for output
     ///
     /// The character map is interpreted from dark(first character) to light(last character).
diff --git a/src/image_manipulation.rs b/src/image_manipulation.rs
index 627e40f..bfbbb82 100644
--- a/src/image_manipulation.rs
+++ b/src/image_manipulation.rs
@@ -1,5 +1,5 @@
 use termion::terminal_size;
-use log::{debug, error};
+use log::{debug, error, trace};
 use std::process::exit;
 use std::path::PathBuf;
 use image::DynamicImage;
@@ -18,7 +18,7 @@ fn get_terminal_size() -> (u32, u32) {
     }
 }
 
-pub fn resize_image(img: DynamicImage, full: bool, opt_w: Option<u32>) -> DynamicImage {
+pub fn resize_image(img: DynamicImage, full: bool, braille: bool, opt_w: Option<u32>) -> DynamicImage {
     let (mut w, mut h) = (1,1);
     let (max_w, max_h) = get_terminal_size();
     if full {
@@ -36,6 +36,12 @@ pub fn resize_image(img: DynamicImage, full: bool, opt_w: Option<u32>) -> Dynami
             h = (img.height() as f32 * w as f32 / img.width() as f32 * 0.5) as u32;
         }
     }
+
+    //braille has a 2x4 character map
+    if braille {
+        w *= 2;
+        h *= 4;
+    }
     debug!("Resizing image to (w|h): {} | {}", w, h);
     img.resize_exact(w, h, FilterType::CatmullRom)
 }
diff --git a/src/main.rs b/src/main.rs
index f373371..e0d2550 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -28,12 +28,12 @@ fn main() {
 
     //preprocess image
     let mut img = open_image(cli.image);
-    img = resize_image(img, cli.full, cli.width);
+    img = resize_image(img, cli.full, cli.braille, cli.width);
 
     //converting to ASCII
     let out: Vec<Vec<Ascii>>;
     if cli.braille {
-        out = to_braille_ascii(img);
+        out = to_braille_ascii(img, cli.threshold);
     } else if cli.complex {
         out = to_complex_ascii(img);
     } else if let Some(map) = cli.map {