feat: Added option for custom image radius size

src/bin/silicon/config.rs

@@ -76,9 +76,30 @@ fn parse_line_range(s: &str) -> Result<Vec<u32>, ParseIntError> {
     Ok(result)
 }
 
+fn parse_line_col(s: &str) -> Result<Vec<(u32, u32, u32)>, ParseIntError> {
+    let mut result = vec![];
+    for range in s.split(';') {
+        let mut line_col = range.split(',');
+        if line_col.clone().count() != 3 {
+            continue;
+        }
+        let first = line_col.next().unwrap();
+        let second = line_col.next().unwrap();
+        let third = line_col.next().unwrap();
+
+        let first = first.parse::<u32>()?;
+        let second = second.parse::<u32>()?;
+        let third = third.parse::<u32>()?;
+
+        result.push((first, second, third));
+    }
+    Ok(result)
+}
+
 // https://github.com/TeXitoi/structopt/blob/master/CHANGELOG.md#support-optional-vectors-of-arguments-for-distinguishing-between--o-1-2--o-and-no-option-provided-at-all-by-sphynx-180
 type FontList = Vec<(String, f32)>;
 type Lines = Vec<u32>;
+type LineCol = Vec<(u32, u32, u32)>;
 
 #[derive(StructOpt, Debug)]
 #[structopt(name = "silicon")]
@@ -118,6 +139,11 @@ pub struct Config {
     #[structopt(long, value_name = "LINES", parse(try_from_str = parse_line_range))]
     pub highlight_lines: Option<Lines>,
 
+    /// Lines and cols to highlight specified as a triple (e.g. 10,2,8 highlights columns 2 to 8 in
+    /// line 10). To suply multiple highlight ranges separate each triple with a semicolon;
+    #[structopt(long, parse(try_from_str = parse_line_col))]
+    pub highlight_cols: Option<LineCol>,
+
     /// The language for syntax highlighting. You can use full name ("Rust") or file extension ("rs").
     #[structopt(short, value_name = "LANG", long)]
     pub language: Option<String>,
@@ -167,6 +193,10 @@ pub struct Config {
     #[structopt(long)]
     pub no_round_corner: bool,
 
+    /// Set corner radius
+    #[structopt(long, default_value = "12")]
+    pub corner_radius: u8,
+
     /// Pad horiz
     #[structopt(long, value_name = "PAD", default_value = "80")]
     pub pad_horiz: u32,
@@ -282,9 +312,11 @@ impl Config {
             .line_number(!self.no_line_number)
             .font(self.font.clone().unwrap_or_default())
             .round_corner(!self.no_round_corner)
+            .corner_radius(self.corner_radius)
             .shadow_adder(self.get_shadow_adder()?)
             .tab_width(self.tab_width)
             .highlight_lines(self.highlight_lines.clone().unwrap_or_default())
+            .highlight_cols(self.highlight_cols.clone().unwrap_or_default())
             .line_offset(self.line_offset)
             .code_pad_right(self.code_pad_right);
 

src/formatter.rs

@@ -37,6 +37,9 @@ pub struct ImageFormatter<T> {
     /// round corner
     /// Default: true
     round_corner: bool,
+    /// corner radius
+    /// Default: 12
+    corner_radius: u8,
     /// pad between code and line number
     /// Default: 6
     line_number_pad: u32,
@@ -48,6 +51,8 @@ pub struct ImageFormatter<T> {
     font: T,
     /// Highlight lines
     highlight_lines: Vec<u32>,
+    /// Highlight col range in line
+    highlight_cols: Vec<(u32, u32, u32)>,
     /// Shadow adder
     shadow_adder: Option<ShadowAdder>,
     /// Tab width
@@ -68,12 +73,16 @@ pub struct ImageFormatterBuilder<S> {
     font: Vec<(S, f32)>,
     /// Highlight lines
     highlight_lines: Vec<u32>,
+    /// Highlight col range in line
+    highlight_cols: Vec<(u32, u32, u32)>,
     /// Whether show the window controls
     window_controls: bool,
     /// Window title
     window_title: Option<String>,
     /// Whether round the corner of the image
     round_corner: bool,
+    /// Sets corner radius
+    corner_radius: u8,
     /// Shadow adder,
     shadow_adder: Option<ShadowAdder>,
     /// Tab width
@@ -144,6 +153,11 @@ impl<S: AsRef<str> + Default> ImageFormatterBuilder<S> {
         self
     }
 
+    pub fn corner_radius(mut self, r: u8) -> Self {
+        self.corner_radius = r;
+        self
+    }
+
     /// Add the shadow
     pub fn shadow_adder(mut self, adder: ShadowAdder) -> Self {
         self.shadow_adder = Some(adder);
@@ -156,6 +170,11 @@ impl<S: AsRef<str> + Default> ImageFormatterBuilder<S> {
         self
     }
 
+    pub fn highlight_cols(mut self, cols: Vec<(u32, u32, u32)>) -> Self {
+        self.highlight_cols = cols;
+        self
+    }
+
     /// Set tab width
     pub fn tab_width(mut self, width: u8) -> Self {
         self.tab_width = width;
@@ -185,7 +204,9 @@ impl<S: AsRef<str> + Default> ImageFormatterBuilder<S> {
             line_number_pad: 6,
             line_number_chars: 0,
             highlight_lines: self.highlight_lines,
+            highlight_cols: self.highlight_cols,
             round_corner: self.round_corner,
+            corner_radius: self.corner_radius,
             shadow_adder: self.shadow_adder,
             tab_width: self.tab_width,
             font,
@@ -209,11 +230,21 @@ impl<T: TextLineDrawer> ImageFormatter<T> {
         self.font.height(" ") + self.line_pad
     }
 
+    /// width of a single character
+    fn get_col_width(&mut self) -> u32 {
+        self.font.width(" ")
+    }
+
     /// calculate the Y coordinate of a line
     fn get_line_y(&mut self, lineno: u32) -> u32 {
         lineno * self.get_line_height() + self.code_pad + self.code_pad_top
     }
 
+    /// calculate the X coordinate of a column
+    fn get_col_x(&mut self, col: u32) -> u32 {
+        col * self.get_col_width() + self.code_pad
+    }
+
     /// calculate the size of code area
     fn get_image_size(&mut self, max_width: u32, lineno: u32) -> (u32, u32) {
         (
@@ -334,6 +365,38 @@ impl<T: TextLineDrawer> ImageFormatter<T> {
         }
     }
 
+    fn highlight_cols<I: IntoIterator<Item = (u32, u32, u32)>>(
+        &mut self,
+        image: &mut RgbaImage,
+        cols: I,
+        max_lineno_digit_count: u32,
+    ) {
+        let height = self.get_line_height();
+        let mut cloned = image.clone();
+        let color = cloned.get_pixel_mut(20, 20);
+
+        for i in color.0.iter_mut() {
+            *i = (*i).saturating_add(40);
+        }
+
+        for (y, x_start, x_end) in cols {
+            if x_start > x_end {
+                continue;
+            }
+            let x_start = self.get_col_x(x_start - 1);
+            let x_end = self.get_col_x(x_end - 1) + self.get_col_width();
+            let shadow = RgbaImage::from_pixel(x_end - x_start, height, *color);
+            let x = x_start
+                + if self.line_number {
+                    self.get_col_width() * max_lineno_digit_count + 12
+                } else {
+                    0
+                };
+            let y = self.get_line_y(y - 1);
+            copy_alpha(&shadow, image, x, y);
+        }
+    }
+
     // TODO: use &T instead of &mut T ?
     pub fn format(&mut self, v: &[Vec<(Style, &str)>], theme: &Theme) -> RgbaImage {
         if self.line_number {
@@ -362,6 +425,23 @@ impl<T: TextLineDrawer> ImageFormatter<T> {
                 .collect::<Vec<_>>();
             self.highlight_lines(&mut image, highlight_lines);
         }
+
+        if !self.highlight_cols.is_empty() {
+            let mut count = 1;
+            let mut max_lineno = drawables.max_lineno;
+            while max_lineno != 0 {
+                max_lineno /= 10;
+                count += 1;
+            }
+            let highlight_cols = self
+                .highlight_cols
+                .iter()
+                .cloned()
+                .filter(|&(y, _, _)| y >= 1 && y <= drawables.max_lineno + 1)
+                .collect::<Vec<_>>();
+            self.highlight_cols(&mut image, highlight_cols, count);
+        }
+
         if self.line_number {
             self.draw_line_number(&mut image, drawables.max_lineno, foreground.to_rgba());
         }
@@ -381,8 +461,14 @@ impl<T: TextLineDrawer> ImageFormatter<T> {
             add_window_controls(&mut image, &params);
         }
 
-        if self.round_corner {
-            round_corner(&mut image, 12);
+        if self.round_corner && self.corner_radius != 0 {
+            if u32::from(self.corner_radius) > self.code_pad {
+                println!(
+                    "Warning: r = {} > {} (code pad); Parts of the image may start to overlap!",
+                    self.corner_radius, self.code_pad
+                );
+            }
+            round_corner(&mut image, self.corner_radius.into());
         }
 
         if let Some(adder) = &self.shadow_adder {