Add colorbar

Author: nx10

src/ui.rs

@@ -9,7 +9,7 @@ use crate::{
     widgets::{
         key_value_list_widget::KeyValueListWidget,
         slice_widget::{SliceParams, XyzWidget},
-        title_bar::TitleBarWidget,
+        title_bar::TitleBarWidget, color_bar::ColorBarWidget,
     },
 };
 
@@ -19,7 +19,7 @@ static MODE_TITLES: [&str; 2] = ["Voxel", "Metadata"];
 pub fn render<B: Backend>(app: &mut App, frame: &mut Frame<'_, B>) {
     let layout = Layout::default()
         .direction(Direction::Vertical)
-        .constraints([Constraint::Length(1), Constraint::Min(0)].as_ref())
+        .constraints([Constraint::Length(1), Constraint::Min(0), Constraint::Length(1)].as_ref())
         .split(frame.size());
 
     // write out filename
@@ -31,6 +31,8 @@ pub fn render<B: Backend>(app: &mut App, frame: &mut Frame<'_, B>) {
 
     frame.render_widget(TitleBarWidget::new(&app.file_path, &MODE_TITLES, mode_index), layout[0]);
 
+    frame.render_widget(ColorBarWidget::new("Inferno", app.color_map, app.intensity_range.0, app.intensity_range.1), layout[2]);
+
     match app.mode {
         crate::app::AppMode::Xyz => {
             let slice = SliceParams {

src/widgets/color_bar.rs

@@ -0,0 +1,57 @@
+use crate::utils::colors::colorous2tui;
+
+pub struct ColorBarWidget<'a> {
+    pub title: &'a str,
+    pub gradient: colorous::Gradient,
+    pub min: f32,
+    pub max: f32,
+}
+
+impl<'a> ColorBarWidget<'a> {
+    pub fn new(title: &'a str, gradient: colorous::Gradient, min: f32, max: f32) -> Self {
+        Self {
+            title,
+            gradient,
+            min,
+            max,
+        }
+    }
+}
+
+impl tui::widgets::Widget for ColorBarWidget<'_> {
+    fn render(self, area: tui::layout::Rect, buf: &mut tui::buffer::Buffer) {
+        for i in 0..area.width {
+            let color = self.gradient.eval_rational(i as usize, area.width as usize);
+            buf.get_mut(area.x + i, area.y).set_bg(colorous2tui(color));
+        }
+
+        // write title in the middle
+        let title_len = self.title.len();
+        let title_start = (area.width - title_len as u16) / 2;
+        buf.set_stringn(
+            area.x + title_start as u16,
+            area.y,
+            self.title,
+            title_len,
+            tui::style::Style::default(),
+        );
+
+        // write min max values
+        let min_str = format!("{:.2}", self.min);
+        let max_str = format!("{:.2}", self.max);
+        buf.set_stringn(
+            area.x,
+            area.y,
+            &min_str,
+            min_str.len(),
+            tui::style::Style::default(),
+        );
+        buf.set_stringn(
+            area.x + area.width as u16 - max_str.len() as u16,
+            area.y,
+            &max_str,
+            max_str.len(),
+            tui::style::Style::default(),
+        );
+    }
+}

src/widgets/mod.rs

@@ -1,3 +1,4 @@
 pub mod key_value_list_widget;
 pub mod slice_widget;
-pub mod title_bar;
+pub mod title_bar;
+pub mod color_bar;