Fix chart and canvas widgets

examples/prototype.rs

@@ -149,7 +149,7 @@ fn main() {
         show_chart: true,
         progress: 0,
         data: rand_signal.clone().take(200).collect(),
-        data2: sin_signal.clone().take(20).collect(),
+        data2: sin_signal.clone().take(30).collect(),
         data3: sin_signal2.clone().take(200).collect(),
         data4: vec![("B1", 9),
                     ("B2", 12),
@@ -173,7 +173,7 @@ fn main() {
     let (tx, rx) = mpsc::channel();
     let input_tx = tx.clone();
 
-    for _ in 0..20 {
+    for _ in 0..30 {
         sin_signal.next();
     }
     for _ in 0..200 {
@@ -301,7 +301,7 @@ fn draw(t: &mut Terminal, app: &App) {
                             Canvas::default()
                                 .block(Block::default().title("World").borders(border::ALL))
                                 .layers(&[&[Map::default().resolution(MapResolution::High)]])
-                                .x_bounds([180.0, -180.0])
+                                .x_bounds([-180.0, 180.0])
                                 .y_bounds([-90.0, 90.0])
                                 .render(&chunks[1], t);
                         })

src/widgets/canvas/mod.rs

@@ -74,13 +74,13 @@ impl<'a> Widget for Canvas<'a> {
         let width = canvas_area.width as usize;
         let height = canvas_area.height as usize;
 
-
         let mut x_bounds = self.x_bounds;
         x_bounds.sort_by(|a, b| a.partial_cmp(b).unwrap());
         let mut y_bounds = self.y_bounds;
         y_bounds.sort_by(|a, b| a.partial_cmp(b).unwrap());
 
         for layer in self.layers {
+
             let mut grid: Vec<u16> = vec![BRAILLE_OFFSET; width * height + 1];
             let mut colors: Vec<Color> = vec![Color::Reset; width * height + 1];
 
@@ -91,7 +91,7 @@ impl<'a> Widget for Canvas<'a> {
                     let dy = ((self.y_bounds[1] - y) * canvas_area.height as f64 * 4.0 /
                               (self.y_bounds[1] -
                                self.y_bounds[0])) as usize;
-                    let dx = ((self.x_bounds[1] - x) * canvas_area.width as f64 * 2.0 /
+                    let dx = ((x - self.x_bounds[0]) * canvas_area.width as f64 * 2.0 /
                               (self.x_bounds[1] -
                                self.x_bounds[0])) as usize;
                     let index = dy / 4 * width + dx / 2;
@@ -100,16 +100,19 @@ impl<'a> Widget for Canvas<'a> {
                 }
             }
 
-            let string = String::from_utf16(&grid).unwrap();
+            let mut string = String::from_utf16(&grid).unwrap();
+            string.pop();
             for (i, (ch, color)) in string.chars().zip(colors.into_iter()).enumerate() {
                 if ch != BRAILLE_BLANK {
                     let (x, y) = (i % width, i / width);
-                    buf.update_cell(x as u16 + canvas_area.left(), y as u16 + area.top(), |c| {
-                        c.symbol.clear();
-                        c.symbol.push(ch);
-                        c.fg = color;
-                        c.bg = Color::Reset;
-                    });
+                    buf.update_cell(x as u16 + canvas_area.left(),
+                                    y as u16 + canvas_area.top(),
+                                    |c| {
+                                        c.symbol.clear();
+                                        c.symbol.push(ch);
+                                        c.fg = color;
+                                        c.bg = Color::Reset;
+                                    });
                 }
             }
         }

src/widgets/chart.rs

@@ -304,15 +304,14 @@ impl<'a> Widget for Chart<'a> {
         for dataset in self.datasets {
             match dataset.marker {
                 Marker::Dot => {
-                    for &(x, y) in dataset.data.iter() {
-                        if x < self.x_axis.bounds[0] || x > self.x_axis.bounds[1] ||
-                           y < self.y_axis.bounds[0] ||
-                           y > self.y_axis.bounds[1] {
-                            continue;
-                        }
+                    for &(x, y) in dataset.data.iter().filter(|&&(x, y)| {
+                        !(x < self.x_axis.bounds[0] || x > self.x_axis.bounds[1] ||
+                          y < self.y_axis.bounds[0] ||
+                          y > self.y_axis.bounds[1])
+                    }) {
                         let dy = (self.y_axis.bounds[1] - y) * graph_area.height as f64 /
                                  (self.y_axis.bounds[1] - self.y_axis.bounds[0]);
-                        let dx = (self.x_axis.bounds[1] - x) * graph_area.width as f64 /
+                        let dx = (x - self.x_axis.bounds[0]) * graph_area.width as f64 /
                                  (self.x_axis.bounds[1] - self.x_axis.bounds[0]);
 
                         buf.set_cell(dx as u16 + graph_area.left(),