Fix weather plot, close #5

src/weather/data.rs

@@ -28,7 +28,7 @@ pub struct WeatherData {
     #[serde(skip_deserializing)]
     minutely: Vec<()>,
     /// Weather Information for the coming hours
-    hourly: Vec<HourlyWeather>,
+    pub hourly: Vec<HourlyWeather>,
     /// Weather information for the next days _(unused at the moment)_
     #[serde(skip_deserializing)]
     daily: Vec<()>,
@@ -95,6 +95,12 @@ pub struct HourlyWeather {
     pub(self) pop: f32,
 }
 
+impl HourlyWeather {
+    pub fn temperature(&self) -> f32 {
+        self.data.temp
+    }
+}
+
 /// Common weather information shared among different forecast types.
 ///
 /// This struct is not instantiated by the API but merely introduced by the `Deserializer`.

src/weather/mod.rs

@@ -1,22 +1,129 @@
+use crate::error::display_no_data;
+use embedded_graphics::mono_font::MonoTextStyleBuilder;
 use embedded_graphics::{
-    draw_target::DrawTarget,
-    image::Image,
-    mono_font::MonoTextStyle,
-    prelude::*,
-    text::Text
+    draw_target::DrawTarget, image::Image, mono_font::MonoTextStyle, prelude::*, text::Text,
 };
-use embedded_plots::{axis::Scale, curve::Curve, single_plot::SinglePlot};
-use profont::{
-    PROFONT_14_POINT, PROFONT_24_POINT, PROFONT_7_POINT, PROFONT_9_POINT,
+use embedded_plots::{
+    axis::{Axis, Placement, Scale},
+    curve::{Curve, PlotPoint},
+    single_plot::SinglePlot,
 };
+use profont::{PROFONT_14_POINT, PROFONT_24_POINT, PROFONT_7_POINT, PROFONT_9_POINT};
 use ssd1675::Color;
 use std::fmt::Debug;
-use crate::error::display_no_data;
+use std::ops::Range;
+use time::OffsetDateTime;
 
 mod api;
 mod data;
-mod secret;
 mod icons;
+mod secret;
+
+/// Draws the 24hr weather data in a graph with 2 x axes, one for today and one for tomorrow.
+fn draw_weather_plot<D>(
+    wtr: &data::WeatherData,
+    display: &mut D,
+    top_left: Point,
+    bottom_right: Point,
+) where
+    D: DrawTarget<Color = Color>,
+    D::Error: Debug,
+{
+    let local_time =
+        OffsetDateTime::now_local().expect("Failed to retrieve current time from system clock");
+    let now_hour = local_time.hour();
+
+    // Split the plot data into two sets: one for today's data (time up to 23:00), one for tomorrow
+    // (0:00 onwards). This is necessary because if all data were plotted in one graph, it would
+    // show the delta in hours to the current time. If you replaced the delta with the actual hour,
+    // the plot would be re-ordered, leading to confusion.
+    // NOTE(feliix42): We're doing a +1 here to actually also take the 24 for a better overlap
+    let num_entries_today = 24 - now_hour + 1;
+    let num_entries_tomorrow = 24 - num_entries_today;
+
+    let plot_data = wtr.forecast_plot_data();
+
+    // X coordinate where to split between axis 1 and 2
+    let cutoff_point = top_left.x + ((bottom_right.x - top_left.x) / 24) * num_entries_today as i32;
+
+    // computation of scales. We want 5 (plus x origin) labels on the x axis. So we compute as
+    // follows: num_labels % 6 = num labels per section
+    // Note, that the origin of x2 will be printed anyways as well
+    let num_labels_in_x1: u8 = num_entries_today / 6;
+    let x1_labels = if num_labels_in_x1 > 0 {
+        num_labels_in_x1
+    } else {
+        1
+    };
+    let mut x2_labels = 5 - x1_labels;
+    if x2_labels == 0 {
+        x2_labels = 1;
+    }
+
+    let x1_scale = Scale::RangeFraction(x1_labels.into());
+    let x2_scale = Scale::RangeFraction(x2_labels.into());
+    let y_scale = Scale::RangeFraction(2);
+    let thickness = 2;
+    let axis_thickness = thickness;
+    let text_style = MonoTextStyleBuilder::new().text_color(Color::Black).build();
+
+    let curve = [(Curve::from_data(&plot_data), Color::Black)];
+
+    let x1_range: Range<i32> = (now_hour as i32)..((now_hour + num_entries_today) as i32);
+    let x2_range: Range<i32> = 0..(num_entries_tomorrow as i32);
+    let y_range = curve[0].0.y_range.clone();
+
+    Axis::new(x1_range)
+        .set_title("")
+        .set_scale(x1_scale)
+        .into_drawable_axis(Placement::X {
+            x1: top_left.x,
+            x2: cutoff_point,
+            y: bottom_right.y,
+        })
+        .set_color(Color::Black)
+        .set_text_style(text_style)
+        .set_tick_size(2)
+        .set_thickness(axis_thickness)
+        .draw(display)
+        .expect("Failed to draw the temperature plot");
+    Axis::new(x2_range)
+        .set_title("t")
+        .set_scale(x2_scale)
+        .into_drawable_axis(Placement::X {
+            x1: cutoff_point,
+            x2: bottom_right.x,
+            y: bottom_right.y,
+        })
+        .set_color(Color::Black)
+        .set_text_style(text_style)
+        .set_tick_size(2)
+        .set_thickness(axis_thickness)
+        .draw(display)
+        .expect("Failed to draw the temperature plot");
+    Axis::new(y_range)
+        .set_title("C")
+        .set_scale(y_scale)
+        .into_drawable_axis(Placement::Y {
+            y1: top_left.y,
+            y2: bottom_right.y,
+            x: top_left.x,
+        })
+        .set_color(Color::Black)
+        .set_text_style(text_style)
+        .set_tick_size(2)
+        .set_thickness(axis_thickness)
+        .draw(display)
+        .expect("Failed to draw the temperature plot");
+
+    curve[0]
+        .0
+        .into_drawable_curve(&top_left, &bottom_right)
+        .set_color(curve[0].1)
+        .set_thickness(thickness)
+        .draw(display)
+        .expect("Failed to draw the temperature plot");
+}
 
 pub fn get_weather<D>(display: &mut D)
 where
@@ -107,15 +214,10 @@ where
     .expect("error drawing text");
 
     // Plot the forecast
-    // TODO(feliix42): Annotate the plot better??
-    let data_points = weather_data.forecast_plot_data();
-    let curve = [(Curve::from_data(&data_points), Color::Black)];
-
-    let plot = SinglePlot::new(&curve, Scale::RangeFraction(4), Scale::RangeFraction(2))
-        .into_drawable(Point::new(100, 54), Point::new(206, 94))
-        .set_color(Color::Black);
-
-    plot.draw(display)
-        .expect("Failed to draw the temperature plot");
+    draw_weather_plot(
+        &weather_data,
+        display,
+        Point::new(100, 54),
+        Point::new(206, 94),
+    );
 }
-