Merge pull request #452 from jonaspleyer/master

Introduce Colormaps

Author: AaronErhardt

plotters/Cargo.toml

@@ -70,7 +70,8 @@ default = [
         "ttf",
         "image",
         "deprecated_items",  "all_series", "all_elements",
-        "full_palette"
+        "full_palette",
+        "colormaps"
 ]
 all_series = ["area_series", "line_series", "point_series", "surface_series"]
 all_elements = ["errorbar", "candlestick", "boxplot", "histogram"]
@@ -83,6 +84,7 @@ svg_backend = ["plotters-svg"]
 
 # Colors
 full_palette = []
+colormaps = []
 
 # Elements
 errorbar = []

plotters/examples/3d-plot2.rs

@@ -36,9 +36,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
                 (-15..=15).map(|x| x as f64 / 5.0),
                 pdf,
             )
-            .style_func(&|&v| {
-                (&HSLColor(240.0 / 360.0 - 240.0 / 360.0 * v / 5.0, 1.0, 0.7)).into()
-            }),
+            .style_func(&|&v| (VulcanoHSL::get_color(v / 5.0)).into()),
         )?;
 
         root.present()?;

plotters/examples/colormaps.rs

@@ -0,0 +1,69 @@
+use plotters::prelude::*;
+
+const OUT_FILE_NAME: &'static str = "plotters-doc-data/colormaps.png";
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let colormaps_rgb: [(Box<dyn ColorMap<RGBColor>>, &str); 4] = [
+        (Box::new(ViridisRGB {}), "Viridis"),
+        (Box::new(BlackWhite {}), "BlackWhite"),
+        (Box::new(Bone {}), "Bone"),
+        (Box::new(Copper {}), "Copper"),
+    ];
+
+    let colormaps_hsl: [(Box<dyn ColorMap<HSLColor>>, &str); 2] = [
+        (Box::new(MandelbrotHSL {}), "MandelbrotHSL"),
+        (Box::new(VulcanoHSL {}), "VulcanoHSL"),
+    ];
+
+    let size_x: i32 = 800;
+    let n_colormaps = colormaps_rgb.len() + colormaps_hsl.len();
+    let size_y = 200 + n_colormaps as u32 * 100;
+    let root = BitMapBackend::new(OUT_FILE_NAME, (size_x as u32, size_y)).into_drawing_area();
+
+    root.fill(&WHITE)?;
+
+    let mut chart = ChartBuilder::on(&root)
+        .caption("Demonstration of predefined colormaps", ("sans-serif", 20))
+        .build_cartesian_2d(
+            -150.0..size_x as f32 + 50.0,
+            0.0..3.0 * (n_colormaps as f32),
+        )?;
+
+    use plotters::style::text_anchor::*;
+    let centered = Pos::new(HPos::Center, VPos::Center);
+    let label_style = TextStyle::from(("monospace", 14.0).into_font()).pos(centered);
+
+    let mut colormap_counter = 0;
+    macro_rules! plot_colormaps(
+        ($colormap:expr) => {
+            for (colormap, colormap_name) in $colormap.iter() {
+                chart.draw_series(
+                    (0..size_x as i32).map(|x| {
+                        Rectangle::new([
+                            (x as f32,     3.0*(n_colormaps - 1 - colormap_counter) as f32 + 0.5),
+                            (x as f32+1.0, 3.0*(n_colormaps - 1 - colormap_counter) as f32 + 2.5)
+                        ],
+                    colormap.get_color_normalized(x as f32, 0.0, size_x as f32).filled())
+                    })
+                )?;
+                chart.draw_series(
+                    [Text::new(colormap_name.to_owned(), (-75.0, 3.0*(n_colormaps-1-colormap_counter) as f32 + 1.5), &label_style)]
+                )?;
+                colormap_counter+=1;
+            }
+        }
+    );
+
+    plot_colormaps!(colormaps_rgb);
+    plot_colormaps!(colormaps_hsl);
+
+    // To avoid the IO failure being ignored silently, we manually call the present function
+    root.present().expect("Unable to write result to file, please make sure 'plotters-doc-data' dir exists under current dir");
+    println!("Result has been saved to {}", OUT_FILE_NAME);
+
+    Ok(())
+}
+#[test]
+fn entry_point() {
+    main().unwrap()
+}

plotters/examples/mandelbrot.rs

@@ -28,7 +28,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
 
     for (x, y, c) in mandelbrot_set(xr, yr, (pw as usize, ph as usize), 100) {
         if c != 100 {
-            plotting_area.draw_pixel((x, y), &HSLColor(c as f64 / 100.0, 1.0, 0.5))?;
+            plotting_area.draw_pixel((x, y), &MandelbrotHSL::get_color(c as f64 / 100.0))?;
         } else {
             plotting_area.draw_pixel((x, y), &BLACK)?;
         }

plotters/src/lib.rs

@@ -852,6 +852,9 @@ pub mod prelude {
     #[cfg(feature = "full_palette")]
     pub use crate::style::full_palette;
 
+    #[cfg(feature = "colormaps")]
+    pub use crate::style::colors::colormaps::*;
+
     pub use crate::style::{
         AsRelative, Color, FontDesc, FontFamily, FontStyle, FontTransform, HSLColor, IntoFont,
         IntoTextStyle, Palette, Palette100, Palette99, Palette9999, PaletteColor, RGBAColor,