[geometry] fix 0.0 scalar formatting

Author: aslpavel

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "rasterize"
-version = "0.6.0"
+version = "0.6.1"
 authors = ["Pavel Aslanov <asl.pavel@gmail.com>"]
 description = "Simple and small 2D rendering library"
 edition = "2021"

src/geometry.rs

@@ -71,9 +71,13 @@ impl ScalarFormatter {
     }
 
     pub fn round_significant(value: f64, precision: usize) -> f64 {
-        let shift = precision as i32 - value.abs().log10().ceil() as i32;
-        let shift_factor = 10_f64.powi(shift);
-        (value * shift_factor).round() / shift_factor
+        if value.abs() < EPSILON {
+            return 0.0;
+        } else {
+            let shift = precision as i32 - value.abs().log10().ceil() as i32;
+            let shift_factor = 10_f64.powi(shift);
+            (value * shift_factor).round() / shift_factor
+        }
     }
 }
 
@@ -825,4 +829,29 @@ mod tests {
         assert_eq!(expected, expected.to_string().parse()?);
         Ok(())
     }
+
+    #[test]
+    fn test_scalar_format() -> Result<(), Error> {
+        let value: Scalar = 0.1234567;
+        assert_eq!(format!("{}", ScalarFormat(value)), "0.1235".to_owned());
+        assert_eq!(format!("{:#}", ScalarFormat(value)), "0.1235".to_owned());
+        assert_eq!(format!("{:.3}", ScalarFormat(value)), "0.123".to_owned());
+
+        let value: Scalar = 12.3001;
+        assert_eq!(format!("{}", ScalarFormat(value)), "12.30".to_owned());
+        assert_eq!(format!("{:#}", ScalarFormat(value)), "12.3".to_owned());
+        assert_eq!(format!("{:.3}", ScalarFormat(value)), "12.3".to_owned());
+
+        let value: Scalar = 12300.0;
+        assert_eq!(format!("{}", ScalarFormat(value)), "12300".to_owned());
+        assert_eq!(format!("{:#}", ScalarFormat(value)), "12300".to_owned());
+        assert_eq!(format!("{:.3}", ScalarFormat(value)), "12300".to_owned());
+
+        let value: Scalar = 0.0;
+        assert_eq!(format!("{}", ScalarFormat(value)), "0".to_owned());
+        assert_eq!(format!("{:#}", ScalarFormat(value)), "0".to_owned());
+        assert_eq!(format!("{:.3}", ScalarFormat(value)), "0".to_owned());
+
+        Ok(())
+    }
 }

src/path.rs

@@ -594,27 +594,16 @@ impl PathSvgDisplay<'_> {
     ) -> Result<Point, fmt::Error> {
         let point_tr = self.tr.apply(point);
         let point = previous.map_or_else(|| point_tr, |point_prev| point_tr - point_prev);
-
         let x = point.x();
         let y = point.y();
-        let eps = 10_f64.powi(-(out.precision().unwrap_or(4) as i32));
-
         if sep && x >= 0.0 {
             out.write_str(" ")?;
         }
-        if x.abs() < eps {
-            out.write_str("0")?;
-        } else {
-            out.write_str(formatter.format_str(x))?;
-        }
+        out.write_str(formatter.format_str(x))?;
         if y >= 0.0 {
             out.write_str(",")?;
         }
-        if y.abs() < eps {
-            out.write_str("0")?;
-        } else {
-            out.write_str(formatter.format_str(y))?;
-        }
+        out.write_str(formatter.format_str(y))?;
         Ok(point_tr)
     }
 }