Move all crates into a crates directory (#1940)

crates/epaint/src/stroke.rs

@@ -0,0 +1,54 @@
+#![allow(clippy::derive_hash_xor_eq)] // We need to impl Hash for f32, but we don't implement Eq, which is fine
+
+use super::*;
+
+/// Describes the width and color of a line.
+///
+/// The default stroke is the same as [`Stroke::none`].
+#[derive(Clone, Copy, Debug, Default, PartialEq)]
+#[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
+pub struct Stroke {
+    pub width: f32,
+    pub color: Color32,
+}
+
+impl Stroke {
+    /// Same as [`Stroke::default`].
+    #[inline(always)]
+    pub fn none() -> Self {
+        Self::new(0.0, Color32::TRANSPARENT)
+    }
+
+    #[inline]
+    pub fn new(width: impl Into<f32>, color: impl Into<Color32>) -> Self {
+        Self {
+            width: width.into(),
+            color: color.into(),
+        }
+    }
+
+    /// True if width is zero or color is transparent
+    #[inline]
+    pub fn is_empty(&self) -> bool {
+        self.width <= 0.0 || self.color == Color32::TRANSPARENT
+    }
+}
+
+impl<Color> From<(f32, Color)> for Stroke
+where
+    Color: Into<Color32>,
+{
+    #[inline(always)]
+    fn from((width, color): (f32, Color)) -> Stroke {
+        Stroke::new(width, color)
+    }
+}
+
+impl std::hash::Hash for Stroke {
+    #[inline(always)]
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        let Self { width, color } = *self;
+        crate::f32_hash(state, width);
+        color.hash(state);
+    }
+}