Adds linear gradient support to 2D meshes in the canvas widget.

graphics/src/shader.rs

@@ -0,0 +1,42 @@
+//! Supported shaders;
+
+use crate::{Color, widget};
+use crate::gradient::Gradient;
+use crate::widget::canvas::{FillStyle, StrokeStyle};
+
+#[derive(Debug, Clone)]
+/// Supported shaders for primitives.
+pub enum Shader {
+    /// Fill a primitive with a solid color.
+    Solid(Color),
+    /// Fill a primitive with an interpolated color.
+    Gradient(Gradient)
+}
+
+impl <'a> Into<Shader> for StrokeStyle<'a> {
+    fn into(self) -> Shader {
+        match self {
+            StrokeStyle::Solid(color) => Shader::Solid(color),
+            StrokeStyle::Gradient(gradient) => gradient.clone().into()
+        }
+    }
+}
+
+impl <'a> Into<Shader> for FillStyle<'a> {
+    fn into(self) -> Shader {
+        match self {
+            FillStyle::Solid(color) => Shader::Solid(color),
+            FillStyle::Gradient(gradient) => gradient.clone().into()
+        }
+    }
+}
+
+impl <'a> Into<Shader> for widget::canvas::Gradient {
+    fn into(self) -> Shader {
+        match self {
+            widget::canvas::Gradient::Linear(linear) => {
+                Shader::Gradient(Gradient::Linear(linear))
+            }
+        }
+    }
+}