♻️ Refactor blend mode and fills into their own submodules

render-wasm/src/shapes/fills.rs

@@ -0,0 +1,80 @@
+use skia_safe as skia;
+
+use super::Color;
+use crate::math;
+
+#[derive(Debug, Clone, PartialEq)]
+pub struct Gradient {
+    colors: Vec<Color>,
+    offsets: Vec<f32>,
+    opacity: f32,
+    start: (f32, f32),
+    end: (f32, f32),
+}
+
+impl Gradient {
+    pub fn add_stop(&mut self, color: Color, offset: f32) {
+        self.colors.push(color);
+        self.offsets.push(offset);
+    }
+
+    fn to_shader(&self, rect: &math::Rect) -> skia::Shader {
+        let start = (
+            rect.left + self.start.0 * rect.width(),
+            rect.top + self.start.1 * rect.height(),
+        );
+        let end = (
+            rect.left + self.end.0 * rect.width(),
+            rect.top + self.end.1 * rect.height(),
+        );
+        let shader = skia::shader::Shader::linear_gradient(
+            (start, end),
+            self.colors.as_slice(),
+            self.offsets.as_slice(),
+            skia::TileMode::Clamp,
+            None,
+            None,
+        )
+        .unwrap();
+        shader
+    }
+}
+
+#[derive(Debug, Clone, PartialEq)]
+pub enum Fill {
+    Solid(Color),
+    LinearGradient(Gradient),
+}
+
+impl Fill {
+    pub fn new_linear_gradient(start: (f32, f32), end: (f32, f32), opacity: f32) -> Self {
+        Self::LinearGradient(Gradient {
+            start,
+            end,
+            opacity,
+            colors: vec![],
+            offsets: vec![],
+        })
+    }
+
+    pub fn to_paint(&self, rect: &math::Rect) -> skia::Paint {
+        match self {
+            Self::Solid(color) => {
+                let mut p = skia::Paint::default();
+                p.set_color(*color);
+                p.set_style(skia::PaintStyle::Fill);
+                p.set_anti_alias(true);
+                p.set_blend_mode(skia::BlendMode::SrcOver);
+                p
+            }
+            Self::LinearGradient(gradient) => {
+                let mut p = skia::Paint::default();
+                p.set_shader(gradient.to_shader(&rect));
+                p.set_alpha((gradient.opacity * 255.) as u8);
+                p.set_style(skia::PaintStyle::Fill);
+                p.set_blend_mode(skia::BlendMode::SrcOver);
+                p
+            }
+        }
+    }
+}