feat: quad shadows

graphics/src/damage.rs

@@ -78,9 +78,28 @@ impl<T: Damage> Damage for Primitive<T> {
                 // damage bounds (?)
                 raw.clip_bounds.expand(1.5)
             }
-            Self::Quad { bounds, .. }
-            | Self::Image { bounds, .. }
-            | Self::Svg { bounds, .. } => bounds.expand(1.0),
+            Self::Quad {
+                bounds,
+                shadow_offset,
+                shadow_blur_radius,
+                ..
+            } => {
+                let bounds_with_shadow = Rectangle {
+                    x: bounds.x + shadow_offset.x.min(0.0) - shadow_blur_radius,
+                    y: bounds.y + shadow_offset.y.min(0.0) - shadow_blur_radius,
+                    width: bounds.width
+                        + shadow_offset.x.abs()
+                        + shadow_blur_radius * 2.0,
+                    height: bounds.height
+                        + shadow_offset.y.abs()
+                        + shadow_blur_radius * 2.0,
+                };
+
+                bounds_with_shadow.expand(1.0)
+            }
+            Self::Image { bounds, .. } | Self::Svg { bounds, .. } => {
+                bounds.expand(1.0)
+            }
             Self::Clip { bounds, .. } => bounds.expand(1.0),
             Self::Group { primitives } => primitives
                 .iter()

graphics/src/primitive.rs

@@ -71,6 +71,12 @@ pub enum Primitive<T> {
         border_width: f32,
         /// The border color of the quad
         border_color: Color,
+        /// The shadow color of the quad
+        shadow_color: Color,
+        /// The shadow offset of the quad
+        shadow_offset: Vector,
+        /// The shadow blur radius of the quad
+        shadow_blur_radius: f32,
     },
     /// An image primitive
     Image {

graphics/src/renderer.rs

@@ -127,6 +127,9 @@ impl<B: Backend, T> iced_core::Renderer for Renderer<B, T> {
             border_radius: quad.border_radius.into(),
             border_width: quad.border_width,
             border_color: quad.border_color,
+            shadow_color: quad.shadow.color,
+            shadow_offset: quad.shadow.offset,
+            shadow_blur_radius: quad.shadow.blur_radius,
         });
     }