3 files changed, 104 insertions, 1 deletions

diff --git a/src/render_helpers/clipped_surface.rs b/src/render_helpers/clipped_surface.rs
index 69c2a012..43ba8594 100644
--- a/src/render_helpers/clipped_surface.rs
+++ b/src/render_helpers/clipped_surface.rs
@@ -6,8 +6,9 @@ use smithay::backend::renderer::gles::{
     GlesError, GlesFrame, GlesRenderer, GlesTexProgram, Uniform,
 };
 use smithay::backend::renderer::utils::{CommitCounter, DamageSet};
-use smithay::utils::{Buffer, Logical, Physical, Rectangle, Scale, Transform};
+use smithay::utils::{Buffer, Logical, Physical, Rectangle, Scale, Size, Transform};
 
+use super::damage::ExtraDamage;
 use super::renderer::{AsGlesFrame as _, NiriRenderer};
 use super::shaders::{mat3_uniform, Shaders};
 use crate::backend::tty::{TtyFrame, TtyRenderer, TtyRendererError};
@@ -21,6 +22,12 @@ pub struct ClippedSurfaceRenderElement<R: NiriRenderer> {
     input_to_geo: Mat3,
 }
 
+#[derive(Debug, Default, Clone)]
+pub struct RoundedCornerDamage {
+    damage: ExtraDamage,
+    corner_radius: CornerRadius,
+}
+
 impl<R: NiriRenderer> ClippedSurfaceRenderElement<R> {
     pub fn new(
         elem: WaylandSurfaceRenderElement<R>,
@@ -267,3 +274,23 @@ impl<'render> RenderElement<TtyRenderer<'render>>
         None
     }
 }
+
+impl RoundedCornerDamage {
+    pub fn set_size(&mut self, size: Size<i32, Logical>) {
+        self.damage.set_size(size);
+    }
+
+    pub fn set_corner_radius(&mut self, corner_radius: CornerRadius) {
+        if self.corner_radius == corner_radius {
+            return;
+        }
+
+        // FIXME: make the damage granular.
+        self.corner_radius = corner_radius;
+        self.damage.damage_all();
+    }
+
+    pub fn element(&self) -> ExtraDamage {
+        self.damage.clone()
+    }
+}
diff --git a/src/render_helpers/damage.rs b/src/render_helpers/damage.rs
new file mode 100644
index 00000000..ef7b125f
--- /dev/null
+++ b/src/render_helpers/damage.rs
@@ -0,0 +1,75 @@
+use smithay::backend::renderer::element::{Element, Id, RenderElement};
+use smithay::backend::renderer::utils::CommitCounter;
+use smithay::backend::renderer::Renderer;
+use smithay::utils::{Buffer, Logical, Physical, Point, Rectangle, Scale, Size};
+
+#[derive(Debug, Clone)]
+pub struct ExtraDamage {
+    id: Id,
+    commit: CommitCounter,
+    geometry: Rectangle<i32, Logical>,
+}
+
+impl ExtraDamage {
+    pub fn new() -> Self {
+        Self {
+            id: Id::new(),
+            commit: Default::default(),
+            geometry: Default::default(),
+        }
+    }
+
+    pub fn set_size(&mut self, size: Size<i32, Logical>) {
+        if self.geometry.size == size {
+            return;
+        }
+
+        self.geometry.size = size;
+        self.commit.increment();
+    }
+
+    pub fn damage_all(&mut self) {
+        self.commit.increment();
+    }
+
+    pub fn with_location(mut self, location: Point<i32, Logical>) -> Self {
+        self.geometry.loc = location;
+        self
+    }
+}
+
+impl Default for ExtraDamage {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl Element for ExtraDamage {
+    fn id(&self) -> &Id {
+        &self.id
+    }
+
+    fn current_commit(&self) -> CommitCounter {
+        self.commit
+    }
+
+    fn src(&self) -> Rectangle<f64, Buffer> {
+        Rectangle::from_loc_and_size((0., 0.), (1., 1.))
+    }
+
+    fn geometry(&self, scale: Scale<f64>) -> Rectangle<i32, Physical> {
+        self.geometry.to_physical_precise_round(scale)
+    }
+}
+
+impl<R: Renderer> RenderElement<R> for ExtraDamage {
+    fn draw(
+        &self,
+        _frame: &mut <R as Renderer>::Frame<'_>,
+        _src: Rectangle<f64, Buffer>,
+        _dst: Rectangle<i32, Physical>,
+        _damage: &[Rectangle<i32, Physical>],
+    ) -> Result<(), R::Error> {
+        Ok(())
+    }
+}
diff --git a/src/render_helpers/mod.rs b/src/render_helpers/mod.rs
index ebc4b49e..b1f8fd03 100644
--- a/src/render_helpers/mod.rs
+++ b/src/render_helpers/mod.rs
@@ -18,6 +18,7 @@ use self::primary_gpu_texture::PrimaryGpuTextureRenderElement;
 
 pub mod border;
 pub mod clipped_surface;
+pub mod damage;
 pub mod offscreen;
 pub mod primary_gpu_texture;
 pub mod render_elements;