feat(core/rust): introduce unlock-screen animated overlay

[no changelog]

core/embed/rust/src/ui/shape/mod.rs

@@ -14,6 +14,7 @@ mod rawimage;
 mod render;
 mod text;
 mod toif;
+mod unlock_overlay;
 mod utils;
 
 pub use bar::Bar;
@@ -34,4 +35,5 @@ pub use rawimage::RawImage;
 pub use render::{DirectRenderer, ProgressiveRenderer, Renderer};
 pub use text::Text;
 pub use toif::ToifImage;
+pub use unlock_overlay::UnlockOverlay;
 pub use utils::ImageBuffer;

core/embed/rust/src/ui/shape/unlock_overlay.rs

@@ -0,0 +1,116 @@
+use crate::ui::{
+    display::Color,
+    geometry::{Offset, Point, Rect},
+};
+
+use super::{Canvas, DrawingCache, Mono8Canvas, Renderer, Shape, ShapeClone};
+
+use without_alloc::alloc::LocalAllocLeakExt;
+
+/// A special shape for rendering 7 differently rotated circular
+/// sectors on 5 concentric circles, used as an overlay on the background
+/// image on the lock screen.
+///
+/// The overlay covers area of 170x170 pixels (centered at `pos`).
+pub struct UnlockOverlay {
+    /// Center of the overlay
+    pos: Point,
+    // Angle of the rotation (in degrees)
+    angle: f32,
+}
+
+impl UnlockOverlay {
+    /// Outer radius
+    pub const RADIUS: i16 = 85;
+    /// Distance between the circles
+    pub const SPAN: i16 = 10;
+    /// Thickness of the circles
+    pub const THICKNESS: i16 = 4;
+
+    /// Create a new overlay with the given center and rotation angle.
+    pub fn new(pos: Point, angle: f32) -> Self {
+        Self { pos, angle }
+    }
+
+    pub fn render<'a>(self, renderer: &mut impl Renderer<'a>) {
+        renderer.render_shape(self);
+    }
+
+    fn prepare_overlay(&self, canvas: &mut dyn Canvas) {
+        let center = canvas.bounds().center();
+
+        let transp = Color::black();
+        let opaque = Color::white();
+
+        canvas.fill_background(opaque);
+
+        // The most outer circle (with two sectors)
+        let angle = self.angle;
+        let r = Self::RADIUS;
+        canvas.fill_sector(center, r, 0.0 + angle, 140.0 + angle, transp);
+        canvas.fill_sector(center, r, 235.0 + angle, 270.0 + angle, transp);
+        canvas.fill_circle(center, r - Self::THICKNESS, opaque, 255);
+
+        // The second circle (with one sector)
+        let angle = -self.angle - 20.0;
+        let r = Self::RADIUS - Self::SPAN;
+        canvas.fill_sector(center, r, 0.0 + angle, 135.0 + angle, transp);
+        canvas.fill_circle(center, r - Self::THICKNESS, opaque, 255);
+
+        // The third circle (with one sector)
+        let angle = self.angle / 2.0 + 90.0;
+        let r = Self::RADIUS - 2 * Self::SPAN;
+        canvas.fill_sector(center, r, 0.0 + angle, 270.0 + angle, transp);
+        canvas.fill_circle(center, r - Self::THICKNESS, opaque, 255);
+
+        // The fourth circle (with two sectors)
+        let angle = -self.angle / 2.0 + 60.0;
+        let r = Self::RADIUS - 3 * Self::SPAN;
+        canvas.fill_sector(center, r, 0.0 + angle, 110.0 + angle, transp);
+        canvas.fill_sector(center, r, 180.0 + angle, 280.0 + angle, transp);
+        canvas.fill_circle(center, r - Self::THICKNESS, opaque, 255);
+
+        // Innner fixed circle
+        let r = Self::RADIUS - (9 * Self::SPAN) / 2;
+        canvas.fill_circle(center, r, transp, 255);
+        canvas.fill_circle(center, r - Self::THICKNESS, opaque, 255);
+    }
+}
+
+impl<'a> Shape<'a> for UnlockOverlay {
+    fn bounds(&self) -> Rect {
+        Rect::new(
+            self.pos - Offset::uniform(Self::RADIUS),
+            self.pos + Offset::uniform(Self::RADIUS + 1),
+        )
+    }
+
+    fn cleanup(&mut self, _cache: &DrawingCache<'a>) {
+        // TODO: inform the cache that we won't use the zlib slot anymore
+    }
+
+    fn draw(&mut self, canvas: &mut dyn Canvas, cache: &DrawingCache<'a>) {
+        let bounds = self.bounds();
+
+        let overlay_buff = &mut unwrap!(cache.image_buff(), "No image buffer");
+
+        let mut overlay_canvas = unwrap!(
+            Mono8Canvas::new(bounds.size(), None, None, &mut overlay_buff[..]),
+            "Too small buffer"
+        );
+
+        self.prepare_overlay(&mut overlay_canvas);
+
+        canvas.blend_bitmap(bounds, overlay_canvas.view().with_fg(Color::black()));
+    }
+}
+
+impl<'a> ShapeClone<'a> for UnlockOverlay {
+    fn clone_at_bump<T>(self, bump: &'a T) -> Option<&'a mut dyn Shape<'a>>
+    where
+        T: LocalAllocLeakExt<'a>,
+    {
+        let clone = bump.alloc_t()?;
+        Some(clone.uninit.init(UnlockOverlay { ..self }))
+    }
+}