feat(core/rust): introduce small indeterminate loader

[no changelog]

core/embed/rust/src/ui/display/loader/mod.rs

@@ -1,5 +1,6 @@
 mod circular;
 mod rectangular;
+mod small;
 mod starry;
 
 use crate::ui::display::{Color, Icon};
@@ -16,6 +17,8 @@ use crate::ui::display::loader::rectangular::loader_rectangular as determinate;
 #[cfg(not(feature = "model_tt"))]
 use crate::ui::display::loader::starry::loader_starry_indeterminate as indeterminate;
 
+pub use small::loader_small_indeterminate;
+
 pub const LOADER_MIN: u16 = 0;
 pub const LOADER_MAX: u16 = 1000;
 

core/embed/rust/src/ui/display/loader/small.rs

@@ -0,0 +1,53 @@
+use crate::ui::{
+    constant::screen,
+    display::{rect_fill, Color},
+    geometry::{Offset, Point, Rect},
+};
+use core::f32::consts::SQRT_2;
+
+const STAR_COUNT: usize = 8;
+const RADIUS: i16 = 3;
+const DIAGONAL: i16 = ((RADIUS as f32 * SQRT_2) / 2_f32) as i16;
+const LOADER_SIZE: Offset = Offset::uniform(2 * RADIUS + 3);
+
+fn fill_point(point: Point, color: Color) {
+    let area = Rect::from_center_and_size(point, Offset::uniform(1));
+    rect_fill(area, color);
+}
+
+pub fn loader_small_indeterminate(progress: u16, y_offset: i16, fg_color: Color, bg_color: Color) {
+    let area =
+        Rect::from_center_and_size(screen().center(), LOADER_SIZE).translate(Offset::y(y_offset));
+
+    rect_fill(area, bg_color);
+
+    // Offset of the normal point and then the extra offset for the main point
+    let offsets: [(Offset, Offset); STAR_COUNT] = [
+        (Offset::y(-RADIUS), Offset::y(-1)),
+        (Offset::new(DIAGONAL, -DIAGONAL), Offset::new(1, -1)),
+        (Offset::x(RADIUS), Offset::x(1)),
+        (Offset::new(DIAGONAL, DIAGONAL), Offset::new(1, 1)),
+        (Offset::y(RADIUS), Offset::y(1)),
+        (Offset::new(-DIAGONAL, DIAGONAL), Offset::new(-1, 1)),
+        (Offset::x(-RADIUS), Offset::x(-1)),
+        (Offset::new(-DIAGONAL, -DIAGONAL), Offset::new(-1, -1)),
+    ];
+
+    let main_idx = (STAR_COUNT * progress as usize / 1000) % STAR_COUNT;
+
+    for (i, (point_offset, main_offset)) in offsets.iter().enumerate() {
+        // Skip it when it is behind the main one (clockwise)
+        if (main_idx + 1) % STAR_COUNT == i {
+            continue;
+        }
+
+        // Draw the normal point
+        let point = area.center() + *point_offset;
+        fill_point(point, fg_color);
+
+        // Draw the main point
+        if main_idx == i {
+            fill_point(point + *main_offset, fg_color);
+        }
+    }
+}

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

@@ -35,7 +35,9 @@ use crate::{
 pub use crate::ui::display::toif::Icon;
 pub use color::Color;
 pub use font::{Font, Glyph, GlyphMetrics};
-pub use loader::{loader, loader_indeterminate, LOADER_MAX, LOADER_MIN};
+pub use loader::{
+    loader, loader_indeterminate, loader_small_indeterminate, LOADER_MAX, LOADER_MIN,
+};
 
 pub fn backlight() -> u16 {
     display::backlight(-1) as u16