Fixed a few bugs, implemented cursor VFX on state change

src/renderer/cursor_renderer.rs

@@ -1,6 +1,6 @@
 use std::time::{Duration, Instant};
 
-use skulpin::skia_safe::{Canvas, Paint, Path, Point};
+use skulpin::skia_safe::{BlendMode, Canvas, Color, Paint, Path, Point, Rect};
 
 use crate::settings::SETTINGS;
 use crate::renderer::animation_utils::*;
@@ -9,9 +9,8 @@ use crate::editor::{EDITOR, Colors, Cursor, CursorShape};
 use crate::redraw_scheduler::REDRAW_SCHEDULER;
 
 
-
 const BASE_ANIMATION_LENGTH_SECONDS: f32 = 0.06;
-const CURSOR_TRAIL_SIZE: f32 = 0.6;
+const CURSOR_TRAIL_SIZE: f32 = 0.9;
 const COMMAND_LINE_DELAY_FRAMES: u64 = 5;
 const DEFAULT_CELL_PERCENTAGE: f32 = 1.0 / 8.0;
 
@@ -151,10 +150,10 @@ impl Corner {
             d
         };
 
-        let direction_alignment = corner_direction.dot(self.relative_position);
+        let direction_alignment = -corner_direction.dot(self.relative_position); // TODO -- Fix math below so this doesn't have to be negated
 
         self.current_position =
-            ease_point(ease_linear, self.start_position, corner_destination, self.t);
+            ease_point(ease_out_quad, self.start_position, corner_destination, self.t);
 
         if self.t == 1.0 {
             // We are at destination, move t out of 0-1 range to stop the animation
@@ -168,12 +167,52 @@ impl Corner {
     }
 }
 
+// TODO -- Split into own file, make it a trait to have several impls
+// TODO -- Rename this impl as SonicBoom
+pub struct CursorVFX {
+    t: f32,
+    center_position: Point,
+}
+
+impl CursorVFX {
+    fn update(&mut self, dt: f32) -> bool {
+        self.t = (self.t + dt * 5.0).min(1.0); // TODO - speed config
+        return self.t < 1.0
+    }
+
+    fn reset(&mut self, position: Point) {
+        self.t = 0.0;
+        self.center_position = position;
+    }
+
+    fn render(&self, _paint: &mut Paint, canvas: &mut Canvas, cursor: &Cursor, colors: &Colors) {
+        if self.t == 1.0 {
+            return;
+        }
+        let mut paint = Paint::new(skulpin::skia_safe::colors::WHITE, None);
+        paint.set_blend_mode(BlendMode::SrcOver);
+
+        let base_color : Color = cursor.background(&colors).to_color();
+        let alpha = ((1.0 - self.t) * 255.0) as u8;
+        let color = Color::from_argb(alpha, base_color.r(), base_color.g(), base_color.b());
+        paint.set_color(color);
+
+        let size = 40.0; // TODO -- Compute from font size
+        let radius = self.t * size;
+        let hr = radius * 0.5;
+        let rect = Rect::from_xywh(self.center_position.x - hr, self.center_position.y - hr, radius, radius);
+
+        canvas.draw_oval(&rect, &paint);
+    }
+}
+
 pub struct CursorRenderer {
     pub corners: Vec<Corner>,
     pub previous_position: (u64, u64),
     pub command_line_delay: u64,
     blink_status: BlinkStatus,
     previous_cursor_shape: Option<CursorShape>,
+    cursor_vfx: CursorVFX,
 }
 
 impl CursorRenderer {
@@ -184,19 +223,13 @@ impl CursorRenderer {
             command_line_delay: 0,
             blink_status: BlinkStatus::new(),
             previous_cursor_shape: None,
+            cursor_vfx:  CursorVFX{t: 0.0, center_position: Point{x:0.0, y:0.0}},
         };
         renderer.set_cursor_shape(&CursorShape::Block, DEFAULT_CELL_PERCENTAGE);
         renderer
     }
 
     fn set_cursor_shape(&mut self, cursor_shape: &CursorShape, cell_percentage: f32) {
-        let new_cursor = Some(cursor_shape.clone());
-        if self.previous_cursor_shape == new_cursor {
-            return;
-        }
-
-        self.previous_cursor_shape = new_cursor;
-
         self.corners = self.corners
             .clone()
             .into_iter().enumerate()
@@ -229,6 +262,8 @@ impl CursorRenderer {
             canvas: &mut Canvas) {
         let render = self.blink_status.update_status(&cursor);
 
+        paint.set_anti_alias(true);
+
         self.previous_position = {
             let editor = EDITOR.lock();
             let (_, grid_y) = cursor.position;
@@ -247,6 +282,7 @@ impl CursorRenderer {
             }
         };
         
+
         let (grid_x, grid_y) = self.previous_position;
 
         let (character, font_dimensions): (String, Point) = {
@@ -270,8 +306,15 @@ impl CursorRenderer {
         let destination: Point = (grid_x as f32 * font_width, grid_y as f32 * font_height).into();
         let center_destination = destination + font_dimensions * 0.5;
 
+        let new_cursor = Some(cursor.shape.clone());
+
+        if self.previous_cursor_shape != new_cursor {
+            self.previous_cursor_shape = new_cursor;
             self.set_cursor_shape(&cursor.shape, cursor.cell_percentage.unwrap_or(DEFAULT_CELL_PERCENTAGE)); 
         
+            self.cursor_vfx.reset(center_destination);
+        }
+
         let dt = 1.0 / (SETTINGS.get("refresh_rate").read_u16() as f32);
 
         let mut animating = false;
@@ -280,6 +323,8 @@ impl CursorRenderer {
                 let corner_animating = corner.update(font_dimensions, center_destination, dt);
                 animating |= corner_animating;
             }
+            let vfx_animating = self.cursor_vfx.update(dt);
+            animating |= vfx_animating;
         }
 
         if animating || self.command_line_delay != 0 {
@@ -310,6 +355,7 @@ impl CursorRenderer {
                 canvas.draw_text_blob(&blob, destination, &paint);
             }
             canvas.restore();
+            self.cursor_vfx.render(paint, canvas, &cursor, &default_colors);
         }
     }
 }