fix rare index error, more functional flood fill algo

2 files changed, 46 insertions, 34 deletions

diff --git a/src/app.rs b/src/app.rs
index 84869a3..725a45a 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -176,8 +176,10 @@ impl<'ctx> AppState<'ctx> {
             .chain(sym_circle)
             .filter(|&pt| dither::bayer(dither_level, pt))
         {
-            let old_val = self.pixmap.set(point, val);
-            modify_record.push(PaintRecord::new(point, old_val, val));
+            if self.pixmap.contains(point) {
+                let old_val = self.pixmap.set(point, val);
+                modify_record.push(PaintRecord::new(point, old_val, val));
+            }
         }
         Ok(modify_record)
     }
@@ -203,8 +205,10 @@ impl<'ctx> AppState<'ctx> {
                 .into_iter()
                 .filter(|&pt| dither::bayer(dither_level, pt))
             {
-                let old_val = self.pixmap.set(c, val);
-                line_modify_record.push(PaintRecord::new(c, old_val, val));
+                if self.pixmap.contains(c) {
+                    let old_val = self.pixmap.set(c, val);
+                    line_modify_record.push(PaintRecord::new(c, old_val, val));
+                }
             }
         }
         Ok(line_modify_record)
@@ -353,9 +357,11 @@ impl<'ctx> AppState<'ctx> {
         container.place(&mut padding_box, HorAlign::Right, VertAlign::Center);
         padding_box.place(&mut primary, HorAlign::Center, VertAlign::Center);
 
-        self.canvas.set_draw_color(if !self.active_color { WHITE } else { BLACK });
+        self.canvas
+            .set_draw_color(if !self.active_color { WHITE } else { BLACK });
         self.canvas.fill_rect(primary.area()).unwrap();
-        self.canvas.set_draw_color(if self.active_color { WHITE } else { BLACK });
+        self.canvas
+            .set_draw_color(if self.active_color { WHITE } else { BLACK });
 
         let brush_box = (0..8)
             .map(|x| (0..8).map(|y| (x, y).into()).collect::<Vec<MapPoint>>())
@@ -364,9 +370,11 @@ impl<'ctx> AppState<'ctx> {
             .collect::<Vec<_>>();
 
         for pt in brush_box {
-            let canvas_pt = Point::from(primary.start) 
-                + Point::from((pt.x as i32 * 2, pt.y as i32 * 2));
-            self.canvas.fill_rect(rect!(canvas_pt.x(), canvas_pt.y(), 2, 2)).unwrap();
+            let canvas_pt =
+                Point::from(primary.start) + Point::from((pt.x as i32 * 2, pt.y as i32 * 2));
+            self.canvas
+                .fill_rect(rect!(canvas_pt.x(), canvas_pt.y(), 2, 2))
+                .unwrap();
         }
 
         let mouse_coords = if let Some((x, y)) = self.idx_at_coord(self.mouse) {
@@ -735,20 +743,19 @@ impl<'ctx> AppState<'ctx> {
                                     Brush::Fill => {
                                         if let Some(c) = contact {
                                             let target = self.pixmap.get(c);
-                                            let mut operation = vec![];
-                                            self.pixmap.flood_fill(
-                                                c,
-                                                target,
-                                                self.active_color,
-                                                &mut operation,
-                                            );
+                                            let replacement = self.active_color;
+                                            let operation =
+                                                self.pixmap.flood_fill(c, target, replacement);
+                                            for o in operation.iter() {
+                                                self.pixmap.set(o.clone(), replacement);
+                                            }
                                             self.current_operation.extend(
                                                 operation
                                                     .into_iter()
                                                     .map(|point| PaintRecord {
                                                         point,
                                                         old: target,
-                                                        new: self.active_color,
+                                                        new: replacement,
                                                     })
                                                     .collect::<Vec<PaintRecord>>(),
                                             )
diff --git a/src/bitmap.rs b/src/bitmap.rs
index dc66d73..6aa6b12 100644
--- a/src/bitmap.rs
+++ b/src/bitmap.rs
@@ -1,4 +1,5 @@
 use std::{
+    collections::HashSet,
     convert::{From, Into, TryFrom},
     ops::{Add, Sub},
 };
@@ -10,7 +11,7 @@ pub struct Pixmap<T> {
     pub data: Vec<T>,
 }
 
-#[derive(Copy, Clone, Debug)]
+#[derive(Copy, Clone, Debug, Hash, PartialEq, Eq)]
 pub struct MapPoint {
     pub x: u32,
     pub y: u32,
@@ -249,22 +250,26 @@ where
             .collect()
     }
 
-    pub fn flood_fill(
-        &mut self,
-        start: MapPoint,
-        target: T,
-        replacement: T,
-        pts: &mut Vec<MapPoint>,
-    ) {
-        if !self.contains(start) || self.get(start) != target || self.get(start) == replacement {
-            return;
-        } else {
-            pts.push(start);
-            self.set(start, replacement);
-            for (x, y) in [(1, 0), (0, 1), (-1, 0), (0, -1)].iter() {
-                let dir = MapPoint::try_from((start.x as i64 - x, start.y as i64 + y));
-                if let Ok(pt) = dir {
-                    self.flood_fill(pt, target, replacement, pts);
+    pub fn flood_fill(&mut self, start: MapPoint, target: T, replacement: T) -> Vec<MapPoint> {
+        let mut queue = vec![start];
+        let mut area = HashSet::new();
+        loop {
+            if queue.is_empty() {
+                break area.drain().collect();
+            } else {
+                let last = queue.pop().unwrap();
+                area.insert(last);
+                for (x, y) in [(1, 0), (0, 1), (-1, 0), (0, -1)].iter() {
+                    let dir = MapPoint::try_from((last.x as i64 + x, last.y as i64 + y));
+                    if let Ok(pt) = dir {
+                        if self.contains(pt)
+                            && self.get(pt) == target
+                            && self.get(pt) != replacement
+                            && !area.contains(&pt)
+                        {
+                            queue.push(pt);
+                        }
+                    }
                 }
             }
         }