Editor: remove tiles from painted zones, scrollable zone list

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/editor/map.rs

@@ -61,6 +61,8 @@ pub struct MapEdit {
     zone: usize,       // selected zone
     zone_shape: usize, // shape for a new zone
     zone_name: String,
+    zone_erase: bool,   // painting a tiles zone takes tiles out of it again
+    zone_scroll: usize, // first zone shown in the list (usize::MAX: scroll to the end)
     last_mouse: Option<Vec2>,
 }
 
@@ -117,6 +119,8 @@ impl MapEdit {
             zone: 0,
             zone_shape: 0,
             zone_name: String::new(),
+            zone_erase: false,
+            zone_scroll: 0,
             last_mouse: None,
         }
     }
@@ -460,9 +464,18 @@ impl MapEdit {
         }
         m.zones.push(z);
         self.zone = m.zones.len() - 1;
+        self.zone_scroll = usize::MAX;
         self.zone_name.clear();
     }
 
+    // the brush takes tiles out of the selected tiles zone
+    fn erase_zone_tiles(&mut self, m: &mut MissionDoc, x: i32, y: i32) {
+        let targets = self.targets(x, y);
+        if let Some(t) = m.zones.get_mut(self.zone).filter(|z| z.shape == "tiles").and_then(|z| z.tiles.as_mut()) {
+            t.retain(|p| !targets.contains(p));
+        }
+    }
+
     pub fn frame(&mut self, im: &mut Im, gfx: &Gfx, r3d: &mut R3d, dt: f32, now: f64, m: &mut MissionDoc) -> MapResult {
         let (cssx, cssy) = mouse_position();
         let bar_w = CW() * 30.0;
@@ -547,6 +560,15 @@ impl MapEdit {
                 }
                 im.pressed = false;
             }
+            // a tiles zone is painted (or erased) all along the drag
+            let tiles_zone = self.cat == Cat::Zones && ZONE_SHAPES[self.zone_shape] == "tiles";
+            if tiles_zone && im.down && self.drag.is_some() {
+                if self.zone_erase {
+                    self.erase_zone_tiles(m, x, y);
+                } else {
+                    self.draw_zone(m, x, y, x, y);
+                }
+            }
             if self.stroke && im.down {
                 for (tx, ty) in self.targets(x, y) {
                     self.paint_tile(tx, ty);
@@ -555,7 +577,11 @@ impl MapEdit {
             if im.released {
                 if let Some((sx, sy)) = self.drag {
                     if self.cat == Cat::Zones {
-                        self.draw_zone(m, sx, sy, x, y);
+                        if ZONE_SHAPES[self.zone_shape] == "tiles" && self.zone_erase {
+                            self.erase_zone_tiles(m, x, y);
+                        } else {
+                            self.draw_zone(m, sx, sy, x, y);
+                        }
                     } else {
                         for (tx, ty) in self.targets(x, y) {
                             self.paint_tile(tx, ty);
@@ -738,7 +764,24 @@ impl MapEdit {
             label(gfx, x, y, &tr("ed.zones"), FRAME_HI);
             y += CH() * 1.4;
             let mut remove = None;
-            for k in 0..m.zones.len() {
+            // the list scrolls (wheel over it) when there are more zones than room
+            let row = CH() * 1.7;
+            let room = (((h - CH() * 3.0 - y) / row).floor() as usize).max(1);
+            let over_list = im.mx < bar_w && im.my >= y && im.my < y + room as f32 * row;
+            if over_list && im.wheel != 0.0 {
+                self.zone_scroll = if im.wheel > 0.0 { self.zone_scroll.min(m.zones.len()).saturating_sub(1) } else { self.zone_scroll.saturating_add(1) };
+            }
+            let max_scroll = m.zones.len().saturating_sub(room);
+            if self.zone_scroll == usize::MAX {
+                // a new zone: show it
+                self.zone_scroll = self.zone.saturating_sub(room - 1);
+            }
+            self.zone_scroll = self.zone_scroll.min(max_scroll);
+            if self.zone_scroll > 0 || max_scroll > 0 {
+                let more = format!("{}-{} / {}", self.zone_scroll + 1, (self.zone_scroll + room).min(m.zones.len()), m.zones.len());
+                gfx.text(&more, x + fw - gfx.measure(&more, SMALL()), y - CH() * 1.3, SMALL(), DIM);
+            }
+            for k in self.zone_scroll..m.zones.len() {
                 if y > h - CH() * 3.0 {
                     break;
                 }
@@ -778,6 +821,10 @@ impl MapEdit {
             }
             bx += gfx.measure(&tr("ed.fill"), S()) + CW() * 4.0;
         }
+        if self.cat == Cat::Zones && ZONE_SHAPES[self.zone_shape] == "tiles" {
+            im.toggle(gfx, bx, by + CH() * 0.15, &tr("ed.zone_erase"), &mut self.zone_erase);
+            bx += gfx.measure(&tr("ed.zone_erase"), S()) + CW() * 4.0;
+        }
         let mirrors: Vec<String> = (0..4).map(|k| tr(&format!("ed.mirror{}", k))).collect();
         if let Some(c) = im.dropdown(gfx, id("mirror", 0), Rect::new(bx, by, CW() * 23.0, CH() * 1.7), &mirrors[self.mirror as usize], &mirrors) {
             self.mirror = c as u8;
@@ -799,3 +846,27 @@ impl MapEdit {
         done
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn tiles_of_a_painted_zone_can_be_taken_out_again() {
+        let mut ed = MapEdit::new(Game::new(3, 64, 64));
+        let mut m = MissionDoc::default();
+        ed.zone_shape = ZONE_SHAPES.iter().position(|s| *s == "tiles").unwrap();
+        ed.brush = 2;
+        ed.draw_zone(&mut m, 10, 10, 10, 10);
+        ed.draw_zone(&mut m, 14, 10, 14, 10);
+        assert_eq!(m.zones.len(), 1, "painting goes on in the selected tiles zone");
+        let n = m.zones[0].tiles.as_ref().unwrap().len();
+        assert!(n >= 2);
+        ed.erase_zone_tiles(&mut m, 10, 10);
+        let t = m.zones[0].tiles.as_ref().unwrap();
+        assert!(!t.contains(&(10, 10)) && t.contains(&(14, 10)));
+        assert!(t.len() < n);
+        // a new zone scrolls the list to it
+        assert_eq!(ed.zone_scroll, usize::MAX);
+    }
+}