1 files changed, 65 insertions, 31 deletions

diff --git a/src/systems/view.rs b/src/systems/view.rs
index 209b1a5..b854348 100644
--- a/src/systems/view.rs
+++ b/src/systems/view.rs
@@ -1,8 +1,14 @@
 
-use std::collections::HashMap;
+use std::collections::{HashMap, HashSet};
 
 use specs::{
+	BitSet,
+	storage::ComponentEvent,
+	ReaderId,
+	World,
+	SystemData,
 	ReadStorage,
+	WriteStorage,
 	Read,
 	Write,
 	System,
@@ -10,39 +16,29 @@ use specs::{
 };
 
 use super::super::pos::Pos;
-
-use super::super::components::{
-	Visible,
-	Played
-};
-
-use super::super::resources::{
-	Size,
-	Output
-};
-
-use super::super::worldmessages::{
-	WorldMessage,
-	WorldUpdate,
-	FieldMessage
-};
+use super::super::components::{Visible, Played, Position};
+use super::super::resources::{Size, Output};
+use super::super::worldmessages::{WorldMessage, WorldUpdate, FieldMessage};
 
 
+#[derive(Default)]
+pub struct View {
+    reader_id: Option<ReaderId<ComponentEvent>>,
+    dirty: BitSet
+}
 
-pub struct View;
 impl <'a> System<'a> for View {
-	type SystemData = (ReadStorage<'a, Pos>, ReadStorage<'a, Visible>, Read<'a, Size>, ReadStorage<'a, Played>, Write<'a, Output>);
-	fn run(&mut self, (positions, visible, size, players, mut output): Self::SystemData) {
-		
+	type SystemData = (ReadStorage<'a, Position>, ReadStorage<'a, Visible>, Read<'a, Size>, WriteStorage<'a, Played>, Write<'a, Output>);
+	fn run(&mut self, (positions, visible, size, mut players, mut output): Self::SystemData) {
 		
 		let mut cells: HashMap<Pos, Vec<Visible>> = HashMap::new();
 		for (pos, vis) in (&positions, &visible).join(){
-			cells.entry(*pos).or_insert(Vec::new()).push(vis.clone());
-			cells.get_mut(pos).unwrap().sort_by(|a, b| b.height.partial_cmp(&a.height).unwrap());
+			cells.entry(pos.pos).or_insert(Vec::new()).push(vis.clone());
+			cells.get_mut(&pos.pos).unwrap().sort_by(|a, b| b.height.partial_cmp(&a.height).unwrap());
 		}
 		let width = size.width;
 		let height = size.height;
-		let (values, mapping) = draw_room(cells, (width, height));
+		let (values, mapping) = draw_room(cells.clone(), (width, height));
 		
 		let field = WorldUpdate::Field(FieldMessage{
 			width,
@@ -50,19 +46,57 @@ impl <'a> System<'a> for View {
 			field: values,
 			mapping
 		});
+		
+		
+		self.dirty.clear();
+		{
+			let events = positions.channel().read(self.reader_id.as_mut().unwrap());
+			for event in events {
+				match event {
+					ComponentEvent::Modified(id) | ComponentEvent::Inserted(id) | ComponentEvent::Removed(id) => { 
+						self.dirty.add(*id);
+					}
+				};
+			}
+		}
+		let mut changed: HashSet<Pos> = HashSet::new();
+		for (pos, _) in (&positions, &self.dirty).join(){
+			changed.insert(pos.pos);
+			if let Some(prev) = pos.prev{
+				changed.insert(prev);
+			}
+		}
+		let has_changed: bool = changed.len() > 0;
+		let mut changes: Vec<(Pos, Vec<String>)> = Vec::new();
+		for pos in changed {
+			changes.push((pos, cells.get(&pos).unwrap().iter().map(|v| v.sprite.clone()).collect()));
+		}
+		let changed_msg = WorldUpdate::Change(changes);
+		
+		
 		output.output.clear();
-		for (player, pos) in (&players, &positions).join() {
-			
-			let message = WorldMessage{updates: vec![
-				field.clone(),
-				WorldUpdate::Pos(*pos)
-			]};
+		for (mut player, pos) in (&mut players, &positions).join() {
+			let mut updates: Vec<WorldUpdate> = Vec::new();
+			if player.is_new {
+				updates.push(field.clone());
+			} else if has_changed {
+				updates.push(changed_msg.clone());
+			}
+			updates.push(WorldUpdate::Pos(pos.pos));
+			let message = WorldMessage{updates};
 			output.output.insert(player.name.clone(), message);
+			player.is_new = false;
 		}
 	}
+	
+	fn setup(&mut self, world: &mut World) {
+		Self::SystemData::setup(world);
+		self.reader_id = Some(
+			WriteStorage::<Position>::fetch(&world).register_reader()
+		);
+	}
 }
 
-
 fn draw_room(cells: HashMap<Pos, Vec<Visible>>, (width, height): (i32, i32)) -> (Vec<usize>, Vec<Vec<String>>){
 	
 	let size = width * height;