From bf3c501353e099786353c95dd662461439040ea3 Mon Sep 17 00:00:00 2001
From: "Eevee (Evelyn Woods)" <eevee.git@veekun.com>
Date: Mon, 14 Dec 2020 23:14:31 -0700
Subject: [PATCH] Fix yellow tank behavior to be faux simultaneous

---
 js/game.js      | 14 +++++++++-----
 js/tiletypes.js | 14 +++++++++++---
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/js/game.js b/js/game.js
index e595b39..40b78c9 100644
--- a/js/game.js
+++ b/js/game.js
@@ -943,11 +943,7 @@ export class Level {
 
             direction = actor.cell.redirect_exit(actor, direction);
 
-            let dest_cell = this.get_neighboring_cell(actor.cell, direction);
-            if (dest_cell &&
-                ! actor.cell.blocks_leaving(actor, direction) &&
-                ! dest_cell.blocks_entering(actor, direction, this, actor === this.player ? 'move' : 'trace'))
-            {
+            if (this.is_move_allowed(actor, direction, 'trace')) {
                 // We found a good direction!  Stop here
                 actor.decision = direction;
                 all_blocked = false;
@@ -988,6 +984,14 @@ export class Level {
         }
     }
 
+    // FIXME make this interact with railroads correctly and use it for players and in attempt_step
+    is_move_allowed(actor, direction, push_mode) {
+        let dest_cell = this.get_neighboring_cell(actor.cell, direction);
+        return (dest_cell &&
+            ! actor.cell.blocks_leaving(actor, direction) &&
+            ! dest_cell.blocks_entering(actor, direction, this, push_mode));
+    }
+
     // Try to move the given actor one tile in the given direction and update their cooldown.
     // Return true if successful.
     attempt_step(actor, direction) {
diff --git a/js/tiletypes.js b/js/tiletypes.js
index a505606..36ec134 100644
--- a/js/tiletypes.js
+++ b/js/tiletypes.js
@@ -1339,14 +1339,22 @@ const TILE_TYPES = {
         on_arrive(me, level, other) {
             level.sfx.play_once('button-press', me.cell);
 
-            // Move all yellow tanks one tile in the direction of the pressing actor
+            // Move all yellow tanks one tile in the direction of the pressing actor.  But pretend
+            // it's simultaneous, so one in front will block one behind as usual.
+            // XXX this feels really weird, i'm wondering if cc2 does some other weird thing like
+            // not move any actor out of its cell until its first cooldown tick??
+            // FIXME not sure this interacts with railroads correctly
+            let unblocked_tanks = [];
             for (let i = level.actors.length - 1; i >= 0; i--) {
                 let actor = level.actors[i];
                 // TODO generify somehow??
-                if (actor.type.name === 'tank_yellow') {
-                    level.attempt_out_of_turn_step(actor, other.direction);
+                if (actor.type.name === 'tank_yellow' && level.is_move_allowed(actor, other.direction, 'trace')) {
+                    unblocked_tanks.push(actor);
                 }
             }
+            for (let actor of unblocked_tanks) {
+                level.attempt_out_of_turn_step(actor, other.direction);
+            }
         },
         on_depart(me, level, other) {
             level.sfx.play_once('button-release', me.cell);