From 4ee56fad013cf83c2daa88ebd911f44bcbf56f8f Mon Sep 17 00:00:00 2001
From: "Eevee (Evelyn Woods)" <eevee.git@veekun.com>
Date: Tue, 8 Dec 2020 12:48:25 -0700
Subject: [PATCH] Briefly reveal invisible walls, as in CC2

---
 js/tileset.js   |  3 +++
 js/tiletypes.js | 15 ++++++++++++++-
 2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/js/tileset.js b/js/tileset.js
index ef564f8..0382098 100644
--- a/js/tileset.js
+++ b/js/tileset.js
@@ -72,6 +72,8 @@ export const CC2_TILESET_LAYOUT = {
         hidden: [0, 2],
         revealed: [9, 31],
     },
+    // FIXME this shouldn't be visible with seeing eye (or should it not spawn at all?)
+    wall_invisible_revealed: [1, 2],
     wall_appearing: {
         special: 'perception',
         threshold: 2,
@@ -627,6 +629,7 @@ export const TILE_WORLD_TILESET_LAYOUT = {
     water: [0, 3],
     fire: [0, 4],
     wall_invisible: [0, 5],
+    wall_invisible_revealed: [0, 1],
     thinwall_n: [0, 6],
     thinwall_w: [0, 7],
     thinwall_s: [0, 8],
diff --git a/js/tiletypes.js b/js/tiletypes.js
index 5a3114d..51d2598 100644
--- a/js/tiletypes.js
+++ b/js/tiletypes.js
@@ -175,8 +175,12 @@ const TILE_TYPES = {
     },
     wall_invisible: {
         draw_layer: DRAW_LAYERS.terrain,
-        // FIXME cc2 seems to make these flicker briefly
         blocks_collision: COLLISION.all_but_ghost,
+        on_bump(me, level, other) {
+            if (other.type.can_reveal_walls) {
+                level.spawn_animation(me.cell, 'wall_invisible_revealed');
+            }
+        },
     },
     wall_appearing: {
         draw_layer: DRAW_LAYERS.terrain,
@@ -2155,6 +2159,15 @@ const TILE_TYPES = {
         blocks_collision: COLLISION.player,
         ttl: 6,
     },
+    // Used as an easy way to show an invisible wall when bumped
+    wall_invisible_revealed: {
+        draw_layer: DRAW_LAYERS.terrain,
+        is_actor: true,
+        collision_mask: 0,
+        blocks_collision: 0,
+        // determined experimentally
+        ttl: 12,
+    },
     // Custom VFX (identical function, but different aesthetic)
     splash_slime: {
         draw_layer: DRAW_LAYERS.overlay,