From b1b3105a8069d558323025dcd7a893e914815f0b Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Mon, 15 Nov 2021 14:12:27 -0500
Subject: [PATCH] Complete section 3.1

---
 src/map.rs     | 48 +++++++++++++++++++++++++++++++++++++++++++++++-
 src/spawner.rs |  2 +-
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/src/map.rs b/src/map.rs
index 248cfdf..4e5211c 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -226,7 +226,7 @@ pub fn draw_map(ecs: &World, ctx: &mut Rltk) {
                     fg = RGB::from_f32(0., 0.5, 0.5);
                 }
                 TileType::Wall => {
-                    glyph = rltk::to_cp437('#');
+                    glyph = wall_glyph(&*map, x, y);
                     fg = RGB::from_f32(0., 1.0, 0.);
                 }
                 TileType::DownStairs => {
@@ -250,3 +250,49 @@ pub fn draw_map(ecs: &World, ctx: &mut Rltk) {
         }
     }
 }
+
+fn wall_glyph(map: &Map, x: i32, y: i32) -> rltk::FontCharType {
+    if x < 1 || x > map.width - 1 || y < 1 || y > map.height - 1 as i32 {
+        return 35;
+    }
+
+    let mut mask = 0u8;
+
+    if is_revealed_and_wall(map, x, y - 1) {
+        mask += 1;
+    }
+    if is_revealed_and_wall(map, x, y + 1) {
+        mask += 2;
+    }
+    if is_revealed_and_wall(map, x - 1, y) {
+        mask += 4;
+    }
+    if is_revealed_and_wall(map, x + 1, y) {
+        mask += 8;
+    }
+
+    match mask {
+        0 => 9,    // Pillar because we can't see neighbors
+        1 => 186,  // Wall only to the north
+        2 => 186,  // Wall only to the south
+        3 => 186,  // Wall to the north and south
+        4 => 205,  // Wall only to the west
+        5 => 188,  // Wall to the north and west
+        6 => 187,  // Wall to the south and west
+        7 => 185,  // Wall to the north, south, and west
+        8 => 205,  // Wall only to the east
+        9 => 200,  // Wall to the north and east
+        10 => 201, // Wall to the sound and east
+        11 => 204, // Wall to the north, south, and east
+        12 => 205, // Wall to the east and west
+        13 => 202, // Wall to the east, west, and south
+        14 => 203, // Wall to the east, west, and north
+        15 => 206, // ╬ Wall on all sides
+        _ => 35,   // We missed one?
+    }
+}
+
+fn is_revealed_and_wall(map: &Map, x: i32, y: i32) -> bool {
+    let idx = map.xy_idx(x, y);
+    map.tiles[idx] == TileType::Wall && map.revealed_tiles[idx]
+}
diff --git a/src/spawner.rs b/src/spawner.rs
index a176352..ea41aeb 100644
--- a/src/spawner.rs
+++ b/src/spawner.rs
@@ -3,7 +3,7 @@ use crate::components::{
     Equippable, InflictsDamage, Item, MeleePowerBonus, Monster, Name, Player, Position,
     ProvidesHealing, Ranged, Renderable, SerializeMe, Viewshed,
 };
-use crate::{random_table::RandomTable, Rect, map::MAP_WIDTH};
+use crate::{map::MAP_WIDTH, random_table::RandomTable, Rect};
 use rltk::{RandomNumberGenerator, RGB};
 use specs::prelude::*;
 use specs::saveload::{MarkedBuilder, SimpleMarker};