From 27b6cc385dc8fa56c0fafbf862889457137383b3 Mon Sep 17 00:00:00 2001
From: Timothy Warren <twarren@nabancard.com>
Date: Tue, 4 Jan 2022 15:34:07 -0500
Subject: [PATCH] Improve forest map generation

---
 src/gamesystem.rs          |   2 +-
 src/map_builders/forest.rs | 121 +++++++++++++++++++++++++++++++++++--
 2 files changed, 117 insertions(+), 6 deletions(-)

diff --git a/src/gamesystem.rs b/src/gamesystem.rs
index 2821759..9632f81 100644
--- a/src/gamesystem.rs
+++ b/src/gamesystem.rs
@@ -9,7 +9,7 @@ pub fn player_hp_per_level(fitness: i32) -> i32 {
 }
 
 pub fn player_hp_at_level(fitness: i32, level: i32) -> i32 {
-    player_hp_per_level(fitness) * level
+    10 + player_hp_per_level(fitness) * level
 }
 
 pub fn npc_hp(fitness: i32, level: i32) -> i32 {
diff --git a/src/map_builders/forest.rs b/src/map_builders/forest.rs
index b4ddc1f..858ec28 100644
--- a/src/map_builders/forest.rs
+++ b/src/map_builders/forest.rs
@@ -1,9 +1,11 @@
 use ::rltk::RandomNumberGenerator;
 
 use super::{
-    AreaStartingPosition, BuilderChain, CellularAutomataBuilder, CullUnreachable, DistantExit,
+    AreaStartingPosition, BuilderChain, CellularAutomataBuilder, CullUnreachable, MetaMapBuilder,
     VoronoiSpawning, XStart, YStart,
 };
+use crate::map_builders::BuilderMap;
+use crate::{map, TileType};
 
 pub fn forest_builder(
     new_depth: i32,
@@ -17,10 +19,119 @@ pub fn forest_builder(
         .start_with(CellularAutomataBuilder::new())
         .with(AreaStartingPosition::new(XStart::Center, YStart::Center))
         .with(CullUnreachable::new())
-        .with(AreaStartingPosition::new(XStart::Left, YStart::Center));
-
-    // Setup an exit and spawn mobs
-    chain.with(VoronoiSpawning::new()).with(DistantExit::new());
+        .with(AreaStartingPosition::new(XStart::Left, YStart::Center))
+        .with(VoronoiSpawning::new())
+        .with(YellowBrickRoad::new());
 
     chain
 }
+
+pub struct YellowBrickRoad {}
+
+impl MetaMapBuilder for YellowBrickRoad {
+    fn build_map(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        self.build(rng, build_data);
+    }
+}
+
+impl YellowBrickRoad {
+    #[allow(dead_code)]
+    pub fn new() -> Box<YellowBrickRoad> {
+        Box::new(YellowBrickRoad {})
+    }
+
+    fn find_exit(&self, build_data: &mut BuilderMap, seed_x: i32, seed_y: i32) -> (i32, i32) {
+        let mut available_floors: Vec<(usize, f32)> = Vec::new();
+        for (idx, tiletype) in build_data.map.tiles.iter().enumerate() {
+            if map::tile_walkable(*tiletype) {
+                available_floors.push((
+                    idx,
+                    rltk::DistanceAlg::PythagorasSquared.distance2d(
+                        rltk::Point::new(
+                            idx as i32 % build_data.map.width,
+                            idx as i32 / build_data.map.width,
+                        ),
+                        rltk::Point::new(seed_x, seed_y),
+                    ),
+                ));
+            }
+        }
+
+        if available_floors.is_empty() {
+            panic!("No valid floors to start on");
+        }
+
+        available_floors.sort_by(|a, b| a.1.partial_cmp(&b.1).unwrap());
+
+        let end_x = available_floors[0].0 as i32 % build_data.map.width;
+        let end_y = available_floors[0].0 as i32 / build_data.map.width;
+
+        (end_x, end_y)
+    }
+
+    fn paint_road(&self, build_data: &mut BuilderMap, x: i32, y: i32) {
+        if x < 1 || x > build_data.map.width - 2 || y < 1 || y > build_data.map.height - 2 {
+            return;
+        }
+
+        let idx = build_data.map.xy_idx(x, y);
+        if build_data.map.tiles[idx] != TileType::DownStairs {
+            build_data.map.tiles[idx] = TileType::Road;
+        }
+    }
+
+    fn build(&mut self, rng: &mut RandomNumberGenerator, build_data: &mut BuilderMap) {
+        let starting_pos = build_data.starting_position.as_ref().unwrap().clone();
+        let start_idx = build_data.map.xy_idx(starting_pos.x, starting_pos.y);
+
+        let (end_x, end_y) = self.find_exit(
+            build_data,
+            build_data.map.width - 2,
+            build_data.map.height / 2,
+        );
+        let end_idx = build_data.map.xy_idx(end_x, end_y);
+
+        build_data.map.populate_blocked();
+        let path = rltk::a_star_search(start_idx, end_idx, &mut build_data.map);
+
+        for idx in path.steps.iter() {
+            let x = *idx as i32 % build_data.map.width;
+            let y = *idx as i32 / build_data.map.width;
+            self.paint_road(build_data, x, y);
+            self.paint_road(build_data, x - 1, y);
+            self.paint_road(build_data, x + 1, y);
+            self.paint_road(build_data, x, y - 1);
+            self.paint_road(build_data, x, y + 1);
+        }
+        build_data.map.tiles[end_idx] = TileType::DownStairs;
+        build_data.take_snapshot();
+
+        // Place exit
+        let exit_dir = rng.roll_dice(1, 2);
+        let (seed_x, seed_y, stream_startx, stream_starty) = if exit_dir == 1 {
+            (build_data.map.width - 1, 1, 0, build_data.height - 1)
+        } else {
+            (
+                build_data.map.width - 1,
+                build_data.height - 1,
+                1,
+                build_data.height - 1,
+            )
+        };
+
+        let (stairs_x, stairs_y) = self.find_exit(build_data, seed_x, seed_y);
+        let stairs_idx = build_data.map.xy_idx(stairs_x, stairs_y);
+        build_data.take_snapshot();
+
+        let (stream_x, stream_y) = self.find_exit(build_data, stream_startx, stream_starty);
+        let stream_idx = build_data.map.xy_idx(stream_x, stream_y) as usize;
+        let stream = rltk::a_star_search(stairs_idx, stream_idx, &mut build_data.map);
+        for tile in stream.steps.iter() {
+            if build_data.map.tiles[*tile as usize] == TileType::Floor {
+                build_data.map.tiles[*tile as usize] = TileType::ShallowWater;
+            }
+        }
+        build_data.map.tiles[stairs_idx] = TileType::DownStairs;
+        build_data.take_snapshot();
+    }
+}