From 34655d5c0a24444a05c1e6b768b3501b346d8003 Mon Sep 17 00:00:00 2001
From: En Yi <en.yi@tutanota.com>
Date: Thu, 20 Jul 2023 22:51:15 +0800
Subject: [PATCH] Visualine reachable scanline

Also tweak logic for lowest point
---
 scenes/water_flow.c | 15 ++++++++++-----
 water_test.c        | 19 +++++++++++++++++++
 2 files changed, 29 insertions(+), 5 deletions(-)

diff --git a/scenes/water_flow.c b/scenes/water_flow.c
index 1748615..5314bf7 100644
--- a/scenes/water_flow.c
+++ b/scenes/water_flow.c
@@ -117,14 +117,19 @@ void update_water_runner_system(Scene_t* scene)
                     bool to_go[4] = {false, false, false, false};
                     Tile_t* curr_tile = tilemap.tiles + curr_idx;
 
-                    if (curr_height > curr_low && curr_tile->water_level < tilemap.max_water_level)
+                    unsigned int next = curr_idx + p_crunner->bfs_tilemap.width;
+                    Tile_t* next_tile = tilemap.tiles + next;
+
+                    if (
+                        curr_height > curr_low
+                        && curr_tile->water_level < tilemap.max_water_level
+                        && next_tile->water_level < tilemap.max_water_level
+                    )
                     {
                         lowest_tile = curr_idx;
                     }
 
 
-                    unsigned int next = curr_idx + p_crunner->bfs_tilemap.width;
-                    Tile_t* next_tile = tilemap.tiles + next;
                     if (next < p_crunner->bfs_tilemap.len)
                     {
                         to_go[0] = next_tile->solid != SOLID;
@@ -136,9 +141,9 @@ void update_water_runner_system(Scene_t* scene)
                         || curr_tile->water_level == tilemap.max_water_level
                     )
                     {
-                        next = curr_idx - 1;
-                        if (next % p_crunner->bfs_tilemap.width != 0)
+                        if (curr_idx % p_crunner->bfs_tilemap.width != 0)
                         {
+                            next = curr_idx - 1;
                             next_tile = tilemap.tiles + next;
                             to_go[1] = next_tile->solid != SOLID;
                         }
diff --git a/water_test.c b/water_test.c
index f22ee64..ed99ea5 100644
--- a/water_test.c
+++ b/water_test.c
@@ -109,6 +109,25 @@ static void level_scene_render_func(Scene_t* scene)
                     next_idx = p_runner->bfs_tilemap.tilemap[curr_idx].to;
                 }
             }
+            else if (p_runner->state == SCANLINE_FILL)
+            {
+                unsigned int tile_y = ((p_runner->current_tile) / tilemap.width);
+                for (size_t i = 0; i < tilemap.width; ++i)
+                {
+                    unsigned int tile_idx = i + tile_y * tilemap.width;
+                    if (
+                        p_runner->bfs_tilemap.tilemap[tile_idx].reachable
+                        && tilemap.tiles[tile_idx].water_level < tilemap.max_water_level
+                    )
+                    {
+                        DrawRectangle(
+                            i * tilemap.tile_size, tile_y * tilemap.tile_size,
+                            tilemap.tile_size, tilemap.tile_size, ColorAlpha(GREEN, 0.4)
+                        );
+                    }
+
+                }
+            }
         }
 
         char buffer[64] = {0};