From d7113d42fe7398b30800d5998ea507b1fd478c41 Mon Sep 17 00:00:00 2001
From: En Yi <en.yi@tutanota.com>
Date: Mon, 6 May 2024 22:04:53 +0800
Subject: [PATCH] Add neighbour solid counts

This is preparing for the tile sprites rework
---
 engine/collisions.h    |  3 ++
 scenes/editor_scene.c  |  5 ++++
 scenes/scene_systems.c | 62 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 70 insertions(+)

diff --git a/engine/collisions.h b/engine/collisions.h
index 189c7a0..4fc3b73 100644
--- a/engine/collisions.h
+++ b/engine/collisions.h
@@ -17,8 +17,11 @@ typedef enum TileRotation
     TILE_180ROT
 }TileRotation_t;
 
+// Some of the fields are game-dependent, may have to think about doing OOP
+// to separate out standard fields vs context-dependent fields
 typedef struct Tile {
     unsigned int tile_type;
+    uint8_t connectivity;
     SolidType_t solid;
     TileRotation_t rotation;
     uint8_t def;
diff --git a/scenes/editor_scene.c b/scenes/editor_scene.c
index 3440013..34d943d 100644
--- a/scenes/editor_scene.c
+++ b/scenes/editor_scene.c
@@ -479,6 +479,11 @@ static void render_editor_game_scene(Scene_t* scene)
                         // Draw water tile
                         DrawText(buffer, x, y, 10, BLACK);
                     }
+                    if (tilemap.tiles[i].solid == SOLID)
+                    {
+                        sprintf(buffer, "%u", tilemap.tiles[i].connectivity);
+                        DrawText(buffer, x + tilemap.tile_size / 2, y + tilemap.tile_size / 2, 12, WHITE);
+                    }
                 }
             }
 
diff --git a/scenes/scene_systems.c b/scenes/scene_systems.c
index 3ea4934..b98b8e8 100644
--- a/scenes/scene_systems.c
+++ b/scenes/scene_systems.c
@@ -223,6 +223,7 @@ void change_a_tile(TileGrid_t* tilemap, unsigned int tile_idx, TileType_t new_ty
     }
 
     tilemap->tiles[tile_idx].rotation = TILE_NOROTATE;
+
     if (new_type == SPIKES)
     {
         // Priority: Down, Up, Left, Right
@@ -272,4 +273,65 @@ void change_a_tile(TileGrid_t* tilemap, unsigned int tile_idx, TileType_t new_ty
     );
     tilemap->tiles[tile_idx].def = (tilemap->tiles[tile_idx].tile_type == SOLID_TILE) ? 5: 2;
 
+    tilemap->tiles[tile_idx].connectivity = 0;
+
+    const uint8_t LEFT_BIT = 0;
+    const uint8_t UP_BIT = 1;
+    const uint8_t RIGHT_BIT = 2;
+    const uint8_t DOWN_BIT = 3;
+    {
+        // Priority: Left, Up, Right, Down
+        if (tile_idx % tilemap->width != 0)
+        {
+            tilemap->tiles[tile_idx].connectivity |= (tilemap->tiles[tile_idx - 1].tile_type == SOLID_TILE) ? (1 << LEFT_BIT) : 0;
+            if (new_type == SOLID_TILE)
+            {
+                tilemap->tiles[tile_idx - 1].connectivity |= (1 << RIGHT_BIT);
+            }
+            else
+            {
+                tilemap->tiles[tile_idx - 1].connectivity &= ~(1 << RIGHT_BIT);
+            }
+        }
+
+        if (tile_idx - tilemap->width >= 0)
+        {
+            tilemap->tiles[tile_idx].connectivity |= (tilemap->tiles[tile_idx - tilemap->width].tile_type == SOLID_TILE) ? (1 << UP_BIT) : 0;
+            if (new_type == SOLID_TILE)
+            {
+                tilemap->tiles[tile_idx - tilemap->width].connectivity |= (1 << DOWN_BIT);
+            }
+            else
+            {
+                tilemap->tiles[tile_idx - tilemap->width].connectivity &= ~(1 << DOWN_BIT);
+            }
+        }
+
+        if (tile_idx + tilemap->width < tilemap->n_tiles)
+        {
+            tilemap->tiles[tile_idx].connectivity |= (tilemap->tiles[tile_idx + tilemap->width].tile_type == SOLID_TILE) ? (1 << DOWN_BIT) : 0;
+            if (new_type == SOLID_TILE)
+            {
+                tilemap->tiles[tile_idx + tilemap->width].connectivity |= (1 << UP_BIT);
+            }
+            else
+            {
+                tilemap->tiles[tile_idx + tilemap->width].connectivity &= ~(1 << UP_BIT);
+            }
+        }
+
+        if ((tile_idx + 1) % tilemap->width != 0)
+        {
+            tilemap->tiles[tile_idx].connectivity |= (tilemap->tiles[tile_idx + 1].tile_type == SOLID_TILE) ? (1 << RIGHT_BIT) : 0;
+            if (new_type == SOLID_TILE)
+            {
+                tilemap->tiles[tile_idx + 1].connectivity |= (1 << LEFT_BIT);
+            }
+            else
+            {
+                tilemap->tiles[tile_idx + 1].connectivity &= ~(1 << LEFT_BIT);
+            }
+        }
+    }
+
 }