From 2fc0d7196a8aadb3f58ecba1392d0efe0dfa380d Mon Sep 17 00:00:00 2001
From: Klemen Plestenjak <plestenjak.klemen@gmail.com>
Date: Sat, 18 Nov 2023 18:07:22 +0100
Subject: [PATCH] Rename variables in pathfinding.c to be more clear

---
 game/main.c        |  2 +-
 game/pathfinding.c | 45 ++++++++++++++++++++++++---------------------
 game/pathfinding.h | 10 +++-------
 3 files changed, 28 insertions(+), 29 deletions(-)

diff --git a/game/main.c b/game/main.c
index a6c2b0f..801903a 100644
--- a/game/main.c
+++ b/game/main.c
@@ -275,7 +275,7 @@ void render(float dt, void *userData) {
                     },
                 .target=(TilePosition) {tileX, tileY},
                 .map=&game->map,
-                .heap=heap,
+                .openSet=heap,
                 .outPath=&path,
                 .pool=game->pools.pathData
         });
diff --git a/game/pathfinding.c b/game/pathfinding.c
index 9ce277a..dfb90f3 100644
--- a/game/pathfinding.c
+++ b/game/pathfinding.c
@@ -24,20 +24,25 @@ bool findPath(const PathfindingDesc *desc) {
         i8 x : 3;
         i8 y : 3;
     } Visited;
-    Visited visited[map->width * map->height] = {};
-    bzMemSet(visited, 0, sizeof(visited));
+    Visited closedSet[map->width * map->height] = {};
 
-    PathNode *heap = desc->heap;
-    if (!heap) heap = bzHeapCreate(PathNode, map->width * map->height);
-    else bzHeapClear(heap);
+    PathNode *openSet = desc->openSet;
+    if (!openSet) openSet = bzHeapCreate(PathNode, map->width * map->height);
+    else bzHeapClear(openSet);
 
     i32 toTargetCost = dst(desc->start, desc->target);
-    bzHeapPush(heap, (PathNode) {toTargetCost, 0, toTargetCost, desc->start});
+    bzHeapPush(openSet, (PathNode) {
+        .weight=toTargetCost,
+        .gCost=0,
+        .hCost=toTargetCost,
+        .visited=false,
+        .pos=desc->start
+    });
 
     bool foundPath = false;
 
-    while (!bzHeapIsEmpty(heap)) {
-        PathNode node = bzHeapPop(heap);
+    while (!bzHeapIsEmpty(openSet)) {
+        PathNode node = bzHeapPop(openSet);
         if (node.pos.x == desc->target.x &&
             node.pos.y == desc->target.y) {
             // Found path
@@ -45,8 +50,7 @@ bool findPath(const PathfindingDesc *desc) {
             break;
         }
 
-        visited[node.pos.y * map->width + node.pos.x].visited = true;
-
+        // Node edges
         for (int y = node.pos.y - 1; y <= node.pos.y + 1; y++) {
             for (int x = node.pos.x - 1; x <= node.pos.x + 1; x++) {
                 if (x == node.pos.x && y == node.pos.y)
@@ -54,22 +58,23 @@ bool findPath(const PathfindingDesc *desc) {
                 if (y < 0 || y >= map->height ||
                     x < 0 || x >= map->width)
                     continue;
+                // not walkable
                 if (bzTileMapHasCollision(map, x, y))
                     continue;
-                Visited *curVisited = &visited[y * map->width + x];
-                if (curVisited->visited)
+                Visited *curClosed = &closedSet[y * map->width + x];
+                if (curClosed->visited)
                     continue;
-                curVisited->visited = true;
+                curClosed->visited = true;
 
                 TilePosition curPos = {x, y};
                 i32 gCost = node.gCost + dst(node.pos, curPos);
                 //if (gCost >= node.gCost) continue;
                 toTargetCost = dst(curPos, desc->target);
 
-                curVisited->x = (i8) (curPos.x - node.pos.x);
-                curVisited->y = (i8) (curPos.y - node.pos.y);
+                curClosed->x = (i8) (curPos.x - node.pos.x);
+                curClosed->y = (i8) (curPos.y - node.pos.y);
 
-                bzHeapPush(heap, (PathNode) {
+                bzHeapPush(openSet, (PathNode) {
                     .weight = gCost + toTargetCost,
                     .gCost = gCost,
                     .hCost = toTargetCost,
@@ -108,7 +113,7 @@ bool findPath(const PathfindingDesc *desc) {
             pathData->waypoints[numWaypoints++] = waypoint;
             pathData->numWaypoints = numWaypoints;
 
-            Visited visit = visited[pos.y * map->width + pos.x];
+            Visited visit = closedSet[pos.y * map->width + pos.x];
             BZ_ASSERT(visit.x != 0 || visit.y != 0);
             pos.x -= visit.x;
             pos.y -= visit.y;
@@ -134,10 +139,8 @@ bool findPath(const PathfindingDesc *desc) {
         }
     }
 
-    if (!desc->heap) {
-        bzHeapDestroy(heap);
-        heap = NULL;
-    }
+    if (!desc->openSet)
+        bzHeapDestroy(openSet);
 
     return foundPath ? pathLen : -1;
 }
\ No newline at end of file
diff --git a/game/pathfinding.h b/game/pathfinding.h
index 7785489..7ee0b56 100644
--- a/game/pathfinding.h
+++ b/game/pathfinding.h
@@ -5,15 +5,11 @@
 
 #include "components.h"
 
-typedef struct PathMove {
-    i8 x;
-    i8 y;
-} PathMove;
-
 typedef struct PathNode {
-    i32 weight; // g + h
+    i32 weight; // fCost = g + h
     i32 gCost; // from start cost
     i32 hCost; // to target cost
+    bool visited;
     TilePosition pos;
 } PathNode;
 
@@ -22,7 +18,7 @@ typedef struct PathfindingDesc {
     TilePosition target;
     BzObjectPool *pool;
     BzTileMap *map;
-    PathNode *heap;
+    PathNode *openSet; // heap
     Path *outPath;
 } PathfindingDesc;