From 9f2353306996e22b2154b3f8ab1ea68216c0bae1 Mon Sep 17 00:00:00 2001
From: Dominic Masters <dominic@domsplace.com>
Date: Tue, 11 Nov 2025 22:12:08 -0600
Subject: [PATCH] Make stairs work

---
 assets/map/map/0_0_0.json      |  3 +-
 src/rpg/entity/entity.c        | 50 ++++++++++++++++++++++++----------
 src/rpg/entity/entitydir.c     | 10 +++++++
 src/rpg/entity/entitydir.h     |  8 ++++++
 src/rpg/world/chunk.h          |  6 ++--
 src/rpg/world/region.h         | 14 ----------
 src/rpg/world/tile.c           | 29 ++++++++++++++++----
 src/rpg/world/tile.h           | 21 ++++++++++----
 src/rpg/world/worldpos.h       |  2 +-
 tools/assetstool/processmap.py |  8 ++++--
 10 files changed, 103 insertions(+), 48 deletions(-)
 delete mode 100644 src/rpg/world/region.h

diff --git a/assets/map/map/0_0_0.json b/assets/map/map/0_0_0.json
index 3e6bb52..0ca639b 100644
--- a/assets/map/map/0_0_0.json
+++ b/assets/map/map/0_0_0.json
@@ -1,7 +1,7 @@
 {
   "tiles": [
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
-    0, 2, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+    0, 5, 5, 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
@@ -17,7 +17,6 @@
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 
-
     1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
     1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
diff --git a/src/rpg/entity/entity.c b/src/rpg/entity/entity.c
index 7db871e..c081b59 100644
--- a/src/rpg/entity/entity.c
+++ b/src/rpg/entity/entity.c
@@ -76,20 +76,43 @@ void entityWalk(entity_t *entity, const entitydir_t direction) {
   }
 
   // Get tile under foot
-  tile_t tile = mapGetTile(newPos);
-  if(tile == TILE_NULL && newPos.z > 0) {
-    // Check one level down for walkable tile (stairs down)
+  tile_t tileCurrent = mapGetTile(entity->position);
+  tile_t tileNew = mapGetTile(newPos);
+  bool_t fall = false;
+  bool_t raise = false;
+
+  // Are we walking up stairs?
+  if(
+    tileIsStairs(tileCurrent) &&
+    (direction+TILE_STAIRS_SOUTH) == tileCurrent &&
+    newPos.z < (MAP_CHUNK_DEPTH - 1)
+  ) {
+    tileNew = TILE_NULL;// Force check for stairs above.
+    worldpos_t abovePos = newPos;
+    abovePos.z += 1;
+    tile_t tileAbove = mapGetTile(abovePos);
+
+    if(tileAbove != TILE_NULL && tileIsWalkable(tileAbove)) {
+      // We can go up the stairs.
+      raise = true;
+    }
+  } else if(tileNew == TILE_NULL && newPos.z > 0) {
+    // Falling down?
     worldpos_t belowPos = newPos;
     belowPos.z -= 1;
-    tile_t belowTile = mapGetTile(belowPos);
-
-    if(belowTile == TILE_STAIRS_UP) {
-      tile = TILE_STAIRS_DOWN;// Mark current as stairs down
+    tile_t tileBelow = mapGetTile(belowPos);
+    if(
+      tileBelow != TILE_NULL &&
+      tileIsStairs(tileBelow) &&
+      (entityDirGetOpposite(direction)+TILE_STAIRS_SOUTH) == tileBelow
+    ) {
+      // We will fall to this tile.
+      fall = true;
     }
   }
 
-  // Tile walkable?
-  if(!tileIsWalkable(tile)) return;
+  // Can we walk here?
+  if(!raise && !fall && !tileIsWalkable(tileNew)) return;// Blocked
 
   // Entity in way?
   entity_t *other = ENTITIES;
@@ -105,13 +128,10 @@ void entityWalk(entity_t *entity, const entitydir_t direction) {
   entity->animation = ENTITY_ANIM_WALK;
   entity->animTime = ENTITY_ANIM_WALK_DURATION;// TODO: Running vs walking
 
-  // We are comitting, we can run effects here.
-  if(tile == TILE_STAIRS_DOWN) {
-    // Moving down a level
-    entity->position.z -= 1;
-  } else if(tile == TILE_STAIRS_UP) {
-    // Moving up a level
+  if(raise) {
     entity->position.z += 1;
+  } else if(fall) {
+    entity->position.z -= 1;
   }
 }
 
diff --git a/src/rpg/entity/entitydir.c b/src/rpg/entity/entitydir.c
index 0af488d..e272877 100644
--- a/src/rpg/entity/entitydir.c
+++ b/src/rpg/entity/entitydir.c
@@ -8,6 +8,16 @@
 #include "entitydir.h"
 #include "assert/assert.h"
 
+entitydir_t entityDirGetOpposite(const entitydir_t dir) {
+  switch(dir) {
+    case ENTITY_DIR_NORTH: return ENTITY_DIR_SOUTH;
+    case ENTITY_DIR_SOUTH: return ENTITY_DIR_NORTH;
+    case ENTITY_DIR_EAST:  return ENTITY_DIR_WEST;
+    case ENTITY_DIR_WEST:  return ENTITY_DIR_EAST;
+    default: return dir;
+  }
+}
+
 void entityDirGetRelative(
   const entitydir_t from,
   worldunits_t *outX,
diff --git a/src/rpg/entity/entitydir.h b/src/rpg/entity/entitydir.h
index 20fa150..4332b76 100644
--- a/src/rpg/entity/entitydir.h
+++ b/src/rpg/entity/entitydir.h
@@ -20,6 +20,14 @@ typedef enum {
   ENTITY_DIR_RIGHT = ENTITY_DIR_EAST,
 } entitydir_t;
 
+/**
+ * Gets the opposite direction of a given direction.
+ * 
+ * @param dir The direction to get the opposite of.
+ * @return entitydir_t The opposite direction.
+ */
+entitydir_t entityDirGetOpposite(const entitydir_t dir);
+
 /**
  * Asserts a given direction is valid.
  * 
diff --git a/src/rpg/world/chunk.h b/src/rpg/world/chunk.h
index 74b8a40..695c692 100644
--- a/src/rpg/world/chunk.h
+++ b/src/rpg/world/chunk.h
@@ -8,10 +8,10 @@
 #pragma once
 #include "rpg/world/tile.h"
 #include "worldpos.h"
-#include "display/mesh/mesh.h"
+#include "display/mesh/quad.h"
 
-#define CHUNK_VERTEX_COUNT_MAX (6 * CHUNK_TILE_COUNT * 2)
-#define CHUNK_MESH_COUNT_MAX 12
+#define CHUNK_VERTEX_COUNT_MAX (QUAD_VERTEX_COUNT * CHUNK_TILE_COUNT * 2)
+#define CHUNK_MESH_COUNT_MAX 14
 
 typedef struct chunk_s {
   chunkpos_t position;
diff --git a/src/rpg/world/region.h b/src/rpg/world/region.h
deleted file mode 100644
index 0b72c09..0000000
--- a/src/rpg/world/region.h
+++ /dev/null
@@ -1,14 +0,0 @@
-/**
- * Copyright (c) 2025 Dominic Masters
- * 
- * This software is released under the MIT License.
- * https://opensource.org/licenses/MIT
- */
-
-#pragma once
-#include "dusk.h"
-
-typedef struct {
-  vec2 min;
-  vec2 max;
-} region_t;
\ No newline at end of file
diff --git a/src/rpg/world/tile.c b/src/rpg/world/tile.c
index 3e1cac1..d4c706b 100644
--- a/src/rpg/world/tile.c
+++ b/src/rpg/world/tile.c
@@ -8,9 +8,28 @@
 #include "tile.h"
 
 bool_t tileIsWalkable(const tile_t tile) {
-  return (
-    tile == TILE_WALKABLE || 
-    tile == TILE_STAIRS_UP || 
-    tile == TILE_STAIRS_DOWN
-  );
+  switch(tile) {
+    case TILE_WALKABLE:
+    case TILE_STAIRS_NORTH:
+    case TILE_STAIRS_SOUTH:
+    case TILE_STAIRS_EAST:
+    case TILE_STAIRS_WEST:
+      return true;
+
+    default:
+      return false;
+  }
+}
+
+bool_t tileIsStairs(const tile_t tile) {
+  switch(tile) {
+    case TILE_STAIRS_NORTH:
+    case TILE_STAIRS_SOUTH:
+    case TILE_STAIRS_EAST:
+    case TILE_STAIRS_WEST:
+      return true;
+
+    default:
+      return false;
+  }
 }
\ No newline at end of file
diff --git a/src/rpg/world/tile.h b/src/rpg/world/tile.h
index 367ddfc..4f68193 100644
--- a/src/rpg/world/tile.h
+++ b/src/rpg/world/tile.h
@@ -6,15 +6,18 @@
  */
 
 #pragma once
-#include "dusk.h"
-
+#include "rpg/entity/entitydir.h"
 
 typedef uint8_t tile_t;
 
 #define TILE_NULL 0
 #define TILE_WALKABLE 1
-#define TILE_STAIRS_UP 2
-#define TILE_STAIRS_DOWN 3
+#define TILE_STAIRS_SOUTH (2 + ENTITY_DIR_SOUTH)
+#define TILE_STAIRS_EAST (2 + ENTITY_DIR_EAST)
+#define TILE_STAIRS_WEST (2 + ENTITY_DIR_WEST)
+#define TILE_STAIRS_NORTH (2 + ENTITY_DIR_NORTH)
+#define TILE_TEST 6
+
 
 /**
  * Returns whether or not the given tile is walkable.
@@ -22,4 +25,12 @@ typedef uint8_t tile_t;
  * @param tile The tile to check.
  * @return bool_t True if walkable, false if not.
  */
-bool_t tileIsWalkable(const tile_t tile);
\ No newline at end of file
+bool_t tileIsWalkable(const tile_t tile);
+
+/**
+ * Returns whether or not the given tile is a stairs tile.
+ * 
+ * @param tile The tile to check.
+ * @return bool_t True if stairs, false if not.
+ */
+bool_t tileIsStairs(const tile_t tile);
\ No newline at end of file
diff --git a/src/rpg/world/worldpos.h b/src/rpg/world/worldpos.h
index f4e9318..ba73555 100644
--- a/src/rpg/world/worldpos.h
+++ b/src/rpg/world/worldpos.h
@@ -10,7 +10,7 @@
 
 #define CHUNK_WIDTH 16
 #define CHUNK_HEIGHT 16
-#define CHUNK_DEPTH 8
+#define CHUNK_DEPTH 4
 #define CHUNK_TILE_COUNT (CHUNK_WIDTH * CHUNK_HEIGHT * CHUNK_DEPTH)
 
 #define MAP_CHUNK_WIDTH 3
diff --git a/tools/assetstool/processmap.py b/tools/assetstool/processmap.py
index 82a908d..6851449 100644
--- a/tools/assetstool/processmap.py
+++ b/tools/assetstool/processmap.py
@@ -8,7 +8,7 @@ from assethelpers import getAssetRelativePath
 
 CHUNK_WIDTH = 16
 CHUNK_HEIGHT = 16
-CHUNK_DEPTH = 8
+CHUNK_DEPTH = 4
 CHUNK_TILE_COUNT = CHUNK_WIDTH * CHUNK_HEIGHT * CHUNK_DEPTH
 TILE_WIDTH = 16.0
 TILE_HEIGHT = 16.0
@@ -17,6 +17,7 @@ TILE_DEPTH = 11.36
 def processTile(tileIndex, x=0, y=0, z=0):
   vertices = []
   indices = []
+  tileType = tileIndex
 
   # Placement X, Y, Z
   px = x * TILE_WIDTH
@@ -59,7 +60,8 @@ def processTile(tileIndex, x=0, y=0, z=0):
 
   return {
     'vertices': vertices,
-    'indices': indices
+    'indices': indices,
+    'tileType': tileType
   }
 
 def processChunk(path):
@@ -88,7 +90,6 @@ def processChunk(path):
 
   for i, tile in enumerate(inData['tiles']):
     # Set to chunk
-    chunk['tiles'][i] = tile
 
     # Calculate x, y, z from i
     x = i % CHUNK_WIDTH
@@ -104,6 +105,7 @@ def processChunk(path):
       baseModel['indices'].extend(quad_indices)
       baseModel['vertexCount'] = len(baseModel['vertices'])
       baseModel['indexCount'] = len(baseModel['indices'])
+      chunk['tiles'][i] = result['tileType']
 
   # Generate binary buffer for efficient output
   buffer = bytearray()