Make stairs work

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;
   }
 }
 

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,

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.
  * 

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;

src/rpg/world/region.h

@@ -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;

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;
+  }
 }

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);
+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);

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