Add inventory.

archive/rpg/entity/entitydir.c

@@ -0,0 +1,51 @@
+/**
+ * Copyright (c) 2025 Dominic Masters
+ * 
+ * This software is released under the MIT License.
+ * https://opensource.org/licenses/MIT
+ */
+
+#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,
+  worldunits_t *outY
+) {
+  assertValidEntityDir(from, "Invalid direction provided");
+  assertNotNull(outX, "Output X pointer cannot be NULL");
+  assertNotNull(outY, "Output Y pointer cannot be NULL");
+
+  switch(from) {
+    case ENTITY_DIR_NORTH:
+      *outX = 0;
+      *outY = -1;
+      break;
+
+    case ENTITY_DIR_EAST:
+      *outX = 1;
+      *outY = 0;
+      break;
+
+    case ENTITY_DIR_SOUTH:
+      *outX = 0;
+      *outY = 1;
+      break;
+
+    case ENTITY_DIR_WEST:
+      *outX = -1;
+      *outY = 0;
+      break;
+  }
+}