1 files changed, 113 insertions, 0 deletions
diff --git a/src/array.cpp b/src/array.cpp
new file mode 100644
index 0000000..88eb492
--- /dev/null
+++ b/src/array.cpp
@@ -0,0 +1,113 @@
+#include "array.h"
+
+struct EntityArr entity_arr_init(struct Arena *arena, unsigned int capacity) {
+  struct EntityArr arr = {0};
+  void *allocation = arena_alloc(arena, sizeof(struct EntityArr) * capacity);
+
+  // @todo: check if allocation was not possible, log in case of that
+  assert(allocation != NULL);
+  arr.buffer = (struct Entity *)allocation;
+  arr.capacity = capacity;
+  arr.size = 0;
+
+  return arr;
+}
+
+void entity_arr_insert(struct EntityArr *arr, struct Entity to_insert,
+                       unsigned int index) {
+  if (index >= arr->capacity) {
+    return;
+  }
+
+  arr->buffer[index] = to_insert;
+}
+
+struct Entity entity_arr_remove(struct EntityArr *arr, struct Entity to_remove,
+                                unsigned int index) {
+  if (index >= arr->capacity) {
+    return EntityNone;
+  }
+
+  struct Entity removed = arr->buffer[index];
+  arr->buffer[index] = EntityNone;
+
+  return removed;
+}
+
+void entity_arr_push_head(struct EntityArr *arr, struct Entity value) {
+  if (arr->size >= arr->capacity) {
+    return;
+  }
+
+  for (int i = arr->size - 1; i >= 0; i--) {
+    arr->buffer[i + 1] = arr->buffer[i];
+  }
+
+  arr->buffer[0] = value;
+  arr->size++;
+}
+
+void entity_arr_push_tail(struct EntityArr *arr, struct Entity value) {
+  if (arr->size >= arr->capacity) {
+    return;
+  }
+
+  arr->buffer[arr->size] = value;
+  arr->size++;
+}
+
+struct Entity entity_arr_pop_head(struct EntityArr *arr) {
+  if (arr->size == 0)
+    return EntityNone;
+
+  struct Entity popped = arr->buffer[0];
+  for (int i = 1; i < arr->size; i++) {
+    arr->buffer[i - 1] = arr->buffer[i];
+  }
+  arr->size--;
+
+  return popped;
+}
+
+struct Entity entity_arr_pop_tail(struct EntityArr *arr) {
+  if (arr->size == 0)
+    return EntityNone;
+
+  struct Entity popped = arr->buffer[arr->size - 1];
+  arr->size--;
+
+  return popped;
+}
+
+void entity_qpush(EntityQueue *queue, struct Entity value) {
+  entity_arr_push_tail(queue, value);
+}
+
+struct Entity entity_qpop(EntityQueue *queue) {
+  return entity_arr_pop_head(queue);
+}
+
+void entity_spush(EntityStack *stack, struct Entity value) {
+  entity_arr_push_tail(stack, value);
+}
+
+struct Entity entity_spop(EntityStack *stack) {
+  return entity_arr_pop_tail(stack);
+}
+
+int entity_arr_find(struct EntityArr *arr, struct Entity value) {
+  /*
+   * finds value in arr
+   * returns index of value
+   */
+  int find_index = -1;
+  for (int i = 0; i < arr->capacity; i++) {
+    struct Entity entry = arr->buffer[i];
+    if (entry.type == value.type && entry.id == value.id) {
+      find_index = i;
+      break;
+    }
+  }
+
+  return find_index;
+}