Reverse index lookup

main.cpp

@@ -26,6 +26,8 @@ i32 main(void) {
 	EntityID id5 = {5};
 
 	PropTable<Pos> positions = {&arena, 8};
+	PropTable<i32> numbers = {&arena, 8};
+	numbers.add_prop(id5, 1);
 
 	print_positions(&positions);
 
@@ -67,7 +69,7 @@ void print_index(PropTable<Pos> *positions) {
 void print_values(PropTable<Pos> *positions) {
 	printf("==========VALUES==========\n");
 	for (u64 i = 0; i < wapp_array_count(positions->values); ++i) {
-		printf("%" PRIu64 ": (%f, %f, %f)\n", i, positions->values[i].x, positions->values[i].y, positions->values[i].z);
+		printf("%" PRIu64 ": (%f, %f, %f)\n", i, positions->values[i].value.x, positions->values[i].value.y, positions->values[i].value.z);
 	}
 	printf("\n");
 }

prop_table.hpp

@@ -10,7 +10,7 @@ template<typename T>
 struct PropTable {
 	PropTable(const Allocator *allocator, u64 capacity) {
 		index  = wapp_array_alloc_capacity(i32, allocator, capacity, ARRAY_INIT_FILLED);
-		values = wapp_array_alloc_capacity(T, allocator, capacity, ARRAY_INIT_NONE);
+		values = wapp_array_alloc_capacity(Value, allocator, capacity, ARRAY_INIT_NONE);
 
 		for (u64 i = 0; i < wapp_array_count(index); ++i) {
 			index[i] = -1;
@@ -21,8 +21,9 @@ struct PropTable {
 		if (IS_INVALID_ID(id)) { return; }
 
 		i32 idx = (i32)wapp_array_count(values);
+		Value v = {prop, id.index};
 		wapp_array_set(i32, index, id.index, &idx);
-		wapp_array_append_capped(T, values, &prop);
+		wapp_array_append_capped(Value, values, &v);
 	}
 
 	void remove_prop(EntityID id) {
@@ -34,29 +35,22 @@ struct PropTable {
 
 		// Swap values
 		values[idx1] = values[idx2];
-		wapp_array_pop(T, values);
+		wapp_array_pop(Value, values);
 
 		// Update index
 		index[id.index] = -1;
-
-		i64 entity_index = -1;
-		for (u64 i = 0; i < wapp_array_count(index); ++i) {
-			if (index[i] == idx2) {
-				entity_index = (i64)i;
-				break;
-			}
+		index[values[idx1].index_location] = idx1;
 	}
 
-		if (entity_index != -1) {
-			index[entity_index] = idx1;
-		}
-	}
+	struct Value {
+		T value;
+		u32 index_location;
+	};
 
-	// private:
-		typedef T *TArray;
+	typedef Value *ValueArray;
 
 	I32Array index;
-		TArray values;
+	ValueArray values;
 };
 
 #endif // !PROP_TABLE_H