diff --git a/src/generic_vector.h b/src/generic_vector.h
new file mode 100644
index 0000000..6deb13b
--- /dev/null
+++ b/src/generic_vector.h
@@ -0,0 +1,38 @@
+#pragma once
+
+#include "main.h"
+
+#define DEFINE_VECTOR_STRUCT(vector_name, item_t) \
+	struct vector_name { \
+		item_t *items; \
+		size_t len; \
+		size_t capacity; \
+	};
+
+#define DEFINE_VECTOR_ENSURE_METHOD_CAPACITY(func_name, list_t, item_t) \
+	void func_name(list_t *list, size_t expected_capacity) \
+	{ \
+		if (list->capacity < expected_capacity) { \
+			size_t larger_capacity = MAX(MAX(list->capacity*2, expected_capacity), 4); \
+			item_t *larger_items = realloc(list->items, larger_capacity * sizeof(item_t)); \
+			if (larger_items == NULL) { \
+				PANIC_OOM(); \
+			} \
+			list->items = larger_items; \
+			list->capacity = larger_capacity; \
+		} \
+	}
+
+#define DEFINE_VECTOR_METHOD_FREE(func_name, list_t) \
+	void func_name(list_t *list) \
+	{ \
+		free(list->items); \
+		list->len = 0; \
+		list->capacity = 0; \
+	}
+
+#define DEFINE_VECTOR_METHOD_CLEAR_RETAINING_CAPACITY(func_name, list_t) \
+	void func_name(list_t *list) \
+	{ \
+		list->len = 0; \
+	}
diff --git a/src/main.h b/src/main.h
index 1a22a23..eede77d 100644
--- a/src/main.h
+++ b/src/main.h
@@ -36,3 +36,4 @@ extern struct Resources g_resources;
 
 Color rgb(uint8_t r, uint8_t g, uint8_t b);
 Color hex(const char *str);
+int signf(float value);
diff --git a/src/rect.c b/src/rect.c
new file mode 100644
index 0000000..0b07ef0
--- /dev/null
+++ b/src/rect.c
@@ -0,0 +1,57 @@
+#include "rect.h"
+
+float rect_get_left(Rectangle rect)
+{
+    return rect.x;
+}
+
+float rect_get_right(Rectangle rect)
+{
+    return rect.x + rect.width;
+}
+
+float rect_get_top(Rectangle rect)
+{
+    return rect.y;
+}
+
+float rect_get_bottom(Rectangle rect)
+{
+    return rect.y + rect.height;
+}
+
+Rectangle rect_add_position(Rectangle rect, Vector2 pos)
+{
+    rect.x += pos.x;
+    rect.y += pos.y;
+    return rect;
+}
+
+Vector2 rect_get_center(Rectangle rect)
+{
+    return (Vector2){
+        .x = rect.x + rect.width / 2,
+        .y = rect.y + rect.height / 2,
+    };
+}
+
+bool rect_is_overlap(Rectangle rect1, Rectangle rect2)
+{
+    return CheckCollisionRecs(rect1, rect2);
+}
+
+bool rect_is_inside_rect(Rectangle outer_rect, Rectangle inner_rect)
+{
+    return rect_get_left(outer_rect) <= rect_get_left(inner_rect) &&
+            rect_get_right(outer_rect) >= rect_get_right(inner_rect) &&
+            rect_get_top(outer_rect) <= rect_get_top(inner_rect) &&
+            rect_get_bottom(outer_rect) >= rect_get_bottom(inner_rect);
+}
+
+bool rect_is_inside_point(Rectangle outer_rect, Vector2 inner_point)
+{
+    bool is_x_inside = rect_get_left(outer_rect) <= inner_point.x && inner_point.x <= rect_get_right(outer_rect);
+    bool is_y_inside = rect_get_top(outer_rect) <= inner_point.y && inner_point.y <= rect_get_bottom(outer_rect);
+
+    return is_x_inside && is_y_inside;
+}
diff --git a/src/rect.h b/src/rect.h
new file mode 100644
index 0000000..17deefd
--- /dev/null
+++ b/src/rect.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include "main.h"
+
+float rect_get_left(Rectangle rect);
+float rect_get_right(Rectangle rect);
+float rect_get_top(Rectangle rect);
+float rect_get_bottom(Rectangle rect);
+Rectangle rect_add_position(Rectangle rect, Vector2 pos);
+Vector2 rect_get_center(Rectangle rect);
+bool rect_is_inside_point(Rectangle outer_rect, Vector2 inner_point);
+bool rect_is_inside_rect(Rectangle outer_rect, Rectangle inner_rect);
+bool rect_is_overlap(Rectangle rect1, Rectangle rect2);
diff --git a/src/utils.c b/src/utils.c
index 80952ce..3a03618 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -37,3 +37,14 @@ Color hex(const char *str)
     uint8_t b = parse_hex_byte(&str[5]);
     return rgb(r, g, b);
 }
+
+int signf(float value)
+{
+    if (value > 0) {
+        return 1;
+    } else if (value < 0) {
+        return -1;
+    } else {
+        return 0;
+    }
+}