Coverage for topdownengine/math.py: 100%

1# Copyright (c) 2026 Shaurya Sharma 

2# SPDX-License-Identifier: MIT 

3 

4import pygame as pg 

5 

6def lerp(start: float|pg.Vector2, end: float|pg.Vector2, t: float) -> pg.Vector2|float: 

7 """This function linearly interpolates two floats or Vectors. Accepts t values 

8 outside of the [0, 1] range. The start and end MUST be the same type. 

9  

10 Args: 

11 start (float|pygame.Vector2): Start Vector2/float 

12 end (float|pygame.Vector2): End Vector2/float 

13 t (float): Interpolation weight 

14 

15 Returns:  

16 pygame.Vector2|float: The interpolated Vector2/float 

17 

18 Raises: 

19 TypeError: If `start` and `end` are not the same type. 

20 """ 

21 if type(start) != type(end): 

22 raise TypeError(f"{type(start)} and {type(end)} are not the same; they must be equal.") 

23 return start + (end - start) * t 

24 

25def scale_rect(rect: pg.Rect|pg.FRect, scalar: int|float) -> pg.Rect|pg.FRect: 

26 """This function scales a Rect's position and size by a given scalar. 

27  

28 Args: 

29 rect (pygame.Rect|pygame.FRect): The Rect object to scale 

30 scalar (int|float): The number to scale by 

31 

32 Returns: 

33 pygame.Rect|pygame.FRect: The scaled Rect object 

34 

35 Raises: 

36 ValueError: If `scalar` <= 0. 

37 """ 

38 if scalar <= 0: 

39 raise ValueError("Scalar must be greater than 0.") 

40 new_rect = rect.copy() 

41 new_rect.width *= scalar 

42 new_rect.height *= scalar 

43 new_rect.top *= scalar 

44 new_rect.left *= scalar 

45 

46 return new_rect