Fit text to existing Surface in pygame - python-3.x

Question

I'm trying to create text surfaces that are of the same size no matter the text. In other words: I want longer text to have smaller font size and shorter text to have bigger font size in order to fit the text to an already existing Surface.
To create text in pygame I am:
Creating a font object. For example: font = pygame.font.SysFont('Arial', 32)
Creating a text surface from the font object. For example: text = font.render('My text', True, (255, 255, 255))
Bliting the text surface.
The problem is that I first need to create a font object of a certain size before creating the text surface. I've created a function that does what I want:
import pygame
def get_text(surface, text, color=(255, 255, 255), max_size=128, font_name='Arial'):
"""
Returns a text surface that fits inside given surface. The text
will have a font size of 'max_size' or less.
"""
surface_width, surface_height = surface.get_size()
lower, upper = 0, max_size
while True:
font = pygame.font.SysFont(font_name, max_size)
font_width, font_height = font.size(text)
if upper - lower <= 1:
return font.render(text, True, color)
elif max_size < 1:
raise ValueError("Text can't fit in the given surface.")
elif font_width > surface_width or font_height > surface_height:
upper = max_size
max_size = (lower + upper) // 2
elif font_width < surface_width or font_height < surface_height:
lower = max_size
max_size = (lower + upper) // 2
else:
return font.render(text, True, color)
Is there any other way to solve this problem that's cleaner and/or more efficient?

Answer 1

This, unfortunately, seems to be the most appropriate solution. Font sizes are more of a approximation and differs between fonts, so there isn't a uniform way to calculate the area a specific font will take up. Another problem is that certain characters differs in size for certain fonts.
Having a monospace font would theoretically make it more efficient to calculate. Just by dividing the surface's width with the string's length and check which size of a monospace font covers that area.

Answer 2

You can re-scale the text image to fit:
def fit_text_to_width(text, color, pixels, font_face = None):
font = pygame.font.SysFont(font_face, pixels *3 // len(text) )
text_surface = font.render(text, True, color)
size = text_surface.get_size()
size = ( pixels, int(size[1] * pixels / size[0]) )
return pygame.transform.scale(text_surface, size)

Answer 3

The Font object seems to have to methods size() -> (width, height) and metrics() -> list[(minx, maxx, miny, maxy)] that sounds useful for checking the size of each resulting character and width of text.
The simplest way would be to use size and simply scale down text to the required width and height based on some ratio screen_width / font.size()[0] for example.
For breaking the text into lines, the metrics method is needed. It should be possible to loop through the metrics list and split up the text based on the summed width for each line.