test equality for pygame.font.Font

Question

I was trying to make a font cache like this:

from ._utils import SizedDict
def copysurf(x,mod):
    if mod:
        return cs(x)
    return ImmutableSurface(x)
class FontCache:
    def __init__(self):
        self.cache = SizedDict(20)
        self.fmisses = 0
        self.fhits = 0
        self.cmisses = {}
        self.chits = {}
    def getfor(self,font,char,aa,color):
        if font not in self.cache:
            self.cmisses[font] = 0
            self.chits[font] = 0
            self.cache[font] = SizedDict(300)
        if char not in self.cache[font]:
            self.cache[font][char] = font.render(char,aa,color)
        return self.cache[font][char].copy()
fontCache = FontCache()

(Sized dicts are also made by me,they are dicts that deletes the oldest entry if it exeeds the capacity specified in the constructor.)

But the problem arises when i tried to cache the font.You see,

pygame.font.SysFont("Courier",22) == pygame.font.SysFont("Courier",22)

is false,and the hash() function returned different values.As i know,there aren't any methods that returns the original NAME of the font,and we can't test equality by merely knowing the size and the bold and italic flags.

Any thoughts?

score 1 · Accepted Answer · answered Oct 13 '21 at 13:29

You could subclass pygame.font.Font, store the metadata when the font is created. Something like this:

import pygame

pygame.init()


class Font(pygame.font.Font):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.properties = (args, tuple(kwargs.items()))

    def __hash__(self):
        return hash(self.properties)

    def __eq__(self, other):
        return self.properties == other.properties

    @classmethod
    def construct(cls, fontpath, size, bold, italic):
        font = cls(fontpath, size)
        font.strong = bold
        font.oblique = italic
        return font


# Prints True
print(
    pygame.font.SysFont("Courier", 22, constructor=Font.construct)
    == pygame.font.SysFont("Courier", 22, constructor=Font.construct)
)

test equality for pygame.font.Font

1 Answers1