如何在PyOpenGL中更改位图字符的字体大小？

import glfw
from OpenGL.GL import *
import numpy as np
import freetype

def load_font(font_path, font_size):
    face = freetype.Face(font_path)
    face.set_char_size(font_size * 64)  # 字体大小乘以64
    return face

def draw_bitmap_string(face, x, y, text):
    pen = freetype.Vector()
    pen.x = x << 6  # 乘以64
    pen.y = y << 6

    for char in text:
        face.load_char(char)
        bitmap = face.glyph.bitmap
        top = pen.y + face.glyph.bitmap_top * 64
        left = pen.x + face.glyph.bitmap_left * 64
        bottom = top - bitmap.rows * 64

        glRasterPos2f(left / 64, bottom / 64)
        glDrawPixels(bitmap.width, bitmap.rows, GL_RED, GL_UNSIGNED_BYTE, bitmap.buffer)

        pen.x += face.glyph.advance.x
        pen.y += face.glyph.advance.y

def main():
    if not glfw.init():
        return

    window = glfw.create_window(640, 480, "PyOpenGL with FreeType", None, None)
    if not window:
        glfw.terminate()
        return

    glfw.make_context_current(window)
    glEnable(GL_BLEND)
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)

    font = load_font("path/to/your/font.ttf", 32)  # 加载字体并设置大小

    while not glfw.window_should_close(window):
        glClear(GL_COLOR_BUFFER_BIT)

        draw_bitmap_string(font, 10, 50, "Hello, PyOpenGL!")

        glfw.swap_buffers(window)
        glfw.poll_events()

    glfw.terminate()

if __name__ == "__main__":
    main()