PyGame Font Rendering Engine - Very Very Simple

# coding: utf-8

import pygame
import argparse

def rint(x):
    if x % 1 >= 0.5:
        x += 1
    return int(x)

text = """Hello,

Welcome to may world. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet."""

class Node(object):

    width = 0
    height = 0
    margin_x = 0
    margin_y = 0
    x = 0
    y = 0
    background = None

    def get_real_size(self):
        return self.width + self.margin_x * 2, self.height + self.margin_y * 2

    def add(self, node):
        return False

    def layout(self):
        pass

    def paint(self, rel_x, rel_y, screen):
        x, y = self.x + self.margin_x + rel_x, self.y + self.margin_y + rel_y
        w, h = self.width, self.height
        if self.background:
            screen.fill(self.background, pygame.Rect(x, y, w, h))

class ContainerNode(Node):

    def __init__(self):
        super(ContainerNode, self).__init__()
        self.nodes = []

    def layout(self):
        for node in self.nodes:
            node.layout()

    def paint(self, rel_x, rel_y, screen):
        super(ContainerNode, self).paint(rel_x, rel_y, screen)
        for node in self.nodes:
            node.paint(rel_x + self.x, rel_y + self.y, screen)

class TextNode(Node):

    def __init__(self, word, color, font, antialias=True):
        self.word = word
        self.color = color
        self.antialias = antialias
        self.font = font

        self.width, self.height = font.size(word)
        self.margin_x = font.size(' ')[0] / 2.0
        self.margin_y = 2

    def add(self, node):
        raise NotImplementedError

    def paint(self, rel_x, rel_y, screen):
        super(TextNode, self).paint(rel_x, rel_y, screen)
        rel_x += self.x + self.margin_x
        rel_y += self.y + self.margin_y
        label = self.font.render(self.word, self.antialias, self.color)
        screen.blit(label, (rint(rel_x), rint(rel_y)))

class InlineNodeRow(ContainerNode):

    def __init__(self, maxwidth=None, justify='left'):
        super(InlineNodeRow, self).__init__()
        self.maxwidth = maxwidth
        self.justify = justify

    def add(self, node):
        w, h = node.get_real_size()
        if self.maxwidth and self.width + w > self.maxwidth:
            return False

        self.width += w
        if h > self.height:
            self.height = h

        self.nodes.append(node)
        return True

    def layout(self):
        if not self.nodes:
            return

        justify = self.justify
        if justify not in ['left', 'right', 'block', 'center']:
            raise ValueError('invalid justify value %s' % justify)
        if justify in ['right', 'center'] and not self.maxwidth:
            raise RuntimeError('for %s justification, a maxwidth must have been set.' % justify)
        if justify == 'block' and not self.maxwidth:
            justify = 'left'

        if justify == 'center':
            last_x = (self.maxwidth - self.width) * 0.5
        else:
            last_x = 0

        if justify == 'block':
            free_space = self.maxwidth - self.width
        else:
            free_space = 0

        if len(self.nodes) > 1:
            free_space_partial = float(free_space) / (len(self.nodes) - 1)
        else:
            free_space_partial = 0

        for node in self.nodes:
            w, h = node.get_real_size()
            node.x = last_x
            last_x = last_x + w + free_space_partial

            if justify == 'right':
                node.x += (self.maxwidth - self.width)

            free_space_h = self.height - h
            node.y = free_space_h * 0.5

        super(InlineNodeRow, self).layout()

class NodeBox(ContainerNode):

    def add(self, node):
        w, h = node.get_real_size()
        if self.width < w:
            self.width = w
        self.height += h
        self.nodes.append(node)
        return True

    def layout(self):
        last_y = 0
        for node in self.nodes:
            w, h = node.get_real_size()
            node.x = 0
            node.y = last_y
            last_y += h

        super(NodeBox, self).layout()


def draw_text(screen, text, color, font, justify='left', maxwidth=None, x=0, y=0,
              colorize=False):
    lines = text.split('\n')
    box = NodeBox()
    if colorize:
        box.background = (30, 100, 255)

    def make_row():
        row = InlineNodeRow(maxwidth, justify=justify)
        if colorize:
            row.background = (255, 80, 50)
        return row

    pushed_words = []
    for line in lines:
        words = line.split()
        row = make_row()

        for word in words:
            node = TextNode(word, color, font)
            if colorize:
                node.background = (240, 190, 20)

            added = row.add(node)
            if not added:
                box.add(row)
                row = make_row()
                row.add(node)

        if justify == 'block':
            row.justify = 'left'
        box.add(row)

    box.layout()
    box.paint(x, y, screen)

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('justify', choices=['left', 'right', 'center', 'block'])
    parser.add_argument('-c', '--colorize', action='store_true')
    args = parser.parse_args()

    pygame.init()
    pygame.font.init()

    screen = pygame.display.set_mode((600, 400))
    pygame.display.set_caption('Font Drawing Test')

    font = pygame.font.SysFont("monospace", 15)
    justify = args.justify

    clock = pygame.time.Clock()
    running = True
    while running:
        clock.tick(10)
        screen.fill((255, 255, 255))
        draw_text(screen, text, (0, 0, 0), font, justify, maxwidth=600, colorize=args.colorize)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False

        pygame.display.flip()

if __name__ == '__main__':
    main()