tetris/tetris.py

import pygame
import pygame.draw as draw
from collections import namedtuple, defaultdict
from typing import NamedTuple, Any, Iterable, Optional, Callable
from functools import cache
import random
import math
from enum import Enum, auto

Cell = namedtuple("Cell", ["x", "y"])
Size = namedtuple("Size", ["width", "height"])
ColorSet = namedtuple("ColorSet", ["norm", "light", "dark"])


class Direction(int, Enum):
    LEFT = -1
    RIGHT = 1


def make_matrix(w: int, h: int, elt: Any = None) -> list[list]:
    if not w:
        return []
    return [[elt] * w for _ in range(h)]


def flip(mat: list[list]) -> list[list]:
    return list(reversed(mat))


def transpose(mat: list[list]) -> list[list]:
    if not mat:
        return []
    out = make_matrix(len(mat), len(mat[0]))
    for x in range(len(mat[0])):
        for y in range(len(mat)):
            out[x][y] = mat[y][x]
    return out


def mirror(mat: list[list]) -> list[list]:
    return [list(reversed(row)) for row in mat]


class Tetromino(NamedTuple):
    color: str
    shape: list[list]

    @property
    def width(self):
        return len(self.shape[0])

    @property
    def height(self):
        return len(self.shape)

    def rotated(self, times: int):
        """Return self rotated TIMES times to the right."""
        times %= 4
        if times == 0:
            return self
        if times == 1:
            return Tetromino(self.color, mirror(transpose(self.shape)))
        if times == 2:
            return Tetromino(self.color, mirror(flip(self.shape)))
        if times == 3:
            return Tetromino(self.color, flip(transpose(self.shape)))

    def __repr__(self):
        out = []
        for row in self.shape:
            for cell in row:
                out.append("*" if cell else " ")
            out.append("\n")
        return "".join(out)

    def __eq__(self, other):
        return id(self) == id(other)

    def __hash__(self):
        return id(self)


class HashableDict(dict):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    def __eq__(self, other):
        return id(self) == id(other)

    def __hash__(self):
        return id(self)


class Action(NamedTuple):
    class Type(Enum):
        # In Game
        ROTATE_LEFT = auto()
        ROTATE_RIGHT = auto()
        DROP = auto()
        SWAP_HOLD = auto()
        MOVE_LEFT = auto()
        MOVE_RIGHT = auto()
        OPEN_HELP = auto()

        # Game over (also in game)
        RESTART = auto()

        # Help
        CLOSE_HELP = auto()

    key: int
    type: Type
    repeat: bool
    desc: str

    @staticmethod
    def make_map(*acts):
        return HashableDict({act.key: act for act in acts})


class Font:
    class Glyph(NamedTuple):
        char: str
        bitmap: list[str]

        @property
        def width(self):
            return len(self.bitmap[0])

        @property
        def height(self):
            return len(self.bitmap)

        @property
        def size(self) -> Size:
            return Size(self.width, self.height)

    def __init__(
        self,
        scale: int,
        kern: int,
        row_kern: int,
        glyphs: Iterable[Glyph] | dict[str, Glyph],
    ):
        self.scale = scale
        self.kern = kern
        self.row_kern = row_kern
        if isinstance(glyphs, dict):
            self.glyphs: dict[str, Font.Glyph] = dict(glyphs)
        else:
            self.glyphs: dict[str, Font.Glyph] = {g.char: g for g in glyphs}

    def scaled(
        self,
        new_scale: int,
        new_kern: Optional[int],
        new_row_kern: Optional[int],
    ):
        return Font(
            new_scale,
            self.kern if new_kern is None else new_kern,
            self.row_kern if new_row_kern is None else new_row_kern,
            self.glyphs,
        )

    @cache
    def compute_extents(self, text: str) -> Size:
        text = text.lower()
        total_width = 0
        total_height = 0
        last_width = 0
        last_height = 0
        for char in text:
            if char == "\n":
                total_width = max(total_width, last_width)
                if last_width == 0:
                    # empty line
                    last_height = self.glyphs[" "].height * self.scale
                last_width = 0
                total_height += last_height + self.row_kern
                last_height = 0
            else:
                glyph = self.glyphs[char]
                last_width += glyph.width * self.scale + self.kern
                last_height = max(last_height, glyph.height * self.scale)
        total_width = max(last_width, total_width) - self.kern
        if total_width == 0:
            # empty line
            last_height = self.glyphs[" "].height * self.scale
        total_height += last_height
        return Size(total_width, total_height)

    def render_text(
        self, text: str, dest: pygame.surface.Surface, x: int, y: int, color
    ):
        text = text.lower()
        initial_x = x
        max_height = 0
        for char in text:
            if char == "\n":
                if x == initial_x:
                    # empty row
                    max_height = self.glyphs[" "].height * self.scale
                y += max_height + self.row_kern
                max_height = 0
                x = initial_x
            else:
                glyph = self.glyphs[char]
                dest.blit(self.render_glyph(char, color), (x, y))
                x += glyph.width * self.scale + self.kern
                max_height = max(max_height, glyph.height * self.scale)

    def center_text(
        self, text: str, dest: pygame.surface.Surface, x: int, y: int, color
    ):
        text = text.lower()
        exts = self.compute_extents(text)
        self.render_text(
            text, dest, x - (exts.width // 2), y - (exts.height // 2), color
        )

    @cache
    def render_glyph(self, char: str, color) -> pygame.surface.Surface:
        char = char.lower()
        glyph = self.glyphs[char]
        size = tuple(map(lambda d: d * self.scale, glyph.size))
        surf = pygame.surface.Surface(size, pygame.SRCALPHA)
        for y, row in enumerate(glyph.bitmap):
            for x, cell in enumerate(row):
                if cell != " ":
                    pygame.draw.rect(
                        surf,
                        color,
                        (
                            x * self.scale,
                            y * self.scale,
                            self.scale,
                            self.scale,
                        ),
                    )
        return surf


class LazyVariable:
    def __init__(self, thunk: Callable[[], Any]):
        self.thunk = thunk
        self.need_eval = True
        self.value = None

    def __get__(self, instance: Any, owner: Optional[type] = None):
        if self.need_eval:
            self.value = self.thunk()
            self.need_eval = False
        return self.value

    def __set__(self, instance: Any, value: Any):
        self.value = value
        self.need_eval = False


class Game:
    PLACE_POINTS = 10
    CLEAR_POINTS = 100
    MOVE_SPEED = 20  # cells per second
    NORMAL_DROP_SPEED = 3  # cells per second
    FAST_DROP_SPEED = 30  # cells per second
    CLEAR_SPEED = 5  # frames per block
    BOARD_SIZE = Size(10, 20)  # Cell count
    CELL_SIZE = Size(30, 30)
    CELL_BORDER_SIZE = CELL_SIZE.width // 10
    CONTROLS_WIDTH = 160
    FRAMERATE = 120
    WINDOW_SIZE = Size(
        (BOARD_SIZE.width + 2) * CELL_SIZE.width + CONTROLS_WIDTH,
        (BOARD_SIZE.height + 2) * CELL_SIZE.height,
    )
    PALETTE = {
        "gray": ColorSet("#787878", "#9a9a9a", "#303030"),
        "purple": ColorSet("#9a00cd", "#cd00ff", "#66009a"),
        "yellow": ColorSet("#cdcd00", "#ffff00", "#9a9a00"),
        "red": ColorSet("#cd0000", "#ff0000", "#9a0000"),
        "orange": ColorSet("#cd6600", "#ff8900", "#9a4200"),
        "blue": ColorSet("#0000cd", "#0000ff", "#00009a"),
        "aqua": ColorSet("#00cdcd", "#00ffff", "#009a9a"),
        "green": ColorSet("#00cd00", "#00ff00", "#009a00"),
    }
    TETROMINOS = [
        Tetromino("aqua", [[1, 1, 1, 1]]),
        Tetromino("yellow", [[1, 1], [1, 1]]),
        Tetromino("purple", [[1, 1, 1], [0, 1, 0]]),
        Tetromino("blue", [[0, 1], [0, 1], [1, 1]]),
        Tetromino("orange", [[1, 0], [1, 0], [1, 1]]),
        Tetromino("green", [[0, 1, 1], [1, 1, 0]]),
        Tetromino("red", [[1, 1, 0], [0, 1, 1]]),
    ]
    GAME_ACTION_MAP = Action.make_map(
        Action(
            pygame.K_z,
            Action.Type.ROTATE_LEFT,
            False,
            "Rotate the current piece left.",
        ),
        Action(
            pygame.K_x,
            Action.Type.ROTATE_RIGHT,
            False,
            "Rotate the current piece right.",
        ),
        Action(
            pygame.K_s,
            Action.Type.SWAP_HOLD,
            False,
            "Swap the current and held pieces.",
        ),
        Action(
            pygame.K_DOWN, Action.Type.DROP, True, "Drop the current piece."
        ),
        Action(
            pygame.K_LEFT,
            Action.Type.MOVE_LEFT,
            True,
            "Move the current piece left.",
        ),
        Action(
            pygame.K_RIGHT,
            Action.Type.MOVE_RIGHT,
            True,
            "Move the current piece right.",
        ),
        Action(
            pygame.K_r,
            Action.Type.RESTART,
            False,
            "Start a new game.",
        ),
        Action(
            pygame.K_h,
            Action.Type.OPEN_HELP,
            False,
            "Toggle the help menu.",
        ),
    )
    GAME_OVER_ACTION_MAP = Action.make_map(
        Action(pygame.K_r, Action.Type.RESTART, False, "Start a new game.")
    )
    HELP_ACTION_MAP = Action.make_map(
        Action(
            pygame.K_ESCAPE,
            Action.Type.CLOSE_HELP,
            False,
            "Close the help menu.",
        ),
        Action(
            pygame.K_h,
            Action.Type.CLOSE_HELP,
            False,
            "Close the help menu.",
        ),
    )

    # The actual font data is long, so I put it at the end
    FONT = LazyVariable(lambda: Font(6, 3, 3, GLYPH_DATA))
    SMALL_FONT = LazyVariable(lambda: Game.FONT.scaled(4, 2, 2))
    TINY_FONT = LazyVariable(lambda: Game.FONT.scaled(2, 2, 2))
    CONTROL_DISPLAY_BORDER = 5
    INFO_BOX_BORDER_SIZE = 5
    HELP_MENU_INSET = 10
    CONTROLS_START_X = (BOARD_SIZE.width + 2) * CELL_SIZE.width

    @staticmethod
    @cache
    def make_help_string(am: dict[int, Action]):
        key_names = [pygame.key.name(k) for k in am.keys()]
        max_key_len = max(map(len, key_names))
        out = ""
        for act in am.values():
            if out:
                out += "\n"
            out += f"{pygame.key.name(act.key).rjust(max_key_len)}: {act.desc}"
        return out

    def __init__(self):
        self._game_over = False
        self.high_score = 0
        self._score = 0

    @property
    def game_over(self) -> bool:
        return self._game_over

    @game_over.setter
    def game_over(self, newval: bool):
        if newval != self._game_over:
            self.pending_actions = []
        self._game_over = newval
        if self._game_over:
            self.action_map = Game.GAME_OVER_ACTION_MAP
        else:
            self.action_map = Game.GAME_ACTION_MAP

    @property
    def score(self) -> int:
        return self._score

    @score.setter
    def score(self, newval: int):
        self._score = newval
        if newval > self.high_score:
            self.high_score = newval

    def random_tetromino(self):
        if not self.cur_random_peice_seq:
            self.cur_random_peice_seq = list(Game.TETROMINOS)
            random.shuffle(self.cur_random_peice_seq)
        return self.cur_random_peice_seq.pop(0)

    def draw_block(self, x: int, y: int, color, target=None):
        """Draw a block at (X, Y). Coordinates are for the top left corner."""
        if target is None:
            target = self.screen
        draw.rect(
            target,
            Game.PALETTE[color].norm,
            (x, y, Game.CELL_SIZE.width, Game.CELL_SIZE.height),
        )
        draw.polygon(
            target,
            Game.PALETTE[color].light,
            [
                (x, y),
                (x + Game.CELL_SIZE.width, y),
                (
                    x + Game.CELL_SIZE.width - Game.CELL_BORDER_SIZE,
                    y + Game.CELL_BORDER_SIZE,
                ),
                (x + Game.CELL_BORDER_SIZE, y + Game.CELL_BORDER_SIZE),
                (
                    x + Game.CELL_BORDER_SIZE,
                    y + Game.CELL_SIZE.width - Game.CELL_BORDER_SIZE,
                ),
                (x, y + Game.CELL_SIZE.height),
                (x, y),
            ],
        )
        draw.polygon(
            target,
            Game.PALETTE[color].dark,
            [
                (x + Game.CELL_SIZE.width, y),
                (
                    x + Game.CELL_SIZE.width - Game.CELL_BORDER_SIZE,
                    y + Game.CELL_BORDER_SIZE,
                ),
                (
                    x + Game.CELL_SIZE.width - Game.CELL_BORDER_SIZE,
                    y + Game.CELL_SIZE.height - Game.CELL_BORDER_SIZE,
                ),
                (
                    x + Game.CELL_BORDER_SIZE,
                    y + Game.CELL_SIZE.width - Game.CELL_BORDER_SIZE,
                ),
                (x, y + Game.CELL_SIZE.height),
                (x + Game.CELL_SIZE.width, y + Game.CELL_SIZE.height),
                (x + Game.CELL_SIZE.width, y),
            ],
        )

    def draw_board_border(self):
        bwidth = (Game.BOARD_SIZE.width + 2) * Game.CELL_SIZE.width
        bheight = Game.WINDOW_SIZE.height
        for x in range(Game.BOARD_SIZE.width + 2):
            self.draw_block(x * Game.CELL_SIZE.width, 0, "gray")
            self.draw_block(
                x * Game.CELL_SIZE.width,
                bheight - Game.CELL_SIZE.height,
                "gray",
            )
        for y in range(1, Game.BOARD_SIZE.height + 1):
            self.draw_block(0, y * game.CELL_SIZE.height, "gray")
            self.draw_block(
                bwidth - Game.CELL_SIZE.width,
                y * game.CELL_SIZE.height,
                "gray",
            )

    def draw_board_content(self):
        for x in range(Game.BOARD_SIZE.width):
            for y in range(Game.BOARD_SIZE.height):
                if self.board[y][x]:
                    self.draw_block(
                        (x + 1) * Game.CELL_SIZE.width,
                        (y + 1) * Game.CELL_SIZE.height,
                        self.board[y][x],
                    )

    def draw_current_block(self):
        start_x, start_y = self.current_block_pos
        for x in range(self.current_block.width):
            for y in range(self.current_block.height):
                if self.current_block.shape[y][x]:
                    screen_x = (start_x + x + 1) * Game.CELL_SIZE.width
                    screen_y = (start_y + y + 1) * Game.CELL_SIZE.height
                    self.draw_block(
                        screen_x, screen_y, self.current_block.color
                    )

    def frame_time(self) -> float:
        ticks = self.clock.get_time()
        if not ticks:
            return 1 / Game.FRAMERATE
        else:
            return ticks / 1000

    def handle_key_event(self, typ, key):
        if typ == pygame.KEYDOWN:
            if key in self.action_map:
                self.pending_actions.append(self.action_map[key].type)
            self.key_states[key] = True
        elif typ == pygame.KEYUP:
            self.key_states[key] = False

    def handle_events(self):
        # process already pushed keys
        for key, state in self.key_states.items():
            if (
                state
                and key in self.action_map
                and self.action_map[key].repeat
            ):
                self.pending_actions.append(self.action_map[key].type)
        # now process new events
        for event in pygame.event.get():
            match event.type:
                case pygame.QUIT:
                    self.running = False
                case pygame.KEYDOWN | pygame.KEYUP:
                    self.handle_key_event(event.type, event.key)

    def swap_with_hold(self):
        to_swap = self.held_piece
        used_next = False
        if not to_swap:
            to_swap = self.next_piece
            used_next = True
        if not self.intersects_board(*self.current_block_pos, to_swap):
            self.held_piece = self.current_block
            self.current_block = to_swap
            if used_next:
                self.next_piece = self.random_tetromino()

    def intersects_board(self, x: int, y: int, piece: Tetromino):
        pw, ph = piece.width, piece.height
        if x < 0 or y < 0:
            return True
        elif x + pw > Game.BOARD_SIZE.width or y + ph > Game.BOARD_SIZE.height:
            return True
        shape = piece.shape
        for cy, row in enumerate(shape):
            for cx, cell in enumerate(row):
                if cell and self.board[y + cy][x + cx]:
                    return True
        return False

    def rotate_current_piece(self, times: int):
        new_piece = self.current_block.rotated(times)
        cx, cy = self.current_block_pos
        for dx in [0, -1]:
            for dy in [1, 0, -1]:
                np = Cell(cx + dx, cy + dy)
                if not self.intersects_board(*np, new_piece):
                    self.current_block = new_piece
                    self.current_block_pos = np
                    return

    def move_current_piece(self, dir: Direction):
        dx = dir * Game.MOVE_SPEED * self.frame_time()
        self.subcell_move += dx
        move_cell = int(self.subcell_move)
        self.subcell_move -= move_cell
        if move_cell:
            new_pos = Cell(
                self.current_block_pos.x + move_cell, self.current_block_pos.y
            )
            if not self.intersects_board(*new_pos, self.current_block):
                self.current_block_pos = new_pos

    def process_game_actions(self):
        if not (
            {Action.Type.MOVE_LEFT, Action.Type.MOVE_RIGHT}
            & set(self.pending_actions)
        ):
            self.subcell_move = 0
        if Action.Type.DROP not in self.pending_actions:
            self.stop_drop = False
        while self.pending_actions:
            match self.pending_actions.pop(0):
                case Action.Type.ROTATE_LEFT:
                    self.rotate_current_piece(Direction.LEFT)
                case Action.Type.ROTATE_RIGHT:
                    self.rotate_current_piece(Direction.RIGHT)
                case Action.Type.SWAP_HOLD:
                    self.swap_with_hold()
                case Action.Type.DROP if not self.stop_drop:
                    self.doing_drop = True
                case Action.Type.MOVE_LEFT:
                    self.move_current_piece(Direction.LEFT)
                case Action.Type.MOVE_RIGHT:
                    self.move_current_piece(Direction.RIGHT)
                case Action.Type.RESTART:
                    self.start_new_game()
                    self.pending_actions = []

    def place_piece(self, x: int, y: int, piece: Tetromino):
        self.score += Game.PLACE_POINTS
        for dy, row in enumerate(piece.shape):
            for dx, cell in enumerate(row):
                if cell:
                    self.board[y + dy][x + dx] = piece.color
        # prevent user from accidentally dropping next piece too
        self.stop_drop = True

    def advance_piece(self):
        speed = (
            Game.FAST_DROP_SPEED if self.doing_drop else Game.NORMAL_DROP_SPEED
        )
        self.subcell_drop += speed * self.frame_time()
        move_cell = int(self.subcell_drop)
        self.subcell_drop -= move_cell
        cp = self.current_block_pos
        if not self.intersects_board(
            cp.x, cp.y + move_cell, self.current_block
        ):
            self.current_block_pos = Cell(cp.x, cp.y + move_cell)
        else:
            for dy in range(move_cell, -1, -1):
                if not self.intersects_board(
                    cp.x, cp.y + dy, self.current_block
                ):
                    self.place_piece(cp.x, cp.y + dy, self.current_block)
                    self.current_block = None
                    return
            self.game_over = True

    @staticmethod
    def generate_clear_cells():
        bw = Game.BOARD_SIZE.width
        if bw % 2 == 0:
            return zip(range(bw // 2 - 1, -1, -1), range(bw // 2, bw))
        else:
            return zip(range(bw // 2, -1, -1), range(bw // 2, bw))

    def maybe_clear_rows(self):
        def do_single_clear(y: int):
            row = self.board[y]
            for x1, x2 in Game.generate_clear_cells():
                if row[x1]:
                    row[x1] = None
                    row[x2] = None
                    break

        def drop_rows_above_for_clear(y: int):
            self.board.pop(y)
            # this also restores indices for future clears
            self.board.insert(0, [None] * Game.BOARD_SIZE.width)

        if not self.clearing_rows:
            for y, row in enumerate(self.board):
                if all(row):
                    self.score += self.CLEAR_POINTS
                    self.clearing_rows.add(y)
        elif not any(self.board[next(iter(self.clearing_rows))]):
            # Order matters here
            for y in sorted(self.clearing_rows):
                drop_rows_above_for_clear(y)
            self.clearing_rows = set()
            self.clearing_frames = self.CLEAR_SPEED
        else:
            if self.clearing_frames == self.CLEAR_SPEED:
                self.clearing_frames = 0
                for y in self.clearing_rows:
                    do_single_clear(y)
            else:
                self.clearing_frames += 1

    def draw_score_and_instructions(self):
        text = (
            "Press <h> \nfor help.\n"
            "\n"
            f"Score: {self.score:05}\n"
            f"   HS: {self.high_score:05}"
        )
        exts = self.TINY_FONT.compute_extents(text)
        x = Game.CONTROLS_START_X + Game.CONTROL_DISPLAY_BORDER
        y = (
            self.screen.get_size()[1]
            - Game.CONTROL_DISPLAY_BORDER
            - exts.height
        )
        self.TINY_FONT.render_text(text, self.screen, x, y, "white")

    @cache
    def get_scaled_piece(
        self, piece: Tetromino, scale: float
    ) -> pygame.surface.Surface:
        ow = piece.width * Game.CELL_SIZE.width
        oh = piece.height * Game.CELL_SIZE.height
        os_surf = pygame.surface.Surface((ow, oh), pygame.SRCALPHA)
        for y, row in enumerate(piece.shape):
            for x, cell in enumerate(row):
                if cell:
                    self.draw_block(
                        x * Game.CELL_SIZE.width,
                        y * Game.CELL_SIZE.height,
                        piece.color,
                        os_surf,
                    )
        sw, sh = int(ow * scale), int(oh * scale)
        return pygame.transform.scale(os_surf, (sw, sh))

    def draw_boxed_piece(
        self,
        text: str,
        piece: Tetromino | None,
        x: int,
        y: int,
        box_size: int,
    ) -> Size:
        """Return the overall bounding box."""
        text_ext = Game.TINY_FONT.compute_extents(text)
        Game.TINY_FONT.center_text(
            text,
            self.screen,
            x + box_size // 2,
            y + text_ext.height // 2,
            "white",
        )
        pygame.draw.rect(
            self.screen,
            Game.PALETTE["gray"].norm,
            (
                x,
                y + text_ext.height + Game.TINY_FONT.row_kern,
                box_size,
                box_size,
            ),
            width=Game.INFO_BOX_BORDER_SIZE,
        )
        if piece:
            piece_surf = self.get_scaled_piece(piece, 0.75)
            pw, ph = piece_surf.get_size()
            self.screen.blit(
                piece_surf,
                (
                    x + box_size // 2 - pw // 2,
                    y
                    + text_ext.height
                    + Game.TINY_FONT.row_kern
                    + box_size // 2
                    - ph // 2,
                ),
            )
        return Size(
            max(box_size, text_ext.width),
            text_ext.height + box_size + Game.TINY_FONT.row_kern,
        )

    def draw_held_and_next_piece(self):
        width = int(Game.CONTROLS_WIDTH * 0.8)
        y = Game.CONTROL_DISPLAY_BORDER
        x = Game.CONTROLS_START_X + Game.CONTROLS_WIDTH // 2 - width // 2
        exts = self.draw_boxed_piece("Hold", self.held_piece, x, y, width)
        self.draw_boxed_piece(
            "Next",
            self.next_piece,
            x,
            y + exts.height + 2 * Game.CONTROL_DISPLAY_BORDER,
            width,
        )

    def process_and_draw_help_overlay(self):
        self.draw_gray_overlay()

        hs = Game.make_help_string(Game.GAME_ACTION_MAP)
        exts = Game.TINY_FONT.compute_extents(hs)

        sw, sh = self.screen.get_size()

        tot_border = Game.INFO_BOX_BORDER_SIZE + Game.HELP_MENU_INSET
        box_x = sw // 2 - exts.width // 2 - tot_border
        box_y = sh // 2 - exts.height // 2 - tot_border
        box_w = exts.width + 2 * tot_border
        box_h = exts.height + 2 * tot_border

        pygame.draw.rect(self.screen, "black", (box_x, box_y, box_w, box_h))
        pygame.draw.rect(
            self.screen,
            Game.PALETTE["gray"].norm,
            (box_x, box_y, box_w, box_h),
            width=Game.INFO_BOX_BORDER_SIZE,
        )

        Game.TINY_FONT.center_text(hs, self.screen, sw // 2, sh // 2, "white")

        if Action.Type.CLOSE_HELP in self.pending_actions:
            self.pending_actions = []
            self.action_map = Game.GAME_ACTION_MAP
            self.help_mode = False

    def game_loop(self):
        self.doing_drop = False

        self.maybe_clear_rows()
        if Action.Type.OPEN_HELP in self.pending_actions:
            # do no matter what
            self.help_mode = True
            self.action_map = Game.HELP_ACTION_MAP
        elif not self.clearing_rows:
            self.process_game_actions()
            self.advance_piece()
        else:
            # ignore input while clearing
            self.pending_actions = []

        if not self.current_block:
            self.swap_in_next_piece()

        self.screen.fill("black")
        if not self.clearing_rows:
            self.draw_current_block()
        self.draw_board_content()
        self.draw_board_border()
        self.draw_held_and_next_piece()

        self.draw_score_and_instructions()

        if self.help_mode:
            self.process_and_draw_help_overlay()

    def start_new_game(self):
        self.clear_board()
        self.next_piece = None
        self.swap_in_next_piece(True)
        self.held_piece = None
        self.subcell_move = 0
        self.subcell_drop = 0
        self.clearing_rows = set()
        # immediately clear the first block
        self.clearing_frames = Game.CLEAR_SPEED
        self.score = 0
        self.held_piece = None
        self.game_over = False

    def handle_game_over_actions(self):
        while self.pending_actions:
            act = self.pending_actions.pop(0)
            if act == Action.Type.RESTART:
                self.start_new_game()

    def make_gray_overlay(self):
        s = pygame.surface.Surface(self.screen.get_size(), pygame.SRCALPHA)
        pygame.draw.rect(s, "#44444466", (0, 0, *s.get_size()))
        return s

    def draw_gray_overlay(self):
        self.screen.blit(self.gray_overlay, (0, 0))

    def game_over_loop(self):
        self.handle_game_over_actions()
        if not self.game_over:
            return
        self.screen.fill("black")
        self.draw_board_content()
        self.draw_current_block()
        self.draw_board_border()
        self.draw_held_and_next_piece()

        self.draw_score_and_instructions()

        self.draw_gray_overlay()

        sw, sh = self.screen.get_size()
        exts = self.FONT.compute_extents("Game Over!")
        score_text = f"Score: {self.score:05}"
        exts2 = self.SMALL_FONT.compute_extents(score_text)
        exts3 = self.SMALL_FONT.compute_extents("Press <r> to retry.")
        text_width = max(exts.width, exts2.width, exts3.width)
        text_height = (
            exts.height + exts2.height + exts3.height + 2 * self.FONT.row_kern
        )

        tot_border = Game.INFO_BOX_BORDER_SIZE + Game.HELP_MENU_INSET
        box_x = sw // 2 - text_width // 2 - tot_border
        box_y = sh // 2 - text_height // 2 - tot_border
        box_w = text_width + 2 * tot_border
        box_h = text_height + 2 * tot_border

        pygame.draw.rect(self.screen, "black", (box_x, box_y, box_w, box_h))
        pygame.draw.rect(
            self.screen,
            Game.PALETTE["gray"].norm,
            (box_x, box_y, box_w, box_h),
            width=Game.INFO_BOX_BORDER_SIZE,
        )

        self.FONT.render_text(
            "Game Over!",
            self.screen,
            sw // 2 - exts.width // 2,
            sh // 2 - text_height // 2,
            "white",
        )
        self.SMALL_FONT.render_text(
            score_text,
            self.screen,
            sw // 2 - exts2.width // 2,
            sh // 2 - text_height // 2 + exts.height + self.FONT.row_kern,
            "white",
        )
        self.SMALL_FONT.render_text(
            "Press <r> to retry.",
            self.screen,
            sw // 2 - exts3.width // 2,
            sh // 2
            - text_height // 2
            + exts.height
            + exts2.height
            + 2 * self.FONT.row_kern,
            "white",
        )

    def loop(self):
        self.running = True
        while self.running:
            self.handle_events()
            if self.game_over:
                self.game_over_loop()
            else:
                self.game_loop()

            pygame.display.flip()
            self.clock.tick(Game.FRAMERATE)

    def swap_in_next_piece(self, force: bool = False):
        self.cur_random_peice_seq = None
        if not self.next_piece or force:
            self.next_piece = self.random_tetromino()
            self.current_block = self.random_tetromino()
        else:
            self.current_block = self.next_piece
            self.next_piece = self.random_tetromino()
        # top left corner
        self.current_block_pos = Cell(
            self.BOARD_SIZE.width // 2
            - math.ceil(self.current_block.width / 2),
            0,
        )

    def clear_board(self):
        self.board = make_matrix(*Game.BOARD_SIZE)

    # not in __init__ to facilitate debugging in ipython
    def init(self):
        pygame.init()
        self.screen = pygame.display.set_mode(
            Game.WINDOW_SIZE, pygame.SCALED | pygame.HWACCEL
        )
        pygame.display.set_caption("Tetris")
        self.clock = pygame.time.Clock()

        self.gray_overlay = self.make_gray_overlay()

        pygame.key.stop_text_input()
        self.key_states = defaultdict(lambda: False)
        self.pending_actions = []
        self.stop_drop = False

        self.help_mode = False
        self.high_score = 0
        self.start_new_game()

    def run(self):
        self.init()
        self.loop()


GLYPH_DATA = [
    Font.Glyph(
        " ",
        [
            "     ",
            "     ",
            "     ",
            "     ",
            "     ",
        ],
    ),
    Font.Glyph(
        "a",
        [
            "*****",
            "*   *",
            "*****",
            "*   *",
            "*   *",
        ],
    ),
    Font.Glyph(
        "b",
        [
            "**** ",
            "*   *",
            "*****",
            "*   *",
            "**** ",
        ],
    ),
    Font.Glyph(
        "c",
        [
            "*****",
            "*   *",
            "*    ",
            "*   *",
            "*****",
        ],
    ),
    Font.Glyph(
        "d",
        [
            "**** ",
            "*   *",
            "*   *",
            "*   *",
            "**** ",
        ],
    ),
    Font.Glyph(
        "e",
        [
            "*****",
            "*    ",
            "**** ",
            "*    ",
            "*****",
        ],
    ),
    Font.Glyph(
        "f",
        [
            "*****",
            "*    ",
            "**** ",
            "*    ",
            "*    ",
        ],
    ),
    Font.Glyph(
        "g",
        [
            "*****",
            "*    ",
            "*  **",
            "*   *",
            "*****",
        ],
    ),
    Font.Glyph(
        "h",
        [
            "*   *",
            "*   *",
            "*****",
            "*   *",
            "*   *",
        ],
    ),
    Font.Glyph(
        "i",
        [
            "*****",
            "  *  ",
            "  *  ",
            "  *  ",
            "*****",
        ],
    ),
    Font.Glyph(
        "j",
        [
            "*****",
            "   * ",
            "   * ",
            "*  * ",
            " **  ",
        ],
    ),
    Font.Glyph(
        "k",
        [
            "*   *",
            "*  * ",
            "***  ",
            "*  * ",
            "*   *",
        ],
    ),
    Font.Glyph(
        "l",
        [
            "*    ",
            "*    ",
            "*    ",
            "*    ",
            "*****",
        ],
    ),
    Font.Glyph(
        "m",
        [
            "*   *",
            "** **",
            "* * *",
            "*   *",
            "*   *",
        ],
    ),
    Font.Glyph(
        "n",
        [
            "*   *",
            "**  *",
            "* * *",
            "*  **",
            "*   *",
        ],
    ),
    Font.Glyph(
        "o",
        [
            " *** ",
            "*   *",
            "*   *",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "p",
        [
            "**** ",
            "*   *",
            "**** ",
            "*    ",
            "*    ",
        ],
    ),
    Font.Glyph(
        "q",
        [
            " *** ",
            "*   *",
            "* * *",
            "*  * ",
            " ** *",
        ],
    ),
    Font.Glyph(
        "r",
        [
            "**** ",
            "*   *",
            "**** ",
            "*  * ",
            "*   *",
        ],
    ),
    Font.Glyph(
        "s",
        [
            " ****",
            "*    ",
            " *** ",
            "    *",
            "**** ",
        ],
    ),
    Font.Glyph(
        "t",
        [
            "*****",
            "  *  ",
            "  *  ",
            "  *  ",
            "  *  ",
        ],
    ),
    Font.Glyph(
        "u",
        [
            "*   *",
            "*   *",
            "*   *",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "v",
        [
            "*   *",
            "*   *",
            "*   *",
            " * * ",
            "  *  ",
        ],
    ),
    Font.Glyph(
        "w",
        [
            "*   *",
            "*   *",
            "* * *",
            "** **",
            "*   *",
        ],
    ),
    Font.Glyph(
        "x",
        [
            "*   *",
            " * * ",
            "  *  ",
            " * * ",
            "*   *",
        ],
    ),
    Font.Glyph(
        "y",
        [
            "*   *",
            " * * ",
            "  *  ",
            "  *  ",
            "  *  ",
        ],
    ),
    Font.Glyph(
        "z",
        [
            "*****",
            "   * ",
            "  *  ",
            " *   ",
            "*****",
        ],
    ),
    Font.Glyph(
        "0",
        [
            " *** ",
            "*   *",
            "* * *",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "1",
        [
            " **  ",
            "* *  ",
            "  *  ",
            "  *  ",
            "*****",
        ],
    ),
    Font.Glyph(
        "2",
        [
            " *** ",
            "*   *",
            "   * ",
            "  *  ",
            " ****",
        ],
    ),
    Font.Glyph(
        "3",
        [
            " *** ",
            "*   *",
            "  ***",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "4",
        [
            "*  * ",
            "*  * ",
            "*****",
            "   * ",
            "   * ",
        ],
    ),
    Font.Glyph(
        "5",
        [
            "*****",
            "*    ",
            "**** ",
            "    *",
            "**** ",
        ],
    ),
    Font.Glyph(
        "6",
        [
            " ****",
            "*    ",
            "**** ",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "7",
        [
            "*****",
            "   * ",
            "  *  ",
            " *   ",
            "*    ",
        ],
    ),
    Font.Glyph(
        "8",
        [
            " *** ",
            "*   *",
            " *** ",
            "*   *",
            " *** ",
        ],
    ),
    Font.Glyph(
        "9",
        [
            " *** ",
            "*   *",
            " ****",
            "    *",
            "**** ",
        ],
    ),
    Font.Glyph(
        ".",
        [
            "  ",
            "  ",
            "  ",
            "  ",
            " *",
        ],
    ),
    Font.Glyph(
        "!",
        [
            " *",
            " *",
            " *",
            "  ",
            " *",
        ],
    ),
    Font.Glyph(
        ":",
        [
            "  ",
            " *",
            "  ",
            " *",
            "  ",
        ],
    ),
    Font.Glyph(
        "<",
        [
            "   **",
            " **  ",
            "*    ",
            " **  ",
            "   **",
        ],
    ),
    Font.Glyph(
        ">",
        [
            "**   ",
            "  ** ",
            "    *",
            "  ** ",
            "**   ",
        ],
    ),
]


if __name__ == "__main__":
    game = Game()
    game.run()