Games

Some two-player games implemented using scene click events.

import time
from typing import Literal

import numpy as np
import trimesh.creation
from typing_extensions import assert_never

import viser
import viser.transforms as tf


def main() -> None:
    server = viser.ViserServer()
    play_connect_4(server)

    server.gui.add_button("Tic-Tac-Toe").on_click(lambda _: play_tic_tac_toe(server))
    server.gui.add_button("Connect 4").on_click(lambda _: play_connect_4(server))

    while True:
        time.sleep(10.0)


def play_connect_4(server: viser.ViserServer) -> None:
    """Play a game of Connect 4."""
    server.scene.reset()

    num_rows = 6
    num_cols = 7

    whose_turn: Literal["red", "yellow"] = "red"
    pieces_in_col = [0] * num_cols

    # Create the board frame.
    for col in range(num_cols):
        for row in range(num_rows):
            server.scene.add_mesh_trimesh(
                f"/structure/{row}_{col}",
                trimesh.creation.annulus(0.45, 0.55, 0.125),
                position=(0.0, col, row),
                wxyz=tf.SO3.from_y_radians(np.pi / 2.0).wxyz,
            )

    # Create a sphere to click on for each column.
    def setup_column(col: int) -> None:
        sphere = server.scene.add_icosphere(
            f"/spheres/{col}",
            radius=0.25,
            position=(0, col, num_rows - 0.25),
            color=(255, 255, 255),
        )

        # Drop piece into the column.
        @sphere.on_click
        def _(_) -> None:
            nonlocal whose_turn
            whose_turn = "red" if whose_turn != "red" else "yellow"

            row = pieces_in_col[col]
            if row == num_rows - 1:
                sphere.remove()

            pieces_in_col[col] += 1
            cylinder = trimesh.creation.cylinder(radius=0.4, height=0.125)
            piece = server.scene.add_mesh_simple(
                f"/game_pieces/{row}_{col}",
                cylinder.vertices,
                cylinder.faces,
                wxyz=tf.SO3.from_y_radians(np.pi / 2.0).wxyz,
                color={"red": (255, 0, 0), "yellow": (255, 255, 0)}[whose_turn],
            )
            for row_anim in np.linspace(num_rows - 1, row, num_rows - row + 1):
                piece.position = (
                    0,
                    col,
                    row_anim,
                )
                time.sleep(1.0 / 30.0)

    for col in range(num_cols):
        setup_column(col)


def play_tic_tac_toe(server: viser.ViserServer) -> None:
    """Play a game of tic-tac-toe."""
    server.scene.reset()

    whose_turn: Literal["x", "o"] = "x"

    for i in range(4):
        server.scene.add_spline_catmull_rom(
            f"/gridlines/{i}",
            ((-0.5, -1.5, 0), (-0.5, 1.5, 0)),
            color=(127, 127, 127),
            position=(1, 1, 0),
            wxyz=tf.SO3.from_z_radians(np.pi / 2 * i).wxyz,
        )

    def draw_symbol(symbol: Literal["x", "o"], i: int, j: int) -> None:
        """Draw an X or O in the given cell."""
        for scale in np.linspace(0.01, 1.0, 5):
            if symbol == "x":
                for k in range(2):
                    server.scene.add_box(
                        f"/symbols/{i}_{j}/{k}",
                        dimensions=(0.7 * scale, 0.125 * scale, 0.125),
                        position=(i, j, 0),
                        color=(0, 0, 255),
                        wxyz=tf.SO3.from_z_radians(np.pi / 2.0 * k + np.pi / 4.0).wxyz,
                    )
            elif symbol == "o":
                mesh = trimesh.creation.annulus(0.25 * scale, 0.35 * scale, 0.125)
                server.scene.add_mesh_simple(
                    f"/symbols/{i}_{j}",
                    mesh.vertices,
                    mesh.faces,
                    position=(i, j, 0),
                    color=(255, 0, 0),
                )
            else:
                assert_never(symbol)
            server.flush()
            time.sleep(1.0 / 30.0)

    def setup_cell(i: int, j: int) -> None:
        """Create a clickable sphere in a given cell."""
        sphere = server.scene.add_icosphere(
            f"/spheres/{i}_{j}",
            radius=0.25,
            position=(i, j, 0),
            color=(255, 255, 255),
        )

        @sphere.on_click
        def _(_) -> None:
            nonlocal whose_turn
            whose_turn = "x" if whose_turn != "x" else "o"
            sphere.remove()
            draw_symbol(whose_turn, i, j)

    for i in range(3):
        for j in range(3):
            setup_cell(i, j)


if __name__ == "__main__":
    main()