Pygame實戰(zhàn)：方塊連接世界，云游大好河山—《我的世界》已上線！確定不進來康康嘛？

icattlecoder 發(fā)布于2021-10-13 09:40 / 3005人閱讀

摘要：導(dǎo)語我的世界是一款自由度極高的游戲，每個新存檔的開啟，就像是作為造物主的玩家在虛擬空間開辟了一個全新的宇宙。主題我的世界版本圖片效果圖如下。

導(dǎo)語

《我的世界》是一款自由度極高的游戲，每個新存檔的開啟，就像是作為造物主的玩家在虛擬空間開辟了一個全新的宇宙。

方塊連接世界，云游大好河山。

? ? ? 國慶不是回家了一趟嘛？隔壁家的小胖墩在跟家里的小孩子一起玩手機，一起下載了這款《我的世界》的游戲，玩兒的可是非常起勁兒了，建房子打怪，別說那房子的模型著實蠻驚艷的哈！

至少我作為一個沒玩過的人來說確實是很牛逼了~至少我做不來哈哈哈！這游戲看著怪好玩兒的撒，小編沒忍住，畢竟長假嘛，怎得找點兒事情可做！

于是——今天木木子帶大家一起編寫的Python 1.0初級版本《我的世界》就要隆重出場了，期不期待吖~

正文

（1）《我是世界》游戲規(guī)則。

移動—前進：W，后退：S，向左：A，向右：D，環(huán)顧四周:鼠標，跳起：空格鍵，切換飛行模式:Tab。

選擇建筑材料—磚：1，草：2，沙子：3，刪除建筑：鼠標左鍵單擊，創(chuàng)建建筑塊：鼠標右鍵單擊。

ESC退出程序。

（2）主要程序代碼。

"""主題：我的世界1.0版本"""from __future__ import divisionimport sysimport mathimport randomimport timefrom collections import dequefrom pyglet import imagefrom pyglet.gl import *from pyglet.graphics import TextureGroupfrom pyglet.window import key, mouseTICKS_PER_SEC = 60# Size of sectors used to ease block loading.SECTOR_SIZE = 16WALKING_SPEED = 5FLYING_SPEED = 15GRAVITY = 20.0MAX_JUMP_HEIGHT = 1.0 # About the height of a block.# To derive the formula for calculating jump speed, first solve#    v_t = v_0 + a * t# for the time at which you achieve maximum height, where a is the acceleration# due to gravity and v_t = 0. This gives:#    t = - v_0 / a# Use t and the desired MAX_JUMP_HEIGHT to solve for v_0 (jump speed) in#    s = s_0 + v_0 * t + (a * t^2) / 2JUMP_SPEED = math.sqrt(2 * GRAVITY * MAX_JUMP_HEIGHT)TERMINAL_VELOCITY = 50PLAYER_HEIGHT = 2if sys.version_info[0] >= 3:    xrange = rangedef cube_vertices(x, y, z, n):    """ Return the vertices of the cube at position x, y, z with size 2*n.    """    return [        x-n,y+n,z-n, x-n,y+n,z+n, x+n,y+n,z+n, x+n,y+n,z-n,  # top        x-n,y-n,z-n, x+n,y-n,z-n, x+n,y-n,z+n, x-n,y-n,z+n,  # bottom        x-n,y-n,z-n, x-n,y-n,z+n, x-n,y+n,z+n, x-n,y+n,z-n,  # left        x+n,y-n,z+n, x+n,y-n,z-n, x+n,y+n,z-n, x+n,y+n,z+n,  # right        x-n,y-n,z+n, x+n,y-n,z+n, x+n,y+n,z+n, x-n,y+n,z+n,  # front        x+n,y-n,z-n, x-n,y-n,z-n, x-n,y+n,z-n, x+n,y+n,z-n,  # back    ]def tex_coord(x, y, n=4):    """ Return the bounding vertices of the texture square.    """    m = 1.0 / n    dx = x * m    dy = y * m    return dx, dy, dx + m, dy, dx + m, dy + m, dx, dy + mdef tex_coords(top, bottom, side):    """ Return a list of the texture squares for the top, bottom and side.    """    top = tex_coord(*top)    bottom = tex_coord(*bottom)    side = tex_coord(*side)    result = []    result.extend(top)    result.extend(bottom)    result.extend(side * 4)    return resultTEXTURE_PATH = "texture.png"GRASS = tex_coords((1, 0), (0, 1), (0, 0))SAND = tex_coords((1, 1), (1, 1), (1, 1))BRICK = tex_coords((2, 0), (2, 0), (2, 0))STONE = tex_coords((2, 1), (2, 1), (2, 1))FACES = [    ( 0, 1, 0),    ( 0,-1, 0),    (-1, 0, 0),    ( 1, 0, 0),    ( 0, 0, 1),    ( 0, 0,-1),]def normalize(position):    """ Accepts `position` of arbitrary precision and returns the block    containing that position.    Parameters    ----------    position : tuple of len 3    Returns    -------    block_position : tuple of ints of len 3    """    x, y, z = position    x, y, z = (int(round(x)), int(round(y)), int(round(z)))    return (x, y, z)def sectorize(position):    """ Returns a tuple representing the sector for the given `position`.    Parameters    ----------    position : tuple of len 3    Returns    -------    sector : tuple of len 3    """    x, y, z = normalize(position)    x, y, z = x // SECTOR_SIZE, y // SECTOR_SIZE, z // SECTOR_SIZE    return (x, 0, z)class Model(object):    def __init__(self):        # A Batch is a collection of vertex lists for batched rendering.        self.batch = pyglet.graphics.Batch()        # A TextureGroup manages an OpenGL texture.        self.group = TextureGroup(image.load(TEXTURE_PATH).get_texture())        # A mapping from position to the texture of the block at that position.        # This defines all the blocks that are currently in the world.        self.world = {}        # Same mapping as `world` but only contains blocks that are shown.        self.shown = {}        # Mapping from position to a pyglet `VertextList` for all shown blocks.        self._shown = {}        # Mapping from sector to a list of positions inside that sector.        self.sectors = {}        # Simple function queue implementation. The queue is populated with        # _show_block() and _hide_block() calls        self.queue = deque()        self._initialize()    def _initialize(self):        """ Initialize the world by placing all the blocks.        """        n = 80  # 1/2 width and height of world        s = 1  # step size        y = 0  # initial y height        for x in xrange(-n, n + 1, s):            for z in xrange(-n, n + 1, s):                # create a layer stone an grass everywhere.                self.add_block((x, y - 2, z), GRASS, immediate=False)                self.add_block((x, y - 3, z), STONE, immediate=False)                if x in (-n, n) or z in (-n, n):                    # create outer walls.                    for dy in xrange(-2, 3):                        self.add_block((x, y + dy, z), STONE, immediate=False)        # generate the hills randomly        o = n - 10        for _ in xrange(120):            a = random.randint(-o, o)  # x position of the hill            b = random.randint(-o, o)  # z position of the hill            c = -1  # base of the hill            h = random.randint(1, 6)  # height of the hill            s = random.randint(4, 8)  # 2 * s is the side length of the hill            d = 1  # how quickly to taper off the hills            t = random.choice([GRASS, SAND, BRICK])            for y in xrange(c, c + h):                for x in xrange(a - s, a + s + 1):                    for z in xrange(b - s, b + s + 1):                        if (x - a) ** 2 + (z - b) ** 2 > (s + 1) ** 2:                            continue                        if (x - 0) ** 2 + (z - 0) ** 2 < 5 ** 2:                            continue                        self.add_block((x, y, z), t, immediate=False)                s -= d  # decrement side lenth so hills taper off    def hit_test(self, position, vector, max_distance=8):        """ Line of sight search from current position. If a block is        intersected it is returned, along with the block previously in the line        of sight. If no block is found, return None, None.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position to check visibility from.        vector : tuple of len 3            The line of sight vector.        max_distance : int            How many blocks away to search for a hit.        """        m = 8        x, y, z = position        dx, dy, dz = vector        previous = None        for _ in xrange(max_distance * m):            key = normalize((x, y, z))            if key != previous and key in self.world:                return key, previous            previous = key            x, y, z = x + dx / m, y + dy / m, z + dz / m        return None, None    def exposed(self, position):        """ Returns False is given `position` is surrounded on all 6 sides by        blocks, True otherwise.        """        x, y, z = position        for dx, dy, dz in FACES:            if (x + dx, y + dy, z + dz) not in self.world:                return True        return False    def add_block(self, position, texture, immediate=True):        """ Add a block with the given `texture` and `position` to the world.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position of the block to add.        texture : list of len 3            The coordinates of the texture squares. Use `tex_coords()` to            generate.        immediate : bool            Whether or not to draw the block immediately.        """        if position in self.world:            self.remove_block(position, immediate)        self.world[position] = texture        self.sectors.setdefault(sectorize(position), []).append(position)        if immediate:            if self.exposed(position):                self.show_block(position)            self.check_neighbors(position)    def remove_block(self, position, immediate=True):        """ Remove the block at the given `position`.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position of the block to remove.        immediate : bool            Whether or not to immediately remove block from canvas.        """        del self.world[position]        self.sectors[sectorize(position)].remove(position)        if immediate:            if position in self.shown:                self.hide_block(position)            self.check_neighbors(position)    def check_neighbors(self, position):        """ Check all blocks surrounding `position` and ensure their visual        state is current. This means hiding blocks that are not exposed and        ensuring that all exposed blocks are shown. Usually used after a block        is added or removed.        """        x, y, z = position        for dx, dy, dz in FACES:            key = (x + dx, y + dy, z + dz)            if key not in self.world:                continue            if self.exposed(key):                if key not in self.shown:                    self.show_block(key)            else:                if key in self.shown:                    self.hide_block(key)    def show_block(self, position, immediate=True):        """ Show the block at the given `position`. This method assumes the        block has already been added with add_block()        Parameters        ----------        position : tuple of len 3            The (x, y, z) position of the block to show.        immediate : bool            Whether or not to show the block immediately.        """        texture = self.world[position]        self.shown[position] = texture        if immediate:            self._show_block(position, texture)        else:            self._enqueue(self._show_block, position, texture)    def _show_block(self, position, texture):        """ Private implementation of the `show_block()` method.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position of the block to show.        texture : list of len 3            The coordinates of the texture squares. Use `tex_coords()` to            generate.        """        x, y, z = position        vertex_data = cube_vertices(x, y, z, 0.5)        texture_data = list(texture)        # create vertex list        # FIXME Maybe `add_indexed()` should be used instead        self._shown[position] = self.batch.add(24, GL_QUADS, self.group,            ("v3f/static", vertex_data),            ("t2f/static", texture_data))    def hide_block(self, position, immediate=True):        """ Hide the block at the given `position`. Hiding does not remove the        block from the world.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position of the block to hide.        immediate : bool            Whether or not to immediately remove the block from the canvas.        """        self.shown.pop(position)        if immediate:            self._hide_block(position)        else:            self._enqueue(self._hide_block, position)    def _hide_block(self, position):        """ Private implementation of the "hide_block()` method.        """        self._shown.pop(position).delete()    def show_sector(self, sector):        """ Ensure all blocks in the given sector that should be shown are        drawn to the canvas.        """        for position in self.sectors.get(sector, []):            if position not in self.shown and self.exposed(position):                self.show_block(position, False)    def hide_sector(self, sector):        """ Ensure all blocks in the given sector that should be hidden are        removed from the canvas.        """        for position in self.sectors.get(sector, []):            if position in self.shown:                self.hide_block(position, False)    def change_sectors(self, before, after):        """ Move from sector `before` to sector `after`. A sector is a        contiguous x, y sub-region of world. Sectors are used to speed up        world rendering.        """        before_set = set()        after_set = set()        pad = 4        for dx in xrange(-pad, pad + 1):            for dy in [0]:  # xrange(-pad, pad + 1):                for dz in xrange(-pad, pad + 1):                    if dx ** 2 + dy ** 2 + dz ** 2 > (pad + 1) ** 2:                        continue                    if before:                        x, y, z = before                        before_set.add((x + dx, y + dy, z + dz))                    if after:                        x, y, z = after                        after_set.add((x + dx, y + dy, z + dz))        show = after_set - before_set        hide = before_set - after_set        for sector in show:            self.show_sector(sector)        for sector in hide:            self.hide_sector(sector)    def _enqueue(self, func, *args):        """ Add `func` to the internal queue.        """        self.queue.append((func, args))    def _dequeue(self):        """ Pop the top function from the internal queue and call it.        """        func, args = self.queue.popleft()        func(*args)    def process_queue(self):        """ Process the entire queue while taking periodic breaks. This allows        the game loop to run smoothly. The queue contains calls to        _show_block() and _hide_block() so this method should be called if        add_block() or remove_block() was called with immediate=False        """        start = time.clock()        while self.queue and time.clock() - start < 1.0 / TICKS_PER_SEC:            self._dequeue()    def process_entire_queue(self):        """ Process the entire queue with no breaks.        """        while self.queue:            self._dequeue()class Window(pyglet.window.Window):    def __init__(self, *args, **kwargs):        super(Window, self).__init__(*args, **kwargs)        # Whether or not the window exclusively captures the mouse.        self.exclusive = False        # When flying gravity has no effect and speed is increased.        self.flying = False        # Strafing is moving lateral to the direction you are facing,        # e.g. moving to the left or right while continuing to face forward.        #        # First element is -1 when moving forward, 1 when moving back, and 0        # otherwise. The second element is -1 when moving left, 1 when moving        # right, and 0 otherwise.        self.strafe = [0, 0]        # Current (x, y, z) position in the world, specified with floats. Note        # that, perhaps unlike in math class, the y-axis is the vertical axis.        self.position = (0, 0, 0)        # First element is rotation of the player in the x-z plane (ground        # plane) measured from the z-axis down. The second is the rotation        # angle from the ground plane up. Rotation is in degrees.        #        # The vertical plane rotation ranges from -90 (looking straight down) to        # 90 (looking straight up). The horizontal rotation range is unbounded.        self.rotation = (0, 0)        # Which sector the player is currently in.        self.sector = None        # The crosshairs at the center of the screen.        self.reticle = None        # Velocity in the y (upward) direction.        self.dy = 0        # A list of blocks the player can place. Hit num keys to cycle.        self.inventory = [BRICK, GRASS, SAND]        # The current block the user can place. Hit num keys to cycle.        self.block = self.inventory[0]        # Convenience list of num keys.        self.num_keys = [            key._1, key._2, key._3, key._4, key._5,            key._6, key._7, key._8, key._9, key._0]        # Instance of the model that handles the world.        self.model = Model()        # The label that is displayed in the top left of the canvas.        self.label = pyglet.text.Label("", font_name="Arial", font_size=18,            x=10, y=self.height - 10, anchor_x="left", anchor_y="top",            color=(0, 0, 0, 255))        # This call schedules the `update()` method to be called        # TICKS_PER_SEC. This is the main game event loop.        pyglet.clock.schedule_interval(self.update, 1.0 / TICKS_PER_SEC)    def set_exclusive_mouse(self, exclusive):        """ If `exclusive` is True, the game will capture the mouse, if False        the game will ignore the mouse.        """        super(Window, self).set_exclusive_mouse(exclusive)        self.exclusive = exclusive    def get_sight_vector(self):        """ Returns the current line of sight vector indicating the direction        the player is looking.        """        x, y = self.rotation        # y ranges from -90 to 90, or -pi/2 to pi/2, so m ranges from 0 to 1 and        # is 1 when looking ahead parallel to the ground and 0 when looking        # straight up or down.        m = math.cos(math.radians(y))        # dy ranges from -1 to 1 and is -1 when looking straight down and 1 when        # looking straight up.        dy = math.sin(math.radians(y))        dx = math.cos(math.radians(x - 90)) * m        dz = math.sin(math.radians(x - 90)) * m        return (dx, dy, dz)    def get_motion_vector(self):        """ Returns the current motion vector indicating the velocity of the        player.        Returns        -------        vector : tuple of len 3            Tuple containing the velocity in x, y, and z respectively.        """        if any(self.strafe):            x, y = self.rotation            strafe = math.degrees(math.atan2(*self.strafe))            y_angle = math.radians(y)            x_angle = math.radians(x + strafe)            if self.flying:                m = math.cos(y_angle)                dy = math.sin(y_angle)                if self.strafe[1]:                    # Moving left or right.                    dy = 0.0                    m = 1                if self.strafe[0] > 0:                    # Moving backwards.                    dy *= -1                # When you are flying up or down, you have less left and right                # motion.                dx = math.cos(x_angle) * m                dz = math.sin(x_angle) * m            else:                dy = 0.0                dx = math.cos(x_angle)                dz = math.sin(x_angle)        else:            dy = 0.0            dx = 0.0            dz = 0.0        return (dx, dy, dz)    def update(self, dt):        """ This method is scheduled to be called repeatedly by the pyglet        clock.        Parameters        ----------        dt : float            The change in time since the last call.        """        self.model.process_queue()        sector = sectorize(self.position)        if sector != self.sector:            self.model.change_sectors(self.sector, sector)            if self.sector is None:                self.model.process_entire_queue()            self.sector = sector        m = 8        dt = min(dt, 0.2)        for _ in xrange(m):            self._update(dt / m)    def _update(self, dt):        """ Private implementation of the `update()` method. This is where most        of the motion logic lives, along with gravity and collision detection.        Parameters        ----------        dt : float            The change in time since the last call.        """        # walking        speed = FLYING_SPEED if self.flying else WALKING_SPEED        d = dt * speed # distance covered this tick.        dx, dy, dz = self.get_motion_vector()        # New position in space, before accounting for gravity.        dx, dy, dz = dx * d, dy * d, dz * d        # gravity        if not self.flying:            # Update your vertical speed: if you are falling, speed up until you            # hit terminal velocity; if you are jumping, slow down until you            # start falling.            self.dy -= dt * GRAVITY            self.dy = max(self.dy, -TERMINAL_VELOCITY)            dy += self.dy * dt        # collisions        x, y, z = self.position        x, y, z = self.collide((x + dx, y + dy, z + dz), PLAYER_HEIGHT)        self.position = (x, y, z)    def collide(self, position, height):        """ Checks to see if the player at the given `position` and `height`        is colliding with any blocks in the world.        Parameters        ----------        position : tuple of len 3            The (x, y, z) position to check for collisions at.        height : int or float            The height of the player.        Returns        -------        position : tuple of len 3            The new position of the player taking into account collisions.        """        # How much overlap with a dimension of a surrounding block you need to        # have to count as a collision. If 0, touching terrain at all counts as        # a collision. If .49, you sink into the ground, as if walking through        # tall grass. If >= .5, you"ll fall through the ground.        pad = 0.25        p = list(position)        np = normalize(position)        for face in FACES:  # check all surrounding blocks            for i in xrange(3):  # check each dimension independently                if not face[i]:                    continue                # How much overlap you have with this dimension.                d = (p[i] - np[i]) * face[i]                if d < pad:                    continue                for dy in xrange(height):  # check each height                    op = list(np)                    op[1] -= dy                    op[i] += face[i]                    if tuple(op) not in self.model.world:                        continue                    p[i] -= (d - pad) * face[i]                    if face == (0, -1, 0) or face == (0, 1, 0):                        # You are colliding with the ground or ceiling, so stop                        # falling / rising.                        self.dy = 0                    break        return tuple(p)    def on_mouse_press(self, x, y, button, modifiers):        """ Called when a mouse button is pressed. See pyglet docs for button        amd modifier mappings.        Parameters        ----------        x, y : int            The coordinates of the mouse click. Always center of the screen if            the mouse is captured.        button : int            Number representing mouse button that was clicked. 1 = left button,            4 = right button.        modifiers : int            Number representing any modifying keys that were pressed when the            mouse button was clicked.        """        if self.exclusive:            vector = self.get_sight_vector()            block, previous = self.model.hit_test(self.position, vector)            if (button == mouse.RIGHT) or /                    ((button == mouse.LEFT) and (modifiers & key.MOD_CTRL)):                # ON OSX, control + left click = right click.                if previous:                    self.model.add_block(previous, self.block)            elif button == pyglet.window.mouse.LEFT and block:                texture = self.model.world[block]                if texture != STONE:                    self.model.remove_block(block)        else:            self.set_exclusive_mouse(True)    def on_mouse_motion(self, x, y, dx, dy):        """ Called when the player moves the mouse.        Parameters        ----------        x, y : int            The coordinates of the mouse click. Always center of the screen if            the mouse is captured.        dx, dy : float            The movement of the mouse.        """        if self.exclusive:            m = 0.15            x, y = self.rotation            x, y = x + dx * m, y + dy * m            y = max(-90, min(90, y))            self.rotation = (x, y)    def on_key_press(self, symbol, modifiers):        """ Called when the player presses a key. See pyglet docs for key        mappings.        Parameters        ----------        symbol : int            Number representing the key that was pressed.        modifiers : int            Number representing any modifying keys that were pressed.        """        if symbol == key.W:            self.strafe[0] -= 1        elif symbol == key.S:            self.strafe[0] += 1        elif symbol == key.A:            self.strafe[1] -= 1        elif symbol == key.D:            self.strafe[1] += 1        elif symbol == key.SPACE:            if self.dy == 0:                self.dy = JUMP_SPEED        elif symbol == key.ESCAPE:            self.set_exclusive_mouse(False)        elif symbol == key.TAB:            self.flying = not self.flying        elif symbol in self.num_keys:            index = (symbol - self.num_keys[0]) % len(self.inventory)            self.block = self.inventory[index]    def on_key_release(self, symbol, modifiers):        """ Called when the player releases a key. See pyglet docs for key        mappings.        Parameters        ----------        symbol : int            Number representing the key that was pressed.        modifiers : int            Number representing any modifying keys that were pressed.        """        if symbol == key.W:            self.strafe[0] += 1        elif symbol == key.S:            self.strafe[0] -= 1        elif symbol == key.A:            self.strafe[1] += 1        elif symbol == key.D:            self.strafe[1] -= 1    def on_resize(self, width, height):        """ Called when the window is resized to a new `width` and `height`.        """        # label        self.label.y = height - 10        # reticle        if self.reticle:            self.reticle.delete()        x, y = self.width // 2, self.height // 2        n = 10        self.reticle = pyglet.graphics.vertex_list(4,            ("v2i", (x - n, y, x + n, y, x, y - n, x, y + n))        )    def set_2d(self):        """ Configure OpenGL to draw in 2d.        """        width, height = self.get_size()        glDisable(GL_DEPTH_TEST)        viewport = self.get_viewport_size()        glViewport(0, 0, max(1, viewport[0]), max(1, viewport[1]))        glMatrixMode(GL_PROJECTION)        glLoadIdentity()        glOrtho(0, max(1, width), 0, max(1, height), -1, 1)        glMatrixMode(GL_MODELVIEW)        glLoadIdentity()    def set_3d(self):        """ Configure OpenGL to draw in 3d.        """        width, height = self.get_size()        glEnable(GL_DEPTH_TEST)        viewport = self.get_viewport_size()        glViewport(0, 0, max(1, viewport[0]), max(1, viewport[1]))        glMatrixMode(GL_PROJECTION)        glLoadIdentity()        gluPerspective(65.0, width / float(height), 0.1, 60.0)        glMatrixMode(GL_MODELVIEW)        glLoadIdentity()        x, y = self.rotation        glRotatef(x, 0, 1, 0)        glRotatef(-y, math.cos(math.radians(x)), 0, math.sin(math.radians(x)))        x, y, z = self.position        glTranslatef(-x, -y, -z)    def on_draw(self):        """ Called by pyglet to draw the canvas.        """        self.clear()        self.set_3d()        glColor3d(1, 1, 1)        self.model.batch.draw()        self.draw_focused_block()        self.set_2d()        self.draw_label()        self.draw_reticle()    def draw_focused_block(self):        """ Draw black edges around the block that is currently under the        crosshairs.        """        vector = self.get_sight_vector()        block = self.model.hit_test(self.position, vector)[0]        if block:            x, y, z = block            vertex_data = cube_vertices(x, y, z, 0.51)            glColor3d(0, 0, 0)            glPolygonMode(GL_FRONT_AND_BACK, GL_LINE)            pyglet.graphics.draw(24, GL_QUADS, ("v3f/static", vertex_data))            glPolygonMode(GL_FRONT_AND_BACK, GL_FILL)    def draw_label(self):        """ Draw the label in the top left of the screen.        """        x, y, z = self.position        self.label.text = "%02d (%.2f, %.2f, %.2f) %d / %d" % (            pyglet.clock.get_fps(), x, y, z,            len(self.model._shown), len(self.model.world))        self.label.draw()    def draw_reticle(self):        """ Draw the crosshairs in the center of the screen.        """        glColor3d(0, 0, 0)        self.reticle.draw(GL_LINES)def setup_fog():    """ Configure the OpenGL fog properties.    """    # Enable fog. Fog "blends a fog color with each rasterized pixel fragment"s    # post-texturing color."    glEnable(GL_FOG)    # Set the fog color.    glFogfv(GL_FOG_COLOR, (GLfloat * 4)(0.5, 0.69, 1.0, 1))    # Say we have no preference between rendering speed and quality.    glHint(GL_FOG_HINT, GL_DONT_CARE)    # Specify the equation used to compute the blending factor.    glFogi(GL_FOG_MODE, GL_LINEAR)    # How close and far away fog starts and ends. The closer the start and end,    # the denser the fog in the fog range.    glFogf(GL_FOG_START, 20.0)    glFogf(GL_FOG_END, 60.0)def setup():    """ Basic OpenGL configuration.    """    # Set the color of "clear", i.e. the sky, in rgba.    glClearColor(0.5, 0.69, 1.0, 1)    # Enable culling (not rendering) of back-facing facets -- facets that aren"t    # visible to you.    glEnable(GL_CULL_FACE)    # Set the texture minification/magnification function to GL_NEAREST (nearest    # in Manhattan distance) to the specified texture coordinates. GL_NEAREST    # "is generally faster than GL_LINEAR, but it can produce textured 圖片    # with sharper edges because the transition between texture elements is not    # as smooth."    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST)    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST)    setup_fog()def main():    window = Window(width=1800, height=1600, caption="Pyglet", resizable=True)    # Hide the mouse cursor and prevent the mouse from leaving the window.    window.set_exclusive_mouse(True)    setup()    pyglet.app.run()if __name__ == "__main__":    main()