def _render_gui()

in gym/envs/toy_text/cliffwalking.py [0:0]

• 86 lines of code
• 23 McCabe index (conditional complexity)

    def _render_gui(self, mode):
        try:
            import pygame
        except ImportError:
            raise DependencyNotInstalled(
                "pygame is not installed, run `pip install gym[toy_text]`"
            )
        if self.window_surface is None:
            pygame.init()

            if mode == "human":
                pygame.display.init()
                pygame.display.set_caption("CliffWalking")
                self.window_surface = pygame.display.set_mode(self.window_size)
            else:  # rgb_array
                self.window_surface = pygame.Surface(self.window_size)
        if self.clock is None:
            self.clock = pygame.time.Clock()
        if self.elf_images is None:
            hikers = [
                path.join(path.dirname(__file__), "img/elf_up.png"),
                path.join(path.dirname(__file__), "img/elf_right.png"),
                path.join(path.dirname(__file__), "img/elf_down.png"),
                path.join(path.dirname(__file__), "img/elf_left.png"),
            ]
            self.elf_images = [
                pygame.transform.scale(pygame.image.load(f_name), self.cell_size)
                for f_name in hikers
            ]
        if self.start_img is None:
            file_name = path.join(path.dirname(__file__), "img/stool.png")
            self.start_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )
        if self.goal_img is None:
            file_name = path.join(path.dirname(__file__), "img/cookie.png")
            self.goal_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )
        if self.mountain_bg_img is None:
            bg_imgs = [
                path.join(path.dirname(__file__), "img/mountain_bg1.png"),
                path.join(path.dirname(__file__), "img/mountain_bg2.png"),
            ]
            self.mountain_bg_img = [
                pygame.transform.scale(pygame.image.load(f_name), self.cell_size)
                for f_name in bg_imgs
            ]
        if self.near_cliff_img is None:
            near_cliff_imgs = [
                path.join(path.dirname(__file__), "img/mountain_near-cliff1.png"),
                path.join(path.dirname(__file__), "img/mountain_near-cliff2.png"),
            ]
            self.near_cliff_img = [
                pygame.transform.scale(pygame.image.load(f_name), self.cell_size)
                for f_name in near_cliff_imgs
            ]
        if self.cliff_img is None:
            file_name = path.join(path.dirname(__file__), "img/mountain_cliff.png")
            self.cliff_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )

        for s in range(self.nS):
            row, col = np.unravel_index(s, self.shape)
            pos = (col * self.cell_size[0], row * self.cell_size[1])
            check_board_mask = row % 2 ^ col % 2
            self.window_surface.blit(self.mountain_bg_img[check_board_mask], pos)

            if self._cliff[row, col]:
                self.window_surface.blit(self.cliff_img, pos)
            if row < self.shape[0] - 1 and self._cliff[row + 1, col]:
                self.window_surface.blit(self.near_cliff_img[check_board_mask], pos)
            if s == self.start_state_index:
                self.window_surface.blit(self.start_img, pos)
            if s == self.nS - 1:
                self.window_surface.blit(self.goal_img, pos)
            if s == self.s:
                elf_pos = (pos[0], pos[1] - 0.1 * self.cell_size[1])
                last_action = self.lastaction if self.lastaction is not None else 2
                self.window_surface.blit(self.elf_images[last_action], elf_pos)

        if mode == "human":
            pygame.event.pump()
            pygame.display.update()
            self.clock.tick(self.metadata["render_fps"])
        else:  # rgb_array
            return np.transpose(
                np.array(pygame.surfarray.pixels3d(self.window_surface)), axes=(1, 0, 2)
            )