def _render_gui()

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

• 86 lines of code
• 22 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("Frozen Lake")
                self.window_surface = pygame.display.set_mode(self.window_size)
            elif mode == "rgb_array":
                self.window_surface = pygame.Surface(self.window_size)

        assert (
            self.window_surface is not None
        ), "Something went wrong with pygame. This should never happen."

        if self.clock is None:
            self.clock = pygame.time.Clock()
        if self.hole_img is None:
            file_name = path.join(path.dirname(__file__), "img/hole.png")
            self.hole_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )
        if self.cracked_hole_img is None:
            file_name = path.join(path.dirname(__file__), "img/cracked_hole.png")
            self.cracked_hole_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )
        if self.ice_img is None:
            file_name = path.join(path.dirname(__file__), "img/ice.png")
            self.ice_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/goal.png")
            self.goal_img = pygame.transform.scale(
                pygame.image.load(file_name), self.cell_size
            )
        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.elf_images is None:
            elfs = [
                path.join(path.dirname(__file__), "img/elf_left.png"),
                path.join(path.dirname(__file__), "img/elf_down.png"),
                path.join(path.dirname(__file__), "img/elf_right.png"),
                path.join(path.dirname(__file__), "img/elf_up.png"),
            ]
            self.elf_images = [
                pygame.transform.scale(pygame.image.load(f_name), self.cell_size)
                for f_name in elfs
            ]

        desc = self.desc.tolist()
        assert isinstance(desc, list), f"desc should be a list or an array, got {desc}"
        for y in range(self.nrow):
            for x in range(self.ncol):
                pos = (x * self.cell_size[0], y * self.cell_size[1])
                rect = (*pos, *self.cell_size)

                self.window_surface.blit(self.ice_img, pos)
                if desc[y][x] == b"H":
                    self.window_surface.blit(self.hole_img, pos)
                elif desc[y][x] == b"G":
                    self.window_surface.blit(self.goal_img, pos)
                elif desc[y][x] == b"S":
                    self.window_surface.blit(self.start_img, pos)

                pygame.draw.rect(self.window_surface, (180, 200, 230), rect, 1)

        # paint the elf
        bot_row, bot_col = self.s // self.ncol, self.s % self.ncol
        cell_rect = (bot_col * self.cell_size[0], bot_row * self.cell_size[1])
        last_action = self.lastaction if self.lastaction is not None else 1
        elf_img = self.elf_images[last_action]

        if desc[bot_row][bot_col] == b"H":
            self.window_surface.blit(self.cracked_hole_img, cell_rect)
        else:
            self.window_surface.blit(elf_img, cell_rect)

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