Store python modules on './bin/modules/' subdirectory. [#37]

4 files changed, 1572 insertions, 0 deletions

diff --git a/bin/modules/__init__.py b/bin/modules/__init__.py
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/bin/modules/__init__.py
diff --git a/bin/modules/handler.py b/bin/modules/handler.py
new file mode 100644
index 0000000..3325391
--- /dev/null
+++ b/bin/modules/handler.py
@@ -0,0 +1,435 @@
+""" SALIS: Viewer/controller for the SALIS simulator.
+
+file: handler.py
+Author: Paul Oliver
+Email: paul.t.oliver.design@gmail.com
+
+This module should be considered the 'controller' part of the Salis simulator.
+It receives and parses all user input via keyboard and console commands. It
+also takes care of genome compilation (via genome files located on the
+'genomes' directory).
+
+An user may open the Salis console by pressing the 'c' key while in a running
+session. A nice quirk is the possibility to run python commands from within the
+Salis console. As an example, to get the memory size, an user could type:
+
+>>> exec output = self.__sim.lib.sal_mem_get_size()
+
+Note that 'output' denotes a storage variable that will get printed on the
+console response. This ability gives an user a whole lot of power, and should
+be used with care.
+"""
+
+import curses
+import os
+import time
+
+
+class Handler:
+	KEY_ESCAPE = 27
+	CYCLE_TIMEOUT = 0.1
+
+	def __init__(self, sim):
+		""" Handler constructor. Simply link this class to the main simulation
+		class and printer class and create symbol dictionary.
+		"""
+		self.__sim = sim
+		self.__printer = sim.printer
+		self.__inst_dict = self.__get_inst_dict()
+		self.__min_commands = [
+			ord("M"),
+			ord(" "),
+			curses.KEY_RESIZE,
+			self.KEY_ESCAPE,
+		]
+		self.console_history = []
+
+		# Set short delay for ESCAPE key (which is used to exit the simulator).
+		os.environ.setdefault("ESCDELAY", "25")
+
+	def process_cmd(self, cmd):
+		""" Process incoming commands from curses. Commands are received via
+		ncurses' getch() function, thus, they must be transformed into their
+		character representations with 'ord()'.
+		"""
+		# If in minimal mode, only listen to a subset of commands.
+		if self.__sim.minimal and cmd not in self.__min_commands:
+			return
+
+		if cmd == self.KEY_ESCAPE:
+			self.__on_quit([None], save=True)
+		elif cmd == ord("M"):
+			self.__printer.screen.clear()
+			self.__sim.minimal = not self.__sim.minimal
+		elif cmd == ord(" "):
+			self.__sim.toggle_state()
+		elif cmd == curses.KEY_LEFT:
+			self.__printer.flip_page(-1)
+		elif cmd == curses.KEY_RIGHT:
+			self.__printer.flip_page(1)
+		elif cmd == curses.KEY_DOWN:
+			self.__printer.scroll_main(-1)
+		elif cmd == curses.KEY_UP:
+			self.__printer.scroll_main(1)
+		elif cmd == curses.KEY_RESIZE:
+			self.__printer.on_resize()
+		elif cmd == ord("X"):
+			self.__printer.toggle_hex()
+		elif cmd == ord("x"):
+			self.__printer.world.zoom_out()
+		elif cmd == ord("z"):
+			self.__printer.world.zoom_in()
+		elif cmd == ord("a"):
+			self.__printer.world.pan_left()
+			self.__printer.proc_scroll_left()
+		elif cmd == ord("d"):
+			self.__printer.world.pan_right()
+			self.__printer.proc_scroll_right()
+		elif cmd == ord("s"):
+			self.__printer.world.pan_down()
+			self.__printer.proc_scroll_down()
+		elif cmd == ord("w"):
+			self.__printer.world.pan_up()
+			self.__printer.proc_scroll_up()
+		elif cmd == ord("S"):
+			self.__printer.world.pan_down(fast=True)
+			self.__printer.proc_scroll_down(fast=True)
+		elif cmd == ord("W"):
+			self.__printer.world.pan_up(fast=True)
+			self.__printer.proc_scroll_up(fast=True)
+		elif cmd == ord("Q"):
+			self.__printer.world.pan_reset()
+			self.__printer.proc_scroll_vertical_reset()
+		elif cmd == ord("A"):
+			self.__printer.world.pan_reset()
+			self.__printer.proc_scroll_horizontal_reset()
+		elif cmd == ord("o"):
+			self.__printer.proc_select_prev()
+		elif cmd == ord("p"):
+			self.__printer.proc_select_next()
+		elif cmd == ord("f"):
+			self.__printer.proc_select_first()
+		elif cmd == ord("l"):
+			self.__printer.proc_select_last()
+		elif cmd == ord("k"):
+			self.__printer.proc_scroll_to_selected()
+		elif cmd == ord("g"):
+			self.__printer.proc_toggle_gene_view()
+		elif cmd == ord("i"):
+			self.__printer.world.toggle_ip_view()
+		elif cmd == ord("\n"):
+			self.__printer.run_cursor()
+		elif cmd == ord("c"):
+			self.__printer.run_console()
+		else:
+			# Check for numeric input. Number keys [1 to 0] cycle the
+			# simulation [2 ** ((n - 1) % 10] times.
+			try:
+				if chr(cmd).isdigit():
+					factor = int(chr(cmd))
+					factor = int(2 ** ((factor - 1) % 10))
+					self.__cycle_sim(factor)
+			except ValueError:
+				pass
+
+	def handle_console(self, command_raw):
+		""" Process console commands. We parse and check for input errors. Any
+		python exception messages are redirected to the console-response
+		window.
+		"""
+		if command_raw:
+			command = command_raw.split()
+
+			try:
+				# Handle both python and self-thrown exceptions.
+				if command[0] in ["q", "quit"]:
+					self.__on_quit(command, save=True)
+				elif command[0] in ["q!", "quit!"]:
+					self.__on_quit(command, save=False)
+				elif command[0] in ["i", "input"]:
+					self.__on_input(command)
+				elif command[0] in ["c", "compile"]:
+					self.__on_compile(command)
+				elif command[0] in ["n", "new"]:
+					self.__on_new(command)
+				elif command[0] in ["k", "kill"]:
+					self.__on_kill(command)
+				elif command[0] in ["e", "exec"]:
+					self.__on_exec(command)
+				elif command[0] in ["s", "scroll"]:
+					self.__on_scroll(command)
+				elif command[0] in ["p", "process"]:
+					self.__on_proc_select(command)
+				elif command[0] in ["r", "rename"]:
+					self.__on_rename(command)
+				elif command[0] in ["save"]:
+					self.__on_save(command)
+				elif command[0] in ["a", "auto"]:
+					self.__on_set_autosave(command)
+				else:
+					# Raise if a non-existing command has been given.
+					self.__raise("Invalid command: '{}'".format(command[0]))
+			except BaseException as exep:
+				# We parse and redirect python exceptions to the error
+				# console-window.
+				message = str(exep).strip()
+				message = message[0].upper() + message[1:]
+				self.__printer.show_console_error(message)
+			finally:
+				# Store command on console history.
+				self.console_history.append(command_raw.strip())
+
+
+	###############################
+	# Private methods
+	###############################
+
+	def __raise(self, message):
+		""" Generic exception thrower. Throws a 'RuntimeError' initialized with
+		the given message.
+		"""
+		raise RuntimeError("ERROR: {}".format(message))
+
+	def __respond(self, message):
+		""" Generic console responder. Throws a 'RuntimeError' initialized with
+		the given message.
+		"""
+		raise RuntimeError(message)
+
+	def __cycle_sim(self, factor):
+		""" Simply cycle Salis 'factor' number of times. Do not cycle for more
+		than a given amount of time.
+		"""
+		time_max = time.time() + self.CYCLE_TIMEOUT
+
+		for _ in range(factor):
+			self.__sim.lib.sal_main_cycle()
+			self.__sim.check_autosave()
+
+			if time.time() > time_max:
+				break
+
+	def __get_inst_dict(self):
+		""" Transform the instruction list of the printer module into a
+		dictionary that's more useful for genome compilation. Instruction
+		symbols are keys, values are the actual byte representation.
+		"""
+		inst_dict = {}
+
+		for i, inst in enumerate(self.__printer.inst_list):
+			inst_dict[inst[1]] = i
+
+		return inst_dict
+
+	def __on_quit(self, command, save):
+		""" Exit simulation. We can choose whether to save the simulation into
+		a save file or not.
+		"""
+		if len(command) > 1:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		if save:
+			self.__sim.lib.sal_main_save(
+				self.__sim.save_file_path.encode("utf-8")
+			)
+
+		self.__sim.exit()
+
+	def __write_genome(self, genome, address_list):
+		""" Write genome stream into a given list of memory addresses. All
+		addresses must be valid or an exception is thrown.
+		"""
+		# All addresses we will write to must be valid.
+		for base_addr in address_list:
+			address = int(base_addr, 0)
+
+			for _ in range(len(genome)):
+				if not self.__sim.lib.sal_mem_is_address_valid(address):
+					self.__raise("Address '{}' is invalid".format(address))
+
+				address += 1
+
+		# All looks well! Let's compile the genome into memory.
+		for base_addr in address_list:
+			address = int(base_addr, 0)
+
+			for symbol in genome:
+				self.__sim.lib.sal_mem_set_inst(
+					address, self.__inst_dict[symbol]
+				)
+				address += 1
+
+	def __on_input(self, command):
+		""" Compile organism from user typed input. Compilation can only occur
+		on valid memory addresses. An exception will be thrown when trying to
+		write into non-valid address or when input stream is invalid.
+		"""
+		if len(command) < 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		# All characters in file must be actual instruction symbols.
+		for character in command[1]:
+			if character not in self.__inst_dict:
+				self.__raise("Invalid symbol '{}' found on stream".format(
+					character
+				))
+
+		# All looks well, Let's write the genome into memory.
+		self.__write_genome(command[1], command[2:])
+
+	def __on_compile(self, command):
+		""" Compile organism from source genome file. Genomes must be placed on
+		the './genomes' directory. Compilation can only occur on valid memory
+		addresses. An exception will be thrown when trying to write into
+		non-valid address or when genome file is invalid.
+		"""
+		if len(command) < 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		# Open genome file for compilation.
+		gen_file = os.path.join(self.__sim.path, "genomes", command[1])
+
+		with open(gen_file, "r") as f:
+			genome = f.read().strip()
+
+		# Entire genome must be written on a single line.
+		if "\n" in genome:
+			self.__raise("Newline detected on '{}'".format(gen_file))
+
+		# All characters in file must be actual instruction symbols.
+		for character in genome:
+			if character not in self.__inst_dict:
+				self.__raise("Invalid symbol '{}' found on '{}'".format(
+					character, gen_file
+				))
+
+		# All looks well, Let's write the genome into memory.
+		self.__write_genome(genome, command[2:])
+
+	def __on_new(self, command):
+		""" Instantiate new organism of given size on given address. These
+		memory areas must be free and valid or an exception is thrown.
+		"""
+		if len(command) < 3:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		# Check that all addresses we will allocate are free and valid.
+		for base_addr in command[2:]:
+			address = int(base_addr, 0)
+
+			for _ in range(int(command[1])):
+				if not self.__sim.lib.sal_mem_is_address_valid(address):
+					self.__raise("Address '{}' is invalid".format(address))
+				elif self.__sim.lib.sal_mem_is_allocated(address):
+					self.__raise("Address '{}' is allocated".format(address))
+
+				address += 1
+
+		# All looks well! Let's instantiate our new organism.
+		for base_addr in command[2:]:
+			address = int(base_addr, 0)
+			size = int(command[1], 0)
+			self.__sim.lib.sal_proc_create(address, size)
+
+	def __on_kill(self, command):
+		""" Kill organism on bottom of reaper queue.
+		"""
+		if len(command) > 1:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		# Call proc kill function only if there's any organisms to kill.
+		if not self.__sim.lib.sal_proc_get_count():
+			self.__raise("No organisms currently alive")
+		else:
+			self.__sim.lib.sal_proc_kill()
+
+	def __on_exec(self, command):
+		""" Allow a user to execute a python command from within the console.
+		Using this is very hack-ish, and not recommended unless you're certain
+		of what you're doing!
+		"""
+		if len(command) < 2:
+			self.__raise(
+				"'{}' must be followed by an executable string".format(
+					command[0]
+				)
+			)
+
+		# User may query any simulation variable or status and the console will
+		# respond. For example, to query memory size or order, type one of the
+		# following:
+		#
+		#     >>> exec output = self.__sim.lib.sal_mem_get_size()
+		#     >>> exec output = self.__sim.lib.sal_mem_get_order()
+		#
+		output = {}
+		exec(" ".join(command[1:]), locals(), output)
+
+		if output:
+			self.__respond("EXEC RESPONDS: {}".format(str(output)))
+
+	def __on_scroll(self, command):
+		""" We can scroll to a specific process (on PROCESS view) or to a
+		specific world address (on WORLD view) via the console.
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		target = int(command[1], 0)
+
+		# If on PROCESS page, scroll to given process.
+		if self.__printer.current_page == "PROCESS":
+			if target < self.__sim.lib.sal_proc_get_capacity():
+				self.__printer.proc_scroll_to(target)
+			else:
+				self.__raise("No process with ID '{}' found".format(target))
+		elif self.__printer.current_page == "WORLD":
+			if self.__sim.lib.sal_mem_is_address_valid(target):
+				self.__printer.world.scroll_to(target)
+			else:
+				self.__raise("Address '{}' is invalid".format(address))
+		else:
+			self.__raise("'{}' must be called on PROCESS or WORLD page".format(
+				command[0])
+			)
+
+	def __on_proc_select(self, command):
+		""" Select a specific process (on PROCESS or WORLD page).
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		target = int(command[1], 0)
+
+		# If on PROCESS page, scroll to given process.
+		if target < self.__sim.lib.sal_proc_get_capacity():
+			self.__printer.proc_select_by_id(target)
+		else:
+			self.__raise("No process with ID '{}' found".format(target))
+
+	def __on_rename(self, command):
+		""" Set a new simulation name. Future auto-saved files will use this
+		name as prefix.
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		self.__sim.rename(command[1])
+
+	def __on_save(self, command):
+		""" Save simulation on its current state.
+		"""
+		if len(command) != 1:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		self.__sim.lib.sal_main_save(self.__sim.save_file_path.encode("utf-8"))
+
+	def __on_set_autosave(self, command):
+		""" Set the simulation's auto save interval. Provide any integer
+		between 0 and (2**32 - 1). If zero is provided, auto saving will be
+		disabled.
+		"""
+		if len(command) != 2:
+			self.__raise("Invalid parameters for '{}'".format(command[0]))
+
+		self.__sim.set_autosave(int(command[1], 0))
diff --git a/bin/modules/printer.py b/bin/modules/printer.py
new file mode 100644
index 0000000..51a5b33
--- /dev/null
+++ b/bin/modules/printer.py
@@ -0,0 +1,858 @@
+""" SALIS: Viewer/controller for the SALIS simulator.
+
+File: printer.py
+Author: Paul Oliver
+Email: paul.t.oliver.design@gmail.com
+
+This module should be considered the 'view' part of the Salis simulator. It
+takes care of displaying the simulator's state in a nicely formatted, intuitive
+format. It makes use of the curses library for terminal handling.
+"""
+
+import curses
+import curses.textpad
+import os
+import time
+
+from collections import OrderedDict
+from ctypes import c_uint8, c_uint32, cast, POINTER
+from modules.handler import Handler
+from modules.world import World
+
+
+class Printer:
+	ESCAPE_KEY = 27
+
+	def __init__(self, sim):
+		""" Printer constructor. It takes care of starting up curses, defining
+		the data pages and setting the printer on its initial state.
+		"""
+		self.__sim = sim
+		self.__color_pair_count = 0
+
+		# Initialize curses screen, instruction and proc-element list before
+		# other private elements that depend on them.
+		self.screen = self.__get_screen()
+		self.inst_list = self.__get_inst_list()
+		self.proc_elements = self.__get_proc_elements()
+
+		# We can now initialize all other privates.
+		self.__main = self.__get_main()
+		self.__pages = self.__get_pages()
+		self.__minimal = self.__get_minimal()
+		self.__main_scroll = 0
+		self.__proc_element_scroll = 0
+		self.__proc_gene_scroll = 0
+		self.__proc_gene_view = False
+		self.__curs_y = 0
+		self.__curs_x = 0
+		self.__print_hex = False
+		self.size = self.screen.getmaxyx()
+		self.current_page = "MEMORY"
+		self.selected_proc = 0
+		self.selected_proc_data = (c_uint32 * len(self.proc_elements))()
+		self.proc_list_scroll = 0
+		self.world = World(self, self.__sim)
+
+	def __del__(self):
+		""" Printer destructor exits curses.
+		"""
+		curses.endwin()
+
+	def get_color_pair(self, fg, bg=-1):
+		""" We use this method to set new color pairs, keeping track of the
+		number of pairs already set. We return the new color pair ID.
+		"""
+		self.__color_pair_count += 1
+		curses.init_pair(self.__color_pair_count, fg, bg)
+		return self.__color_pair_count
+
+	def get_cmd(self):
+		""" This returns the pressed key from the curses handler. It's called
+		during the simulation's main loop. Flushing input is important when in
+		non-blocking mode.
+		"""
+		ch = self.screen.getch()
+		curses.flushinp()
+		return ch
+
+	def set_nodelay(self, nodelay):
+		""" Toggles between blocking and non-blocking mode on curses.
+		"""
+		self.screen.nodelay(nodelay)
+
+	def toggle_hex(self):
+		""" Toggle between decimal or hexadecimal printing of all simulation
+		state elements.
+		"""
+		self.__print_hex = not self.__print_hex
+
+	def on_resize(self):
+		""" Called whenever the terminal window gets resized.
+		"""
+		self.size = self.screen.getmaxyx()
+		self.scroll_main()
+		self.world.zoom_reset()
+
+	def flip_page(self, offset):
+		""" Change data page by given offset (i.e. '1' for next page or '-1'
+		for previous one).
+		"""
+		pidx = list(self.__pages.keys()).index(self.current_page)
+		pidx = (pidx + offset) % len(self.__pages)
+		self.current_page = list(self.__pages.keys())[pidx]
+		self.scroll_main()
+
+	def scroll_main(self, offset=0):
+		""" Scrolling is allowed whenever the current page does not fit inside
+		the terminal window. This method gets called, with no offset, under
+		certain situations, like changing pages, just to make sure the screen
+		gets cleared and at least some of the data is always scrolled into
+		view.
+		"""
+		self.screen.clear()
+		len_main = len(self.__main)
+		len_page = len(self.__pages[self.current_page])
+		max_scroll = (len_main + len_page + 5) - self.size[0]
+		self.__main_scroll += offset
+		self.__main_scroll = max(0, min(self.__main_scroll, max_scroll))
+
+	def proc_scroll_left(self):
+		""" Scroll process data elements or genomes (on PROCESS view) to the
+		left.
+		"""
+		if self.current_page == "PROCESS":
+			if self.__proc_gene_view:
+				self.__proc_gene_scroll -= 1
+				self.__proc_gene_scroll = max(0, self.__proc_gene_scroll)
+			else:
+				self.__proc_element_scroll -= 1
+				self.__proc_element_scroll = max(0, self.__proc_element_scroll)
+
+	def proc_scroll_right(self):
+		""" Scroll process data elements or genomes (on PROCESS view) to the
+		right.
+		"""
+		if self.current_page == "PROCESS":
+			if self.__proc_gene_view:
+				self.__proc_gene_scroll += 1
+			else:
+				self.__proc_element_scroll += 1
+				max_scroll = len(self.proc_elements) - 1
+				self.__proc_element_scroll = min(
+					max_scroll, self.__proc_element_scroll
+				)
+
+	def proc_scroll_down(self, fast=False):
+		""" Scroll process data table (on PROCESS view) up.
+		"""
+		if self.current_page == "PROCESS":
+			if fast:
+				len_page = len(self.__main) + len(self.__pages["PROCESS"]) + 6
+				scroll = max(0, self.size[0] - len_page)
+			else:
+				scroll = 1
+
+			self.proc_list_scroll = max(0, self.proc_list_scroll - scroll)
+
+	def proc_scroll_up(self, fast=False):
+		""" Scroll process data table (on PROCESS view) down.
+		"""
+		if self.current_page == "PROCESS":
+			if fast:
+				len_page = len(self.__main) + len(self.__pages["PROCESS"]) + 6
+				scroll = max(0, self.size[0] - len_page)
+			else:
+				scroll = 1
+
+			self.proc_list_scroll = min(
+				self.__sim.lib.sal_proc_get_capacity() - 1,
+				self.proc_list_scroll + scroll
+			)
+
+	def proc_scroll_to(self, proc_id):
+		""" Scroll process data table (on PROCESS view) to a specific position.
+		"""
+		if self.current_page == "PROCESS":
+			if proc_id < self.__sim.lib.sal_proc_get_capacity():
+				self.proc_list_scroll = proc_id
+			else:
+				raise RuntimeError("Error: scrolling to invalid process")
+
+	def proc_scroll_vertical_reset(self):
+		""" Scroll process data table (on PROCESS view) back to top.
+		"""
+		if self.current_page == "PROCESS":
+			self.proc_list_scroll = 0
+
+	def proc_scroll_horizontal_reset(self):
+		""" Scroll process data or genome table (on PROCESS view) back to the
+		left.
+		"""
+		if self.current_page == "PROCESS":
+			if self.__proc_gene_view:
+				self.__proc_gene_scroll = 0
+			else:
+				self.__proc_element_scroll = 0
+
+	def proc_select_prev(self):
+		""" Select previous process.
+		"""
+		if self.current_page in ["PROCESS", "WORLD"]:
+			self.selected_proc -= 1
+			self.selected_proc %= self.__sim.lib.sal_proc_get_capacity()
+
+	def proc_select_next(self):
+		""" Select next process.
+		"""
+		if self.current_page in ["PROCESS", "WORLD"]:
+			self.selected_proc += 1
+			self.selected_proc %= self.__sim.lib.sal_proc_get_capacity()
+
+	def proc_select_first(self):
+		""" Select first process on reaper queue.
+		"""
+		if self.current_page in ["PROCESS", "WORLD"]:
+			if self.__sim.lib.sal_proc_get_count():
+				self.selected_proc = self.__sim.lib.sal_proc_get_first()
+
+	def proc_select_last(self):
+		""" Select last process on reaper queue.
+		"""
+		if self.current_page in ["PROCESS", "WORLD"]:
+			if self.__sim.lib.sal_proc_get_count():
+				self.selected_proc = self.__sim.lib.sal_proc_get_last()
+
+	def proc_select_by_id(self, proc_id):
+		""" Select process from given ID.
+		"""
+		if proc_id < self.__sim.lib.sal_proc_get_capacity():
+			self.selected_proc = proc_id
+		else:
+			raise RuntimeError("Error: attempting to select non-existing proc")
+
+	def proc_scroll_to_selected(self):
+		""" Scroll WORLD or PROCESS page so that selected process becomes
+		visible.
+		"""
+		if self.current_page == "PROCESS":
+			self.proc_list_scroll = self.selected_proc
+		elif self.current_page == "WORLD":
+			if not self.__sim.lib.sal_proc_is_free(self.selected_proc):
+				index = self.proc_elements.index("mb1a")
+				address = self.selected_proc_data[index]
+				self.world.scroll_to(address)
+
+	def proc_toggle_gene_view(self):
+		""" Toggle between data element or genome view on PROCESS page.
+		"""
+		if self.current_page == "PROCESS":
+			self.__proc_gene_view = not self.__proc_gene_view
+
+	def run_cursor(self):
+		""" We can toggle a visible cursor on WORLD view to aid us in selecting
+		processes.
+		"""
+		if self.current_page == "WORLD" and self.size[1] > World.PADDING:
+			curses.curs_set(True)
+
+			while True:
+				self.__curs_y = max(0, min(self.__curs_y, self.size[0] - 1))
+				self.__curs_x = max(World.PADDING, min(
+					self.__curs_x, self.size[1] - 1
+				))
+				self.screen.move(self.__curs_y, self.__curs_x)
+				cmd = self.screen.getch()
+
+				if cmd in [ord("c"), curses.KEY_RESIZE, self.ESCAPE_KEY]:
+					self.on_resize()
+					break
+				elif cmd == curses.KEY_LEFT:
+					self.__curs_x -= 1
+				elif cmd == curses.KEY_RIGHT:
+					self.__curs_x += 1
+				elif cmd == curses.KEY_DOWN:
+					self.__curs_y += 1
+				elif cmd == curses.KEY_UP:
+					self.__curs_y -= 1
+				elif cmd == ord("\n"):
+					self.__proc_select_by_cursor()
+					break
+
+			curses.curs_set(False)
+
+	def run_console(self):
+		""" Run the Salis console. You can use the console to control all main
+		aspects of the simulation, like compiling genomes into memory, creating
+		or killing organisms, setting auto-save interval, among other stuff.
+		"""
+		# Print a pythonic prompt.
+		self.__print_line(self.size[0] - 1, ">>> ", scroll=False)
+		self.screen.refresh()
+
+		# Create the console child window. We turn it into a Textbox object in
+		# order to allow line-editing and extract output easily.
+		console = curses.newwin(1, self.size[1] - 5, self.size[0] - 1, 5)
+		textbox = curses.textpad.Textbox(console, insert_mode=True)
+		textbox.stripspaces = True
+
+		# Grab a copy of the console history and instantiate a pointer to the
+		# last element.
+		history = self.__sim.handler.console_history + [""]
+		pointer = len(history) - 1
+
+		# Nested method reinserts recorded commands from history into console.
+		def access_history(cmd):
+			nonlocal pointer
+
+			if pointer == len(history) - 1:
+				history[-1] = console.instr().strip()
+
+			if cmd == "up" and pointer != 0:
+				pointer -= 1
+			elif cmd == "down" and pointer < len(history) - 1:
+				pointer += 1
+
+			console.clear()
+			console.addstr(0, 0, history[pointer])
+			console.refresh()
+
+		# Declare custom validator to control special commands.
+		def validator(cmd):
+			EXIT = 7
+
+			if cmd in [curses.KEY_RESIZE, self.ESCAPE_KEY]:
+				console.clear()
+				return EXIT
+			# Provide general code for back-space key, in case it's not
+			# correctly defined.
+			elif cmd in [127, curses.KEY_BACKSPACE]:
+				return curses.KEY_BACKSPACE
+			elif cmd == curses.KEY_UP:
+				access_history("up")
+			elif cmd == curses.KEY_DOWN:
+				access_history("down")
+			else:
+				return cmd
+
+		# Run the Textbox object with our custom validator.
+		curses.curs_set(True)
+		output = textbox.edit(validator)
+		curses.curs_set(False)
+
+		# Finally, extract data from console and send to handler. Respond to
+		# any possible resize event here.
+		self.__sim.handler.handle_console(output)
+		self.screen.clear()
+		self.on_resize()
+
+	def show_console_error(self, message):
+		""" Shows Salis console error messages, if any. These messages might
+		contain actual python exception output.
+		"""
+		self.__print_line(self.size[0] - 1, ">>>", curses.color_pair(
+			self.__pair_error
+		) | curses.A_BOLD)
+		self.screen.refresh()
+
+		# We also use a Textbox object, just so that execution gets halted
+		# until a key gets pressed (even on non-blocking mode).
+		console = curses.newwin(1, self.size[1] - 5, self.size[0] - 1, 5)
+		textbox = curses.textpad.Textbox(console)
+
+		# Curses may raise an exception if printing on the edge of the screen;
+		# we can just ignore it.
+		try:
+			console.addstr(0, 0, message, curses.color_pair(
+				self.__pair_error
+			) | curses.A_BOLD)
+		except curses.error:
+			pass
+
+		# Custom validator simply exits on any key.
+		def validator(cmd):
+			EXIT = 7
+			return EXIT
+
+		textbox.edit(validator)
+		self.screen.clear()
+		self.on_resize()
+
+	def print_page(self):
+		""" Print current page to screen. We use the previously generated
+		'__pages' dictionary to easily associate a label to a Salis function.
+		"""
+		# If in minimal mode, print only minial widget.
+		if self.__sim.minimal:
+			self.__print_minimal()
+			return
+
+		# Update selected proc data if in WORLD view.
+		if self.current_page == "WORLD":
+			self.__sim.lib.sal_proc_get_proc_data(self.selected_proc, cast(
+				self.selected_proc_data, POINTER(c_uint32)
+			))
+
+		# Print MAIN simulation data.
+		self.__print_line(
+			1, "SALIS[{}]".format(self.__sim.args.file), curses.color_pair(
+				self.__pair_header
+			) | curses.A_BOLD
+		)
+		self.__print_widget(2, self.__main)
+
+		# Print data of currently selected page.
+		main_lines = len(self.__main) + 3
+		self.__print_header(main_lines, self.current_page)
+		self.__print_widget(main_lines + 1, self.__pages[self.current_page])
+
+		# Print special widgets (WORLD view and PROCESS list).
+		if self.current_page == "WORLD":
+			self.world.render()
+		elif self.current_page == "PROCESS":
+			self.__print_proc_list()
+
+
+	###############################
+	# Private methods
+	###############################
+
+	def __set_colors(self):
+		""" Define the color pairs for the data printer.
+		"""
+		curses.start_color()
+		curses.use_default_colors()
+		self.__pair_header = self.get_color_pair(curses.COLOR_BLUE)
+		self.__pair_selected = self.get_color_pair(curses.COLOR_YELLOW)
+		self.__pair_error = self.get_color_pair(curses.COLOR_RED)
+
+	def __get_screen(self):
+		""" Prepare and return the main curses window. We also set a shorter
+		delay when responding to a pressed escape key.
+		"""
+		# Set a shorter delay to the ESCAPE key, so that we may use it to exit
+		# Salis.
+		os.environ.setdefault("ESCDELAY", "25")
+
+		# Prepare curses screen.
+		screen = curses.initscr()
+		curses.noecho()
+		curses.cbreak()
+		screen.keypad(True)
+		curses.curs_set(False)
+
+		# We need color support in order to run the printer module.
+		if curses.has_colors():
+			self.__set_colors()
+		else:
+			raise RuntimeError("Error: no color support.")
+
+		return screen
+
+	def __get_inst_list(self):
+		""" Parse instruction set from C header file named 'instset.h'. We're
+		using the keyword 'SALIS_INST' to identify an instruction definition,
+		so be careful not to use this keyword anywhere else on the headers.
+		"""
+		inst_list = []
+		inst_file = os.path.join(self.__sim.path, "../include/instset.h")
+
+		with open(inst_file, "r") as f:
+			lines = f.read().splitlines()
+
+		for line in lines:
+			if line and line.split()[0] == "SALIS_INST":
+				inst_name = line.split()[1][:4]
+				inst_symb = line.split()[3]
+				inst_list.append((inst_name, inst_symb))
+
+		return inst_list
+
+	def __get_proc_elements(self):
+		""" Parse process structure member variables from C header file named
+		'process.h'. We're using the keyword 'SALIS_PROC_ELEMENT' to identify
+		element declarations, so be careful not to use this keyword anywhere
+		else on the headers.
+		"""
+		proc_elem_list = []
+		proc_elem_file = os.path.join(self.__sim.path, "../include/process.h")
+
+		with open(proc_elem_file, "r") as f:
+			lines = f.read().splitlines()
+
+		for line in lines:
+			if line and line.split()[0] == "SALIS_PROC_ELEMENT":
+				proc_elem_name = line.split()[2].split(";")[0]
+
+				if proc_elem_name == "stack[8]":
+					# The stack is a special member variable, an array. We
+					# translate it by returning a list of stack identifiers.
+					proc_elem_list += ["stack[{}]".format(i) for i in range(8)]
+				else:
+					# We can assume all other struct elements are single
+					# variables.
+					proc_elem_list.append(proc_elem_name)
+
+		return proc_elem_list
+
+	def __get_main(self):
+		""" Generate main set of data fields to be printed. We associate, on a
+		list object, a label to each Salis function to be called. The following
+		elements get printed on all pages.
+		"""
+		return [
+			("e", "cycle", self.__sim.lib.sal_main_get_cycle),
+			("e", "epoch", self.__sim.lib.sal_main_get_epoch),
+			("e", "state", lambda: self.__sim.state),
+			("e", "autosave", lambda: self.__sim.autosave),
+		]
+
+	def __get_pages(self):
+		""" Generate data fields to be printed on each page. We associate, on a
+		list object, a label to each Salis function to be called. Each list
+		represents a PAGE. We initialize all pages inside an ordered dictionary
+		object.
+		"""
+		# The following comprehensions build up widgets to help up print sets
+		# of data elements. The use of nested lambdas is needed to receive
+		# updated values.
+		# Instruction counter widget:
+		inst_widget = [("e", inst[0], (lambda j: (
+			lambda: self.__sim.lib.sal_mem_get_inst_count(j)
+		))(i)) for i, inst in enumerate(self.inst_list)]
+
+		# Evolver module state widget:
+		state_widget = [("e", "state[{}]".format(i), (lambda j: (
+			lambda: self.__sim.lib.sal_evo_get_state(j)
+		))(i)) for i in range(4)]
+
+		# Selected process state widget:
+		selected_widget = [("p", element, (lambda j: (
+			lambda: self.selected_proc_data[j]
+		))(i)) for i, element in enumerate(self.proc_elements)]
+
+		# With the help of the widgets above, we can declare the PAGES
+		# dictionary object.
+		return OrderedDict([
+			("MEMORY", [
+				("e", "order", self.__sim.lib.sal_mem_get_order),
+				("e", "size", self.__sim.lib.sal_mem_get_size),
+				("e", "allocated", self.__sim.lib.sal_mem_get_allocated),
+				("s", ""),
+				("h", "INSTRUCTIONS"),
+			] + inst_widget),
+			("EVOLVER", [
+				("e", "last", self.__sim.lib.sal_evo_get_last_changed_address),
+				("e", "calls", self.__sim.lib.sal_evo_get_calls_on_last_cycle),
+			] + state_widget),
+			("PROCESS", [
+				("e", "count", self.__sim.lib.sal_proc_get_count),
+				("e", "capacity", self.__sim.lib.sal_proc_get_capacity),
+				("e", "first", self.__sim.lib.sal_proc_get_first),
+				("e", "last", self.__sim.lib.sal_proc_get_last),
+				("e", "selected", lambda: self.selected_proc),
+			]),
+			("WORLD", [
+				("e", "position", lambda: self.world.pos),
+				("e", "zoom", lambda: self.world.zoom),
+				("e", "selected", lambda: self.selected_proc),
+				("s", ""),
+				("h", "SELECTED PROC"),
+			] + selected_widget),
+		])
+
+	def __print_line(self, ypos, line, attrs=curses.A_NORMAL, scroll=True):
+		""" Print a single line on screen only when it's visible.
+		"""
+		if scroll:
+			ypos -= self.__main_scroll
+
+		if 0 <= ypos < self.size[0]:
+			# Curses raises an exception each time we print on the screen's
+			# edge. We can just catch and ignore it.
+			try:
+				line = line[:self.size[1] - 1]
+				self.screen.addstr(ypos, 1, line, attrs)
+			except curses.error:
+				pass
+
+	def __print_header(self, ypos, line):
+		""" Print a bold header.
+		"""
+		header_attr = curses.A_BOLD | curses.color_pair(self.__pair_header)
+		self.__print_line(ypos, line, header_attr)
+
+	def __print_value(self, ypos, element, value, attr=curses.A_NORMAL):
+		""" Print a label:value pair.
+		"""
+		if type(value) == int:
+			if value == ((2 ** 32) - 1):
+				# In Salis, UINT32_MAX is used to represent NULL. We print NULL
+				# as three dashes.
+				value = "---"
+			elif self.__print_hex:
+				value = hex(value)
+
+		line = "{:<10} : {:>10}".format(element, value)
+		self.__print_line(ypos, line, attr)
+
+	def __print_proc_element(self, ypos, element, value):
+		""" Print elements of currently selected process. We highlight in
+		YELLOW if the selected process is running.
+		"""
+		if self.__sim.lib.sal_proc_is_free(self.selected_proc):
+			attr = curses.A_NORMAL
+		else:
+			attr = curses.color_pair(self.__pair_selected)
+
+		self.__print_value(ypos, element, value, attr)
+
+	def __print_widget(self, ypos, widget):
+		""" Print a widget (data PAGE) on screen.
+		"""
+		for i, element in enumerate(widget):
+			if element[0] == "s":
+				continue
+			elif element[0] == "h":
+				self.__print_header(i + ypos, element[1])
+			elif element[0] == "e":
+				self.__print_value(i + ypos, element[1], element[2]())
+			elif element[0] == "p":
+				self.__print_proc_element(i + ypos, element[1], element[2]())
+
+	def __clear_line(self, ypos):
+		""" Clear the specified line.
+		"""
+		if 0 <= ypos < self.size[0]:
+			self.screen.move(ypos, 0)
+			self.screen.clrtoeol()
+
+	def __print_proc_data_list(self):
+		""" Print list of process data elements in PROCESS page. We can toggle
+		between printing the data elements or the genomes by pressing the 'g'
+		key.
+		"""
+		# First, print the table header, by extracting element names from the
+		# previously generated proc element list.
+		ypos = len(self.__main) + len(self.__pages["PROCESS"]) + 5
+		header = " | ".join(["{:<10}".format("pidx")] + [
+			"{:>10}".format(element)
+			for element in self.proc_elements[self.__proc_element_scroll:]
+		])
+		self.__clear_line(ypos)
+		self.__print_header(ypos, header)
+		ypos += 1
+		proc_id = self.proc_list_scroll
+
+		# Print all proc IDs and elements in decimal or hexadecimal format,
+		# depending on hex-flag being set.
+		if self.__print_hex:
+			data_format = lambda x: hex(x)
+		else:
+			data_format = lambda x: x
+
+		# Lastly, iterate all lines and print as much process data as it fits.
+		# We can scroll the process data table using the 'wasd' keys.
+		while ypos < self.size[0]:
+			self.__clear_line(ypos)
+
+			if proc_id < self.__sim.lib.sal_proc_get_capacity():
+				if proc_id == self.selected_proc:
+					# Always highlight the selected process.
+					attr = curses.color_pair(self.__pair_selected)
+				else:
+					attr = curses.A_NORMAL
+
+				# Retrieve a copy of the selected process state and store it in
+				# a list object.
+				proc_data = (c_uint32 * len(self.proc_elements))()
+				self.__sim.lib.sal_proc_get_proc_data(proc_id, cast(
+					proc_data, POINTER(c_uint32))
+				)
+
+				# Lastly, assemble and print the next table row.
+				row = " | ".join(["{:<10}".format(data_format(proc_id))] + [
+					"{:>10}".format(data_format(element))
+					for element in proc_data[self.__proc_element_scroll:]
+				])
+				self.__print_line(ypos, row, attr)
+
+			proc_id += 1
+			ypos += 1
+
+	def __print_proc_gene_block(
+		self, ypos, gidx, xpos, mbs, mba, ip, sp, pair
+	):
+		""" Print a sub-set of a process genome. Namely, on of its two memory
+		blocks.
+		"""
+		while gidx < mbs and xpos < self.size[1]:
+			gaddr = mba + gidx
+
+			if gaddr == ip:
+				attr = curses.color_pair(self.world.pair_sel_ip)
+			elif gaddr == sp:
+				attr = curses.color_pair(self.world.pair_sel_sp)
+			else:
+				attr = curses.color_pair(pair)
+
+			# Retrieve instruction from memory and transform it to correct
+			# symbol.
+			inst = self.__sim.lib.sal_mem_get_inst(gaddr)
+			symb = self.inst_list[inst][1]
+
+			# Curses raises an exception each time we print on the screen's
+			# edge. We can just catch and ignore it.
+			try:
+				self.screen.addstr(ypos, xpos, symb, attr)
+			except curses.error:
+				pass
+
+			gidx += 1
+			xpos += 1
+
+		return xpos
+
+	def __print_proc_gene(self, ypos, proc_id):
+		""" Print a single process genome on the genome table. We use the same
+		colors to represent memory blocks, IP and SP of each process, as those
+		used to represent the selected process on WORLD view.
+		"""
+		# There's nothing to print if process is free.
+		if self.__sim.lib.sal_proc_is_free(proc_id):
+			return
+
+		# Process is alive. Retrieve a copy of the current process state and
+		# store it in a list object.
+		proc_data = (c_uint32 * len(self.proc_elements))()
+		self.__sim.lib.sal_proc_get_proc_data(proc_id, cast(
+			proc_data, POINTER(c_uint32))
+		)
+
+		# Let's extract all data of interest.
+		mb1a = proc_data[self.proc_elements.index("mb1a")]
+		mb1s = proc_data[self.proc_elements.index("mb1s")]
+		mb2a = proc_data[self.proc_elements.index("mb2a")]
+		mb2s = proc_data[self.proc_elements.index("mb2s")]
+		ip = proc_data[self.proc_elements.index("ip")]
+		sp = proc_data[self.proc_elements.index("sp")]
+
+		# Always print MAIN memory block (mb1) first (on the left side). That
+		# way we can keep most of our attention on the parent.
+		xpos = self.__print_proc_gene_block(
+			ypos, self.__proc_gene_scroll, 14, mb1s, mb1a, ip, sp,
+			self.world.pair_sel_mb1
+		)
+
+		# Reset gene counter and print child memory block, if it exists.
+		if mb1s < self.__proc_gene_scroll:
+			gidx = self.__proc_gene_scroll - mb1s
+		else:
+			gidx = 0
+
+		self.__print_proc_gene_block(
+			ypos, gidx, xpos, mb2s, mb2a, ip, sp, self.world.pair_sel_mb2
+		)
+
+	def __print_proc_gene_list(self):
+		""" Print list of process genomes in PROCESS page. We can toggle
+		between printing the genomes or the data elements by pressing the 'g'
+		key.
+		"""
+		# Print all proc IDs and gene scroll in decimal or hexadecimal format,
+		# depending on hex-flag being set.
+		if self.__print_hex:
+			data_format = lambda x: hex(x)
+		else:
+			data_format = lambda x: x
+
+		# First, print the table header. We print the current gene-scroll
+		# position for easy reference. Return back to zero scroll with the 'A'
+		# key.
+		ypos = len(self.__main) + len(self.__pages["PROCESS"]) + 5
+		header = "{:<10} | genes {} -->".format(
+			"pidx", data_format(self.__proc_gene_scroll)
+		)
+		self.__clear_line(ypos)
+		self.__print_header(ypos, header)
+		ypos += 1
+		proc_id = self.proc_list_scroll
+
+		# Iterate all lines and print as much genetic data as it fits. We can
+		# scroll the gene data table using the 'wasd' keys.
+		while ypos < self.size[0]:
+			self.__clear_line(ypos)
+
+			if proc_id < self.__sim.lib.sal_proc_get_capacity():
+				if proc_id == self.selected_proc:
+					# Always highlight the selected process.
+					attr = curses.color_pair(self.__pair_selected)
+				else:
+					attr = curses.A_NORMAL
+
+				# Assemble and print the next table row.
+				row = "{:<10} |".format(data_format(proc_id))
+				self.__print_line(ypos, row, attr)
+				self.__print_proc_gene(ypos, proc_id)
+
+			proc_id += 1
+			ypos += 1
+
+	def __print_proc_list(self):
+		""" Print list of process genomes or process data elements in PROCESS
+		page. We can toggle between printing the genomes or the data elements
+		by pressing the 'g' key.
+		"""
+		if self.__proc_gene_view:
+			self.__print_proc_gene_list()
+		else:
+			self.__print_proc_data_list()
+
+	def __proc_select_by_cursor(self):
+		""" Select process located on address under cursor, if any exists.
+		"""
+		# First, calculate address under cursor.
+		ypos = self.__curs_y
+		xpos = self.__curs_x - World.PADDING
+		line_size = self.size[1] - World.PADDING
+		address = self.world.pos + (
+			((ypos * line_size) + xpos) * self.world.zoom
+		)
+
+		# Now, iterate all living processes and try to find one that owns the
+		# calculated address.
+		if self.__sim.lib.sal_mem_is_address_valid(address):
+			for proc_id in range(self.__sim.lib.sal_proc_get_capacity()):
+				if not self.__sim.lib.sal_proc_is_free(proc_id):
+					proc_data = (c_uint32 * len(self.proc_elements))()
+					self.__sim.lib.sal_proc_get_proc_data(proc_id, cast(
+						proc_data, POINTER(c_uint32))
+					)
+					mb1a = proc_data[self.proc_elements.index("mb1a")]
+					mb1s = proc_data[self.proc_elements.index("mb1s")]
+					mb2a = proc_data[self.proc_elements.index("mb2a")]
+					mb2s = proc_data[self.proc_elements.index("mb2s")]
+
+					if (
+						mb1a <= address < (mb1a + mb1s) or
+						mb2a <= address < (mb2a + mb2s)
+					):
+						self.selected_proc = proc_id
+						break
+
+	def __get_minimal(self):
+		""" Generate set of data fields to be printed on minimal mode.
+		"""
+		return [
+			("cycle", self.__sim.lib.sal_main_get_cycle),
+			("epoch", self.__sim.lib.sal_main_get_epoch),
+			("procs", self.__sim.lib.sal_proc_get_count),
+		]
+
+	def __print_minimal(self):
+		""" Print minimal mode data fields.
+		"""
+		self.__print_line(1, "Salis --- Minimal mode")
+
+		for i, field in enumerate(self.__minimal):
+			self.__print_line(i + 2, "{}: {}".format(field[0], field[1]()))
diff --git a/bin/modules/world.py b/bin/modules/world.py
new file mode 100644
index 0000000..08f2734
--- /dev/null
+++ b/bin/modules/world.py
@@ -0,0 +1,279 @@
+""" SALIS: Viewer/controller for the SALIS simulator.
+
+File: world.py
+Author: Paul Oliver
+Email: paul.t.oliver.design@gmail.com
+
+This module should be considered an extension of the 'printer' module. It takes
+care of getting a pre-redered image from Salis and post-processing it in order
+to print it into the curses screen. It also keeps track of user controllable
+rendering parameters (position and zoom).
+"""
+
+import curses
+
+from ctypes import c_uint8, cast, POINTER
+
+
+class World:
+	PADDING = 25
+
+	def __init__(self, printer, sim):
+		""" World constructor. We link to the printer and main simulation
+		classes. We also setup the colors for rendering the world.
+		"""
+		self.__printer = printer
+		self.__sim = sim
+		self.__set_world_colors()
+		self.__show_ip = True
+		self.pos = 0
+		self.zoom = 1
+
+	def render(self):
+		""" Function for rendering the world. We get a pre-rendered buffer from
+		Salis' memory module (its way faster to pre-render in C) and use that
+		to assemble the world image in Python.
+		"""
+		# Window is so narrow that world is not visible.
+		if self.__printer.size[1] <= self.PADDING:
+			return
+
+		# Get pre-rendered image from Salis' memory module.
+		line_width = self.__printer.size[1] - self.PADDING
+		print_area = self.__printer.size[0] * line_width
+		c_buffer = (c_uint8 * print_area)()
+		self.__sim.lib.sal_ren_get_image(
+			self.pos, self.zoom, print_area, cast(c_buffer, POINTER(c_uint8))
+		)
+
+		# Get data elements of selected process, if it's running, and store
+		# them into a convenient dict object.
+		if self.__sim.lib.sal_proc_is_free(self.__printer.selected_proc):
+			sel_data = None
+		else:
+			out_data = self.__printer.selected_proc_data
+			out_elem = self.__printer.proc_elements
+			sel_data = {
+				"ip": out_data[out_elem.index("ip")],
+				"sp": out_data[out_elem.index("sp")],
+				"mb1a": out_data[out_elem.index("mb1a")],
+				"mb1s": out_data[out_elem.index("mb1s")],
+				"mb2a": out_data[out_elem.index("mb2a")],
+				"mb2s": out_data[out_elem.index("mb2s")],
+			}
+
+		# Iterate all cells on printable area and print the post-rendered
+		# cells. Rendered cells contain info about bit flags and instructions
+		# currently written into memory.
+		bidx = 0
+
+		for y in range(self.__printer.size[0]):
+			for x in range(line_width):
+				xpad = x + self.PADDING
+				addr = self.pos + (self.zoom * bidx)
+				symb, attr = self.__render_cell(c_buffer[bidx], addr, sel_data)
+
+				# Curses raises an exception when printing on the edge of the
+				# screen; we can just ignore it.
+				try:
+					self.__printer.screen.addstr(y, xpad, symb, attr)
+				except curses.error:
+					pass
+
+				bidx += 1
+
+	def zoom_out(self):
+		""" Zoom out by a factor of 2 (zoom *= 2).
+		"""
+		if self.__is_world_editable():
+			self.zoom = min(self.zoom * 2, self.__get_max_zoom())
+
+	def zoom_in(self):
+		""" Zoom in by a factor of 2 (zoom //= 2).
+		"""
+		if self.__is_world_editable():
+			self.zoom = max(self.zoom // 2, 1)
+
+	def zoom_reset(self):
+		""" Reset zoom to a valid value on certain events (i.e. during terminal
+		resizing).
+		"""
+		self.zoom = min(self.zoom, self.__get_max_zoom())
+
+	def pan_left(self):
+		""" Pan world to the left (pos -= zoom).
+		"""
+		if self.__is_world_editable():
+			self.pos = max(self.pos - self.zoom, 0)
+
+	def pan_right(self):
+		""" Pan world to the right (pos += zoom).
+		"""
+		if self.__is_world_editable():
+			max_pos = self.__sim.lib.sal_mem_get_size() - 1
+			self.pos = min(self.pos + self.zoom, max_pos)
+
+	def pan_down(self, fast=False):
+		""" Pan world downward.
+		"""
+		if self.__is_world_editable():
+			if fast:
+				self.pos = max(self.pos - self.__get_world_area(), 0)
+			else:
+				self.pos = max(self.pos - self.__get_line_area(), 0)
+
+	def pan_up(self, fast=False):
+		""" Pan world upward.
+		"""
+		if self.__is_world_editable():
+			max_pos = self.__sim.lib.sal_mem_get_size() - 1
+
+			if fast:
+				self.pos = min(self.pos + self.__get_world_area(), max_pos)
+			else:
+				self.pos = min(self.pos + self.__get_line_area(), max_pos)
+
+	def pan_reset(self):
+		""" Set world position to zero.
+		"""
+		if self.__is_world_editable():
+			self.pos = 0
+
+	def scroll_to(self, pos):
+		""" Move world pos to a specified position.
+		"""
+		if self.__is_world_editable():
+			if self.__sim.lib.sal_mem_is_address_valid(pos):
+				self.pos = pos
+			else:
+				raise RuntimeError("Error: scrolling to an invalid address")
+
+	def toggle_ip_view(self):
+		""" Turn on/off IP visualization. Turning off IPs might make it easier
+		to visualize the underlying memory block structure.
+		"""
+		if self.__is_world_editable():
+			self.__show_ip = not self.__show_ip
+
+
+	###############################
+	# Private methods
+	###############################
+
+	def __set_world_colors(self):
+		""" Define color pairs for rendering the world. Each color has a
+		special meaning, referring to the selected process IP, SP and memory
+		blocks, or to bit flags currently set on rendered cells.
+		"""
+		self.pair_free = self.__printer.get_color_pair(
+			curses.COLOR_BLUE
+		)
+		self.pair_alloc = self.__printer.get_color_pair(
+			curses.COLOR_BLACK, curses.COLOR_BLUE
+		)
+		self.pair_mbstart = self.__printer.get_color_pair(
+			curses.COLOR_BLACK, curses.COLOR_CYAN
+		)
+		self.pair_ip = self.__printer.get_color_pair(
+			curses.COLOR_BLACK, curses.COLOR_WHITE
+		)
+		self.pair_sel_mb2 = self.__printer.get_color_pair(
+			curses.COLOR_BLACK, curses.COLOR_GREEN
+		)
+		self.pair_sel_mb1 = self.__printer.get_color_pair(
+			curses.COLOR_BLACK, curses.COLOR_YELLOW
+		)
+		self.pair_sel_sp = self.__printer.get_color_pair(
+			 curses.COLOR_BLACK, curses.COLOR_MAGENTA
+		)
+		self.pair_sel_ip = self.__printer.get_color_pair(
+			 curses.COLOR_BLACK, curses.COLOR_RED
+		)
+
+	def __render_cell(self, byte, addr, sel_data=None):
+		""" Render a single cell on the WORLD view. All cells are rendered by
+		interpreting the values coming in from the buffer. We overlay special
+		colors for representing the selected organism's state, on top of the
+		more common colors used to represent memory state.
+		"""
+		# Paint black all cells that are out of memory bounds.
+		if not self.__sim.lib.sal_mem_is_address_valid(addr):
+			return " ", curses.A_NORMAL
+
+		# Check if cell contains part of the currently selected process.
+		if sel_data:
+			top_addr = addr + self.zoom
+			top_mb1a = sel_data["mb1a"] + sel_data["mb1s"]
+			top_mb2a = sel_data["mb2a"] + sel_data["mb2s"]
+
+			if addr <= sel_data["ip"] < top_addr:
+				pair = self.pair_sel_ip
+			elif addr <= sel_data["sp"] < top_addr:
+				pair = self.pair_sel_sp
+			elif top_addr > sel_data["mb1a"] and top_mb1a > addr:
+				pair = self.pair_sel_mb1
+			elif top_addr > sel_data["mb2a"] and top_mb2a > addr:
+				pair = self.pair_sel_mb2
+
+		# No pair has been selected yet; select pair based on bit-flags.
+		if not "pair" in locals():
+			if self.__show_ip and byte >= 0x80:
+				pair = self.pair_ip
+			elif (byte % 0x80) >= 0x40:
+				pair = self.pair_mbstart
+			elif (byte % 0x40) >= 0x20:
+				pair = self.pair_alloc
+			else:
+				pair = self.pair_free
+
+		# Select symbol to represent instructions currently on cell.
+		inst = byte % 32
+
+		if self.zoom == 1:
+			symb = self.__printer.inst_list[inst][1]
+		elif inst > 16:
+			symb = ":"
+		else:
+			symb = "."
+
+		# Return tuple containing our post-redered cell.
+		return symb, curses.color_pair(pair)
+
+	def __get_max_zoom(self):
+		""" Calculate maximum needed zoom so that the entire world fits on the
+		terminal window.
+		"""
+		max_zoom = 1
+		line_size = self.__printer.size[1] - self.PADDING
+		coverage = self.__printer.size[0] * line_size
+
+		# We fix a maximum zoom level; otherwise, program may halt on extreme
+		# zoom levels.
+		while (
+			(coverage * max_zoom) < self.__sim.lib.sal_mem_get_size() and
+			max_zoom < 2 ** 16
+		):
+			max_zoom *= 2
+
+		return max_zoom
+
+	def __is_world_editable(self):
+		""" For this to return True, printer's current page must be WORLD page.
+		Additionally, the WORLD panel must be visible on the terminal window
+		(i.e. curses.COLS > data_margin).
+		"""
+		correct_page = self.__printer.current_page == "WORLD"
+		correct_size = self.__printer.size[1] > self.PADDING
+		return correct_page and correct_size
+
+	def __get_line_area(self):
+		""" Return amount of bytes contained in a printed WORLD line.
+		"""
+		line_size = self.__printer.size[1] - self.PADDING
+		line_area = self.zoom * line_size
+		return line_area
+
+	def __get_world_area(self):
+		""" Return amount of bytes contained in the entire WORLD view.
+		"""
+		return self.__get_line_area() * self.__printer.size[0]