dcs-retribution/theater/frontline.py
2020-11-12 21:47:13 -06:00

240 lines
8.4 KiB
Python

"""Battlefield front lines."""
from __future__ import annotations
import logging
import json
from dataclasses import dataclass
from pathlib import Path
from itertools import tee
from typing import Tuple, List, Union, Dict, Optional, TYPE_CHECKING
from dcs.mapping import Point
from .controlpoint import ControlPoint, MissionTarget
if TYPE_CHECKING:
from theater.conflicttheater import ConflictTheater
Numeric = Union[int, float]
# TODO: Dedup by moving everything to using this class.
FRONTLINE_MIN_CP_DISTANCE = 5000
def pairwise(iterable):
"""
itertools recipe
s -> (s0,s1), (s1,s2), (s2, s3), ...
"""
a, b = tee(iterable)
next(b, None)
return zip(a, b)
@dataclass
class ComplexFrontLine:
"""
Stores data necessary for building a multi-segment frontline.
"points" should be ordered from closest to farthest distance originating from start_cp.position
"""
start_cp: ControlPoint
points: List[Point]
# control_points: List[ControlPoint]
@dataclass
class FrontLineSegment:
"""
Describes a line segment of a FrontLine
"""
point_a: Point
point_b: Point
@property
def attack_heading(self) -> Numeric:
"""The heading of the frontline segment from player to enemy control point"""
return self.point_a.heading_between_point(self.point_b)
@property
def attack_distance(self) -> Numeric:
"""Length of the segment"""
return self.point_a.distance_to_point(self.point_b)
class FrontLine(MissionTarget):
"""Defines a front line location between two control points.
Front lines are the area where ground combat happens.
Overwrites the entirety of MissionTarget __init__ method to allow for
dynamic position calculation.
"""
theater: ConflictTheater
def __init__(
self,
control_point_a: ControlPoint,
control_point_b: ControlPoint,
) -> None:
self.control_point_a = control_point_a
self.control_point_b = control_point_b
self.segments: List[FrontLineSegment] = []
self._build_segments()
self.name = f"Front line {control_point_a}/{control_point_b}"
@property
def position(self):
return self._calculate_position()
@property
def control_points(self) -> Tuple[ControlPoint, ControlPoint]:
"""Returns a tuple of the two control points."""
return self.control_point_a, self.control_point_b
@property
def middle_point(self):
self.point_from_a(self.attack_distance / 2)
@property
def attack_distance(self):
"""The total distance of all segments"""
return sum(i.attack_distance for i in self.segments)
@property
def attack_heading(self):
"""The heading of the active attack segment from player to enemy control point"""
return self.active_segment.attack_heading
@property
def active_segment(self) -> FrontLineSegment:
"""The FrontLine segment where there can be an active conflict"""
if self._position_distance <= self.segments[0].attack_distance:
return self.segments[0]
remaining_dist = self._position_distance
for segment in self.segments:
if remaining_dist <= segment.attack_distance:
return segment
else:
remaining_dist -= segment.attack_distance
logging.error(
"Frontline attack distance is greater than the sum of its segments"
)
return self.segments[0]
def _calculate_position(self) -> Point:
"""
The position where the conflict should occur
according to the current strength of each control point.
"""
return self.point_from_a(self._position_distance)
def point_from_a(self, distance: Numeric) -> Point:
"""
Returns a point {distance} away from control_point_a along the frontline segments.
"""
if distance < self.segments[0].attack_distance:
return self.control_point_a.position.point_from_heading(
self.segments[0].attack_heading, distance
)
remaining_dist = distance
for segment in self.segments:
if remaining_dist < segment.attack_distance:
return segment.point_a.point_from_heading(
segment.attack_heading, remaining_dist
)
else:
remaining_dist -= segment.attack_distance
@property
def _position_distance(self) -> float:
"""
The distance from point a where the conflict should occur
according to the current strength of each control point
"""
total_strength = (
self.control_point_a.base.strength + self.control_point_b.base.strength
)
if self.control_point_a.base.strength == 0:
return self._adjust_for_min_dist(0)
if self.control_point_b.base.strength == 0:
return self._adjust_for_min_dist(self.attack_distance)
strength_pct = self.control_point_a.base.strength / total_strength
return self._adjust_for_min_dist(strength_pct * self.attack_distance)
def _adjust_for_min_dist(self, distance: Numeric) -> Numeric:
"""
Ensures the frontline conflict is never located within the minimum distance
constant of either end control point.
"""
if (distance > self.attack_distance / 2) and (
distance + FRONTLINE_MIN_CP_DISTANCE > self.attack_distance
):
distance = self.attack_distance - FRONTLINE_MIN_CP_DISTANCE
elif (distance < self.attack_distance / 2) and (
distance < FRONTLINE_MIN_CP_DISTANCE
):
distance = FRONTLINE_MIN_CP_DISTANCE
return distance
def _build_segments(self) -> None:
"""Create line segments for the frontline"""
control_point_ids = "|".join(
[str(self.control_point_a.id), str(self.control_point_b.id)]
) # from_cp.id|to_cp.id
reversed_cp_ids = "|".join(
[str(self.control_point_b.id), str(self.control_point_a.id)]
)
complex_frontlines = self.theater.frontline_data
if (complex_frontlines) and (
(control_point_ids in complex_frontlines)
or (reversed_cp_ids in complex_frontlines)
):
# The frontline segments must be stored in the correct order for the distance algorithms to work.
# The points in the frontline are ordered from the id before the | to the id after.
# First, check if control point id pair matches in order, and create segments if a match is found.
if control_point_ids in complex_frontlines:
point_pairs = pairwise(complex_frontlines[control_point_ids].points)
for i in point_pairs:
self.segments.append(FrontLineSegment(i[0], i[1]))
# Check the reverse order and build in reverse if found.
elif reversed_cp_ids in complex_frontlines:
point_pairs = pairwise(
reversed(complex_frontlines[reversed_cp_ids].points)
)
for i in point_pairs:
self.segments.append(FrontLineSegment(i[0], i[1]))
# If no complex frontline has been configured, fall back to the old straight line method.
else:
self.segments.append(
FrontLineSegment(
self.control_point_a.position, self.control_point_b.position
)
)
@classmethod
def load_json_frontlines(
cls, theater: ConflictTheater
) -> Optional[Dict[str, ComplexFrontLine]]:
"""Load complex frontlines from json and set the theater class variable to current theater instance"""
cls.theater = theater
try:
path = Path(f"resources/frontlines/{theater.terrain.name.lower()}.json")
with open(path, "r") as file:
logging.debug(f"Loading frontline from {path}...")
data = json.load(file)
return {
frontline: ComplexFrontLine(
data[frontline]["start_cp"],
[Point(i[0], i[1]) for i in data[frontline]["points"]],
)
for frontline in data
}
except OSError:
logging.warning(
f"Unable to load preset frontlines for {theater.terrain.name}"
)
return None