abian/0ad
1
0
Fork 0
forked from 0ad/0ad
Code Pull Requests Activity
f82fc6431b
0ad/source/simulation2/helpers/VertexPathfinder.cpp
wraitii f1467d10fd Make pathfinder debug rendering thread-safe. 
Also cleans up the jump point cache const-correctness.

Differential Revision: https://code.wildfiregames.com/D3966
This was SVN commit r25452.
2021-05-17 09:38:24 +00:00

1011 lines
34 KiB
C++
Raw Blame History

/* Copyright (C) 2021 Wildfire Games.
* This file is part of 0 A.D.
*
* 0 A.D. is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* 0 A.D. is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with 0 A.D. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file
* Vertex-based algorithm for CCmpPathfinder.
* Computes paths around the corners of rectangular obstructions.
*
* Useful search term for this algorithm: "points of visibility".
*
* Since we sometimes want to use this for avoiding moving units, there is no
* pre-computation - the whole visibility graph is effectively regenerated for
* each path, and it does A* over that graph.
*
* This scales very poorly in the number of obstructions, so it should be used
* with a limited range and not exceedingly frequently.
*/
#include "precompiled.h"
#include "VertexPathfinder.h"
#include "lib/timer.h"
#include "ps/Profile.h"
#include "renderer/Scene.h"
#include "simulation2/components/ICmpObstructionManager.h"
#include "simulation2/helpers/Grid.h"
#include "simulation2/helpers/PriorityQueue.h"
#include "simulation2/helpers/Render.h"
#include "simulation2/system/SimContext.h"
#include <mutex>
namespace
{
static std::mutex g_DebugMutex;
}
VertexPathfinderDebugOverlay g_VertexPathfinderDebugOverlay;
/* Quadrant optimisation:
* (loosely based on GPG2 "Optimizing Points-of-Visibility Pathfinding")
*
* Consider the vertex ("@") at a corner of an axis-aligned rectangle ("#"):
*
* TL : TR
* :
* ####@ - - -
* #####
* #####
* BL ## BR
*
* The area around the vertex is split into TopLeft, BottomRight etc quadrants.
*
* If the shortest path reaches this vertex, it cannot continue to a vertex in
* the BL quadrant (it would be blocked by the shape).
* Since the shortest path is wrapped tightly around the edges of obstacles,
* if the path approached this vertex from the TL quadrant,
* it cannot continue to the TL or TR quadrants (the path could be shorter if it
* skipped this vertex).
* Therefore it must continue to a vertex in the BR quadrant (so this vertex is in
* *that* vertex's TL quadrant).
*
* That lets us significantly reduce the search space by quickly discarding vertexes
* from the wrong quadrants.
*
* (This causes badness if the path starts from inside the shape, so we add some hacks
* for that case.)
*
* (For non-axis-aligned rectangles it's harder to do this computation, so we'll
* not bother doing any discarding for those.)
*/
static const u8 QUADRANT_NONE = 0;
static const u8 QUADRANT_BL = 1;
static const u8 QUADRANT_TR = 2;
static const u8 QUADRANT_TL = 4;
static const u8 QUADRANT_BR = 8;
static const u8 QUADRANT_BLTR = QUADRANT_BL|QUADRANT_TR;
static const u8 QUADRANT_TLBR = QUADRANT_TL|QUADRANT_BR;
static const u8 QUADRANT_ALL = QUADRANT_BLTR|QUADRANT_TLBR;
// When computing vertexes to insert into the search graph,
// add a small delta so that the vertexes of an edge don't get interpreted
// as crossing the edge (given minor numerical inaccuracies)
static const entity_pos_t EDGE_EXPAND_DELTA = entity_pos_t::FromInt(1)/16;
/**
* Check whether a ray from 'a' to 'b' crosses any of the edges.
* (Edges are one-sided so it's only considered a cross if going from front to back.)
*/
inline static bool CheckVisibility(const CFixedVector2D& a, const CFixedVector2D& b, const std::vector<Edge>& edges)
{
CFixedVector2D abn = (b - a).Perpendicular();
// Edges of general non-axis-aligned shapes
for (size_t i = 0; i < edges.size(); ++i)
{
CFixedVector2D p0 = edges[i].p0;
CFixedVector2D p1 = edges[i].p1;
CFixedVector2D d = (p1 - p0).Perpendicular();
// If 'a' is behind the edge, we can't cross
fixed q = (a - p0).Dot(d);
if (q < fixed::Zero())
continue;
// If 'b' is in front of the edge, we can't cross
fixed r = (b - p0).Dot(d);
if (r > fixed::Zero())
continue;
// The ray is crossing the infinitely-extended edge from in front to behind.
// Check the finite edge is crossing the infinitely-extended ray too.
// (Given the previous tests, it can only be crossing in one direction.)
fixed s = (p0 - a).Dot(abn);
if (s > fixed::Zero())
continue;
fixed t = (p1 - a).Dot(abn);
if (t < fixed::Zero())
continue;
return false;
}
return true;
}
// Handle the axis-aligned shape edges separately (for performance):
// (These are specialised versions of the general unaligned edge code.
// They assume the caller has already excluded edges for which 'a' is
// on the wrong side.)
inline static bool CheckVisibilityLeft(const CFixedVector2D& a, const CFixedVector2D& b, const std::vector<EdgeAA>& edges)
{
if (a.X >= b.X)
return true;
CFixedVector2D abn = (b - a).Perpendicular();
for (size_t i = 0; i < edges.size(); ++i)
{
if (b.X < edges[i].p0.X)
continue;
CFixedVector2D p0 (edges[i].p0.X, edges[i].c1);
fixed s = (p0 - a).Dot(abn);
if (s > fixed::Zero())
continue;
CFixedVector2D p1 (edges[i].p0.X, edges[i].p0.Y);
fixed t = (p1 - a).Dot(abn);
if (t < fixed::Zero())
continue;
return false;
}
return true;
}
inline static bool CheckVisibilityRight(const CFixedVector2D& a, const CFixedVector2D& b, const std::vector<EdgeAA>& edges)
{
if (a.X <= b.X)
return true;
CFixedVector2D abn = (b - a).Perpendicular();
for (size_t i = 0; i < edges.size(); ++i)
{
if (b.X > edges[i].p0.X)
continue;
CFixedVector2D p0 (edges[i].p0.X, edges[i].c1);
fixed s = (p0 - a).Dot(abn);
if (s > fixed::Zero())
continue;
CFixedVector2D p1 (edges[i].p0.X, edges[i].p0.Y);
fixed t = (p1 - a).Dot(abn);
if (t < fixed::Zero())
continue;
return false;
}
return true;
}
inline static bool CheckVisibilityBottom(const CFixedVector2D& a, const CFixedVector2D& b, const std::vector<EdgeAA>& edges)
{
if (a.Y >= b.Y)
return true;
CFixedVector2D abn = (b - a).Perpendicular();
for (size_t i = 0; i < edges.size(); ++i)
{
if (b.Y < edges[i].p0.Y)
continue;
CFixedVector2D p0 (edges[i].p0.X, edges[i].p0.Y);
fixed s = (p0 - a).Dot(abn);
if (s > fixed::Zero())
continue;
CFixedVector2D p1 (edges[i].c1, edges[i].p0.Y);
fixed t = (p1 - a).Dot(abn);
if (t < fixed::Zero())
continue;
return false;
}
return true;
}
inline static bool CheckVisibilityTop(const CFixedVector2D& a, const CFixedVector2D& b, const std::vector<EdgeAA>& edges)
{
if (a.Y <= b.Y)
return true;
CFixedVector2D abn = (b - a).Perpendicular();
for (size_t i = 0; i < edges.size(); ++i)
{
if (b.Y > edges[i].p0.Y)
continue;
CFixedVector2D p0 (edges[i].p0.X, edges[i].p0.Y);
fixed s = (p0 - a).Dot(abn);
if (s > fixed::Zero())
continue;
CFixedVector2D p1 (edges[i].c1, edges[i].p0.Y);
fixed t = (p1 - a).Dot(abn);
if (t < fixed::Zero())
continue;
return false;
}
return true;
}
typedef PriorityQueueHeap<u16, fixed, fixed> VertexPriorityQueue;
/**
* Add edges and vertexes to represent the boundaries between passable and impassable
* navcells (for impassable terrain).
* Navcells i0 <= i <= i1, j0 <= j <= j1 will be considered.
*/
static void AddTerrainEdges(std::vector<Edge>& edges, std::vector<Vertex>& vertexes,
int i0, int j0, int i1, int j1,
pass_class_t passClass, const Grid<NavcellData>& grid)
{
// Clamp the coordinates so we won't attempt to sample outside of the grid.
// (This assumes the outermost ring of navcells (which are always impassable)
// won't have a boundary with any passable navcells. TODO: is that definitely
// safe enough?)
i0 = Clamp(i0, 1, grid.m_W-2);
j0 = Clamp(j0, 1, grid.m_H-2);
i1 = Clamp(i1, 1, grid.m_W-2);
j1 = Clamp(j1, 1, grid.m_H-2);
for (int j = j0; j <= j1; ++j)
{
for (int i = i0; i <= i1; ++i)
{
if (IS_PASSABLE(grid.get(i, j), passClass))
continue;
if (IS_PASSABLE(grid.get(i+1, j), passClass) && IS_PASSABLE(grid.get(i, j+1), passClass) && IS_PASSABLE(grid.get(i+1, j+1), passClass))
{
Vertex vert;
vert.status = Vertex::UNEXPLORED;
vert.quadOutward = QUADRANT_ALL;
vert.quadInward = QUADRANT_BL;
vert.p = CFixedVector2D(fixed::FromInt(i+1)+EDGE_EXPAND_DELTA, fixed::FromInt(j+1)+EDGE_EXPAND_DELTA).Multiply(Pathfinding::NAVCELL_SIZE);
vertexes.push_back(vert);
}
if (IS_PASSABLE(grid.get(i-1, j), passClass) && IS_PASSABLE(grid.get(i, j+1), passClass) && IS_PASSABLE(grid.get(i-1, j+1), passClass))
{
Vertex vert;
vert.status = Vertex::UNEXPLORED;
vert.quadOutward = QUADRANT_ALL;
vert.quadInward = QUADRANT_BR;
vert.p = CFixedVector2D(fixed::FromInt(i)-EDGE_EXPAND_DELTA, fixed::FromInt(j+1)+EDGE_EXPAND_DELTA).Multiply(Pathfinding::NAVCELL_SIZE);
vertexes.push_back(vert);
}
if (IS_PASSABLE(grid.get(i+1, j), passClass) && IS_PASSABLE(grid.get(i, j-1), passClass) && IS_PASSABLE(grid.get(i+1, j-1), passClass))
{
Vertex vert;
vert.status = Vertex::UNEXPLORED;
vert.quadOutward = QUADRANT_ALL;
vert.quadInward = QUADRANT_TL;
vert.p = CFixedVector2D(fixed::FromInt(i+1)+EDGE_EXPAND_DELTA, fixed::FromInt(j)-EDGE_EXPAND_DELTA).Multiply(Pathfinding::NAVCELL_SIZE);
vertexes.push_back(vert);
}
if (IS_PASSABLE(grid.get(i-1, j), passClass) && IS_PASSABLE(grid.get(i, j-1), passClass) && IS_PASSABLE(grid.get(i-1, j-1), passClass))
{
Vertex vert;
vert.status = Vertex::UNEXPLORED;
vert.quadOutward = QUADRANT_ALL;
vert.quadInward = QUADRANT_TR;
vert.p = CFixedVector2D(fixed::FromInt(i)-EDGE_EXPAND_DELTA, fixed::FromInt(j)-EDGE_EXPAND_DELTA).Multiply(Pathfinding::NAVCELL_SIZE);
vertexes.push_back(vert);
}
}
}
// XXX rewrite this stuff
std::vector<u16> segmentsR;
std::vector<u16> segmentsL;
for (int j = j0; j < j1; ++j)
{
segmentsR.clear();
segmentsL.clear();
for (int i = i0; i <= i1; ++i)
{
bool a = IS_PASSABLE(grid.get(i, j+1), passClass);
bool b = IS_PASSABLE(grid.get(i, j), passClass);
if (a && !b)
segmentsL.push_back(i);
if (b && !a)
segmentsR.push_back(i);
}
if (!segmentsR.empty())
{
segmentsR.push_back(0); // sentinel value to simplify the loop
u16 ia = segmentsR[0];
u16 ib = ia + 1;
for (size_t n = 1; n < segmentsR.size(); ++n)
{
if (segmentsR[n] == ib)
++ib;
else
{
CFixedVector2D v0 = CFixedVector2D(fixed::FromInt(ia), fixed::FromInt(j+1)).Multiply(Pathfinding::NAVCELL_SIZE);
CFixedVector2D v1 = CFixedVector2D(fixed::FromInt(ib), fixed::FromInt(j+1)).Multiply(Pathfinding::NAVCELL_SIZE);
edges.emplace_back(Edge{ v0, v1 });
ia = segmentsR[n];
ib = ia + 1;
}
}
}
if (!segmentsL.empty())
{
segmentsL.push_back(0); // sentinel value to simplify the loop
u16 ia = segmentsL[0];
u16 ib = ia + 1;
for (size_t n = 1; n < segmentsL.size(); ++n)
{
if (segmentsL[n] == ib)
++ib;
else
{
CFixedVector2D v0 = CFixedVector2D(fixed::FromInt(ib), fixed::FromInt(j+1)).Multiply(Pathfinding::NAVCELL_SIZE);
CFixedVector2D v1 = CFixedVector2D(fixed::FromInt(ia), fixed::FromInt(j+1)).Multiply(Pathfinding::NAVCELL_SIZE);
edges.emplace_back(Edge{ v0, v1 });
ia = segmentsL[n];
ib = ia + 1;
}
}
}
}
std::vector<u16> segmentsU;
std::vector<u16> segmentsD;
for (int i = i0; i < i1; ++i)
{
segmentsU.clear();
segmentsD.clear();
for (int j = j0; j <= j1; ++j)
{
bool a = IS_PASSABLE(grid.get(i+1, j), passClass);
bool b = IS_PASSABLE(grid.get(i, j), passClass);
if (a && !b)
segmentsU.push_back(j);
if (b && !a)
segmentsD.push_back(j);
}
if (!segmentsU.empty())
{
segmentsU.push_back(0); // sentinel value to simplify the loop
u16 ja = segmentsU[0];
u16 jb = ja + 1;
for (size_t n = 1; n < segmentsU.size(); ++n)
{
if (segmentsU[n] == jb)
++jb;
else
{
CFixedVector2D v0 = CFixedVector2D(fixed::FromInt(i+1), fixed::FromInt(ja)).Multiply(Pathfinding::NAVCELL_SIZE);
CFixedVector2D v1 = CFixedVector2D(fixed::FromInt(i+1), fixed::FromInt(jb)).Multiply(Pathfinding::NAVCELL_SIZE);
edges.emplace_back(Edge{ v0, v1 });
ja = segmentsU[n];
jb = ja + 1;
}
}
}
if (!segmentsD.empty())
{
segmentsD.push_back(0); // sentinel value to simplify the loop
u16 ja = segmentsD[0];
u16 jb = ja + 1;
for (size_t n = 1; n < segmentsD.size(); ++n)
{
if (segmentsD[n] == jb)
++jb;
else
{
CFixedVector2D v0 = CFixedVector2D(fixed::FromInt(i+1), fixed::FromInt(jb)).Multiply(Pathfinding::NAVCELL_SIZE);
CFixedVector2D v1 = CFixedVector2D(fixed::FromInt(i+1), fixed::FromInt(ja)).Multiply(Pathfinding::NAVCELL_SIZE);
edges.emplace_back(Edge{ v0, v1 });
ja = segmentsD[n];
jb = ja + 1;
}
}
}
}
}
static void SplitAAEdges(const CFixedVector2D& a,
const std::vector<Edge>& edges,
const std::vector<Square>& squares,
std::vector<Edge>& edgesUnaligned,
std::vector<EdgeAA>& edgesLeft, std::vector<EdgeAA>& edgesRight,
std::vector<EdgeAA>& edgesBottom, std::vector<EdgeAA>& edgesTop)
{
for (const Square& square : squares)
{
if (a.X <= square.p0.X)
edgesLeft.emplace_back(EdgeAA{ square.p0, square.p1.Y });
if (a.X >= square.p1.X)
edgesRight.emplace_back(EdgeAA{ square.p1, square.p0.Y });
if (a.Y <= square.p0.Y)
edgesBottom.emplace_back(EdgeAA{ square.p0, square.p1.X });
if (a.Y >= square.p1.Y)
edgesTop.emplace_back(EdgeAA{ square.p1, square.p0.X });
}
for (const Edge& edge : edges)
{
if (edge.p0.X == edge.p1.X)
{
if (edge.p1.Y < edge.p0.Y)
{
if (!(a.X <= edge.p0.X))
continue;
edgesLeft.emplace_back(EdgeAA{ edge.p1, edge.p0.Y });
}
else
{
if (!(a.X >= edge.p0.X))
continue;
edgesRight.emplace_back(EdgeAA{ edge.p1, edge.p0.Y });
}
}
else if (edge.p0.Y == edge.p1.Y)
{
if (edge.p0.X < edge.p1.X)
{
if (!(a.Y <= edge.p0.Y))
continue;
edgesBottom.emplace_back(EdgeAA{ edge.p0, edge.p1.X });
}
else
{
if (!(a.Y >= edge.p0.Y))
continue;
edgesTop.emplace_back(EdgeAA{ edge.p0, edge.p1.X });
}
}
else
edgesUnaligned.push_back(edge);
}
}
/**
* Functor for sorting edge-squares by approximate proximity to a fixed point.
*/
struct SquareSort
{
CFixedVector2D src;
SquareSort(CFixedVector2D src) : src(src) { }
bool operator()(const Square& a, const Square& b) const
{
if ((a.p0 - src).CompareLength(b.p0 - src) < 0)
return true;
return false;
}
};
WaypointPath VertexPathfinder::ComputeShortPath(const ShortPathRequest& request, CmpPtr<ICmpObstructionManager> cmpObstructionManager) const
{
PROFILE2("ComputeShortPath");
g_VertexPathfinderDebugOverlay.DebugRenderGoal(cmpObstructionManager->GetSimContext(), request.goal);
// Create impassable edges at the max-range boundary, so we can't escape the region
// where we're meant to be searching
fixed rangeXMin = request.x0 - request.range;
fixed rangeXMax = request.x0 + request.range;
fixed rangeZMin = request.z0 - request.range;
fixed rangeZMax = request.z0 + request.range;
// If the goal is outside the bounds, move the center of the search-space towards it slightly,
// as the vertex pathfinder tends to be used to get around entities in front of us
// (this makes it possible to use smaller search ranges, but still find good paths).
// Don't do this for the largest ranges: it makes it harder to backtrack, and large search domains
// indicate a rather stuck unit, which means having to backtrack is probable.
// (keep this in sync, slightly below unitMotion's max-search range).
// (this also ensures symmetrical behaviour for goals inside/outside the max search range).
CFixedVector2D toGoal = CFixedVector2D(request.goal.x, request.goal.z) - CFixedVector2D(request.x0, request.z0);
if (toGoal.CompareLength(request.range) >= 0 && request.range < Pathfinding::NAVCELL_SIZE * 46)
{
fixed toGoalLength = toGoal.Length();
fixed inv = fixed::FromInt(1) / toGoalLength;
rangeXMin += (toGoal.Multiply(std::min(toGoalLength / 2, request.range * 3 / 5)).Multiply(inv)).X;
rangeXMax += (toGoal.Multiply(std::min(toGoalLength / 2, request.range * 3 / 5)).Multiply(inv)).X;
rangeZMin += (toGoal.Multiply(std::min(toGoalLength / 2, request.range * 3 / 5)).Multiply(inv)).Y;
rangeZMax += (toGoal.Multiply(std::min(toGoalLength / 2, request.range * 3 / 5)).Multiply(inv)).Y;
}
// Add domain edges
// (Inside-out square, so edges are in reverse from the usual direction.)
m_Edges.emplace_back(Edge{ CFixedVector2D(rangeXMin, rangeZMin), CFixedVector2D(rangeXMin, rangeZMax) });
m_Edges.emplace_back(Edge{ CFixedVector2D(rangeXMin, rangeZMax), CFixedVector2D(rangeXMax, rangeZMax) });
m_Edges.emplace_back(Edge{ CFixedVector2D(rangeXMax, rangeZMax), CFixedVector2D(rangeXMax, rangeZMin) });
m_Edges.emplace_back(Edge{ CFixedVector2D(rangeXMax, rangeZMin), CFixedVector2D(rangeXMin, rangeZMin) });
// Add the start point to the graph
CFixedVector2D posStart(request.x0, request.z0);
fixed hStart = (posStart - request.goal.NearestPointOnGoal(posStart)).Length();
Vertex start = { posStart, fixed::Zero(), hStart, 0, Vertex::OPEN, QUADRANT_NONE, QUADRANT_ALL };
m_Vertexes.push_back(start);
const size_t START_VERTEX_ID = 0;
// Add the goal vertex to the graph.
// Since the goal isn't always a point, this a special magic virtual vertex which moves around - whenever
// we look at it from another vertex, it is moved to be the closest point on the goal shape to that vertex.
Vertex end = { CFixedVector2D(request.goal.x, request.goal.z), fixed::Zero(), fixed::Zero(), 0, Vertex::UNEXPLORED, QUADRANT_NONE, QUADRANT_ALL };
m_Vertexes.push_back(end);
const size_t GOAL_VERTEX_ID = 1;
// Find all the obstruction squares that might affect us
std::vector<ICmpObstructionManager::ObstructionSquare> squares;
size_t staticShapesNb = 0;
ControlGroupMovementObstructionFilter filter(request.avoidMovingUnits, request.group);
cmpObstructionManager->GetStaticObstructionsInRange(filter, rangeXMin - request.clearance, rangeZMin - request.clearance, rangeXMax + request.clearance, rangeZMax + request.clearance, squares);
staticShapesNb = squares.size();
cmpObstructionManager->GetUnitObstructionsInRange(filter, rangeXMin - request.clearance, rangeZMin - request.clearance, rangeXMax + request.clearance, rangeZMax + request.clearance, squares);
// Change array capacities to reduce reallocations
m_Vertexes.reserve(m_Vertexes.size() + squares.size()*4);
m_EdgeSquares.reserve(m_EdgeSquares.size() + squares.size()); // (assume most squares are AA)
entity_pos_t pathfindClearance = request.clearance;
// Convert each obstruction square into collision edges and search graph vertexes
for (size_t i = 0; i < squares.size(); ++i)
{
CFixedVector2D center(squares[i].x, squares[i].z);
CFixedVector2D u = squares[i].u;
CFixedVector2D v = squares[i].v;
if (i >= staticShapesNb)
pathfindClearance = request.clearance - entity_pos_t::FromInt(1)/2;
// Expand the vertexes by the moving unit's collision radius, to find the
// closest we can get to it
CFixedVector2D hd0(squares[i].hw + pathfindClearance + EDGE_EXPAND_DELTA, squares[i].hh + pathfindClearance + EDGE_EXPAND_DELTA);
CFixedVector2D hd1(squares[i].hw + pathfindClearance + EDGE_EXPAND_DELTA, -(squares[i].hh + pathfindClearance + EDGE_EXPAND_DELTA));
// Check whether this is an axis-aligned square
bool aa = (u.X == fixed::FromInt(1) && u.Y == fixed::Zero() && v.X == fixed::Zero() && v.Y == fixed::FromInt(1));
Vertex vert;
vert.status = Vertex::UNEXPLORED;
vert.quadInward = QUADRANT_NONE;
vert.quadOutward = QUADRANT_ALL;
vert.p.X = center.X - hd0.Dot(u);
vert.p.Y = center.Y + hd0.Dot(v);
if (aa)
{
vert.quadInward = QUADRANT_BR;
vert.quadOutward = (~vert.quadInward) & 0xF;
}
if (vert.p.X >= rangeXMin && vert.p.Y >= rangeZMin && vert.p.X <= rangeXMax && vert.p.Y <= rangeZMax)
m_Vertexes.push_back(vert);
vert.p.X = center.X - hd1.Dot(u);
vert.p.Y = center.Y + hd1.Dot(v);
if (aa)
{
vert.quadInward = QUADRANT_TR;
vert.quadOutward = (~vert.quadInward) & 0xF;
}
if (vert.p.X >= rangeXMin && vert.p.Y >= rangeZMin && vert.p.X <= rangeXMax && vert.p.Y <= rangeZMax)
m_Vertexes.push_back(vert);
vert.p.X = center.X + hd0.Dot(u);
vert.p.Y = center.Y - hd0.Dot(v);
if (aa)
{
vert.quadInward = QUADRANT_TL;
vert.quadOutward = (~vert.quadInward) & 0xF;
}
if (vert.p.X >= rangeXMin && vert.p.Y >= rangeZMin && vert.p.X <= rangeXMax && vert.p.Y <= rangeZMax)
m_Vertexes.push_back(vert);
vert.p.X = center.X + hd1.Dot(u);
vert.p.Y = center.Y - hd1.Dot(v);
if (aa)
{
vert.quadInward = QUADRANT_BL;
vert.quadOutward = (~vert.quadInward) & 0xF;
}
if (vert.p.X >= rangeXMin && vert.p.Y >= rangeZMin && vert.p.X <= rangeXMax && vert.p.Y <= rangeZMax)
m_Vertexes.push_back(vert);
// Add the edges:
CFixedVector2D h0(squares[i].hw + pathfindClearance, squares[i].hh + pathfindClearance);
CFixedVector2D h1(squares[i].hw + pathfindClearance, -(squares[i].hh + pathfindClearance));
CFixedVector2D ev0(center.X - h0.Dot(u), center.Y + h0.Dot(v));
CFixedVector2D ev1(center.X - h1.Dot(u), center.Y + h1.Dot(v));
CFixedVector2D ev2(center.X + h0.Dot(u), center.Y - h0.Dot(v));
CFixedVector2D ev3(center.X + h1.Dot(u), center.Y - h1.Dot(v));
if (aa)
m_EdgeSquares.emplace_back(Square{ ev1, ev3 });
else
{
m_Edges.emplace_back(Edge{ ev0, ev1 });
m_Edges.emplace_back(Edge{ ev1, ev2 });
m_Edges.emplace_back(Edge{ ev2, ev3 });
m_Edges.emplace_back(Edge{ ev3, ev0 });
}
}
// Add terrain obstructions
{
u16 i0, j0, i1, j1;
Pathfinding::NearestNavcell(rangeXMin, rangeZMin, i0, j0, m_GridSize, m_GridSize);
Pathfinding::NearestNavcell(rangeXMax, rangeZMax, i1, j1, m_GridSize, m_GridSize);
AddTerrainEdges(m_Edges, m_Vertexes, i0, j0, i1, j1, request.passClass, *m_TerrainOnlyGrid);
}
// Clip out vertices that are inside an edgeSquare (i.e. trivially unreachable)
for (size_t i = 2; i < m_EdgeSquares.size(); ++i)
{
// If the start point is inside the square, ignore it
if (start.p.X >= m_EdgeSquares[i].p0.X &&
start.p.Y >= m_EdgeSquares[i].p0.Y &&
start.p.X <= m_EdgeSquares[i].p1.X &&
start.p.Y <= m_EdgeSquares[i].p1.Y)
continue;
// Remove every non-start/goal vertex that is inside an edgeSquare;
// since remove() would be inefficient, just mark it as closed instead.
for (size_t j = 2; j < m_Vertexes.size(); ++j)
if (m_Vertexes[j].p.X >= m_EdgeSquares[i].p0.X &&
m_Vertexes[j].p.Y >= m_EdgeSquares[i].p0.Y &&
m_Vertexes[j].p.X <= m_EdgeSquares[i].p1.X &&
m_Vertexes[j].p.Y <= m_EdgeSquares[i].p1.Y)
m_Vertexes[j].status = Vertex::CLOSED;
}
ENSURE(m_Vertexes.size() < 65536); // We store array indexes as u16.
g_VertexPathfinderDebugOverlay.DebugRenderGraph(cmpObstructionManager->GetSimContext(), m_Vertexes, m_Edges, m_EdgeSquares);
// Do an A* search over the vertex/visibility graph:
// Since we are just measuring Euclidean distance the heuristic is admissible,
// so we never have to re-examine a node once it's been moved to the closed set.
// To save time in common cases, we don't precompute a graph of valid edges between vertexes;
// we do it lazily instead. When the search algorithm reaches a vertex, we examine every other
// vertex and see if we can reach it without hitting any collision edges, and ignore the ones
// we can't reach. Since the algorithm can only reach a vertex once (and then it'll be marked
// as closed), we won't be doing any redundant visibility computations.
VertexPriorityQueue open;
VertexPriorityQueue::Item qiStart = { START_VERTEX_ID, start.h, start.h };
open.push(qiStart);
u16 idBest = START_VERTEX_ID;
fixed hBest = start.h;
while (!open.empty())
{
// Move best tile from open to closed
VertexPriorityQueue::Item curr = open.pop();
m_Vertexes[curr.id].status = Vertex::CLOSED;
// If we've reached the destination, stop
if (curr.id == GOAL_VERTEX_ID)
{
idBest = curr.id;
break;
}
// Sort the edges by distance in order to check those first that have a high probability of blocking a ray.
// The heuristic based on distance is very rough, especially for squares that are further away;
// we're also only really interested in the closest squares since they are the only ones that block a lot of rays.
// Thus we only do a partial sort; the threshold is just a somewhat reasonable value.
if (m_EdgeSquares.size() > 8)
std::partial_sort(m_EdgeSquares.begin(), m_EdgeSquares.begin() + 8, m_EdgeSquares.end(), SquareSort(m_Vertexes[curr.id].p));
m_EdgesUnaligned.clear();
m_EdgesLeft.clear();
m_EdgesRight.clear();
m_EdgesBottom.clear();
m_EdgesTop.clear();
SplitAAEdges(m_Vertexes[curr.id].p, m_Edges, m_EdgeSquares, m_EdgesUnaligned, m_EdgesLeft, m_EdgesRight, m_EdgesBottom, m_EdgesTop);
// Check the lines to every other vertex
for (size_t n = 0; n < m_Vertexes.size(); ++n)
{
if (m_Vertexes[n].status == Vertex::CLOSED)
continue;
// If this is the magical goal vertex, move it to near the current vertex
CFixedVector2D npos;
if (n == GOAL_VERTEX_ID)
{
npos = request.goal.NearestPointOnGoal(m_Vertexes[curr.id].p);
// To prevent integer overflows later on, we need to ensure all vertexes are
// 'close' to the source. The goal might be far away (not a good idea but
// sometimes it happens), so clamp it to the current search range
npos.X = Clamp(npos.X, rangeXMin + EDGE_EXPAND_DELTA, rangeXMax - EDGE_EXPAND_DELTA);
npos.Y = Clamp(npos.Y, rangeZMin + EDGE_EXPAND_DELTA, rangeZMax - EDGE_EXPAND_DELTA);
}
else
npos = m_Vertexes[n].p;
// Work out which quadrant(s) we're approaching the new vertex from
u8 quad = 0;
if (m_Vertexes[curr.id].p.X <= npos.X && m_Vertexes[curr.id].p.Y <= npos.Y) quad |= QUADRANT_BL;
if (m_Vertexes[curr.id].p.X >= npos.X && m_Vertexes[curr.id].p.Y >= npos.Y) quad |= QUADRANT_TR;
if (m_Vertexes[curr.id].p.X <= npos.X && m_Vertexes[curr.id].p.Y >= npos.Y) quad |= QUADRANT_TL;
if (m_Vertexes[curr.id].p.X >= npos.X && m_Vertexes[curr.id].p.Y <= npos.Y) quad |= QUADRANT_BR;
// Check that the new vertex is in the right quadrant for the old vertex
if (!(m_Vertexes[curr.id].quadOutward & quad) && curr.id != START_VERTEX_ID)
{
// Hack: Always head towards the goal if possible, to avoid missing it if it's
// inside another unit
if (n != GOAL_VERTEX_ID)
continue;
}
bool visible =
CheckVisibilityLeft(m_Vertexes[curr.id].p, npos, m_EdgesLeft) &&
CheckVisibilityRight(m_Vertexes[curr.id].p, npos, m_EdgesRight) &&
CheckVisibilityBottom(m_Vertexes[curr.id].p, npos, m_EdgesBottom) &&
CheckVisibilityTop(m_Vertexes[curr.id].p, npos, m_EdgesTop) &&
CheckVisibility(m_Vertexes[curr.id].p, npos, m_EdgesUnaligned);
// Render the edges that we examine.
g_VertexPathfinderDebugOverlay.DebugRenderEdges(cmpObstructionManager->GetSimContext(), visible, m_Vertexes[curr.id].p, npos);
if (visible)
{
fixed g = m_Vertexes[curr.id].g + (m_Vertexes[curr.id].p - npos).Length();
// If this is a new tile, compute the heuristic distance
if (m_Vertexes[n].status == Vertex::UNEXPLORED)
{
// Add it to the open list:
m_Vertexes[n].status = Vertex::OPEN;
m_Vertexes[n].g = g;
m_Vertexes[n].h = request.goal.DistanceToPoint(npos);
m_Vertexes[n].pred = curr.id;
if (n == GOAL_VERTEX_ID)
m_Vertexes[n].p = npos; // remember the new best goal position
VertexPriorityQueue::Item t = { (u16)n, g + m_Vertexes[n].h, m_Vertexes[n].h };
open.push(t);
// Remember the heuristically best vertex we've seen so far, in case we never actually reach the target
if (m_Vertexes[n].h < hBest)
{
idBest = (u16)n;
hBest = m_Vertexes[n].h;
}
}
else // must be OPEN
{
// If we've already seen this tile, and the new path to this tile does not have a
// better cost, then stop now
if (g >= m_Vertexes[n].g)
continue;
// Otherwise, we have a better path, so replace the old one with the new cost/parent
fixed gprev = m_Vertexes[n].g;
m_Vertexes[n].g = g;
m_Vertexes[n].pred = curr.id;
if (n == GOAL_VERTEX_ID)
m_Vertexes[n].p = npos; // remember the new best goal position
open.promote((u16)n, gprev + m_Vertexes[n].h, g + m_Vertexes[n].h, m_Vertexes[n].h);
}
}
}
}
// Reconstruct the path (in reverse)
WaypointPath path;
for (u16 id = idBest; id != START_VERTEX_ID; id = m_Vertexes[id].pred)
path.m_Waypoints.emplace_back(Waypoint{ m_Vertexes[id].p.X, m_Vertexes[id].p.Y });
m_Edges.clear();
m_EdgeSquares.clear();
m_Vertexes.clear();
m_EdgesUnaligned.clear();
m_EdgesLeft.clear();
m_EdgesRight.clear();
m_EdgesBottom.clear();
m_EdgesTop.clear();
return path;
}
void VertexPathfinderDebugOverlay::DebugRenderGoal(const CSimContext& simContext, const PathGoal& goal)
{
if (!m_DebugOverlay)
return;
std::lock_guard<std::mutex> lock(g_DebugMutex);
g_VertexPathfinderDebugOverlay.m_DebugOverlayShortPathLines.clear();
// Render the goal shape
m_DebugOverlayShortPathLines.push_back(SOverlayLine());
m_DebugOverlayShortPathLines.back().m_Color = CColor(1, 0, 0, 1);
switch (goal.type)
{
case PathGoal::POINT:
{
SimRender::ConstructCircleOnGround(simContext, goal.x.ToFloat(), goal.z.ToFloat(), 0.2f, m_DebugOverlayShortPathLines.back(), true);
break;
}
case PathGoal::CIRCLE:
case PathGoal::INVERTED_CIRCLE:
{
SimRender::ConstructCircleOnGround(simContext, goal.x.ToFloat(), goal.z.ToFloat(), goal.hw.ToFloat(), m_DebugOverlayShortPathLines.back(), true);
break;
}
case PathGoal::SQUARE:
case PathGoal::INVERTED_SQUARE:
{
float a = atan2f(goal.v.X.ToFloat(), goal.v.Y.ToFloat());
SimRender::ConstructSquareOnGround(simContext, goal.x.ToFloat(), goal.z.ToFloat(), goal.hw.ToFloat()*2, goal.hh.ToFloat()*2, a, m_DebugOverlayShortPathLines.back(), true);
break;
}
}
}
void VertexPathfinderDebugOverlay::DebugRenderGraph(const CSimContext& simContext, const std::vector<Vertex>& vertexes, const std::vector<Edge>& edges, const std::vector<Square>& edgeSquares)
{
if (!m_DebugOverlay)
return;
std::lock_guard<std::mutex> lock(g_DebugMutex);
#define PUSH_POINT(p) STMT(xz.push_back(p.X.ToFloat()); xz.push_back(p.Y.ToFloat()))
// Render the vertexes as little Pac-Man shapes to indicate quadrant direction
for (size_t i = 0; i < vertexes.size(); ++i)
{
m_DebugOverlayShortPathLines.emplace_back();
m_DebugOverlayShortPathLines.back().m_Color = CColor(1, 1, 0, 1);
float x = vertexes[i].p.X.ToFloat();
float z = vertexes[i].p.Y.ToFloat();
float a0 = 0, a1 = 0;
// Get arc start/end angles depending on quadrant (if any)
if (vertexes[i].quadInward == QUADRANT_BL) { a0 = -0.25f; a1 = 0.50f; }
else if (vertexes[i].quadInward == QUADRANT_TR) { a0 = 0.25f; a1 = 1.00f; }
else if (vertexes[i].quadInward == QUADRANT_TL) { a0 = -0.50f; a1 = 0.25f; }
else if (vertexes[i].quadInward == QUADRANT_BR) { a0 = 0.00f; a1 = 0.75f; }
if (a0 == a1)
SimRender::ConstructCircleOnGround(simContext, x, z, 0.5f,
m_DebugOverlayShortPathLines.back(), true);
else
SimRender::ConstructClosedArcOnGround(simContext, x, z, 0.5f,
a0 * ((float)M_PI*2.0f), a1 * ((float)M_PI*2.0f),
m_DebugOverlayShortPathLines.back(), true);
}
// Render the edges
for (size_t i = 0; i < edges.size(); ++i)
{
m_DebugOverlayShortPathLines.emplace_back();
m_DebugOverlayShortPathLines.back().m_Color = CColor(0, 1, 1, 1);
std::vector<float> xz;
PUSH_POINT(edges[i].p0);
PUSH_POINT(edges[i].p1);
// Add an arrowhead to indicate the direction
CFixedVector2D d = edges[i].p1 - edges[i].p0;
d.Normalize(fixed::FromInt(1)/8);
CFixedVector2D p2 = edges[i].p1 - d*2;
CFixedVector2D p3 = p2 + d.Perpendicular();
CFixedVector2D p4 = p2 - d.Perpendicular();
PUSH_POINT(p3);
PUSH_POINT(p4);
PUSH_POINT(edges[i].p1);
SimRender::ConstructLineOnGround(simContext, xz, m_DebugOverlayShortPathLines.back(), true);
}
#undef PUSH_POINT
// Render the axis-aligned squares
for (size_t i = 0; i < edgeSquares.size(); ++i)
{
m_DebugOverlayShortPathLines.push_back(SOverlayLine());
m_DebugOverlayShortPathLines.back().m_Color = CColor(0, 1, 1, 1);
std::vector<float> xz;
Square s = edgeSquares[i];
xz.push_back(s.p0.X.ToFloat());
xz.push_back(s.p0.Y.ToFloat());
xz.push_back(s.p0.X.ToFloat());
xz.push_back(s.p1.Y.ToFloat());
xz.push_back(s.p1.X.ToFloat());
xz.push_back(s.p1.Y.ToFloat());
xz.push_back(s.p1.X.ToFloat());
xz.push_back(s.p0.Y.ToFloat());
xz.push_back(s.p0.X.ToFloat());
xz.push_back(s.p0.Y.ToFloat());
SimRender::ConstructLineOnGround(simContext, xz, m_DebugOverlayShortPathLines.back(), true);
}
}
void VertexPathfinderDebugOverlay::DebugRenderEdges(const CSimContext& UNUSED(simContext), bool UNUSED(visible), CFixedVector2D UNUSED(curr), CFixedVector2D UNUSED(npos))
{
if (!m_DebugOverlay)
return;
std::lock_guard<std::mutex> lock(g_DebugMutex);
// Disabled by default.
/*
m_DebugOverlayShortPathLines.push_back(SOverlayLine());
m_DebugOverlayShortPathLines.back().m_Color = visible ? CColor(0, 1, 0, 0.5) : CColor(1, 0, 0, 0.5);
m_DebugOverlayShortPathLines.push_back(SOverlayLine());
m_DebugOverlayShortPathLines.back().m_Color = visible ? CColor(0, 1, 0, 0.5) : CColor(1, 0, 0, 0.5);
std::vector<float> xz;
xz.push_back(curr.X.ToFloat());
xz.push_back(curr.Y.ToFloat());
xz.push_back(npos.X.ToFloat());
xz.push_back(npos.Y.ToFloat());
SimRender::ConstructLineOnGround(simContext, xz, m_DebugOverlayShortPathLines.back(), false);
SimRender::ConstructLineOnGround(simContext, xz, m_DebugOverlayShortPathLines.back(), false);
*/
}
void VertexPathfinderDebugOverlay::RenderSubmit(SceneCollector& collector)
{
if (!m_DebugOverlay)
return;
std::lock_guard<std::mutex> lock(g_DebugMutex);
m_DebugOverlayShortPathLines.swap(m_DebugOverlayShortPathLinesSubmitted);
for (size_t i = 0; i < m_DebugOverlayShortPathLinesSubmitted.size(); ++i)
collector.Submit(&m_DebugOverlayShortPathLinesSubmitted[i]);
}
View Git Blame Copy Permalink