dhewm3-sdk/game/ai/AI_pathing.cpp

1540 lines
45 KiB
C++

/*
===========================================================================
Doom 3 GPL Source Code
Copyright (C) 1999-2011 id Software LLC, a ZeniMax Media company.
This file is part of the Doom 3 GPL Source Code ("Doom 3 Source Code").
Doom 3 Source Code 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 3 of the License, or
(at your option) any later version.
Doom 3 Source Code 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 Doom 3 Source Code. If not, see <http://www.gnu.org/licenses/>.
In addition, the Doom 3 Source Code is also subject to certain additional terms. You should have received a copy of these additional terms immediately following the terms and conditions of the GNU General Public License which accompanied the Doom 3 Source Code. If not, please request a copy in writing from id Software at the address below.
If you have questions concerning this license or the applicable additional terms, you may contact in writing id Software LLC, c/o ZeniMax Media Inc., Suite 120, Rockville, Maryland 20850 USA.
===========================================================================
*/
#include "sys/platform.h"
#include "idlib/containers/Queue.h"
#include "idlib/geometry/Winding2D.h"
#include "gamesys/SysCvar.h"
#include "Moveable.h"
#include "WorldSpawn.h"
#include "ai/AI.h"
#include <stddef.h>
/*
===============================================================================
Dynamic Obstacle Avoidance
- assumes the AI lives inside a bounding box aligned with the gravity direction
- obstacles in proximity of the AI are gathered
- if obstacles are found the AAS walls are also considered as obstacles
- every obstacle is represented by an oriented bounding box (OBB)
- an OBB is projected onto a 2D plane orthogonal to AI's gravity direction
- the 2D windings of the projections are expanded for the AI bbox
- a path tree is build using clockwise and counter clockwise edge walks along the winding edges
- the path tree is pruned and optimized
- the shortest path is chosen for navigation
===============================================================================
*/
const float MAX_OBSTACLE_RADIUS = 256.0f;
const float PUSH_OUTSIDE_OBSTACLES = 0.5f;
const float CLIP_BOUNDS_EPSILON = 10.0f;
const int MAX_AAS_WALL_EDGES = 256;
const int MAX_OBSTACLES = 256;
const int MAX_PATH_NODES = 256;
const int MAX_OBSTACLE_PATH = 64;
typedef struct obstacle_s {
idVec2 bounds[2];
idWinding2D winding;
idEntity * entity;
} obstacle_t;
typedef struct pathNode_s {
int dir;
idVec2 pos;
idVec2 delta;
float dist;
int obstacle;
int edgeNum;
int numNodes;
struct pathNode_s * parent;
struct pathNode_s * children[2];
struct pathNode_s * next;
void Init();
} pathNode_t;
void pathNode_s::Init() {
dir = 0;
pos.Zero();
delta.Zero();
obstacle = -1;
edgeNum = -1;
numNodes = 0;
parent = children[0] = children[1] = next = NULL;
}
idBlockAlloc<pathNode_t, 128> pathNodeAllocator;
/*
============
LineIntersectsPath
============
*/
bool LineIntersectsPath( const idVec2 &start, const idVec2 &end, const pathNode_t *node ) {
float d0, d1, d2, d3;
idVec3 plane1, plane2;
plane1 = idWinding2D::Plane2DFromPoints( start, end );
d0 = plane1.x * node->pos.x + plane1.y * node->pos.y + plane1.z;
while( node->parent ) {
d1 = plane1.x * node->parent->pos.x + plane1.y * node->parent->pos.y + plane1.z;
if ( FLOATSIGNBITSET( d0 ) ^ FLOATSIGNBITSET( d1 ) ) {
plane2 = idWinding2D::Plane2DFromPoints( node->pos, node->parent->pos );
d2 = plane2.x * start.x + plane2.y * start.y + plane2.z;
d3 = plane2.x * end.x + plane2.y * end.y + plane2.z;
if ( FLOATSIGNBITSET( d2 ) ^ FLOATSIGNBITSET( d3 ) ) {
return true;
}
}
d0 = d1;
node = node->parent;
}
return false;
}
/*
============
PointInsideObstacle
============
*/
int PointInsideObstacle( const obstacle_t *obstacles, const int numObstacles, const idVec2 &point ) {
int i;
for ( i = 0; i < numObstacles; i++ ) {
const idVec2 *bounds = obstacles[i].bounds;
if ( point.x < bounds[0].x || point.y < bounds[0].y || point.x > bounds[1].x || point.y > bounds[1].y ) {
continue;
}
if ( !obstacles[i].winding.PointInside( point, 0.1f ) ) {
continue;
}
return i;
}
return -1;
}
/*
============
GetPointOutsideObstacles
============
*/
void GetPointOutsideObstacles( const obstacle_t *obstacles, const int numObstacles, idVec2 &point, int *obstacle, int *edgeNum ) {
int i, j, k, n, bestObstacle, bestEdgeNum, queueStart, queueEnd, edgeNums[2];
float d, bestd, scale[2];
idVec3 plane, bestPlane(0.0f, 0.0f, 0.0f); // DG: init it to shut up compiler
idVec2 newPoint, dir, bestPoint;
int *queue;
bool *obstacleVisited;
idWinding2D w1, w2;
if ( obstacle ) {
*obstacle = -1;
}
if ( edgeNum ) {
*edgeNum = -1;
}
bestObstacle = PointInsideObstacle( obstacles, numObstacles, point );
if ( bestObstacle == -1 ) {
return;
}
const idWinding2D &w = obstacles[bestObstacle].winding;
bestd = idMath::INFINITY;
bestEdgeNum = 0;
for ( i = 0; i < w.GetNumPoints(); i++ ) {
plane = idWinding2D::Plane2DFromPoints( w[(i+1)%w.GetNumPoints()], w[i], true );
d = plane.x * point.x + plane.y * point.y + plane.z;
if ( d < bestd ) {
bestd = d;
bestPlane = plane;
bestEdgeNum = i;
}
// if this is a wall always try to pop out at the first edge
if ( obstacles[bestObstacle].entity == NULL ) {
break;
}
}
if (i == 0)
return;
newPoint = point - ( bestd + PUSH_OUTSIDE_OBSTACLES ) * bestPlane.ToVec2();
if ( PointInsideObstacle( obstacles, numObstacles, newPoint ) == -1 ) {
point = newPoint;
if ( obstacle ) {
*obstacle = bestObstacle;
}
if ( edgeNum ) {
*edgeNum = bestEdgeNum;
}
return;
}
queue = (int *) _alloca( numObstacles * sizeof( queue[0] ) );
obstacleVisited = (bool *) _alloca( numObstacles * sizeof( obstacleVisited[0] ) );
queueStart = 0;
queueEnd = 1;
queue[0] = bestObstacle;
memset( obstacleVisited, 0, numObstacles * sizeof( obstacleVisited[0] ) );
obstacleVisited[bestObstacle] = true;
bestd = idMath::INFINITY;
for ( i = queue[0]; queueStart < queueEnd; i = queue[++queueStart] ) {
w1 = obstacles[i].winding;
w1.Expand( PUSH_OUTSIDE_OBSTACLES );
for ( j = 0; j < numObstacles; j++ ) {
// if the obstacle has been visited already
if ( obstacleVisited[j] ) {
continue;
}
// if the bounds do not intersect
if ( obstacles[j].bounds[0].x > obstacles[i].bounds[1].x || obstacles[j].bounds[0].y > obstacles[i].bounds[1].y ||
obstacles[j].bounds[1].x < obstacles[i].bounds[0].x || obstacles[j].bounds[1].y < obstacles[i].bounds[0].y ) {
continue;
}
queue[queueEnd++] = j;
obstacleVisited[j] = true;
w2 = obstacles[j].winding;
w2.Expand( 0.2f );
for ( k = 0; k < w1.GetNumPoints(); k++ ) {
dir = w1[(k+1)%w1.GetNumPoints()] - w1[k];
if ( !w2.RayIntersection( w1[k], dir, scale[0], scale[1], edgeNums ) ) {
continue;
}
for ( n = 0; n < 2; n++ ) {
newPoint = w1[k] + scale[n] * dir;
if ( PointInsideObstacle( obstacles, numObstacles, newPoint ) == -1 ) {
d = ( newPoint - point ).LengthSqr();
if ( d < bestd ) {
bestd = d;
bestPoint = newPoint;
bestEdgeNum = edgeNums[n];
bestObstacle = j;
}
}
}
}
}
if ( bestd < idMath::INFINITY ) {
point = bestPoint;
if ( obstacle ) {
*obstacle = bestObstacle;
}
if ( edgeNum ) {
*edgeNum = bestEdgeNum;
}
return;
}
}
gameLocal.Warning( "GetPointOutsideObstacles: no valid point found" );
}
/*
============
GetFirstBlockingObstacle
============
*/
bool GetFirstBlockingObstacle( const obstacle_t *obstacles, int numObstacles, int skipObstacle, const idVec2 &startPos, const idVec2 &delta, float &blockingScale, int &blockingObstacle, int &blockingEdgeNum ) {
int i, edgeNums[2];
float dist, scale1, scale2;
idVec2 bounds[2];
// get bounds for the current movement delta
bounds[0] = startPos - idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
bounds[1] = startPos + idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
bounds[FLOATSIGNBITNOTSET(delta.x)].x += delta.x;
bounds[FLOATSIGNBITNOTSET(delta.y)].y += delta.y;
// test for obstacles blocking the path
blockingScale = idMath::INFINITY;
dist = delta.Length();
for ( i = 0; i < numObstacles; i++ ) {
if ( i == skipObstacle ) {
continue;
}
if ( bounds[0].x > obstacles[i].bounds[1].x || bounds[0].y > obstacles[i].bounds[1].y ||
bounds[1].x < obstacles[i].bounds[0].x || bounds[1].y < obstacles[i].bounds[0].y ) {
continue;
}
if ( obstacles[i].winding.RayIntersection( startPos, delta, scale1, scale2, edgeNums ) ) {
if ( scale1 < blockingScale && scale1 * dist > -0.01f && scale2 * dist > 0.01f ) {
blockingScale = scale1;
blockingObstacle = i;
blockingEdgeNum = edgeNums[0];
}
}
}
return ( blockingScale < 1.0f );
}
/*
============
GetObstacles
============
*/
int GetObstacles( const idPhysics *physics, const idAAS *aas, const idEntity *ignore, int areaNum, const idVec3 &startPos, const idVec3 &seekPos, obstacle_t *obstacles, int maxObstacles, idBounds &clipBounds ) {
int i, j, numListedClipModels, numObstacles, numVerts, clipMask, blockingObstacle, blockingEdgeNum;
int wallEdges[MAX_AAS_WALL_EDGES], numWallEdges, verts[2], lastVerts[2], nextVerts[2];
float stepHeight, headHeight, blockingScale, min, max;
idVec3 seekDelta, silVerts[32], start, end, nextStart, nextEnd;
idVec2 expBounds[2], edgeDir, edgeNormal, nextEdgeDir, nextEdgeNormal, lastEdgeNormal;
idVec2 obDelta;
idPhysics *obPhys;
idBox box;
idEntity *obEnt;
idClipModel *clipModel;
idClipModel *clipModelList[ MAX_GENTITIES ];
numObstacles = 0;
seekDelta = seekPos - startPos;
expBounds[0] = physics->GetBounds()[0].ToVec2() - idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
expBounds[1] = physics->GetBounds()[1].ToVec2() + idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
physics->GetAbsBounds().AxisProjection( -physics->GetGravityNormal(), stepHeight, headHeight );
stepHeight += aas->GetSettings()->maxStepHeight;
// clip bounds for the obstacle search space
clipBounds[0] = clipBounds[1] = startPos;
clipBounds.AddPoint( seekPos );
clipBounds.ExpandSelf( MAX_OBSTACLE_RADIUS );
clipMask = physics->GetClipMask();
// find all obstacles touching the clip bounds
numListedClipModels = gameLocal.clip.ClipModelsTouchingBounds( clipBounds, clipMask, clipModelList, MAX_GENTITIES );
for ( i = 0; i < numListedClipModels && numObstacles < MAX_OBSTACLES; i++ ) {
clipModel = clipModelList[i];
obEnt = clipModel->GetEntity();
if ( !clipModel->IsTraceModel() ) {
continue;
}
if ( obEnt->IsType( idActor::Type ) ) {
obPhys = obEnt->GetPhysics();
// ignore myself, my enemy, and dead bodies
if ( ( obPhys == physics ) || ( obEnt == ignore ) || ( obEnt->health <= 0 ) ) {
continue;
}
// if the actor is moving
idVec3 v1 = obPhys->GetLinearVelocity();
if ( v1.LengthSqr() > Square( 10.0f ) ) {
idVec3 v2 = physics->GetLinearVelocity();
if ( v2.LengthSqr() > Square( 10.0f ) ) {
// if moving in about the same direction
if ( v1 * v2 > 0.0f ) {
continue;
}
}
}
} else if ( obEnt->IsType( idMoveable::Type ) ) {
// moveables are considered obstacles
} else {
// ignore everything else
continue;
}
// check if we can step over the object
clipModel->GetAbsBounds().AxisProjection( -physics->GetGravityNormal(), min, max );
if ( max < stepHeight || min > headHeight ) {
// can step over this one
continue;
}
// project a box containing the obstacle onto the floor plane
box = idBox( clipModel->GetBounds(), clipModel->GetOrigin(), clipModel->GetAxis() );
numVerts = box.GetParallelProjectionSilhouetteVerts( physics->GetGravityNormal(), silVerts );
// create a 2D winding for the obstacle;
obstacle_t &obstacle = obstacles[numObstacles++];
obstacle.winding.Clear();
for ( j = 0; j < numVerts; j++ ) {
obstacle.winding.AddPoint( silVerts[j].ToVec2() );
}
if ( ai_showObstacleAvoidance.GetBool() ) {
for ( j = 0; j < numVerts; j++ ) {
silVerts[j].z = startPos.z;
}
for ( j = 0; j < numVerts; j++ ) {
gameRenderWorld->DebugArrow( colorWhite, silVerts[j], silVerts[(j+1)%numVerts], 4 );
}
}
// expand the 2D winding for collision with a 2D box
obstacle.winding.ExpandForAxialBox( expBounds );
obstacle.winding.GetBounds( obstacle.bounds );
obstacle.entity = obEnt;
}
// if there are no dynamic obstacles the path should be through valid AAS space
if ( numObstacles == 0 ) {
return 0;
}
// if the current path doesn't intersect any dynamic obstacles the path should be through valid AAS space
if ( PointInsideObstacle( obstacles, numObstacles, startPos.ToVec2() ) == -1 ) {
if ( !GetFirstBlockingObstacle( obstacles, numObstacles, -1, startPos.ToVec2(), seekDelta.ToVec2(), blockingScale, blockingObstacle, blockingEdgeNum ) ) {
return 0;
}
}
// create obstacles for AAS walls
if ( aas ) {
float halfBoundsSize = ( expBounds[ 1 ].x - expBounds[ 0 ].x ) * 0.5f;
numWallEdges = aas->GetWallEdges( areaNum, clipBounds, TFL_WALK, wallEdges, MAX_AAS_WALL_EDGES );
aas->SortWallEdges( wallEdges, numWallEdges );
lastVerts[0] = lastVerts[1] = 0;
lastEdgeNormal.Zero();
nextEdgeNormal.Zero();
nextVerts[0] = nextVerts[1] = 0;
for ( i = 0; i < numWallEdges && numObstacles < MAX_OBSTACLES; i++ ) {
aas->GetEdge( wallEdges[i], start, end );
aas->GetEdgeVertexNumbers( wallEdges[i], verts );
edgeDir = end.ToVec2() - start.ToVec2();
edgeDir.Normalize();
edgeNormal.x = edgeDir.y;
edgeNormal.y = -edgeDir.x;
if ( i < numWallEdges-1 ) {
aas->GetEdge( wallEdges[i+1], nextStart, nextEnd );
aas->GetEdgeVertexNumbers( wallEdges[i+1], nextVerts );
nextEdgeDir = nextEnd.ToVec2() - nextStart.ToVec2();
nextEdgeDir.Normalize();
nextEdgeNormal.x = nextEdgeDir.y;
nextEdgeNormal.y = -nextEdgeDir.x;
}
obstacle_t &obstacle = obstacles[numObstacles++];
obstacle.winding.Clear();
obstacle.winding.AddPoint( end.ToVec2() );
obstacle.winding.AddPoint( start.ToVec2() );
obstacle.winding.AddPoint( start.ToVec2() - edgeDir - edgeNormal * halfBoundsSize );
obstacle.winding.AddPoint( end.ToVec2() + edgeDir - edgeNormal * halfBoundsSize );
if ( lastVerts[1] == verts[0] ) {
obstacle.winding[2] -= lastEdgeNormal * halfBoundsSize;
} else {
obstacle.winding[1] -= edgeDir;
}
if ( verts[1] == nextVerts[0] ) {
obstacle.winding[3] -= nextEdgeNormal * halfBoundsSize;
} else {
obstacle.winding[0] += edgeDir;
}
obstacle.winding.GetBounds( obstacle.bounds );
obstacle.entity = NULL;
memcpy( lastVerts, verts, sizeof( lastVerts ) );
lastEdgeNormal = edgeNormal;
}
}
// show obstacles
if ( ai_showObstacleAvoidance.GetBool() ) {
for ( i = 0; i < numObstacles; i++ ) {
obstacle_t &obstacle = obstacles[i];
for ( j = 0; j < obstacle.winding.GetNumPoints(); j++ ) {
silVerts[j].ToVec2() = obstacle.winding[j];
silVerts[j].z = startPos.z;
}
for ( j = 0; j < obstacle.winding.GetNumPoints(); j++ ) {
gameRenderWorld->DebugArrow( colorGreen, silVerts[j], silVerts[(j+1)%obstacle.winding.GetNumPoints()], 4 );
}
}
}
return numObstacles;
}
/*
============
FreePathTree_r
============
*/
void FreePathTree_r( pathNode_t *node ) {
if ( node->children[0] ) {
FreePathTree_r( node->children[0] );
}
if ( node->children[1] ) {
FreePathTree_r( node->children[1] );
}
pathNodeAllocator.Free( node );
}
/*
============
DrawPathTree
============
*/
void DrawPathTree( const pathNode_t *root, const float height ) {
int i;
idVec3 start, end;
const pathNode_t *node;
for ( node = root; node; node = node->next ) {
for ( i = 0; i < 2; i++ ) {
if ( node->children[i] ) {
start.ToVec2() = node->pos;
start.z = height;
end.ToVec2() = node->children[i]->pos;
end.z = height;
gameRenderWorld->DebugArrow( node->edgeNum == -1 ? colorYellow : i ? colorBlue : colorRed, start, end, 1 );
break;
}
}
}
}
/*
============
GetPathNodeDelta
============
*/
bool GetPathNodeDelta( pathNode_t *node, const obstacle_t *obstacles, const idVec2 &seekPos, bool blocked ) {
int numPoints, edgeNum;
bool facing;
idVec2 seekDelta, dir;
pathNode_t *n;
numPoints = obstacles[node->obstacle].winding.GetNumPoints();
// get delta along the current edge
while( 1 ) {
edgeNum = ( node->edgeNum + node->dir ) % numPoints;
node->delta = obstacles[node->obstacle].winding[edgeNum] - node->pos;
if ( node->delta.LengthSqr() > 0.01f ) {
break;
}
node->edgeNum = ( node->edgeNum + numPoints + ( 2 * node->dir - 1 ) ) % numPoints;
}
// if not blocked
if ( !blocked ) {
// test if the current edge faces the goal
seekDelta = seekPos - node->pos;
facing = ( ( 2 * node->dir - 1 ) * ( node->delta.x * seekDelta.y - node->delta.y * seekDelta.x ) ) >= 0.0f;
// if the current edge faces goal and the line from the current
// position to the goal does not intersect the current path
if ( facing && !LineIntersectsPath( node->pos, seekPos, node->parent ) ) {
node->delta = seekPos - node->pos;
node->edgeNum = -1;
}
}
// if the delta is along the obstacle edge
if ( node->edgeNum != -1 ) {
// if the edge is found going from this node to the root node
for ( n = node->parent; n; n = n->parent ) {
if ( node->obstacle != n->obstacle || node->edgeNum != n->edgeNum ) {
continue;
}
// test whether or not the edge segments actually overlap
if ( n->pos * node->delta > ( node->pos + node->delta ) * node->delta ) {
continue;
}
if ( node->pos * node->delta > ( n->pos + n->delta ) * node->delta ) {
continue;
}
break;
}
if ( n ) {
return false;
}
}
return true;
}
/*
============
BuildPathTree
============
*/
pathNode_t *BuildPathTree( const obstacle_t *obstacles, int numObstacles, const idBounds &clipBounds, const idVec2 &startPos, const idVec2 &seekPos, obstaclePath_t &path ) {
int blockingEdgeNum, blockingObstacle, obstaclePoints, bestNumNodes = MAX_OBSTACLE_PATH;
float blockingScale;
pathNode_t *root, *node, *child;
// gcc 4.0
idQueueTemplate<pathNode_t, offsetof( pathNode_t, next ) > pathNodeQueue, treeQueue;
root = pathNodeAllocator.Alloc();
root->Init();
root->pos = startPos;
root->delta = seekPos - root->pos;
root->numNodes = 0;
pathNodeQueue.Add( root );
for ( node = pathNodeQueue.Get(); node && pathNodeAllocator.GetAllocCount() < MAX_PATH_NODES; node = pathNodeQueue.Get() ) {
treeQueue.Add( node );
// if this path has more than twice the number of nodes than the best path so far
if ( node->numNodes > bestNumNodes * 2 ) {
continue;
}
// don't move outside of the clip bounds
idVec2 endPos = node->pos + node->delta;
if ( endPos.x - CLIP_BOUNDS_EPSILON < clipBounds[0].x || endPos.x + CLIP_BOUNDS_EPSILON > clipBounds[1].x ||
endPos.y - CLIP_BOUNDS_EPSILON < clipBounds[0].y || endPos.y + CLIP_BOUNDS_EPSILON > clipBounds[1].y ) {
continue;
}
// if an obstacle is blocking the path
if ( GetFirstBlockingObstacle( obstacles, numObstacles, node->obstacle, node->pos, node->delta, blockingScale, blockingObstacle, blockingEdgeNum ) ) {
if ( path.firstObstacle == NULL ) {
path.firstObstacle = obstacles[blockingObstacle].entity;
}
node->delta *= blockingScale;
if ( node->edgeNum == -1 ) {
node->children[0] = pathNodeAllocator.Alloc();
node->children[0]->Init();
node->children[1] = pathNodeAllocator.Alloc();
node->children[1]->Init();
node->children[0]->dir = 0;
node->children[1]->dir = 1;
node->children[0]->parent = node->children[1]->parent = node;
node->children[0]->pos = node->children[1]->pos = node->pos + node->delta;
node->children[0]->obstacle = node->children[1]->obstacle = blockingObstacle;
node->children[0]->edgeNum = node->children[1]->edgeNum = blockingEdgeNum;
node->children[0]->numNodes = node->children[1]->numNodes = node->numNodes + 1;
if ( GetPathNodeDelta( node->children[0], obstacles, seekPos, true ) ) {
pathNodeQueue.Add( node->children[0] );
}
if ( GetPathNodeDelta( node->children[1], obstacles, seekPos, true ) ) {
pathNodeQueue.Add( node->children[1] );
}
} else {
node->children[node->dir] = child = pathNodeAllocator.Alloc();
child->Init();
child->dir = node->dir;
child->parent = node;
child->pos = node->pos + node->delta;
child->obstacle = blockingObstacle;
child->edgeNum = blockingEdgeNum;
child->numNodes = node->numNodes + 1;
if ( GetPathNodeDelta( child, obstacles, seekPos, true ) ) {
pathNodeQueue.Add( child );
}
}
} else {
node->children[node->dir] = child = pathNodeAllocator.Alloc();
child->Init();
child->dir = node->dir;
child->parent = node;
child->pos = node->pos + node->delta;
child->numNodes = node->numNodes + 1;
// there is a free path towards goal
if ( node->edgeNum == -1 ) {
if ( node->numNodes < bestNumNodes ) {
bestNumNodes = node->numNodes;
}
continue;
}
child->obstacle = node->obstacle;
obstaclePoints = obstacles[node->obstacle].winding.GetNumPoints();
child->edgeNum = ( node->edgeNum + obstaclePoints + ( 2 * node->dir - 1 ) ) % obstaclePoints;
if ( GetPathNodeDelta( child, obstacles, seekPos, false ) ) {
pathNodeQueue.Add( child );
}
}
}
return root;
}
/*
============
PrunePathTree
============
*/
void PrunePathTree( pathNode_t *root, const idVec2 &seekPos ) {
int i;
float bestDist;
pathNode_t *node, *lastNode, *n, *bestNode;
node = root;
while( node ) {
node->dist = ( seekPos - node->pos ).LengthSqr();
if ( node->children[0] ) {
node = node->children[0];
} else if ( node->children[1] ) {
node = node->children[1];
} else {
// find the node closest to the goal along this path
bestDist = idMath::INFINITY;
bestNode = node;
for ( n = node; n; n = n->parent ) {
if ( n->children[0] && n->children[1] ) {
break;
}
if ( n->dist < bestDist ) {
bestDist = n->dist;
bestNode = n;
}
}
// free tree down from the best node
for ( i = 0; i < 2; i++ ) {
if ( bestNode->children[i] ) {
FreePathTree_r( bestNode->children[i] );
bestNode->children[i] = NULL;
}
}
for ( lastNode = bestNode, node = bestNode->parent; node; lastNode = node, node = node->parent ) {
if ( node->children[1] && ( node->children[1] != lastNode ) ) {
node = node->children[1];
break;
}
}
}
}
}
/*
============
OptimizePath
============
*/
int OptimizePath( const pathNode_t *root, const pathNode_t *leafNode, const obstacle_t *obstacles, int numObstacles, idVec2 optimizedPath[MAX_OBSTACLE_PATH] ) {
int i, numPathPoints, edgeNums[2];
const pathNode_t *curNode, *nextNode;
idVec2 curPos, curDelta, bounds[2];
float scale1, scale2, curLength;
optimizedPath[0] = root->pos;
numPathPoints = 1;
for ( nextNode = curNode = root; curNode != leafNode; curNode = nextNode ) {
for ( nextNode = leafNode; nextNode->parent != curNode; nextNode = nextNode->parent ) {
// can only take shortcuts when going from one object to another
if ( nextNode->obstacle == curNode->obstacle ) {
continue;
}
curPos = curNode->pos;
curDelta = nextNode->pos - curPos;
curLength = curDelta.Length();
// get bounds for the current movement delta
bounds[0] = curPos - idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
bounds[1] = curPos + idVec2( CM_BOX_EPSILON, CM_BOX_EPSILON );
bounds[FLOATSIGNBITNOTSET(curDelta.x)].x += curDelta.x;
bounds[FLOATSIGNBITNOTSET(curDelta.y)].y += curDelta.y;
// test if the shortcut intersects with any obstacles
for ( i = 0; i < numObstacles; i++ ) {
if ( bounds[0].x > obstacles[i].bounds[1].x || bounds[0].y > obstacles[i].bounds[1].y ||
bounds[1].x < obstacles[i].bounds[0].x || bounds[1].y < obstacles[i].bounds[0].y ) {
continue;
}
if ( obstacles[i].winding.RayIntersection( curPos, curDelta, scale1, scale2, edgeNums ) ) {
if ( scale1 >= 0.0f && scale1 <= 1.0f && ( i != nextNode->obstacle || scale1 * curLength < curLength - 0.5f ) ) {
break;
}
if ( scale2 >= 0.0f && scale2 <= 1.0f && ( i != nextNode->obstacle || scale2 * curLength < curLength - 0.5f ) ) {
break;
}
}
}
if ( i >= numObstacles ) {
break;
}
}
// store the next position along the optimized path
optimizedPath[numPathPoints++] = nextNode->pos;
}
return numPathPoints;
}
/*
============
PathLength
============
*/
float PathLength( idVec2 optimizedPath[MAX_OBSTACLE_PATH], int numPathPoints, const idVec2 &curDir ) {
int i;
float pathLength;
// calculate the path length
pathLength = 0.0f;
for ( i = 0; i < numPathPoints-1; i++ ) {
pathLength += ( optimizedPath[i+1] - optimizedPath[i] ).LengthFast();
}
// add penalty if this path does not go in the current direction
if ( curDir * ( optimizedPath[1] - optimizedPath[0] ) < 0.0f ) {
pathLength += 100.0f;
}
return pathLength;
}
/*
============
FindOptimalPath
Returns true if there is a path all the way to the goal.
============
*/
bool FindOptimalPath( const pathNode_t *root, const obstacle_t *obstacles, int numObstacles, const float height, const idVec3 &curDir, idVec3 &seekPos ) {
int i, numPathPoints, bestNumPathPoints;
const pathNode_t *node, *lastNode, *bestNode;
idVec2 optimizedPath[MAX_OBSTACLE_PATH];
float pathLength, bestPathLength;
bool pathToGoalExists, optimizedPathCalculated;
seekPos.Zero();
seekPos.z = height;
pathToGoalExists = false;
optimizedPathCalculated = false;
bestNode = root;
bestNumPathPoints = 0;
bestPathLength = idMath::INFINITY;
node = root;
while( node ) {
pathToGoalExists |= ( node->dist < 0.1f );
if ( node->dist <= bestNode->dist ) {
if ( idMath::Fabs( node->dist - bestNode->dist ) < 0.1f ) {
if ( !optimizedPathCalculated ) {
bestNumPathPoints = OptimizePath( root, bestNode, obstacles, numObstacles, optimizedPath );
bestPathLength = PathLength( optimizedPath, bestNumPathPoints, curDir.ToVec2() );
seekPos.ToVec2() = optimizedPath[1];
}
numPathPoints = OptimizePath( root, node, obstacles, numObstacles, optimizedPath );
pathLength = PathLength( optimizedPath, numPathPoints, curDir.ToVec2() );
if ( pathLength < bestPathLength ) {
bestNode = node;
bestNumPathPoints = numPathPoints;
bestPathLength = pathLength;
seekPos.ToVec2() = optimizedPath[1];
}
optimizedPathCalculated = true;
} else {
bestNode = node;
optimizedPathCalculated = false;
}
}
if ( node->children[0] ) {
node = node->children[0];
} else if ( node->children[1] ) {
node = node->children[1];
} else {
for ( lastNode = node, node = node->parent; node; lastNode = node, node = node->parent ) {
if ( node->children[1] && node->children[1] != lastNode ) {
node = node->children[1];
break;
}
}
}
}
if ( !pathToGoalExists ) {
seekPos.ToVec2() = root->children[0]->pos;
} else if ( !optimizedPathCalculated ) {
OptimizePath( root, bestNode, obstacles, numObstacles, optimizedPath );
seekPos.ToVec2() = optimizedPath[1];
}
if ( ai_showObstacleAvoidance.GetBool() ) {
idVec3 start, end;
start.z = end.z = height + 4.0f;
numPathPoints = OptimizePath( root, bestNode, obstacles, numObstacles, optimizedPath );
for ( i = 0; i < numPathPoints-1; i++ ) {
start.ToVec2() = optimizedPath[i];
end.ToVec2() = optimizedPath[i+1];
gameRenderWorld->DebugArrow( colorCyan, start, end, 1 );
}
}
return pathToGoalExists;
}
/*
============
idAI::FindPathAroundObstacles
Finds a path around dynamic obstacles using a path tree with clockwise and counter clockwise edge walks.
============
*/
bool idAI::FindPathAroundObstacles( const idPhysics *physics, const idAAS *aas, const idEntity *ignore, const idVec3 &startPos, const idVec3 &seekPos, obstaclePath_t &path ) {
int numObstacles, areaNum, insideObstacle;
obstacle_t obstacles[MAX_OBSTACLES];
idBounds clipBounds;
idBounds bounds;
pathNode_t *root;
bool pathToGoalExists;
path.seekPos = seekPos;
path.firstObstacle = NULL;
path.startPosOutsideObstacles = startPos;
path.startPosObstacle = NULL;
path.seekPosOutsideObstacles = seekPos;
path.seekPosObstacle = NULL;
if ( !aas ) {
return true;
}
bounds[1] = aas->GetSettings()->boundingBoxes[0][1];
bounds[0] = -bounds[1];
bounds[1].z = 32.0f;
// get the AAS area number and a valid point inside that area
areaNum = aas->PointReachableAreaNum( path.startPosOutsideObstacles, bounds, (AREA_REACHABLE_WALK|AREA_REACHABLE_FLY) );
aas->PushPointIntoAreaNum( areaNum, path.startPosOutsideObstacles );
// get all the nearby obstacles
numObstacles = GetObstacles( physics, aas, ignore, areaNum, path.startPosOutsideObstacles, path.seekPosOutsideObstacles, obstacles, MAX_OBSTACLES, clipBounds );
// get a source position outside the obstacles
GetPointOutsideObstacles( obstacles, numObstacles, path.startPosOutsideObstacles.ToVec2(), &insideObstacle, NULL );
if ( insideObstacle != -1 ) {
path.startPosObstacle = obstacles[insideObstacle].entity;
}
// get a goal position outside the obstacles
GetPointOutsideObstacles( obstacles, numObstacles, path.seekPosOutsideObstacles.ToVec2(), &insideObstacle, NULL );
if ( insideObstacle != -1 ) {
path.seekPosObstacle = obstacles[insideObstacle].entity;
}
// if start and destination are pushed to the same point, we don't have a path around the obstacle
if ( ( path.seekPosOutsideObstacles.ToVec2() - path.startPosOutsideObstacles.ToVec2() ).LengthSqr() < Square( 1.0f ) ) {
if ( ( seekPos.ToVec2() - startPos.ToVec2() ).LengthSqr() > Square( 2.0f ) ) {
return false;
}
}
// build a path tree
root = BuildPathTree( obstacles, numObstacles, clipBounds, path.startPosOutsideObstacles.ToVec2(), path.seekPosOutsideObstacles.ToVec2(), path );
// draw the path tree
if ( ai_showObstacleAvoidance.GetBool() ) {
DrawPathTree( root, physics->GetOrigin().z );
}
// prune the tree
PrunePathTree( root, path.seekPosOutsideObstacles.ToVec2() );
// find the optimal path
pathToGoalExists = FindOptimalPath( root, obstacles, numObstacles, physics->GetOrigin().z, physics->GetLinearVelocity(), path.seekPos );
// free the tree
FreePathTree_r( root );
return pathToGoalExists;
}
/*
============
idAI::FreeObstacleAvoidanceNodes
============
*/
void idAI::FreeObstacleAvoidanceNodes( void ) {
pathNodeAllocator.Shutdown();
}
/*
===============================================================================
Path Prediction
Uses the AAS to quickly and accurately predict a path for a certain
period of time based on an initial position and velocity.
===============================================================================
*/
const float OVERCLIP = 1.001f;
const int MAX_FRAME_SLIDE = 5;
typedef struct pathTrace_s {
float fraction;
idVec3 endPos;
idVec3 normal;
const idEntity * blockingEntity;
} pathTrace_t;
/*
============
PathTrace
Returns true if a stop event was triggered.
============
*/
bool PathTrace( const idEntity *ent, const idAAS *aas, const idVec3 &start, const idVec3 &end, int stopEvent, struct pathTrace_s &trace, predictedPath_t &path ) {
trace_t clipTrace;
aasTrace_t aasTrace;
memset( &trace, 0, sizeof( trace ) );
if ( !aas || !aas->GetSettings() ) {
gameLocal.clip.Translation( clipTrace, start, end, ent->GetPhysics()->GetClipModel(),
ent->GetPhysics()->GetClipModel()->GetAxis(), MASK_MONSTERSOLID, ent );
// NOTE: could do (expensive) ledge detection here for when there is no AAS file
trace.fraction = clipTrace.fraction;
trace.endPos = clipTrace.endpos;
trace.normal = clipTrace.c.normal;
trace.blockingEntity = gameLocal.entities[ clipTrace.c.entityNum ];
} else {
aasTrace.getOutOfSolid = true;
if ( stopEvent & SE_ENTER_LEDGE_AREA ) {
aasTrace.flags |= AREA_LEDGE;
}
if ( stopEvent & SE_ENTER_OBSTACLE ) {
aasTrace.travelFlags |= TFL_INVALID;
}
aas->Trace( aasTrace, start, end );
gameLocal.clip.TranslationEntities( clipTrace, start, aasTrace.endpos, ent->GetPhysics()->GetClipModel(),
ent->GetPhysics()->GetClipModel()->GetAxis(), MASK_MONSTERSOLID, ent );
if ( clipTrace.fraction >= 1.0f ) {
trace.fraction = aasTrace.fraction;
trace.endPos = aasTrace.endpos;
trace.normal = aas->GetPlane( aasTrace.planeNum ).Normal();
trace.blockingEntity = gameLocal.world;
if ( aasTrace.fraction < 1.0f ) {
if ( stopEvent & SE_ENTER_LEDGE_AREA ) {
if ( aas->AreaFlags( aasTrace.blockingAreaNum ) & AREA_LEDGE ) {
path.endPos = trace.endPos;
path.endNormal = trace.normal;
path.endEvent = SE_ENTER_LEDGE_AREA;
path.blockingEntity = trace.blockingEntity;
if ( ai_debugMove.GetBool() ) {
gameRenderWorld->DebugLine( colorRed, start, aasTrace.endpos );
}
return true;
}
}
if ( stopEvent & SE_ENTER_OBSTACLE ) {
if ( aas->AreaTravelFlags( aasTrace.blockingAreaNum ) & TFL_INVALID ) {
path.endPos = trace.endPos;
path.endNormal = trace.normal;
path.endEvent = SE_ENTER_OBSTACLE;
path.blockingEntity = trace.blockingEntity;
if ( ai_debugMove.GetBool() ) {
gameRenderWorld->DebugLine( colorRed, start, aasTrace.endpos );
}
return true;
}
}
}
} else {
trace.fraction = clipTrace.fraction;
trace.endPos = clipTrace.endpos;
trace.normal = clipTrace.c.normal;
trace.blockingEntity = gameLocal.entities[ clipTrace.c.entityNum ];
}
}
if ( trace.fraction >= 1.0f ) {
trace.blockingEntity = NULL;
}
return false;
}
/*
============
idAI::PredictPath
Can also be used when there is no AAS file available however ledges are not detected.
============
*/
bool idAI::PredictPath( const idEntity *ent, const idAAS *aas, const idVec3 &start, const idVec3 &velocity, int totalTime, int frameTime, int stopEvent, predictedPath_t &path ) {
int i, j, step, numFrames, curFrameTime;
idVec3 delta, curStart, curEnd, curVelocity, lastEnd, tmpStart;
idVec3 stepUp(0,0,0); // DG: init this to get rid of compiler warning
idVec3 gravity, gravityDir, invGravityDir;
float maxStepHeight, minFloorCos;
pathTrace_t trace;
if ( aas && aas->GetSettings() ) {
gravity = aas->GetSettings()->gravity;
gravityDir = aas->GetSettings()->gravityDir;
invGravityDir = aas->GetSettings()->invGravityDir;
maxStepHeight = aas->GetSettings()->maxStepHeight;
minFloorCos = aas->GetSettings()->minFloorCos;
} else {
gravity = DEFAULT_GRAVITY_VEC3;
gravityDir = idVec3( 0, 0, -1 );
invGravityDir = idVec3( 0, 0, 1 );
maxStepHeight = 14.0f;
minFloorCos = 0.7f;
}
path.endPos = start;
path.endVelocity = velocity;
path.endNormal.Zero();
path.endEvent = 0;
path.endTime = 0;
path.blockingEntity = NULL;
curStart = start;
curVelocity = velocity;
numFrames = ( totalTime + frameTime - 1 ) / frameTime;
curFrameTime = frameTime;
for ( i = 0; i < numFrames; i++ ) {
if ( i == numFrames-1 ) {
curFrameTime = totalTime - i * curFrameTime;
}
delta = curVelocity * curFrameTime * 0.001f;
path.endVelocity = curVelocity;
path.endTime = i * frameTime;
// allow sliding along a few surfaces per frame
for ( j = 0; j < MAX_FRAME_SLIDE; j++ ) {
idVec3 lineStart = curStart;
// allow stepping up three times per frame
for ( step = 0; step < 3; step++ ) {
curEnd = curStart + delta;
if ( PathTrace( ent, aas, curStart, curEnd, stopEvent, trace, path ) ) {
return true;
}
if ( step ) {
// step down at end point
tmpStart = trace.endPos;
curEnd = tmpStart - stepUp;
if ( PathTrace( ent, aas, tmpStart, curEnd, stopEvent, trace, path ) ) {
return true;
}
// if not moved any further than without stepping up, or if not on a floor surface
if ( (lastEnd - start).LengthSqr() > (trace.endPos - start).LengthSqr() - 0.1f ||
( trace.normal * invGravityDir ) < minFloorCos ) {
if ( stopEvent & SE_BLOCKED ) {
path.endPos = lastEnd;
path.endEvent = SE_BLOCKED;
if ( ai_debugMove.GetBool() ) {
gameRenderWorld->DebugLine( colorRed, lineStart, lastEnd );
}
return true;
}
curStart = lastEnd;
break;
}
}
path.endNormal = trace.normal;
path.blockingEntity = trace.blockingEntity;
// if the trace is not blocked or blocked by a floor surface
if ( trace.fraction >= 1.0f || ( trace.normal * invGravityDir ) > minFloorCos ) {
curStart = trace.endPos;
break;
}
// save last result
lastEnd = trace.endPos;
// step up
stepUp = invGravityDir * maxStepHeight;
if ( PathTrace( ent, aas, curStart, curStart + stepUp, stopEvent, trace, path ) ) {
return true;
}
stepUp *= trace.fraction;
curStart = trace.endPos;
}
if ( ai_debugMove.GetBool() ) {
gameRenderWorld->DebugLine( colorRed, lineStart, curStart );
}
if ( trace.fraction >= 1.0f ) {
break;
}
delta.ProjectOntoPlane( trace.normal, OVERCLIP );
curVelocity.ProjectOntoPlane( trace.normal, OVERCLIP );
if ( stopEvent & SE_BLOCKED ) {
// if going backwards
if ( (curVelocity - gravityDir * curVelocity * gravityDir ) *
(velocity - gravityDir * velocity * gravityDir) < 0.0f ) {
path.endPos = curStart;
path.endEvent = SE_BLOCKED;
return true;
}
}
}
if ( j >= MAX_FRAME_SLIDE ) {
if ( stopEvent & SE_BLOCKED ) {
path.endPos = curStart;
path.endEvent = SE_BLOCKED;
return true;
}
}
// add gravity
curVelocity += gravity * frameTime * 0.001f;
}
path.endTime = totalTime;
path.endVelocity = curVelocity;
path.endPos = curStart;
path.endEvent = 0;
return false;
}
/*
===============================================================================
Trajectory Prediction
Finds the best collision free trajectory for a clip model based on an
initial position, target position and speed.
===============================================================================
*/
/*
=====================
Ballistics
get the ideal aim pitch angle in order to hit the target
also get the time it takes for the projectile to arrive at the target
=====================
*/
typedef struct ballistics_s {
float angle; // angle in degrees in the range [-180, 180]
float time; // time it takes before the projectile arrives
} ballistics_t;
static int Ballistics( const idVec3 &start, const idVec3 &end, float speed, float gravity, ballistics_t bal[2] ) {
int n, i;
float x, y, a, b, c, d, sqrtd, inva, p[2];
x = ( end.ToVec2() - start.ToVec2() ).Length();
y = end[2] - start[2];
a = 4.0f * y * y + 4.0f * x * x;
b = -4.0f * speed * speed - 4.0f * y * gravity;
c = gravity * gravity;
d = b * b - 4.0f * a * c;
if ( d <= 0.0f || a == 0.0f ) {
return 0;
}
sqrtd = idMath::Sqrt( d );
inva = 0.5f / a;
p[0] = ( - b + sqrtd ) * inva;
p[1] = ( - b - sqrtd ) * inva;
n = 0;
for ( i = 0; i < 2; i++ ) {
if ( p[i] <= 0.0f ) {
continue;
}
d = idMath::Sqrt( p[i] );
bal[n].angle = atan2( 0.5f * ( 2.0f * y * p[i] - gravity ) / d, d * x );
bal[n].time = x / ( cos( bal[n].angle ) * speed );
bal[n].angle = idMath::AngleNormalize180( RAD2DEG( bal[n].angle ) );
n++;
}
return n;
}
/*
=====================
HeightForTrajectory
Returns the maximum height of a given trajectory
=====================
*/
#if 0
static float HeightForTrajectory( const idVec3 &start, float zVel, float gravity ) {
float maxHeight, t;
t = zVel / gravity;
// maximum height of projectile
maxHeight = start.z - 0.5f * gravity * ( t * t );
return maxHeight;
}
#endif
/*
=====================
idAI::TestTrajectory
=====================
*/
bool idAI::TestTrajectory( const idVec3 &start, const idVec3 &end, float zVel, float gravity, float time, float max_height, const idClipModel *clip, int clipmask, const idEntity *ignore, const idEntity *targetEntity, int drawtime ) {
int i, numSegments;
float maxHeight, t, t2;
idVec3 points[5];
trace_t trace;
bool result;
t = zVel / gravity;
// maximum height of projectile
maxHeight = start.z - 0.5f * gravity * ( t * t );
// time it takes to fall from the top to the end height
t = idMath::Sqrt( ( maxHeight - end.z ) / ( 0.5f * -gravity ) );
// start of parabolic
points[0] = start;
if ( t < time ) {
numSegments = 4;
// point in the middle between top and start
t2 = ( time - t ) * 0.5f;
points[1].ToVec2() = start.ToVec2() + (end.ToVec2() - start.ToVec2()) * ( t2 / time );
points[1].z = start.z + t2 * zVel + 0.5f * gravity * t2 * t2;
// top of parabolic
t2 = time - t;
points[2].ToVec2() = start.ToVec2() + (end.ToVec2() - start.ToVec2()) * ( t2 / time );
points[2].z = start.z + t2 * zVel + 0.5f * gravity * t2 * t2;
// point in the middel between top and end
t2 = time - t * 0.5f;
points[3].ToVec2() = start.ToVec2() + (end.ToVec2() - start.ToVec2()) * ( t2 / time );
points[3].z = start.z + t2 * zVel + 0.5f * gravity * t2 * t2;
} else {
numSegments = 2;
// point halfway through
t2 = time * 0.5f;
points[1].ToVec2() = start.ToVec2() + ( end.ToVec2() - start.ToVec2() ) * 0.5f;
points[1].z = start.z + t2 * zVel + 0.5f * gravity * t2 * t2;
}
// end of parabolic
points[numSegments] = end;
if ( drawtime ) {
for ( i = 0; i < numSegments; i++ ) {
gameRenderWorld->DebugLine( colorRed, points[i], points[i+1], drawtime );
}
}
// make sure projectile doesn't go higher than we want it to go
for ( i = 0; i < numSegments; i++ ) {
if ( points[i].z > max_height ) {
// goes higher than we want to allow
return false;
}
}
result = true;
for ( i = 0; i < numSegments; i++ ) {
gameLocal.clip.Translation( trace, points[i], points[i+1], clip, mat3_identity, clipmask, ignore );
if ( trace.fraction < 1.0f ) {
if ( gameLocal.GetTraceEntity( trace ) == targetEntity ) {
result = true;
} else {
result = false;
}
break;
}
}
if ( drawtime ) {
if ( clip ) {
gameRenderWorld->DebugBounds( result ? colorGreen : colorYellow, clip->GetBounds().Expand( 1.0f ), trace.endpos, drawtime );
} else {
idBounds bnds( trace.endpos );
bnds.ExpandSelf( 1.0f );
gameRenderWorld->DebugBounds( result ? colorGreen : colorYellow, bnds, vec3_zero, drawtime );
}
}
return result;
}
/*
=====================
idAI::PredictTrajectory
returns true if there is a collision free trajectory for the clip model
aimDir is set to the ideal aim direction in order to hit the target
=====================
*/
bool idAI::PredictTrajectory( const idVec3 &firePos, const idVec3 &target, float projectileSpeed, const idVec3 &projGravity, const idClipModel *clip, int clipmask, float max_height, const idEntity *ignore, const idEntity *targetEntity, int drawtime, idVec3 &aimDir ) {
int n, i, j;
float zVel, a, t, pitch, s, c;
trace_t trace;
ballistics_t ballistics[2];
idVec3 dir[2];
idVec3 velocity;
idVec3 lastPos, pos;
assert( targetEntity );
// check if the projectile starts inside the target
if ( targetEntity->GetPhysics()->GetAbsBounds().IntersectsBounds( clip->GetBounds().Translate( firePos ) ) ) {
aimDir = target - firePos;
aimDir.Normalize();
return true;
}
// if no velocity or the projectile is not affected by gravity
if ( projectileSpeed <= 0.0f || projGravity == vec3_origin ) {
aimDir = target - firePos;
aimDir.Normalize();
gameLocal.clip.Translation( trace, firePos, target, clip, mat3_identity, clipmask, ignore );
if ( drawtime ) {
gameRenderWorld->DebugLine( colorRed, firePos, target, drawtime );
idBounds bnds( trace.endpos );
bnds.ExpandSelf( 1.0f );
gameRenderWorld->DebugBounds( ( trace.fraction >= 1.0f || ( gameLocal.GetTraceEntity( trace ) == targetEntity ) ) ? colorGreen : colorYellow, bnds, vec3_zero, drawtime );
}
return ( trace.fraction >= 1.0f || ( gameLocal.GetTraceEntity( trace ) == targetEntity ) );
}
n = Ballistics( firePos, target, projectileSpeed, projGravity[2], ballistics );
if ( n == 0 ) {
// there is no valid trajectory
aimDir = target - firePos;
aimDir.Normalize();
return false;
}
// make sure the first angle is the smallest
if ( n == 2 ) {
if ( ballistics[1].angle < ballistics[0].angle ) {
a = ballistics[0].angle; ballistics[0].angle = ballistics[1].angle; ballistics[1].angle = a;
t = ballistics[0].time; ballistics[0].time = ballistics[1].time; ballistics[1].time = t;
}
}
// test if there is a collision free trajectory
for ( i = 0; i < n; i++ ) {
pitch = DEG2RAD( ballistics[i].angle );
idMath::SinCos( pitch, s, c );
dir[i] = target - firePos;
dir[i].z = 0.0f;
dir[i] *= c * idMath::InvSqrt( dir[i].LengthSqr() );
dir[i].z = s;
zVel = projectileSpeed * dir[i].z;
if ( ai_debugTrajectory.GetBool() ) {
t = ballistics[i].time / 100.0f;
velocity = dir[i] * projectileSpeed;
lastPos = firePos;
pos = firePos;
for ( j = 1; j < 100; j++ ) {
pos += velocity * t;
velocity += projGravity * t;
gameRenderWorld->DebugLine( colorCyan, lastPos, pos );
lastPos = pos;
}
}
if ( TestTrajectory( firePos, target, zVel, projGravity[2], ballistics[i].time, firePos.z + max_height, clip, clipmask, ignore, targetEntity, drawtime ) ) {
aimDir = dir[i];
return true;
}
}
aimDir = dir[0];
// there is no collision free trajectory
return false;
}