Modified source engine (2017) developed by valve and leaked in 2020. Not for commercial purporses
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// NextBotPath.cpp
// Encapsulate and manipulate a path through the world
// Author: Michael Booth, February 2006
//========= Copyright Valve Corporation, All rights reserved. ============//
#include "cbase.h"
#include "nav_mesh.h"
#include "fmtstr.h"
#include "NextBotPath.h"
#include "NextBotInterface.h"
#include "NextBotLocomotionInterface.h"
#include "NextBotBodyInterface.h"
#include "NextBotUtil.h"
#include "tier0/vprof.h"
// memdbgon must be the last include file in a .cpp file!!!
#include "tier0/memdbgon.h"
ConVar NextBotPathDrawIncrement( "nb_path_draw_inc", "100", FCVAR_CHEAT );
ConVar NextBotPathDrawSegmentCount( "nb_path_draw_segment_count", "100", FCVAR_CHEAT );
ConVar NextBotPathSegmentInfluenceRadius( "nb_path_segment_influence_radius", "100", FCVAR_CHEAT );
//--------------------------------------------------------------------------------------------------------------
Path::Path( void )
{
m_segmentCount = 0;
m_cursorPos = 0.0f;
m_isCursorDataDirty = true;
m_cursorData.segmentPrior = NULL;
m_ageTimer.Invalidate();
m_subject = NULL;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Determine actual path positions
*/
bool Path::ComputePathDetails( INextBot *bot, const Vector &start )
{
VPROF_BUDGET( "Path::ComputePathDetails", "NextBot" );
if (m_segmentCount == 0)
return false;
IBody *body = bot->GetBodyInterface();
ILocomotion *mover = bot->GetLocomotionInterface();
const float stepHeight = ( mover ) ? mover->GetStepHeight() : 18.0f;
// inflate hull width slightly as a safety margin
const float hullWidth = ( body ) ? body->GetHullWidth() + 5.0f : 1.0f;
// set first path position
if ( m_path[0].area->Contains( start ) )
{
m_path[0].pos = start;
}
else
{
// start in first area's center
m_path[0].pos = m_path[0].area->GetCenter();
}
m_path[0].ladder = NULL;
m_path[0].how = NUM_TRAVERSE_TYPES;
m_path[0].type = ON_GROUND;
// set positions along the path
for( int i=1; i<m_segmentCount; ++i )
{
Segment *from = &m_path[ i-1 ];
Segment *to = &m_path[ i ];
if ( to->how <= GO_WEST ) // walk along the floor to the next area
{
to->ladder = NULL;
from->area->ComputePortal( to->area, (NavDirType)to->how, &to->m_portalCenter, &to->m_portalHalfWidth );
// compute next point
ComputeAreaCrossing( bot, from->area, from->pos, to->area, (NavDirType)to->how, &to->pos );
// we need to walk out of "from" area, so keep Z where we can reach it
to->pos.z = from->area->GetZ( to->pos );
// if this is a "jump down" connection, we must insert an additional point on the path
//float expectedHeightDrop = from->area->GetZ( from->pos ) - to->area->GetZ( to->pos );
// measure the drop distance relative to the actual slope of the ground
Vector fromPos = from->pos;
fromPos.z = from->area->GetZ( fromPos );
Vector toPos = to->pos;
toPos.z = to->area->GetZ( toPos );
Vector groundNormal;
from->area->ComputeNormal( &groundNormal );
Vector alongPath = toPos - fromPos;
float expectedHeightDrop = -DotProduct( alongPath, groundNormal );
if ( expectedHeightDrop > mover->GetStepHeight() )
{
// NOTE: We can't know this is a drop-down yet, because of subtle interactions
// between nav area links and "portals" and "area crossings"
// compute direction of path just prior to "jump down"
Vector2D dir;
DirectionToVector2D( (NavDirType)to->how, &dir );
// shift top of "jump down" out a bit to "get over the ledge"
const float inc = 10.0f; // 0.25f * hullWidth;
const float maxPushDist = 2.0f * hullWidth; // 75.0f;
float halfWidth = hullWidth/2.0f;
float hullHeight = ( body ) ? body->GetCrouchHullHeight() : 1.0f;
float pushDist;
for( pushDist = 0.0f; pushDist <= maxPushDist; pushDist += inc )
{
Vector pos = to->pos + Vector( pushDist * dir.x, pushDist * dir.y, 0.0f );
Vector lowerPos = Vector( pos.x, pos.y, toPos.z );
trace_t result;
NextBotTraceFilterIgnoreActors filter( bot->GetEntity(), COLLISION_GROUP_NONE );
UTIL_TraceHull( pos, lowerPos,
Vector( -halfWidth, -halfWidth, stepHeight ), Vector( halfWidth, halfWidth, hullHeight ),
bot->GetBodyInterface()->GetSolidMask(), &filter, &result );
if ( result.fraction >= 1.0f )
{
// found clearance to drop
break;
}
}
Vector startDrop( to->pos.x + pushDist * dir.x, to->pos.y + pushDist * dir.y, to->pos.z );
Vector endDrop( startDrop.x, startDrop.y, to->area->GetZ( to->pos ) );
if ( bot->IsDebugging( NEXTBOT_PATH ) )
{
NDebugOverlay::Cross3D( startDrop, 5.0f, 255, 0, 255, true, 5.0f );
NDebugOverlay::Cross3D( endDrop, 5.0f, 255, 255, 0, true, 5.0f );
NDebugOverlay::VertArrow( startDrop, endDrop, 5.0f, 255, 100, 0, 255, true, 5.0f );
}
// verify that there is actually ground down there in case this is a far jump dropdown
float ground;
if ( TheNavMesh->GetGroundHeight( endDrop, &ground ) )
{
if ( startDrop.z > ground + stepHeight )
{
// if "ground" is lower than the next segment along the path
// there is a chasm between - this is not a drop down
// NOTE next->pos is not yet valid - this loop is computing it!
// const Segment *next = NextSegment( to );
// if ( !next || next->area->GetCenter().z < ground + stepHeight )
{
// this is a "jump down" link
to->pos = startDrop;
to->type = DROP_DOWN;
// insert a duplicate node to represent the bottom of the fall
if ( m_segmentCount < MAX_PATH_SEGMENTS-1 )
{
// copy nodes down
for( int j=m_segmentCount; j>i; --j )
m_path[j] = m_path[j-1];
// path is one node longer
++m_segmentCount;
// move index ahead into the new node we just duplicated
++i;
m_path[i].pos.x = endDrop.x;
m_path[i].pos.y = endDrop.y;
m_path[i].pos.z = ground;
m_path[i].type = ON_GROUND;
}
}
}
}
}
}
else if ( to->how == GO_LADDER_UP ) // to get to next area, must go up a ladder
{
// find our ladder
const NavLadderConnectVector *ladders = from->area->GetLadders( CNavLadder::LADDER_UP );
int it;
for( it=0; it<ladders->Count(); ++it )
{
CNavLadder *ladder = (*ladders)[ it ].ladder;
// can't use "behind" area when ascending...
if (ladder->m_topForwardArea == to->area ||
ladder->m_topLeftArea == to->area ||
ladder->m_topRightArea == to->area)
{
to->ladder = ladder;
to->pos = ladder->m_bottom + ladder->GetNormal() * 2.0f * HalfHumanWidth;
to->type = LADDER_UP;
break;
}
}
if (it == ladders->Count())
{
//PrintIfWatched( "ERROR: Can't find ladder in path\n" );
return false;
}
}
else if ( to->how == GO_LADDER_DOWN ) // to get to next area, must go down a ladder
{
// find our ladder
const NavLadderConnectVector *ladders = from->area->GetLadders( CNavLadder::LADDER_DOWN );
int it;
for( it=0; it<ladders->Count(); ++it )
{
CNavLadder *ladder = (*ladders)[ it ].ladder;
if (ladder->m_bottomArea == to->area)
{
to->ladder = ladder;
to->pos = ladder->m_top;
to->pos = ladder->m_top - ladder->GetNormal() * 2.0f * HalfHumanWidth;
to->type = LADDER_DOWN;
break;
}
}
if (it == ladders->Count())
{
//PrintIfWatched( "ERROR: Can't find ladder in path\n" );
return false;
}
}
else if ( to->how == GO_ELEVATOR_UP || to->how == GO_ELEVATOR_DOWN )
{
to->pos = to->area->GetCenter();
to->ladder = NULL;
}
}
//
// Scan for non-adjacent nav areas and add gap-jump-target nodes
// and jump-up target nodes for adjacent ledge mantling
// @todo Adjacency should be baked into the mesh data
//
for( int i=0; i<m_segmentCount-1; ++i )
{
Segment *from = &m_path[ i ];
Segment *to = &m_path[ i+1 ];
// first segment doesnt have a direction
if ( from->how != NUM_TRAVERSE_TYPES && from->how > GO_WEST )
continue;
if ( to->how > GO_WEST || !to->type == ON_GROUND )
continue;
// if areas are separated, we may need to 'gap jump' between them
// add a node to minimize the jump distance
Vector closeFrom, closeTo;
to->area->GetClosestPointOnArea( from->pos, &closeTo );
from->area->GetClosestPointOnArea( closeTo, &closeFrom );
if ( bot->IsDebugging( NEXTBOT_PATH ) )
{
NDebugOverlay::Line( closeFrom, closeTo, 255, 0, 255, true, 5.0f );
}
const float separationTolerance = 1.9f * GenerationStepSize;
if ( (closeFrom - closeTo).AsVector2D().IsLengthGreaterThan( separationTolerance ) && ( closeTo - closeFrom ).AsVector2D().IsLengthGreaterThan( 0.5f * fabs( closeTo.z - closeFrom.z ) ) )
{
// areas are disjoint and mostly level - add gap jump target
// compute landing spot in 'to' area
Vector landingPos;
to->area->GetClosestPointOnArea( to->pos, &landingPos );
// compute launch spot in 'from' area
Vector launchPos;
from->area->GetClosestPointOnArea( landingPos, &launchPos );
Vector forward = landingPos - launchPos;
forward.NormalizeInPlace();
const float halfWidth = hullWidth/2.0f;
// adjust path position to landing spot
to->pos = landingPos + forward * halfWidth;
// insert launch position just before that segment to ensure bot is
// positioned for minimal jump distance
Segment newSegment = *from;
newSegment.pos = launchPos - forward * halfWidth;
newSegment.type = JUMP_OVER_GAP;
InsertSegment( newSegment, i+1 );
++i;
}
else if ( (closeTo.z - closeFrom.z) > stepHeight )
{
// areas are adjacent, but need a jump-up - add a jump-to target
// adjust goal to be at top of ledge
//to->pos.z = to->area->GetZ( to->pos.x, to->pos.y );
// use center of climb-up destination area to make sure bot moves onto actual ground once they finish their climb
to->pos = to->area->GetCenter();
// add launch position at base of jump
Segment newSegment = *from;
Vector launchPos;
from->area->GetClosestPointOnArea( to->pos, &launchPos );
newSegment.pos = launchPos;
newSegment.type = CLIMB_UP;
if ( bot->IsDebugging( NEXTBOT_PATH ) )
{
NDebugOverlay::Cross3D( newSegment.pos, 15.0f, 255, 100, 255, true, 3.0f );
}
InsertSegment( newSegment, i+1 );
++i;
}
/** RETHINK THIS. It doesn't work in general cases, and messes up on doorways
else if ( from->type == ON_GROUND && from->how <= GO_WEST )
{
// if any segment is not directly walkable, add a segment
// fixup corners that are being cut too tightly
if ( mover && !mover->IsPotentiallyTraversable( from->pos, to->pos ) )
{
Segment newSegment = *from;
if ( bot->IsDebugging( INextBot::PATH ) )
{
NDebugOverlay::HorzArrow( from->pos, to->pos, 3.0f, 255, 0, 0, 255, true, 3.0f );
}
//newSegment.pos = from->area->GetCenter();
Vector2D shift;
DirectionToVector2D( OppositeDirection( (NavDirType)to->how ), &shift );
newSegment.pos = to->pos;
newSegment.pos.x += hullWidth * shift.x;
newSegment.pos.y += hullWidth * shift.y;
newSegment.type = ON_GROUND;
if ( bot->IsDebugging( INextBot::PATH ) )
{
NDebugOverlay::Cross3D( newSegment.pos, 15.0f, 255, 0, 255, true, 3.0f );
}
InsertSegment( newSegment, i+1 );
i += 2;
}
}
*/
}
return true;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Insert new segment at index i
*/
void Path::InsertSegment( Segment newSegment, int i )
{
if (m_segmentCount < MAX_PATH_SEGMENTS-1)
{
// shift segments to make room for new one
for( int j=m_segmentCount; j>i; --j )
m_path[j] = m_path[j-1];
// path is one node longer
++m_segmentCount;
m_path[i] = newSegment;
}
}
//--------------------------------------------------------------------------------------------------------------
/**
* Build trivial path when start and goal are in the same nav area
*/
bool Path::BuildTrivialPath( INextBot *bot, const Vector &goal )
{
const Vector &start = bot->GetPosition();
m_segmentCount = 0;
/// @todo Dangerous to use "nearset" nav area - could be far away
CNavArea *startArea = TheNavMesh->GetNearestNavArea( start );
if (startArea == NULL)
return false;
CNavArea *goalArea = TheNavMesh->GetNearestNavArea( goal );
if (goalArea == NULL)
return false;
m_segmentCount = 2;
m_path[0].area = startArea;
m_path[0].pos.x = start.x;
m_path[0].pos.y = start.y;
m_path[0].pos.z = startArea->GetZ( start );
m_path[0].ladder = NULL;
m_path[0].how = NUM_TRAVERSE_TYPES;
m_path[0].type = ON_GROUND;
m_path[1].area = goalArea;
m_path[1].pos.x = goal.x;
m_path[1].pos.y = goal.y;
m_path[1].pos.z = goalArea->GetZ( goal );
m_path[1].ladder = NULL;
m_path[1].how = NUM_TRAVERSE_TYPES;
m_path[1].type = ON_GROUND;
m_path[0].forward = m_path[1].pos - m_path[0].pos;
m_path[0].length = m_path[0].forward.NormalizeInPlace();
m_path[0].distanceFromStart = 0.0f;
m_path[0].curvature = 0.0f;
m_path[1].forward = m_path[0].forward;
m_path[1].length = 0.0f;
m_path[1].distanceFromStart = m_path[0].length;
m_path[1].curvature = 0.0f;
OnPathChanged( bot, COMPLETE_PATH );
return true;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Draw the path for debugging.
*/
void Path::Draw( const Path::Segment *start ) const
{
if ( !IsValid() )
return;
CFmtStr msg;
// limit length of path we draw
int count = NextBotPathDrawSegmentCount.GetInt();
const Segment *s = start ? start : FirstSegment();
int i=0;
while( s && count-- )
{
const Segment *next = NextSegment( s );
if ( next == NULL )
{
// end of the path
break;
}
Vector to = next->pos - s->pos;
float horiz = MAX( abs(to.x), abs(to.y) );
float vert = abs( to.z );
int r,g,b;
switch( s->type )
{
case DROP_DOWN: r = 255; g = 0; b = 255; break;
case CLIMB_UP: r = 0; g = 0; b = 255; break;
case JUMP_OVER_GAP: r = 0; g = 255; b = 255; break;
case LADDER_UP: r = 0; g = 255; b = 0; break;
case LADDER_DOWN: r = 0; g = 100; b = 0; break;
default: r = 255; g = 77; b = 0; break; // ON_GROUND
}
if ( s->ladder )
{
NDebugOverlay::VertArrow( s->ladder->m_bottom, s->ladder->m_top, 5.0f, r, g, b, 255, true, 0.1f );
}
else
{
NDebugOverlay::Line( s->pos, next->pos, r, g, b, true, 0.1f );
}
const float nodeLength = 25.0f;
if ( horiz > vert )
{
NDebugOverlay::HorzArrow( s->pos, s->pos + nodeLength * s->forward, 5.0f, r, g, b, 255, true, 0.1f );
}
else
{
NDebugOverlay::VertArrow( s->pos, s->pos + nodeLength * s->forward, 5.0f, r, g, b, 255, true, 0.1f );
}
NDebugOverlay::Text( s->pos, msg.sprintf( "%d", i ), true, 0.1f );
//NDebugOverlay::Text( s->pos, msg.sprintf( "%d (%3.2f)", i, s->curvature ), false, 0.1f );
s = next;
++i;
}
}
//--------------------------------------------------------------------------------------------------------------
/**
* Draw the path for debugging - MODIFIES cursor position
*/
void Path::DrawInterpolated( float from, float to )
{
if ( !IsValid() )
{
return;
}
float t = from;
MoveCursor( t );
const Data &data = GetCursorData();
Vector lastPos = data.pos;
do
{
t += NextBotPathDrawIncrement.GetFloat();
MoveCursor( t );
const Data &data = GetCursorData();
float curvePower = 3.0f * data.curvature;
int r = 255 * ( 1.0f - curvePower );
r = clamp( r, 0, 255 );
int g = 255 * ( 1.0f + curvePower );
g = clamp( g, 0, 255 );
NDebugOverlay::Line( lastPos, data.pos, r, g, 0, true, 0.1f );
/*
int i = 0xFF & (int)( data.pos.x + data.pos.y + data.pos.z );
i >>= 1;
i += 128;
NDebugOverlay::Line( data.pos, data.pos + 10.0f * data.forward, 0, i, i, true, 0.1f );
*/
lastPos = data.pos;
}
while( t < to );
}
//--------------------------------------------------------------------------------------------------------------
/**
* Check line of sight from 'anchor' node on path to subsequent nodes until
* we find a node that can't been seen from 'anchor'.
*/
int Path::FindNextOccludedNode( INextBot *bot, int anchorIndex )
{
ILocomotion *mover = bot->GetLocomotionInterface();
if ( mover == NULL)
{
return m_segmentCount;
}
Segment *anchor = &m_path[ anchorIndex ];
for( int i=anchorIndex+1; i<m_segmentCount; ++i )
{
Segment *to = &m_path[i];
// if this segment is not on the ground, or is precise, don't skip past it
if ( !to->type == ON_GROUND || (to->area->GetAttributes() & NAV_MESH_PRECISE) )
{
return i;
}
if ( !mover->IsPotentiallyTraversable( anchor->pos, to->pos, ILocomotion::IMMEDIATELY ) )
{
// cant reach this node directly from anchor node
return i;
}
if ( mover->HasPotentialGap( anchor->pos, to->pos ) )
{
// we would fall into a gap if we took this cutoff
return i;
}
}
return m_segmentCount;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Smooth out path, removing redundant nodes
*/
void Path::Optimize( INextBot *bot )
{
// this is SUPER expensive - especially the IsGap() check
return;
VPROF_BUDGET( "Path::Optimize", "NextBot" );
if (m_segmentCount < 3)
return;
int anchor = 0;
while( anchor < m_segmentCount )
{
int occluded = FindNextOccludedNode( bot, anchor );
int nextAnchor = occluded-1;
if (nextAnchor > anchor)
{
// remove redundant nodes between anchor and nextAnchor
int removeCount = nextAnchor - anchor - 1;
if (removeCount > 0)
{
for( int i=nextAnchor; i<m_segmentCount; ++i )
{
m_path[i-removeCount] = m_path[i];
}
m_segmentCount -= removeCount;
}
}
++anchor;
}
}
//--------------------------------------------------------------------------------------------------------------
/**
* Compute final data for completed path
*/
void Path::PostProcess( void )
{
VPROF_BUDGET( "Path::PostProcess", "NextBot" );
m_ageTimer.Start();
if (m_segmentCount == 0)
return;
if (m_segmentCount == 1)
{
m_path[0].forward = vec3_origin;
m_path[0].length = 0.0f;
m_path[0].distanceFromStart = 0.0f;
m_path[0].curvature = 0.0f;
return;
}
float distanceSoFar = 0.0f;
int i;
for( i=0; i < m_segmentCount-1; ++i )
{
Segment *from = &m_path[ i ];
Segment *to = &m_path[ i+1 ];
from->forward = to->pos - from->pos;
from->length = from->forward.NormalizeInPlace();
from->distanceFromStart = distanceSoFar;
distanceSoFar += from->length;
}
// compute curvature in XY plane
Vector2D from, to;
for( i=1; i < m_segmentCount-1; ++i )
{
if (m_path[ i ].type != ON_GROUND)
{
m_path[ i ].curvature = 0.0f;
}
else
{
from = m_path[ i-1 ].forward.AsVector2D();
from.NormalizeInPlace();
to = m_path[ i ].forward.AsVector2D();
to.NormalizeInPlace();
m_path[ i ].curvature = 0.5f * ( 1.0f - from.Dot( to ) );
Vector2D right( -from.y, from.x );
if ( to.Dot( right ) < 0.0f )
{
m_path[ i ].curvature = -m_path[ i ].curvature;
}
}
}
// first segment has no curvature
m_path[ 0 ].curvature = 0.0f;
// last segment maintains direction
m_path[ i ].forward = m_path[ i-1 ].forward;
m_path[ i ].length = 0.0f;
m_path[ i ].distanceFromStart = distanceSoFar;
m_path[ i ].curvature = 0.0f;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Return a position on the path at the given distance from the path start
*/
const Vector &Path::GetPosition( float distanceFromStart, const Segment *start ) const
{
if (!IsValid())
{
return vec3_origin;
}
float lengthSoFar;
const Segment *segment;
if (start)
{
segment = start;
lengthSoFar = start->distanceFromStart;
}
else
{
segment = &m_path[0];
lengthSoFar = 0.0f;
}
if (segment->distanceFromStart > distanceFromStart)
{
// clamp to path start
return segment->pos;
}
const Segment *next = NextSegment( segment );
Vector delta;
float length;
while( next )
{
delta = next->pos - segment->pos;
length = segment->length;
if (lengthSoFar + length >= distanceFromStart)
{
// desired point is on this segment of the path
float overlap = distanceFromStart - lengthSoFar;
float t = overlap / length;
m_pathPos = segment->pos + t * delta;
return m_pathPos;
}
lengthSoFar += length;
segment = next;
next = NextSegment( next );
}
// clamp to path end
return segment->pos;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Return the closest point on the path to the given position
*/
const Vector &Path::GetClosestPosition( const Vector &pos, const Segment *start, float alongLimit ) const
{
const Segment *segment = (start) ? start : &m_path[0];
if (segment == NULL)
{
return pos;
}
m_closePos = pos;
float closeRangeSq = 99999999999.9f;
float distanceSoFar = 0.0f;
while( alongLimit == 0.0f || distanceSoFar <= alongLimit )
{
const Segment *nextSegment = NextSegment( segment );
if (nextSegment)
{
Vector close;
CalcClosestPointOnLineSegment( pos, segment->pos, nextSegment->pos, close );
float rangeSq = (close - pos).LengthSqr();
if (rangeSq < closeRangeSq)
{
m_closePos = close;
closeRangeSq = rangeSq;
}
}
else
{
// end of the path
break;
}
distanceSoFar += segment->length;
segment = nextSegment;
}
return m_closePos;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Replace this path with the given path's data
*/
void Path::Copy( INextBot *bot, const Path &path )
{
VPROF_BUDGET( "Path::Copy", "NextBot" );
Invalidate();
for( int i = 0; i < path.m_segmentCount; ++i )
{
m_path[i] = path.m_path[i];
}
m_segmentCount = path.m_segmentCount;
OnPathChanged( bot, COMPLETE_PATH );
}
//--------------------------------------------------------------------------------------------------------------
/**
* Set cursor position to closest point on path to given position
*/
void Path::MoveCursorToClosestPosition( const Vector &pos, SeekType type, float alongLimit ) const
{
if ( !IsValid() )
{
return;
}
if ( type == SEEK_ENTIRE_PATH || type == SEEK_AHEAD )
{
const Segment *segment;
if ( type == SEEK_AHEAD )
{
// continue search from cursor position onward
if ( m_cursorData.segmentPrior )
{
segment = m_cursorData.segmentPrior;
}
else
{
// no prior segment, start from the start
segment = &m_path[ 0 ];
}
}
else
{
// search entire path from the start
segment = &m_path[ 0 ];
}
m_cursorData.pos = pos;
m_cursorData.segmentPrior = segment;
float closeRangeSq = 99999999999.9f;
float distanceSoFar = 0.0f;
while( alongLimit == 0.0f || distanceSoFar <= alongLimit )
{
const Segment *nextSegment = NextSegment( segment );
if ( nextSegment )
{
Vector close;
CalcClosestPointOnLineSegment( pos, segment->pos, nextSegment->pos, close );
float rangeSq = ( close - pos ).LengthSqr();
if ( rangeSq < closeRangeSq )
{
m_cursorData.pos = close;
m_cursorData.segmentPrior = segment;
closeRangeSq = rangeSq;
}
}
else
{
// end of the path
break;
}
distanceSoFar += segment->length;
segment = nextSegment;
}
//
// Move cursor to closest point on path
//
segment = m_cursorData.segmentPrior;
float t = ( m_cursorData.pos - segment->pos ).Length() / segment->length;
m_cursorPos = segment->distanceFromStart + t * segment->length;
m_isCursorDataDirty = true;
}
else
{
AssertMsg( false, "SEEK_BEHIND not implemented" );
}
}
//--------------------------------------------------------------------------------------------------------------
/**
* Return path state at the current cursor position
*/
const Path::Data &Path::GetCursorData( void ) const
{
if ( IsValid() )
{
if ( m_isCursorDataDirty )
{
const float epsilon = 0.0001f;
if ( m_cursorPos < epsilon || m_segmentCount < 2 )
{
// start of path
m_cursorData.pos = m_path[0].pos;
m_cursorData.forward = m_path[0].forward;
m_cursorData.curvature = m_path[0].curvature;
m_cursorData.segmentPrior = &m_path[0];
}
else if ( m_cursorPos > GetLength() - epsilon )
{
// end of path
m_cursorData.pos = m_path[ m_segmentCount-1 ].pos;
m_cursorData.forward = m_path[ m_segmentCount-1 ].forward;
m_cursorData.curvature = m_path[ m_segmentCount-1 ].curvature;
m_cursorData.segmentPrior = &m_path[ m_segmentCount-1 ];
}
else
{
// along path
float lengthSoFar = 0.0f;
const Segment *segment = &m_path[0];
const Segment *next = NextSegment( segment );
while( next )
{
float length = segment->length;
if ( lengthSoFar + length >= m_cursorPos )
{
// desired point is on this segment of the path
float overlap = m_cursorPos - lengthSoFar;
float t = 1.0f; // 0-length segments are assumed to be complete, to avoid NaNs
if ( length > 0.0f )
{
t = overlap / length;
}
// interpolate data at this point along the path
m_cursorData.pos = segment->pos + t * ( next->pos - segment->pos );
m_cursorData.forward = segment->forward + t * ( next->forward - segment->forward );
m_cursorData.segmentPrior = segment;
// curvature fades to zero along midpoint of long straight segments
// and is influenced as it nears ends of segment
if ( overlap < NextBotPathSegmentInfluenceRadius.GetFloat() )
{
if ( length - overlap < NextBotPathSegmentInfluenceRadius.GetFloat() )
{
// near start and end - interpolate
float startCurvature = segment->curvature * ( 1.0f - ( overlap / NextBotPathSegmentInfluenceRadius.GetFloat() ) );
float endCurvature = next->curvature * ( 1.0f - ( ( length - overlap ) / NextBotPathSegmentInfluenceRadius.GetFloat() ) );
m_cursorData.curvature = ( startCurvature + endCurvature ) / 2.0f;
}
else
{
// near start only
m_cursorData.curvature = segment->curvature * ( 1.0f - ( overlap / NextBotPathSegmentInfluenceRadius.GetFloat() ) );
}
}
else if ( length - overlap < NextBotPathSegmentInfluenceRadius.GetFloat() )
{
// near end only
m_cursorData.curvature = next->curvature * ( 1.0f - ( ( length - overlap ) / NextBotPathSegmentInfluenceRadius.GetFloat() ) );
}
break;
}
lengthSoFar += length;
segment = next;
next = NextSegment( next );
}
}
// data is up to date
m_isCursorDataDirty = false;
}
}
else
{
// path is not valid
m_cursorData.pos = vec3_origin;
m_cursorData.forward = Vector( 1.0f, 0, 0 );
m_cursorData.curvature = 0.0f;
m_cursorData.segmentPrior = NULL;
}
return m_cursorData;
}
//--------------------------------------------------------------------------------------------------------------
/**
* Determine exactly where the path goes between the given two areas
* on the path. Return this point in 'crossPos'.
*/
void Path::ComputeAreaCrossing( INextBot *bot, const CNavArea *from, const Vector &fromPos, const CNavArea *to, NavDirType dir, Vector *crossPos ) const
{
from->ComputeClosestPointInPortal( to, dir, fromPos, crossPos );
// move goal position into the goal area a bit to avoid running directly along the edge of an area against a wall, etc
// don't do this unless area is against a wall - and what if our hull is wider than the area?
// AddDirectionVector( crossPos, dir, bot->GetBodyInterface()->GetHullWidth()/2.0f );
}