TurtleMobility Class Reference

#include <TurtleMobility.h>

Inheritance diagram for TurtleMobility:

List of all members.

---

Detailed Description

LOGO-style movement model, with the script coming from XML. See NED file for more info.

Author:

Andras Varga

Protected Member Functions
virtual void	initialize (int)
	Initializes mobility model parameters.
virtual void	setTargetPosition ()
	Overridden from LineSegmentsMobilityBase. Invokes resumeScript().
virtual void	fixIfHostGetsOutside ()
	Overridden from LineSegmentsMobilityBase.
void	resumeScript ()
	Process next statements from script.
void	executeStatement (cXMLElement *nextStatement)
	Execute the given statement.
double	getValue (const char *s)
	Parse attrs in the script -- accepts things like "uniform(10,50) as well.
void	gotoNextStatement ()
	Advance nextStatement pointer.
Protected Attributes
cXMLElement *	turtleScript
cXMLElement *	nextStatement
double	speed
double	angle
BorderPolicy	borderPolicy
std::stack< long >	loopVars

---

Member Function Documentation

void TurtleMobility::executeStatement (  cXMLElement *  nextStatement  )  [protected]

Execute the given statement. { const char *tag = stmt->getTagName(); EV << "doing <" << tag << ">\n"; if (!strcmp(tag,"repeat")) { const char *nAttr = stmt->getAttribute("n"); long n = -1; // infinity -- that's the default if (nAttr) { n = (long) getValue(nAttr); if (n<0) error("<repeat>: negative repeat count at %s", stmt->getSourceLocation()); } loopVars.push(n); } else if (!strcmp(tag,"set")) { const char *speedAttr = stmt->getAttribute("speed"); const char *angleAttr = stmt->getAttribute("angle"); const char *xAttr = stmt->getAttribute("x"); const char *yAttr = stmt->getAttribute("y"); const char *bpAttr = stmt->getAttribute("borderPolicy"); if (speedAttr) speed = getValue(speedAttr); if (angleAttr) angle = getValue(angleAttr); if (xAttr) targetPos.x = pos.x = getValue(xAttr); if (yAttr) targetPos.y = pos.y = getValue(yAttr); if (speed<=0) error("<set>: speed is negative or zero at %s", stmt->getSourceLocation()); if (bpAttr) { if (!strcmp(bpAttr,"reflect")) borderPolicy = REFLECT; else if (!strcmp(bpAttr,"wrap")) borderPolicy = WRAP; else if (!strcmp(bpAttr,"placerandomly")) borderPolicy = PLACERANDOMLY; else if (!strcmp(bpAttr,"error")) borderPolicy = RAISEERROR; else error("<set>: value for attribute borderPolicy is invalid, should be " "'reflect', 'wrap', 'placerandomly' or 'error' at %s", stmt->getSourceLocation()); } } else if (!strcmp(tag,"forward")) { const char *dAttr = stmt->getAttribute("d"); const char *tAttr = stmt->getAttribute("t"); if (!dAttr && !tAttr) error("<forward>: must have at least attribute 't' or 'd' (or both) at %s", stmt->getSourceLocation()); double d, t; if (tAttr && dAttr) { // cover distance d in time t (current speed is ignored) d = getValue(dAttr); t = getValue(tAttr); } else if (dAttr) { // travel distance d at current speed d = getValue(dAttr); t = d / speed; } else // tAttr only { // travel for time t at current speed t = getValue(tAttr); d = speed * t; } if (t<0) error("<forward>: time (attribute t) is negative at %s", stmt->getSourceLocation()); if (d<0) error("<forward>: distance (attribute d) is negative at %s", stmt->getSourceLocation()); // FIXME handle zeros properly... targetPos.x += d * cos(PI * angle / 180); targetPos.y += d * sin(PI * angle / 180); targetTime += t; } else if (!strcmp(tag,"turn")) { const char *angleAttr = stmt->getAttribute("angle"); if (!angleAttr) error("<turn>: required attribute 'angle' missing at %s", stmt->getSourceLocation()); angle += getValue(angleAttr); } else if (!strcmp(tag,"wait")) { const char *tAttr = stmt->getAttribute("t"); if (!tAttr) error("<wait>: required attribute 't' missing at %s", stmt->getSourceLocation()); double t = getValue(tAttr); if (t<0) error("<wait>: time (attribute t) is negative (%g) at %s", t, stmt->getSourceLocation()); targetTime += t; // targetPos is unchanged } else if (!strcmp(tag,"moveto")) { const char *xAttr = stmt->getAttribute("x"); const char *yAttr = stmt->getAttribute("y"); const char *tAttr = stmt->getAttribute("t"); if (xAttr) targetPos.x = getValue(xAttr); if (yAttr) targetPos.y = getValue(yAttr); // travel to targetPos at current speed, or get there in time t (ignoring current speed then) double t = tAttr ? getValue(tAttr) : pos.distance(targetPos)/speed; if (t<0) error("<wait>: time (attribute t) is negative at %s", stmt->getSourceLocation()); targetTime += t; } else if (!strcmp(tag,"moveby")) { const char *xAttr = stmt->getAttribute("x"); const char *yAttr = stmt->getAttribute("y"); const char *tAttr = stmt->getAttribute("t"); if (xAttr) targetPos.x += getValue(xAttr); if (yAttr) targetPos.y += getValue(yAttr); // travel to targetPos at current speed, or get there in time t (ignoring current speed then) double t = tAttr ? getValue(tAttr) : pos.distance(targetPos)/speed; if (t<0) error("<wait>: time (attribute t) is negative at %s", stmt->getSourceLocation()); targetTime += t; } }

void TurtleMobility::fixIfHostGetsOutside (   )  [protected, virtual]

Overridden from LineSegmentsMobilityBase. Implements LineSegmentsMobilityBase. { handleIfOutside(borderPolicy, targetPos, step, angle); }

double TurtleMobility::getValue (  const char *  s  )  [protected]

Parse attrs in the script -- accepts things like "uniform(10,50) as well. { // first, textually replace $MAXX and $MAXY with their actual values std::string str; if (strchr(s,'$')) { char strMaxX[32], strMaxY[32]; sprintf(strMaxX, "%g", playgroundSizeX()-1); sprintf(strMaxY, "%g", playgroundSizeY()-1); str = s; std::string::size_type pos; while ((pos = str.find("$MAXX")) != std::string::npos) str.replace(pos, sizeof("$MAXX")-1, strMaxX); while ((pos = str.find("$MAXY")) != std::string::npos) str.replace(pos, sizeof("$MAXY")-1, strMaxY); s = str.c_str(); } // then use cPar to evaluate the string cPar tmp; if (!tmp.setFromText(s,'?')) error("wrong value '%s' around %s", s, nextStatement->getSourceLocation()); return tmp.doubleValue(); }

void TurtleMobility::gotoNextStatement (   )  [protected]

Advance nextStatement pointer. { // "statement either doesn't have a child, or it's a <repeat> and loop count is already pushed on the stack" ASSERT(!nextStatement->getFirstChild() || (!strcmp(nextStatement->getTagName(),"repeat") && !loopVars.empty())); if (nextStatement->getFirstChild() && (loopVars.top()!=0 || (loopVars.pop(),false))) // !=0: positive or -1 { // statement must be a <repeat> if it has children; repeat count>0 must be // on the stack; let's start doing the body. nextStatement = nextStatement->getFirstChild(); } else if (!nextStatement->getNextSibling()) { // no sibling -- either end of <repeat> body, or end of script ASSERT(nextStatement->getParentNode()==turtleScript ? loopVars.empty() : !loopVars.empty()); if (!loopVars.empty()) { // decrement and check loop counter if (loopVars.top()!=-1) // -1 means infinity loopVars.top()--; if (loopVars.top()!=0) // positive or -1 { // go to beginning of <repeat> block again nextStatement = nextStatement->getParentNode()->getFirstChild(); } else { // end of loop -- locate next statement after the <repeat> nextStatement = nextStatement->getParentNode(); gotoNextStatement(); } } else { // end of script nextStatement = NULL; } } else { // go to next statement (must exist -- see "if" above) nextStatement = nextStatement->getNextSibling(); } }

void TurtleMobility::initialize (  int  stage  )  [protected, virtual]

Initializes mobility model parameters. Reads the parameters. If the host is not stationary it calculates a random position and schedules a timer to trigger the first movement Reimplemented from LineSegmentsMobilityBase. { LineSegmentsMobilityBase::initialize(stage); EV << "initializing TurtleMobility stage " << stage << endl; if (stage == 1) { turtleScript = par("turtleScript"); nextStatement = turtleScript->getFirstChild(); speed = 1; angle = 0; borderPolicy = REFLECT; // a dirty trick to extract starting position out of the script // (start doing it, but then rewind to the beginning) resumeScript(); targetPos = pos; targetTime = simTime(); nextStatement = turtleScript->getFirstChild(); while (!loopVars.empty()) loopVars.pop(); updatePosition(); WATCH(speed); WATCH(angle); //WATCH(borderPolicy); } }

void TurtleMobility::resumeScript (   )  [protected]

Process next statements from script. Will set a new targetTime and targetPos { if (!nextStatement) { stationary = true; return; } simtime_t now = targetTime; // interpret statement while (nextStatement && targetTime==now) { executeStatement(nextStatement); gotoNextStatement(); } }

void TurtleMobility::setTargetPosition (   )  [protected, virtual]

Overridden from LineSegmentsMobilityBase. Invokes resumeScript(). Implements LineSegmentsMobilityBase. { resumeScript(); }

---

Member Data Documentation

double TurtleMobility::angle [protected]

BorderPolicy TurtleMobility::borderPolicy [protected]

std::stack<long> TurtleMobility::loopVars [protected]

cXMLElement* TurtleMobility::nextStatement [protected]

double TurtleMobility::speed [protected]

cXMLElement* TurtleMobility::turtleScript [protected]

---

The documentation for this class was generated from the following files:

• TurtleMobility.h
• TurtleMobility.cc

---