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// This file may be redistributed and modified only under the terms of
// the GNU General Public License (See COPYING for details).
// Copyright (C) 2003 Damien McGinnes
#include <Mercator/Terrain.h>
#include <Mercator/Segment.h>
#include <Mercator/Intersect.h>
#include <iostream>
//test intersection using a rudimentary physics simulation
//this drops a particle onto the terrain and it bounces around a bit
int main()
{
Mercator::Terrain terrain;
terrain.setBasePoint(0, 0, 2.8);
terrain.setBasePoint(1, 0, 7.1);
terrain.setBasePoint(0, 1, 0.2);
terrain.setBasePoint(1, 1, 14.7);
Mercator::Segment * segment = terrain.getSegment(0, 0);
if (segment == 0) {
std::cerr << "Segment not created by addition of required basepoints"
<< std::endl << std::flush;
return 1;
}
segment->populate();
WFMath::Point<3> pos(30.0,30.0,100.0); //starting position
WFMath::Vector<3> vel(0.0,1.0,0.0); //starting velocity
WFMath::Vector<3> grav(0.0,0.0,-9.8); //gravity
WFMath::Point<3> intersection;
WFMath::Vector<3> intnormal;
float timestep = 0.1;
float e = 0.2; //elasticity of collision
float totalT = 20.0; //time limit
float par = 0.0;
float t = timestep;
while (totalT > timestep) {
vel += t * grav;
if (Mercator::Intersect(terrain, pos, vel * t, intersection, intnormal, par)) {
//set pos to collision time,
//less a small amout to keep objects apart
pos = intersection - (vel * .01 * t);
WFMath::Vector<3> impulse = intnormal * (Dot(vel, intnormal) * -2);
std::cerr << "HIT" << std::endl;
vel = (vel + impulse) * e; //not sure of the impulse equation, but this will do
if (vel.sqrMag() < 0.01) {
//stop if velocities are small
std::cerr << "friction stop" << std::endl;
break;
}
totalT -= par*t;
t = (1.0-par)*t;
}
else {
pos += vel*t;
totalT -= t;
t = timestep;
}
std::cerr << "timeLeft:" << totalT << " end pos" << pos << " vel" << vel << std::endl;
}
return 0;
}
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