OK, here are the two files. Maybe it would be possible to make Particle a
template class, so that the details of tiling and texture handling could be
customized? I guess making the particle a virtual class would kill performance,
so template design could be a way around that. What do you think?
------------------
Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=15746#15746
#include <osgParticle/Particle>
#include <osgParticle/LinearInterpolator>
#include <osgParticle/ParticleSystem>
#include <osg/Vec3>
#include <osg/Vec4>
#include <osg/Matrix>
#include <osg/GL>
#include <osg/Notify>
namespace
{
const float cosPI3 = cosf(osg::PI / 3.0f);
const float sinPI3 = sinf(osg::PI / 3.0f);
const float hex_texcoord_x1 = 0.5f + 0.5f * cosPI3;
const float hex_texcoord_x2 = 0.5f - 0.5f * cosPI3;
const float hex_texcoord_y1 = 0.5f + 0.5f * sinPI3;
const float hex_texcoord_y2 = 0.5f - 0.5f * sinPI3;
}
osgParticle::Particle::Particle()
: _shape(QUAD),
_sr(0.2f, 0.2f),
_ar(1, 0),
_cr(osg::Vec4(1, 1, 1, 1), osg::Vec4(1, 1, 1, 1)),
_si(new LinearInterpolator),
_ai(new LinearInterpolator),
_ci(new LinearInterpolator),
_alive(true),
_mustdie(false),
_lifeTime(2),
_radius(0.2f),
_mass(0.1f),
_massinv(10.0f),
_prev_pos(0, 0, 0),
_position(0, 0, 0),
_velocity(0, 0, 0),
_prev_angle(0, 0, 0),
_angle(0, 0, 0),
_angul_arvel(0, 0, 0),
_t0(0),
_current_size(0),
_current_alpha(0),
_s_tile(1.0f),
_t_tile(1.0f),
_start_tile(0),
_end_tile(0),
_cur_tile(-1),
_s_coord(0.0f),
_t_coord(0.0f),
_previousParticle(INVALID_INDEX),
_nextParticle(INVALID_INDEX)
{
}
bool osgParticle::Particle::update(double dt)
{
// this method should return false when the particle dies;
// so, if we were instructed to die, do it now and return.
if (_mustdie) {
_alive = false;
return false;
}
double x = 0;
// if we don't live forever, compute our normalized age.
if (_lifeTime > 0) {
x = _t0 / _lifeTime;
}
_t0 += dt;
// if our age is over the lifetime limit, then die and return.
if (x > 1) {
_alive = false;
return false;
}
//Compute the current texture tile based on our normalized age
int currentTile = _start_tile + static_cast<int>(x * getNumTiles());
//If the current texture tile is different from previous, then compute new
texture coords
if(currentTile != _cur_tile)
{
_cur_tile = currentTile;
_s_coord = _s_tile * fmod(_cur_tile , 1.0 / _s_tile);
_t_coord = 1.0 - _t_tile * (static_cast<int>(_cur_tile * _t_tile) + 1);
// osg::notify(osg::NOTICE)<<this<<" setting tex coords "<<_s_coord<<"
"<<_t_coord<<std::endl;
}
// compute the current values for size, alpha and color.
if (_lifeTime <= 0) {
if (dt == _t0) {
_current_size = _sr.get_random();
_current_alpha = _ar.get_random();
_current_color = _cr.get_random();
}
} else {
_current_size = _si.get()->interpolate(x, _sr);
_current_alpha = _ai.get()->interpolate(x, _ar);
_current_color = _ci.get()->interpolate(x, _cr);
}
// update position
_prev_pos = _position;
_position += _velocity * dt;
// update angle
_prev_angle = _angle;
_angle += _angul_arvel * dt;
if (_angle.x() > osg::PI*2) _angle.x() -= osg::PI*2;
if (_angle.x() < -osg::PI*2) _angle.x() += osg::PI*2;
if (_angle.y() > osg::PI*2) _angle.y() -= osg::PI*2;
if (_angle.y() < -osg::PI*2) _angle.y() += osg::PI*2;
if (_angle.z() > osg::PI*2) _angle.z() -= osg::PI*2;
if (_angle.z() < -osg::PI*2) _angle.z() += osg::PI*2;
return true;
}
void osgParticle::Particle::render(const osg::Vec3& xpos, const osg::Vec3& px,
const osg::Vec3& py, float scale) const
{
glColor4f( _current_color.x(),
_current_color.y(),
_current_color.z(),
_current_color.w() * _current_alpha);
osg::Vec3 p1(px * _current_size * scale);
osg::Vec3 p2(py * _current_size * scale);
switch (_shape)
{
case POINT:
glVertex3f(xpos.x(), xpos.y(), xpos.z());
break;
case QUAD:
glTexCoord2f(_s_coord, _t_coord);
glVertex3fv((xpos-(p1+p2)).ptr());
glTexCoord2f(_s_coord+_s_tile, _t_coord);
glVertex3fv((xpos+(p1-p2)).ptr());
glTexCoord2f(_s_coord+_s_tile, _t_coord+_t_tile);
glVertex3fv((xpos+(p1+p2)).ptr());
glTexCoord2f(_s_coord, _t_coord+_t_tile);
glVertex3fv((xpos-(p1-p2)).ptr());
break;
case QUAD_TRIANGLESTRIP:
glPushMatrix();
glTranslatef(xpos.x(), xpos.y(), xpos.z());
// we must glBegin() and glEnd() here, because each particle is a
single strip
glBegin(GL_TRIANGLE_STRIP);
glTexCoord2f(_s_coord+_s_tile, _t_coord+_t_tile);
glVertex3fv((p1+p2).ptr());
glTexCoord2f(_s_coord, _t_coord+_t_tile);
glVertex3fv((-p1+p2).ptr());
glTexCoord2f(_s_coord+_s_tile, _t_coord);
glVertex3fv((p1-p2).ptr());
glTexCoord2f(_s_coord, _t_coord);
glVertex3fv((-p1-p2).ptr());
glPopMatrix();
break;
case HEXAGON:
glPushMatrix();
glTranslatef(xpos.x(), xpos.y(), xpos.z());
// we must glBegin() and glEnd() here, because each particle is a
single fan
glBegin(GL_TRIANGLE_FAN);
glTexCoord2f(_s_coord + _s_tile * 0.5f, _t_coord + _t_tile * 0.5f);
glVertex3f(0,0,0);
glTexCoord2f(_s_coord + _s_tile * hex_texcoord_x1, _t_coord + _t_tile *
hex_texcoord_y1);
glVertex3fv((p1*cosPI3+p2*sinPI3).ptr());
glTexCoord2f(_s_coord + _s_tile * hex_texcoord_x2, _t_coord + _t_tile *
hex_texcoord_y1);
glVertex3fv((-p1*cosPI3+p2*sinPI3).ptr());
glTexCoord2f(_s_coord, _t_coord + _t_tile * 0.5f);
glVertex3fv((-p1).ptr());
glTexCoord2f(_s_coord + _s_tile * hex_texcoord_x2, _t_coord + _t_tile *
hex_texcoord_y2);
glVertex3fv((-p1*cosPI3-p2*sinPI3).ptr());
glTexCoord2f(_s_coord + _s_tile * hex_texcoord_x1, _t_coord + _t_tile *
hex_texcoord_y2);
glVertex3fv((p1*cosPI3-p2*sinPI3).ptr());
glTexCoord2f(_s_coord + _s_tile, _t_coord + _t_tile * 0.5f);
glVertex3fv((p1).ptr());
glTexCoord2f(_s_coord + _s_tile * hex_texcoord_x1, _t_coord + _t_tile *
hex_texcoord_y1);
glVertex3fv((p1*cosPI3+p2*sinPI3).ptr());
glEnd();
break;
case LINE:
{
// Get the normalized direction of the particle, to be used in the
// calculation of one of the linesegment endpoints.
float vl = _velocity.length();
if (vl != 0) {
osg::Vec3 v = _velocity * _current_size * scale / vl;
glTexCoord1f(0);
glVertex3f(xpos.x(), xpos.y(), xpos.z());
glTexCoord1f(1);
glVertex3f(xpos.x() + v.x(), xpos.y() + v.y(), xpos.z() +
v.z());
}
}
break;
default:
osg::notify(osg::WARN) << "Invalid shape for particles\n";
}
}
void
osgParticle::Particle::setUpTexCoordsAsPartOfConnectedParticleSystem(ParticleSystem*
ps)
{
if (getPreviousParticle()!=Particle::INVALID_INDEX)
{
update(0.0);
Particle* previousParticle = ps->getParticle(getPreviousParticle());
const osg::Vec3& previousPosition = previousParticle->getPosition();
const osg::Vec3& newPosition = getPosition();
float distance = (newPosition-previousPosition).length();
float s_coord_delta = 0.5f*distance/getCurrentSize();
float s_coord = previousParticle->_s_coord + s_coord_delta;
setTextureTile(1,1,0);
_cur_tile = 0;
_s_coord = s_coord;
_t_coord = 0.0f;
}
}
_______________________________________________
osg-submissions mailing list
[email protected]
http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org
