// this function updates the particle
void Particles::run_particle(float seconds)
{
// handle lifespan
life += seconds;
if(life > lifespan)
{
reset_particle();
return;
}
velocity += acceleration * seconds;
position += velocity * seconds;
if(position.y < 11 && position.z < -14)
reset_particle();
if(position.z > -14)
{
if(!((position.y > ((-11/45)*position.z)) && (position.y < ((-18/45)*position.z + 14))))
reset_particle();
}
if((position.y <= min.y || position.y > max.y) || (position.x <= min.x || position.x > max.x)||(position.z <= min.z || position.z > max.z)){
reset_particle();
}
return;
}
Particles::Particles(D3DXVECTOR3 starting,D3DXVECTOR3 mi, D3DXVECTOR3 ma,D3DXVECTOR3 v, D3DXVECTOR3 a){
start = starting;
min = mi;
max = ma;
startV = v;
startA = a;
reset_particle();
}
// this function updates the particle
void Particles::run_particle(float seconds)
{
// handle lifespan
life += seconds;
if(life > lifespan)
{
reset_particle();
return;
}
velocity += acceleration * seconds;
position += velocity * seconds;
if((position.y <= min.y || position.y > max.y) || (position.x <= min.x || position.x > max.x)||(position.z <= min.z || position.z > max.z)){
reset_particle();
}
return;
}
void SNOW::update(float time) //对所有雪花进行更新，死了的雪花则将其复活
{
list<ATTRIBUTE>::iterator i;
for(i = _particles.begin();i != _particles.end();i++)
{
i->_position += i->_velocity * time; //速度乘以时间等于位移
if(_box.IsPointInside(i->_position) == false)
reset_particle(&(*i));
}
}
HRESULT ParticleSystem::initialise(LPDIRECT3DDEVICE9 device)
{
// Store the render target for later use...
renderTarget_ = device;
Particle p;
reset_particle(p);
particles_.resize(maxParticles_, p); // Create a vector of empty particles - make 'max_particles_' copies of particle 'p'.
// Create a vertex buffer for the particles (each particule represented as an individual vertex).
int buffer_size = maxParticles_ * sizeof(POINTVERTEX);
// The data in the buffer doesn't exist at this point, but the memory space
// is allocated and the pointer to it (g_pPointBuffer) also exists.
if (FAILED(device -> CreateVertexBuffer(buffer_size, 0, D3DFVF_POINTVERTEX, D3DPOOL_DEFAULT, &points_, NULL)))
{
return E_FAIL; // Return if the vertex buffer culd not be created.
}
return S_OK;
}
