//------------------------------------------------------------------------------
//
bool
gosFX::PointCloud::AnimateParticle(
uint32_t index,
const Stuff::LinearMatrix4D* world_to_new_local,
Stuff::Time till
)
{
Check_Object(this);
//
//-----------------------------------------------------------------------
// If this cloud is unparented, we need to transform the point from local
// space into world space and set the internal position/velocity pointers
// to these temporary values
//-----------------------------------------------------------------------
//
Particle* particle = GetParticle(index);
Check_Object(particle);
float age = particle->m_age;
if(age >= 1.0f)
return false;
Set_Statistic(Point_Count, Point_Count + 1);
Stuff::Vector3D* velocity = &particle->m_localLinearVelocity;
Stuff::Point3D* translation = &m_P_localTranslation[index];
int32_t sim_mode = GetSimulationMode();
if(sim_mode == DynamicWorldSpaceSimulationMode)
{
Check_Object(translation);
Check_Object(velocity);
particle->m_worldLinearVelocity.Multiply(*velocity, m_localToWorld);
particle->m_worldTranslation.Multiply(*translation, m_localToWorld);
translation = &particle->m_worldTranslation;
velocity = &particle->m_worldLinearVelocity;
}
Check_Object(translation);
Check_Object(velocity);
//
//------------------------------------------------------------------
// First, calculate the drag on the particle. Drag can never assist
// velocity
//------------------------------------------------------------------
//
float seed = particle->m_seed;
Specification* spec = GetSpecification();
Check_Object(spec);
Stuff::Vector3D ether;
ether.x = spec->m_pEtherVelocityX.ComputeValue(age, seed);
ether.y = spec->m_pEtherVelocityY.ComputeValue(age, seed);
ether.z = spec->m_pEtherVelocityZ.ComputeValue(age, seed);
Stuff::Vector3D accel(Stuff::Vector3D::Identity);
//
//-------------------------------------------------------------------
// Deal with pseudo-world simulation. In this mode, we interpret the
// forces as if they are already in worldspace, and we transform them
// back to local space
//-------------------------------------------------------------------
//
float drag = -spec->m_pDrag.ComputeValue(age, seed);
Max_Clamp(drag, 0.0f);
if(sim_mode == StaticWorldSpaceSimulationMode)
{
Stuff::LinearMatrix4D world_to_effect;
world_to_effect.Invert(m_localToWorld);
Stuff::Vector3D local_ether;
local_ether.MultiplyByInverse(ether, world_to_effect);
Stuff::Vector3D rel_vel;
rel_vel.Subtract(*velocity, local_ether);
accel.Multiply(rel_vel, drag);
//
//-----------------------------------------
// Now, add in acceleration of the particle
//-----------------------------------------
//
Stuff::Vector3D world_accel;
world_accel.x = spec->m_pAccelerationX.ComputeValue(age, seed);
world_accel.y = spec->m_pAccelerationY.ComputeValue(age, seed);
world_accel.z = spec->m_pAccelerationZ.ComputeValue(age, seed);
Stuff::Vector3D local_accel;
local_accel.Multiply(world_accel, world_to_effect);
accel += local_accel;
}
//
//----------------------------------------------------------------------
// Otherwise, just add the forces in the same space the particles are in
//----------------------------------------------------------------------
//
else
{
Stuff::Vector3D rel_vel;
rel_vel.Subtract(*velocity, ether);
accel.Multiply(rel_vel, drag);
//
//-----------------------------------------
// Now, add in acceleration of the particle
//-----------------------------------------
//
accel.x += spec->m_pAccelerationX.ComputeValue(age, seed);
accel.y += spec->m_pAccelerationY.ComputeValue(age, seed);
accel.z += spec->m_pAccelerationZ.ComputeValue(age, seed);
}
//
//-------------------------------------------------
// Compute the particle's new velocity and position
//-------------------------------------------------
//
float time_slice =
static_cast<float>(till - m_lastRan);
velocity->AddScaled(*velocity, accel, time_slice);
translation->AddScaled(*translation, *velocity, time_slice);
//
//---------------------------------------------------------------------
// If we are unparented, we need to transform the velocity and position
// data back into the NEW local space
//---------------------------------------------------------------------
//
if(sim_mode == DynamicWorldSpaceSimulationMode)
{
Check_Object(world_to_new_local);
particle->m_localLinearVelocity.Multiply(
particle->m_worldLinearVelocity,
*world_to_new_local
);
m_P_localTranslation[index].Multiply(
particle->m_worldTranslation,
*world_to_new_local
);
}
//
//------------------
// Animate the color
//------------------
//
Check_Pointer(m_P_color);
m_P_color[index].red = spec->m_pRed.ComputeValue(age, seed);
m_P_color[index].green = spec->m_pGreen.ComputeValue(age, seed);
m_P_color[index].blue = spec->m_pBlue.ComputeValue(age, seed);
m_P_color[index].alpha = spec->m_pAlpha.ComputeValue(age, seed);
return true;
}
