mirror of
https://github.com/Bithack/principia.git
synced 2026-06-24 02:04:08 +00:00
156 lines
3.3 KiB
C++
156 lines
3.3 KiB
C++
/*
|
|
* Copyright (c) 2013 Google, Inc.
|
|
*
|
|
* This software is provided 'as-is', without any express or implied
|
|
* warranty. In no event will the authors be held liable for any damages
|
|
* arising from the use of this software.
|
|
* Permission is granted to anyone to use this software for any purpose,
|
|
* including commercial applications, and to alter it and redistribute it
|
|
* freely, subject to the following restrictions:
|
|
* 1. The origin of this software must not be misrepresented; you must not
|
|
* claim that you wrote the original software. If you use this software
|
|
* in a product, an acknowledgment in the product documentation would be
|
|
* appreciated but is not required.
|
|
* 2. Altered source versions must be plainly marked as such, and must not be
|
|
* misrepresented as being the original software.
|
|
* 3. This notice may not be removed or altered from any source distribution.
|
|
*/
|
|
#include <Box2D/Particle/b2ParticleGroup.h>
|
|
#include <Box2D/Particle/b2ParticleSystem.h>
|
|
|
|
b2ParticleGroup::b2ParticleGroup()
|
|
{
|
|
|
|
m_system = NULL;
|
|
m_firstIndex = 0;
|
|
m_lastIndex = 0;
|
|
m_groupFlags = 0;
|
|
m_strength = 1.0f;
|
|
m_prev = NULL;
|
|
m_next = NULL;
|
|
|
|
m_timestamp = -1;
|
|
m_mass = 0;
|
|
m_inertia = 0;
|
|
m_center = b2Vec2_zero;
|
|
m_linearVelocity = b2Vec2_zero;
|
|
m_angularVelocity = 0;
|
|
m_transform.SetIdentity();
|
|
|
|
m_destroyAutomatically = true;
|
|
m_toBeDestroyed = false;
|
|
m_toBeSplit = false;
|
|
|
|
m_userData = NULL;
|
|
|
|
}
|
|
|
|
b2ParticleGroup::~b2ParticleGroup()
|
|
{
|
|
}
|
|
|
|
int32 b2ParticleGroup::GetBufferIndex() const
|
|
{
|
|
return m_firstIndex;
|
|
}
|
|
|
|
int32 b2ParticleGroup::GetGroupFlags() const
|
|
{
|
|
return m_groupFlags;
|
|
}
|
|
|
|
void b2ParticleGroup::SetGroupFlags(int32 flags)
|
|
{
|
|
m_groupFlags = flags;
|
|
}
|
|
|
|
float32 b2ParticleGroup::GetMass() const
|
|
{
|
|
UpdateStatistics();
|
|
return m_mass;
|
|
}
|
|
|
|
float32 b2ParticleGroup::GetInertia() const
|
|
{
|
|
UpdateStatistics();
|
|
return m_inertia;
|
|
}
|
|
|
|
b2Vec2 b2ParticleGroup::GetCenter() const
|
|
{
|
|
UpdateStatistics();
|
|
return m_center;
|
|
}
|
|
|
|
b2Vec2 b2ParticleGroup::GetLinearVelocity() const
|
|
{
|
|
UpdateStatistics();
|
|
return m_linearVelocity;
|
|
}
|
|
|
|
float32 b2ParticleGroup::GetAngularVelocity() const
|
|
{
|
|
UpdateStatistics();
|
|
return m_angularVelocity;
|
|
}
|
|
|
|
const b2Transform& b2ParticleGroup::GetTransform() const
|
|
{
|
|
return m_transform;
|
|
}
|
|
|
|
const b2Vec2& b2ParticleGroup::GetPosition() const
|
|
{
|
|
return m_transform.p;
|
|
}
|
|
|
|
float32 b2ParticleGroup::GetAngle() const
|
|
{
|
|
return m_transform.q.GetAngle();
|
|
}
|
|
|
|
void* b2ParticleGroup::GetUserData() const
|
|
{
|
|
return m_userData;
|
|
}
|
|
|
|
void b2ParticleGroup::SetUserData(void* data)
|
|
{
|
|
m_userData = data;
|
|
}
|
|
|
|
void b2ParticleGroup::UpdateStatistics() const
|
|
{
|
|
if (m_timestamp != m_system->m_timestamp)
|
|
{
|
|
float32 m = m_system->GetParticleMass();
|
|
m_mass = 0;
|
|
m_center.SetZero();
|
|
m_linearVelocity.SetZero();
|
|
for (int32 i = m_firstIndex; i < m_lastIndex; i++)
|
|
{
|
|
m_mass += m;
|
|
m_center += m * m_system->m_positionBuffer.data[i];
|
|
m_linearVelocity += m * m_system->m_velocityBuffer.data[i];
|
|
}
|
|
if (m_mass > 0)
|
|
{
|
|
m_center *= 1 / m_mass;
|
|
m_linearVelocity *= 1 / m_mass;
|
|
}
|
|
m_inertia = 0;
|
|
m_angularVelocity = 0;
|
|
for (int32 i = m_firstIndex; i < m_lastIndex; i++)
|
|
{
|
|
b2Vec2 p = m_system->m_positionBuffer.data[i] - m_center;
|
|
b2Vec2 v = m_system->m_velocityBuffer.data[i] - m_linearVelocity;
|
|
m_inertia += m * b2Dot(p, p);
|
|
m_angularVelocity += m * b2Cross(p, v);
|
|
}
|
|
if (m_inertia > 0)
|
|
{
|
|
m_angularVelocity *= 1 / m_inertia;
|
|
}
|
|
m_timestamp = m_system->m_timestamp;
|
|
}
|
|
}
|