amuse/lib/Emitter.cpp

143 lines
3.9 KiB
C++

#include "amuse/Emitter.hpp"
#include "amuse/Listener.hpp"
#include "amuse/Voice.hpp"
#include "amuse/Engine.hpp"
namespace amuse
{
static void Delta(Vector3f& out, const Vector3f& a, const Vector3f& b)
{
out[0] = a[0] - b[0];
out[1] = a[1] - b[1];
out[2] = a[2] - b[2];
}
Emitter::~Emitter() {}
Emitter::Emitter(Engine& engine, const AudioGroup& group, ObjToken<Voice> vox,
float maxDist, float minVol, float falloff, bool doppler)
: Entity(engine, group, vox->getGroupId(), vox->getObjectId()), m_vox(vox), m_maxDist(maxDist),
m_minVol(clamp(0.f, minVol, 1.f)), m_falloff(clamp(-1.f, falloff, 1.f)), m_doppler(doppler)
{
}
void Emitter::_destroy()
{
Entity::_destroy();
m_vox->kill();
}
float Emitter::_attenuationCurve(float dist) const
{
if (dist > m_maxDist)
return 0.f;
float t = dist / m_maxDist;
if (m_falloff < 0.f)
{
float tmp = t * 10.f + 1.f;
tmp = 1.f / (tmp * tmp);
return (1.f + m_falloff) * (-t + 1.f) + -m_falloff * tmp;
}
else if (m_falloff > 0.f)
{
float tmp = (t - 1.f) * 10.f - 1.f;
tmp = -1.f / (tmp * tmp) + 1.f;
return (1.f - m_falloff) * (-t + 1.f) + m_falloff * tmp;
}
else
{
return -t + 1.f;
}
}
void Emitter::_update()
{
if (!m_dirty)
{
/* Ensure that all listeners are also not dirty */
bool dirty = false;
for (auto& listener : m_engine.m_activeListeners)
{
if (listener->m_dirty)
{
dirty = true;
break;
}
}
if (!dirty)
return;
}
float coefs[8] = {};
double avgDopplerRatio = 0.0;
for (auto& listener : m_engine.m_activeListeners)
{
Vector3f listenerToEmitter;
Delta(listenerToEmitter, m_pos, listener->m_pos);
float dist = Length(listenerToEmitter);
float panDist = Dot(listenerToEmitter, listener->m_right);
float frontPan = clamp(-1.f, panDist / listener->m_frontDiff, 1.f);
float backPan = clamp(-1.f, panDist / listener->m_backDiff, 1.f);
float spanDist = -Dot(listenerToEmitter, listener->m_heading);
float span = clamp(-1.f, spanDist > 0.f ? spanDist / listener->m_backDiff :
spanDist / listener->m_frontDiff, 1.f);
/* Calculate attenuation */
float att = _attenuationCurve(dist);
if (att > FLT_EPSILON)
{
att = (1.f - att) * m_minVol + att * m_maxVol;
/* Apply pan law */
float thisCoefs[8] = {};
m_vox->_panLaw(thisCoefs, frontPan, backPan, span);
/* Take maximum coefficient across listeners */
for (int i = 0; i < 8; ++i)
coefs[i] = std::max(coefs[i], thisCoefs[i] * att * listener->m_volume);
}
/* Calculate doppler */
if (m_doppler)
{
/* Positive values indicate emitter and listener closing in */
Vector3f dirDelta;
Delta(dirDelta, m_dir, listener->m_dir);
Vector3f posDelta;
Delta(posDelta, listener->m_pos, m_pos);
Normalize(posDelta);
float deltaSpeed = Dot(dirDelta, posDelta);
if (listener->m_soundSpeed != 0.f)
avgDopplerRatio += 1.0 + deltaSpeed / listener->m_soundSpeed;
else
avgDopplerRatio += 1.0;
}
}
if (m_engine.m_activeListeners.size() != 0)
{
m_vox->setChannelCoefs(coefs);
if (m_doppler)
{
m_vox->m_dopplerRatio = avgDopplerRatio / float(m_engine.m_activeListeners.size());
m_vox->m_pitchDirty = true;
}
}
m_dirty = false;
}
void Emitter::setVectors(const float* pos, const float* dir)
{
for (int i=0 ; i<3 ; ++i)
{
m_pos[i] = pos[i];
m_dir[i] = dir[i];
}
m_dirty = true;
}
}