float AnimClip::accumulateTime(float frame, float dt, Triggers& triggersOut) const {
const float startFrame = std::min(_startFrame, _endFrame);
if (startFrame == _endFrame) {
// when startFrame >= endFrame
frame = _endFrame;
} else if (_timeScale > 0.0f) {
// accumulate time, keeping track of loops and end of animation events.
const float FRAMES_PER_SECOND = 30.0f;
float framesRemaining = (dt * _timeScale) * FRAMES_PER_SECOND;
while (framesRemaining > 0.0f) {
float framesTillEnd = _endFrame - _frame;
if (framesRemaining >= framesTillEnd) {
if (_loopFlag) {
// anim loop
triggersOut.push_back(_id + "OnLoop");
framesRemaining -= framesTillEnd;
frame = startFrame;
} else {
// anim end
triggersOut.push_back(_id + "OnDone");
frame = _endFrame;
framesRemaining = 0.0f;
}
} else {
frame += framesRemaining;
framesRemaining = 0.0f;
}
}
}
return frame;
}
void AnimBlendLinearMove::setFrameAndPhase(float dt, float alpha, int prevPoseIndex, int nextPoseIndex,
float* prevDeltaTimeOut, float* nextDeltaTimeOut, Triggers& triggersOut) {
const float FRAMES_PER_SECOND = 30.0f;
auto prevClipNode = std::dynamic_pointer_cast<AnimClip>(_children[prevPoseIndex]);
assert(prevClipNode);
auto nextClipNode = std::dynamic_pointer_cast<AnimClip>(_children[nextPoseIndex]);
assert(nextClipNode);
float v0 = _characteristicSpeeds[prevPoseIndex];
float n0 = (prevClipNode->getEndFrame() - prevClipNode->getStartFrame()) + 1.0f;
float v1 = _characteristicSpeeds[nextPoseIndex];
float n1 = (nextClipNode->getEndFrame() - nextClipNode->getStartFrame()) + 1.0f;
// rate of change in phase space, necessary to achive desired speed.
float omega = (_desiredSpeed * FRAMES_PER_SECOND) / ((1.0f - alpha) * v0 * n0 + alpha * v1 * n1);
float f0 = prevClipNode->getStartFrame() + _phase * n0;
prevClipNode->setCurrentFrame(f0);
float f1 = nextClipNode->getStartFrame() + _phase * n1;
nextClipNode->setCurrentFrame(f1);
// integrate phase forward in time.
_phase += omega * dt;
// detect loop trigger events
if (_phase >= 1.0f) {
triggersOut.push_back(_id + "Loop");
_phase = glm::fract(_phase);
}
*prevDeltaTimeOut = omega * dt * (n0 / FRAMES_PER_SECOND);
*nextDeltaTimeOut = omega * dt * (n1 / FRAMES_PER_SECOND);
}