int main() {
//! [Own Processor Register]
LinearInit::Register();
//! [Own Processor Register]
MotiveEngine engine;
//! [Own Processor Create Instance]
// Move from 10 --> -5 in 100 internal time units.
const MotiveTarget1f target = motive::CurrentToTarget1f(10, 0, -5, 0, 100);
// Create the one dimensional motivator of type Linear by passing in
// LinearInit.
Motivator1f linear_motivator(LinearInit(), &engine, target);
//! [Own Processor Create Instance]
//! [Own Processor Advance Simulation]
// Advance the simulation one tick at a time by calling engine.AdvanceFrame().
std::vector<vec2> points;
points.reserve(target.EndTime() + 1);
for (MotiveTime t = 0; t <= target.EndTime(); ++t) {
points.push_back(vec2(static_cast<float>(t), linear_motivator.Value()));
engine.AdvanceFrame(1);
}
printf("\n%s",
motive::Graph2DPoints(&points[0], static_cast<int>(points.size()))
.c_str());
//! [Own Processor Advance Simulation]
return 0;
}
// TODO: Change to CreateSplineToTarget()
void SetTarget(MotiveIndex index, const MotiveTarget1f& t) {
SplineData& d = Data(index);
// If the first node specifies time=0 or there is no valid data in the
// interpolator, we want to override the current values with the values
// specified in the first node.
const MotiveNode1f& node0 = t.Node(0);
const bool override_current =
node0.time == 0 || !interpolator_.Valid(index);
// TODO(b/65298927): It seems that the animation pipeline can produce data
// that is out of range. Instead of just using node0.value directly, if
// the interpolator is doing modular arithmetic, normalize the y value to
// the modulator's range.
const float start_y =
override_current
? (interpolator_.ModularArithmetic(index)
? interpolator_.ModularRange(index).Normalize(node0.value)
: node0.value)
: interpolator_.NormalizedY(index);
const float start_derivative =
override_current ? node0.velocity : Velocity(index);
const int start_node_index = override_current ? 1 : 0;
// Ensure we have a local spline available, allocated from our pool of
// splines.
if (d.local_spline == nullptr) {
d.local_spline = AllocateSpline();
}
// Initialize the compact spline to hold the sequence of nodes in 't'.
// Add the first node, which has the start condition.
const float end_x = static_cast<float>(t.EndTime());
const Range y_range = CalculateYRange(index, t, start_y);
const float x_granularity = CompactSpline::RecommendXGranularity(end_x);
d.local_spline->Init(y_range, x_granularity);
d.local_spline->AddNode(0.0f, start_y, start_derivative);
// Add subsequent nodes, in turn, taking care to respect the 'direction'
// request when using modular arithmetic.
float prev_y = start_y;
for (int i = start_node_index; i < t.num_nodes(); ++i) {
const MotiveNode1f& n = t.Node(i);
const float y = interpolator_.NextY(index, prev_y, n.value, n.direction);
d.local_spline->AddNode(static_cast<float>(n.time), y, n.velocity,
motive::kAddWithoutModification);
prev_y = y;
}
// Point the interpolator at the spline we just created. Always start our
// spline at time 0.
interpolator_.SetSplines(index, 1, d.local_spline, SplinePlayback());
}
Range CalculateYRange(MotiveIndex index, const MotiveTarget1f& t,
float start_y) const {
if (interpolator_.ModularArithmetic(index)) {
// For modular splines, we need to expand the spline's y-range to match
// the number of nodes in the spline. It's possible for the spline to jump
// up the entire range every node, so the range has to be broad enough
// to hold it all.
//
// Note that we only normalize the first value of the spline, and
// subsequent values are allowed to curve out of the normalized range.
const float num_spline_nodes = static_cast<float>(t.num_nodes());
return interpolator_.ModularRange(index).Lengthen(num_spline_nodes);
}
// Calculate the union of the y ranges in the target, then expand it a
// little to allow for intermediate nodes that jump slightly beyond the
// union's range.
return t.ValueRange(start_y).Lengthen(kYRangeBufferPercent);
}
virtual void SetTarget(MotiveIndex index, const MotiveTarget1f& t) {
OvershootData& d = Data(index);
// A 'time' of 0 means that we're setting the current values.
const MotiveNode1f& current = t.Node(0);
if (current.time == 0) {
d.value = current.value;
d.velocity = current.velocity;
}
// A 'time' > 0 means that we're setting the target values.
// We can also use the second node to set target values, if it exists.
const MotiveNode1f* target =
current.time == 0 ? (t.num_nodes() > 1 ? &t.Node(1) : nullptr)
: &t.Node(0);
if (target != nullptr) {
d.target_value = target->value;
}
}