int main() {
// Since we use the ‘smooth’ animation algorithm, we must register it.
motive::SmoothInit::Register();
// The engine is the central place for animation data.
motive::MotiveEngine engine;
// In this example, we animate a one-dimensional floating point value.
motive::Motivator1f facing_angle;
// Initialize facing_angle Motivator to animate as a 'Smooth' Motivator.
// Alternatively, we could initialize as an 'Overshoot' Motivator. All
// Motivator types have the same interface. Internally, they are animated
// with different algorithms, and they will move differently towards their
// targets. However, to switch between Motivator types it is a simple matter
// of initializing with a different kind of MotiveInit struct.
//
// Angles wrap around with modular arithmetic. That is, -pi is equivalent to
// pi. Valid range for angles is -pi..pi, inclusive of +pi and exclusive of
// -pi.
const motive::SmoothInit init(Range(-kPi, kPi), true);
facing_angle.Initialize(init, &engine);
// Set initial state of the Motivator, and the target parameters.
// 'Smooth' Motivators animate to a target-value in a target-time. Not all
// types of Motivators use all target data.
const Angle start = Angle::FromDegrees(120.0f);
const float start_angular_velocity = 0.0f;
const Angle target = Angle::FromDegrees(-120.0f);
const float target_angular_velocity = 0.0f;
const motive::MotiveTime target_time = 100;
const motive::MotiveTime delta_time = 1;
facing_angle.SetTarget(
motive::CurrentToTarget1f(start.ToRadians(), start_angular_velocity,
target.ToRadians(), target_angular_velocity,
target_time));
std::vector<vec2> points(target_time / delta_time + 1);
for (motive::MotiveTime t = 0; t <= target_time; t += delta_time) {
// All Motivators created with 'engine' are animated here.
engine.AdvanceFrame(delta_time);
// The current value of the variable being animated is always available.
const Angle angle_at_t = Angle::FromWithinThreePi(facing_angle.Value());
points.push_back(
vec2(static_cast<float>(t), angle_at_t.ToDegrees()));
}
printf("\n%s", Graph2DPoints(&points[0], points.size()).c_str());
return 0;
}
