Method GetBox

src/TrackedObjectBBox.cpp:125–175

Return a bounding-box from BoxVec with it's properties adjusted by the Keyframes

// Return a bounding-box from BoxVec with it's properties adjusted by the Keyframes
BBox TrackedObjectBBox::GetBox(int64_t frame_number)
{
	// Get the time position of the given frame.
	double time = this->FrameNToTime(frame_number, this->TimeScale);

	// Return a iterator pointing to the BoxVec pair indexed by time or to the pair indexed
	// by the closest upper time value.
	auto currentBBoxIterator = BoxVec.lower_bound(time);

	// Check if there is a pair indexed by time, returns an empty bbox if there isn't.
	if (currentBBoxIterator == BoxVec.end())
	{
		// Create and return an empty bounding-box object
		BBox emptyBBox;
		return emptyBBox;
	}

	// Check if the iterator matches a BBox indexed by time or points to the first element of BoxVec
	if ((currentBBoxIterator->first == time) || (currentBBoxIterator == BoxVec.begin()))
	{
		// Get the BBox indexed by time
		BBox currentBBox = currentBBoxIterator->second;

		// Adjust the BBox properties by the Keyframes values
		currentBBox.cx += this->delta_x.GetValue(frame_number);
		currentBBox.cy += this->delta_y.GetValue(frame_number);
		currentBBox.width *= this->scale_x.GetValue(frame_number);
		currentBBox.height *= this->scale_y.GetValue(frame_number);
		currentBBox.angle += this->rotation.GetValue(frame_number);

		return currentBBox;
	}

	// BBox indexed by the closest upper time
	BBox currentBBox = currentBBoxIterator->second;
	// BBox indexed by the closet lower time
	BBox previousBBox = prev(currentBBoxIterator, 1)->second;

	// Interpolate a BBox in the middle of previousBBox and currentBBox
	BBox interpolatedBBox = InterpolateBoxes(prev(currentBBoxIterator, 1)->first, currentBBoxIterator->first,
											 previousBBox, currentBBox, time);

	// Adjust the BBox properties by the Keyframes values
	interpolatedBBox.cx += this->delta_x.GetValue(frame_number);
	interpolatedBBox.cy += this->delta_y.GetValue(frame_number);
	interpolatedBBox.width *= this->scale_x.GetValue(frame_number);
	interpolatedBBox.height *= this->scale_y.GetValue(frame_number);
	interpolatedBBox.angle += this->rotation.GetValue(frame_number);

	return interpolatedBBox;
}

// Interpolate the bouding-boxes properties
BBox TrackedObjectBBox::InterpolateBoxes(double t1, double t2, BBox left, BBox right, double target)