Method IsIncreasing

src/KeyFrame.cpp:292–329

Get the direction of the curve at a specific index (increasing or decreasing)

// Get the direction of the curve at a specific index (increasing or decreasing)
bool Keyframe::IsIncreasing(int index) const
{
	if (index <= 1) {
		// Determine direction of frame 1 (and assume previous frames have same direction)
		index = 1;
	} else  if (index >= GetLength()) {
		// Determine direction of last valid frame # (and assume next frames have same direction)
		index = GetLength() - 1;
	}

	// Get current index value
	const double current_value = GetValue(index);

	// Iterate from current index to next significant value change
	int attempts = 1;
	while (attempts < 600 && index + attempts <= GetLength()) {
		// Get next value
		const double next_value = GetValue(index + attempts);

		// Is value significantly different
		const double diff = next_value - current_value;
		if (fabs(diff) > 0.0001) {
			if (diff < 0.0) {
				// Decreasing value found next
				return false;
			} else {
				// Increasing value found next
				return true;
			}
		}

		// increment attempt
		attempts++;
	}

	// If no next value found, assume increasing values
	return true;
}

// Generate JSON string of this object
std::string Keyframe::Json() const {