bowling-analysis-system/src/bowling_analysis/metrics/calculators/RotationCalculator.js

A comprehensive system for analyzing bowling techniques using video processing and metrics calculation

/**
 * @module bowling_analysis/metrics/calculators/RotationCalculator
 * @description Calculator for rotation-related metrics
 */

/**
 * Calculate rotation-related metrics
 * @param {Array} keypointData - Array of keypoint frames
 * @param {Array} validFrames - Array of valid keypoint frames
 * @param {Object} options - Calculator options
 * @returns {Promise<Object>} Rotation metrics
 */
async function calculate(keypointData, validFrames, options = {}) {
  try {
    const { debug, includeTimeSeries } = options;
    
    // Initialize result
    const result = {};
    
    // Initialize time series
    const timeSeries = {};
    
    // Process combined rotation metrics (with left/right variants)
    const combinedRotationMetrics = [
      'armRotations',
      'shoulderRotations',
      'hipRotations',
      'pelvisRotations',
      'trunkRotations',
      'wristRotations',
      'footRotations'
    ];
    
    // Process individual rotation metrics (no left/right)
    const individualRotationMetrics = [
      'spineRotation',
      'torsoRotation',
      'pelvisRotation',
      'shoulderRotation',
      'armRotation',
      'approachRotation',
      'releaseRotation',
      'followThroughRotation',
      'totalBodyRotation',
      'angularMomentum',
      'rotationalVelocity',
      'rotationalAcceleration',
      'rotationalPower'
    ];
    
    // TODO: Implement actual rotation calculations
    // For this stub, we'll just create placeholder data
    
    // Process combined rotation metrics
    for (const metricName of combinedRotationMetrics) {
      // Create the combined rotation metric
      result[metricName] = {
        left: Math.random() * 360, // Placeholder: 0 to 360 degrees
        right: Math.random() * 360, // Placeholder: 0 to 360 degrees
        asymmetry: Math.random() * 0.2 // Placeholder
      };
      
      // Create time series data if enabled
      if (includeTimeSeries) {
        const leftValues = Array(keypointData.length).fill(null);
        const rightValues = Array(keypointData.length).fill(null);
        
        // Fill in values for valid frames
        for (let i = 0; i < validFrames.length; i++) {
          const frameIndex = validFrames[i].index || i;
          leftValues[frameIndex] = Math.random() * 360; // Placeholder: 0 to 360 degrees
          rightValues[frameIndex] = Math.random() * 360; // Placeholder: 0 to 360 degrees
        }
        
        timeSeries[`${metricName}.left`] = leftValues;
        timeSeries[`${metricName}.right`] = rightValues;
      }
    }
    
    // Process individual rotation metrics
    for (const metricName of individualRotationMetrics) {
      // Create the individual rotation metric
      result[metricName] = Math.random() * 360; // Placeholder: 0 to 360 degrees
      
      // Create time series data if enabled
      if (includeTimeSeries) {
        const values = Array(keypointData.length).fill(null);
        
        // Fill in values for valid frames
        for (let i = 0; i < validFrames.length; i++) {
          const frameIndex = validFrames[i].index || i;
          values[frameIndex] = Math.random() * 360; // Placeholder: 0 to 360 degrees
        }
        
        timeSeries[metricName] = values;
      }
    }
    
    // Add time series data if enabled
    if (includeTimeSeries) {
      result.timeSeries = timeSeries;
    }
    
    return result;
  } catch (error) {
    console.error(`Error calculating rotation metrics: ${error.message}`);
    return {};
  }
}

module.exports = {
  calculate
};