//***************************************************
// DFDCGeometry - temporary geometry class for FDC.
// Author: Craig Bookwalter (craigb at jlab.org)
// Date:   March 2006
//***************************************************

#ifndef DFDCGEOMETRY_H
#define DFDCGEOMETRY_H

#include "JANA/JObject.h"
#include "DFDCHit.h"

///
/// class DFDCGeometry: definition of a class providing basic geometry
/// methods for FDC reconstruction.
///
class DFDCGeometry : public JObject {
	public:
		///
		/// DFDCGeometry::gLayer():
		/// Compute the global layer (detection layer 1-24) number based on module and layer
		///
		inline int gLayer(const DFDCHit* h) {
			return 3*(h->module - 1) + (h->layer - 1) + 1;
		}		
		
		///
		/// DFDCGeometry::gPlane():
		/// Compute the global plane (1-74) number based on module, layer, and plane
		///
		inline int gPlane(const DFDCHit* h) {
			return 9*(h->module-1) + 3*(h->layer-1) + (h->plane-1) + 1;
		}
		
		/// 
		/// DFDCGeometry::getLayerZ():
		/// Get the Z position of a layer
		///
		float getLayerZ(const DFDCHit* h) {
			if (h->gPlane <= 18)  
				return 227.5 + h->gPlane*0.5;			// Thing 1
			if (h->gPlane <= 36)	   
				return 283.5 + (h->gPlane - 18)*0.5;	// Thing 2
			if (h->gPlane <= 54)	   
				return 358.5 + (h->gPlane - 36)*0.5;	// Thing 3
			return 394.5 + (h->gPlane - 540*0.5); 		// Thing 4
		}
		
		///		
		/// DFDCGeometry::getWireR():
		/// Return X coordinate of a wire
		/// 
		inline float getWireR(const DFDCHit* h) {
			return h->element - 60.0;
		}
		
		///
		/// DFDCGeometry::getStripR():
		/// Return coordinate in U or V space of a strip
		///
		inline float getStripR(const DFDCHit* h) {
			return (h->element - 119.5)*0.5;
		}
		
		///
		/// DFDCGeometry::getLayerRotation():
		/// Compute the rotation of a detection layer (0, 60, -60)
		///
		inline float getLayerRotation(const int gLayer) {
			switch ((gLayer-1) % 3) {
				case 0:
					return 0.0;
				case 1:
					return 3.1415926 / 3;
				case 2:
					return -3.1415926 / 3;
				return 0.0;
			}
		}
};

#endif // DFDCGEOMETRY_H