[Gcblue-commits] gcb_wx/src/database tcBallisticDBObject.cpp,1.3,1.4

[Dewitt C. <ddc...@us...>]

Update of /cvsroot/gcblue/gcb_wx/src/database
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv30041/src/database

Modified Files:
	tcBallisticDBObject.cpp 
Log Message:


Index: tcBallisticDBObject.cpp
===================================================================
RCS file: /cvsroot/gcblue/gcb_wx/src/database/tcBallisticDBObject.cpp,v
retrieving revision 1.3
retrieving revision 1.4
diff -C2 -d -r1.3 -r1.4
*** tcBallisticDBObject.cpp	8 Aug 2004 00:31:33 -0000	1.3
--- tcBallisticDBObject.cpp	12 Aug 2004 01:14:28 -0000	1.4
***************
*** 48,53 ****
  	{
  		float launchSpeed = launchSpeed_mps;
! 		float fac = range_m * range_m * C_G * C_G; // 4 * 0.25  = 1
  		float b = -launchSpeed * launchSpeed;
  
  		float b2 = b * b;
--- 48,56 ----
  	{
  		float launchSpeed = launchSpeed_mps;
! 		
! 		float fac = range_m * range_m * C_G2; // 4 * 0.25  = 1
  		float b = -launchSpeed * launchSpeed;
+ 		const float two_over_g = 2.0f / C_G;
+ 		float one_over_launchSpeed = 1.0f / launchSpeed_mps;
  
  		float b2 = b * b;
***************
*** 58,66 ****
  		}
  
! 		float vz = sqrtf( 0.5f * (-b - sqrt(b2 - fac)) ); // -b + for lofted trajectory
  
! 		tti_s = 2 * vz / C_G;
  
! 		float elevation_rad = asinf(vz / launchSpeed);
  
  		return elevation_rad;
--- 61,94 ----
  		}
  
! 		float vz = sqrtf( 0.5f * (-b - sqrtf(b2 - fac)) ); // -b + for lofted trajectory
  
! 		tti_s = two_over_g * vz;
  
! 		float elevation_rad = asinf(one_over_launchSpeed * vz);
! 
! 		// if target altitude difference is negligible, return
! 		if (fabsf(dz_m) <= 1.0f) return elevation_rad;
! 
! 		
! 		/* otherwise re-estimate with range adjusted for altitude difference.
! 		** This is a coarse approximation and will still have error.
! 		** A better approximation can be done using an enhanced quadratic (or
! 		** an iterative solution of the exact equation).
! 		*/
! 		wxASSERT(dz_m != 0);
! 		range_m +=  (dz_m / vz) * launchSpeed * cosf(elevation_rad);
! 
! 		// update calculations with new range_m
! 		fac = range_m * range_m * C_G2; 
! 
! 		if (b2 < fac)
! 		{
! 			tti_s = 0;
! 			return 0.25f * C_PI;
! 		}
! 
! 		vz = sqrtf( 0.5f * (-b - sqrtf(b2 - fac)) ); 
! 		tti_s = two_over_g * vz;
! 		elevation_rad = asinf(one_over_launchSpeed * vz);
  
  		return elevation_rad;