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/* Copyright 2012-2018 Steven Oliver <oliver.steven@gmail.com>
*
* This file is part of balística.
*
* balística is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* balística is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with balística. If not, see <http://www.gnu.org/licenses/>.
*/
/* The code in this file was originally part of the GNU Exterior
* Balisitics Computer. It was licensed under the GNU General Public
* License Version 2 by Derek Yates.
*/
namespace LibBalistica{
public class Retard : GLib.Object {
/**
* A function to calculate ballistic retardation values based on standard drag functions.
*
* @param DragFunction G1, G2, G3, G4, G5, G6, G7, or G8. All are enumerated.
* @param DragCoefficient The coefficient of drag for the projectile for the given drag function.
* @param Vi The Velocity of the projectile.
*
* @return The projectile drag retardation velocity, in ft/s per second.
*/
internal static double CalcRetard(DragFunction drag_func, double DragCoefficient, double Velocity) {
double vp = Velocity ;
double val = -1 ;
double A = -1 ;
double M = -1 ;
switch( drag_func ){
case DragFunction.G1:
if( vp > 4230 ){
A = 1.477404177730177e-04 ; M = 1.9565 ;
} else if( vp > 3680 ){
A = 1.920339268755614e-04 ; M = 1.925 ;
} else if( vp > 3450 ){
A = 2.894751026819746e-04 ; M = 1.875 ;
} else if( vp > 3295 ){
A = 4.349905111115636e-04 ; M = 1.825 ;
} else if( vp > 3130 ){
A = 6.520421871892662e-04 ; M = 1.775 ;
} else if( vp > 2960 ){
A = 9.748073694078696e-04 ; M = 1.725 ;
} else if( vp > 2830 ){
A = 1.453721560187286e-03 ; M = 1.675 ;
} else if( vp > 2680 ){
A = 2.162887202930376e-03 ; M = 1.625 ;
} else if( vp > 2460 ){
A = 3.209559783129881e-03 ; M = 1.575 ;
} else if( vp > 2225 ){
A = 3.904368218691249e-03 ; M = 1.55 ;
} else if( vp > 2015 ){
A = 3.222942271262336e-03 ; M = 1.575 ;
} else if( vp > 1890 ){
A = 2.203329542297809e-03 ; M = 1.625 ;
} else if( vp > 1810 ){
A = 1.511001028891904e-03 ; M = 1.675 ;
} else if( vp > 1730 ){
A = 8.609957592468259e-04 ; M = 1.75 ;
} else if( vp > 1595 ){
A = 4.086146797305117e-04 ; M = 1.85 ;
} else if( vp > 1520 ){
A = 1.954473210037398e-04 ; M = 1.95 ;
} else if( vp > 1420 ){
A = 5.431896266462351e-05 ; M = 2.125 ;
} else if( vp > 1360 ){
A = 8.847742581674416e-06 ; M = 2.375 ;
} else if( vp > 1315 ){
A = 1.456922328720298e-06 ; M = 2.625 ;
} else if( vp > 1280 ){
A = 2.419485191895565e-07 ; M = 2.875 ;
} else if( vp > 1220 ){
A = 1.657956321067612e-08 ; M = 3.25 ;
} else if( vp > 1185 ){
A = 4.745469537157371e-10 ; M = 3.75 ;
} else if( vp > 1150 ){
A = 1.379746590025088e-11 ; M = 4.25 ;
} else if( vp > 1100 ){
A = 4.070157961147882e-13 ; M = 4.75 ;
} else if( vp > 1060 ){
A = 2.938236954847331e-14 ; M = 5.125 ;
} else if( vp > 1025 ){
A = 1.228597370774746e-14 ; M = 5.25 ;
} else if( vp > 980 ){
A = 2.916938264100495e-14 ; M = 5.125 ;
} else if( vp > 945 ){
A = 3.855099424807451e-13 ; M = 4.75 ;
} else if( vp > 905 ){
A = 1.185097045689854e-11 ; M = 4.25 ;
} else if( vp > 860 ){
A = 3.566129470974951e-10 ; M = 3.75 ;
} else if( vp > 810 ){
A = 1.045513263966272e-08 ; M = 3.25 ;
} else if( vp > 780 ){
A = 1.291159200846216e-07 ; M = 2.875 ;
} else if( vp > 750 ){
A = 6.824429329105383e-07 ; M = 2.625 ;
} else if( vp > 700 ){
A = 3.569169672385163e-06 ; M = 2.375 ;
} else if( vp > 640 ){
A = 1.839015095899579e-05 ; M = 2.125 ;
} else if( vp > 600 ){
A = 5.71117468873424e-05 ; M = 1.950 ;
} else if( vp > 550 ){
A = 9.226557091973427e-05 ; M = 1.875 ;
} else if( vp > 250 ){
A = 9.337991957131389e-05 ; M = 1.875 ;
} else if( vp > 100 ){
A = 7.225247327590413e-05 ; M = 1.925 ;
} else if( vp > 65 ){
A = 5.792684957074546e-05 ; M = 1.975 ;
} else if( vp > 0 ){
A = 5.206214107320588e-05 ; M = 2.000 ;
}
break ;
case DragFunction.G2:
if( vp > 1674 ){
A = 0.0079470052136733 ; M = 1.36999902851493 ;
} else if( vp > 1172 ){
A = 1.00419763721974e-03 ; M = 1.65392237010294 ;
} else if( vp > 1060 ){
A = 7.15571228255369e-23 ; M = 7.91913562392361 ;
} else if( vp > 949 ){
A = 1.39589807205091e-10 ; M = 3.81439537623717 ;
} else if( vp > 670 ){
A = 2.34364342818625e-04 ; M = 1.71869536324748 ;
} else if( vp > 335 ){
A = 1.77962438921838e-04 ; M = 1.76877550388679 ;
} else if( vp > 0 ){
A = 5.18033561289704e-05 ; M = 1.98160270524632 ;
}
break ;
case DragFunction.G5:
if( vp > 1730 ){
A = 7.24854775171929e-03 ; M = 1.41538574492812 ;
} else if( vp > 1228 ){
A = 3.50563361516117e-05 ; M = 2.13077307854948 ;
} else if( vp > 1116 ){
A = 1.84029481181151e-13 ; M = 4.81927320350395 ;
} else if( vp > 1004 ){
A = 1.34713064017409e-22 ; M = 7.8100555281422 ;
} else if( vp > 837 ){
A = 1.03965974081168e-07 ; M = 2.84204791809926 ;
} else if( vp > 335 ){
A = 1.09301593869823e-04 ; M = 1.81096361579504 ;
} else if( vp > 0 ){
A = 3.51963178524273e-05 ; M = 2.00477856801111 ;
}
break ;
case DragFunction.G6:
if( vp > 3236 ){
A = 0.0455384883480781 ; M = 1.15997674041274 ;
} else if( vp > 2065 ){
A = 7.167261849653769e-02 ; M = 1.10704436538885 ;
} else if( vp > 1311 ){
A = 1.66676386084348e-03 ; M = 1.60085100195952 ;
} else if( vp > 1144 ){
A = 1.01482730119215e-07 ; M = 2.9569674731838 ;
} else if( vp > 1004 ){
A = 4.31542773103552e-18 ; M = 6.34106317069757 ;
} else if( vp > 670 ){
A = 2.04835650496866e-05 ; M = 2.11688446325998 ;
} else if( vp > 0 ){
A = 7.50912466084823e-05 ; M = 1.92031057847052 ;
}
break ;
case DragFunction.G7:
if( vp > 4200 ){
A = 1.29081656775919e-09 ; M = 3.24121295355962 ;
} else if( vp > 3000 ){
A = 0.0171422231434847 ; M = 1.27907168025204 ;
} else if( vp > 1470 ){
A = 2.33355948302505e-03 ; M = 1.52693913274526 ;
} else if( vp > 1260 ){
A = 7.97592111627665e-04 ; M = 1.67688974440324 ;
} else if( vp > 1110 ){
A = 5.71086414289273e-12 ; M = 4.3212826264889 ;
} else if( vp > 960 ){
A = 3.02865108244904e-17 ; M = 5.99074203776707 ;
} else if( vp > 670 ){
A = 7.52285155782535e-06 ; M = 2.1738019851075 ;
} else if( vp > 540 ){
A = 1.31766281225189e-05 ; M = 2.08774690257991 ;
} else if( vp > 0 ){
A = 1.34504843776525e-05 ; M = 2.08702306738884 ;
}
break ;
case DragFunction.G8:
if( vp > 3571 ){
A = 0.0112263766252305 ; M = 1.33207346655961 ;
} else if( vp > 1841 ){
A = 0.0167252613732636 ; M = 1.28662041261785 ;
} else if( vp > 1120 ){
A = 2.20172456619625e-03 ; M = 1.55636358091189 ;
} else if( vp > 1088 ){
A = 2.0538037167098e-16 ; M = 5.80410776994789 ;
} else if( vp > 976 ){
A = 5.92182174254121e-12 ; M = 4.29275576134191 ;
} else if( vp > 0 ){
A = 4.3917343795117e-05 ; M = 1.99978116283334 ;
}
break ;
case DragFunction.I:
if( vp > 2600 ){
A = 4.0648825e-03 ; M = 1.55 ;
} else if( vp > 1800 ){
A = 1.2479524e-03 ; M = 1.70 ;
} else if( vp > 1370 ){
A = 1.3160125e-04 ; M = 2.00 ;
} else if( vp > 1230 ){
A = 9.5697809e-08 ; M = 3.00 ;
} else if( vp > 970 ){
A = 6.3368148e-14 ; M = 5.00 ;
} else if( vp > 790 ){
A = 5.9353046e-08 ; M = 3.00 ;
} else if( vp > 0 ){
A = 4.6761777e-05 ; M = 2.00 ;
}
break ;
case DragFunction.B:
if( vp > 2600 ){
A = 15366e-07 ; M = 1.67 ;
} else if( vp > 2000 ){
A = 58495e-07 ; M = 1.50 ;
} else if( vp > 1460 ){
A = 59814e-08 ; M = 1.80 ;
} else if( vp > 1190 ){
A = 95408e-12 ; M = 3.00 ;
} else if( vp > 1040 ){
A = 23385e-22 ; M = 6.45 ;
} else if( vp > 840 ){
A = 59939e-12 ; M = 3.00 ;
} else if( vp > 0 ){
A = 74422e-08 ; M = 1.60 ;
}
break ;
default:
assert_not_reached () ;
}
debug ("A: %f", A) ;
debug ("M: %f", M) ;
debug ("vp: %f", vp) ;
if((A != -1) && (M != -1) && (vp > 0) && (vp < 10000)){
val = A * Math.pow (vp, M) / DragCoefficient ;
debug ("val: %f", val) ;
return val ;
} else {
return -1 ;
}
}
}
} // namespace