#include <stddef.h>
#include <stdint.h>
#include "lob/lob_export.hpp"

Classes
struct	LobGravity
	Gravity vector. More...

struct	LobWind
	Wind vector. More...

struct	LobCoriolis
	Coriolis effect parameters. More...

struct	LobContext
	Structure of parameters consumed by the solver. More...

struct	LobOutput
	Structure holding the output results of a ballistic calculation. More...

struct	LobBuilder
	Opaque builder type for constructing LobContext objects. More...

Macros
#define	LOB_SPLINE_SEGMENTS 15
	The number of spline pieces comprising a drag function.

#define	LOB_BUILDER_BUFFER_SIZE 272
	The size in bytes of the builder buffer.

Typedefs
typedef uint8_t	LobDragFunctionT
	Drag function type.

typedef uint8_t	LobAtmosphereReferenceT
	Atmosphere reference type.

typedef uint8_t	LobClockAngleT
	Clock angle positions for wind direction.

typedef uint8_t	LobErrorT
	Error codes returned by the builder.

Enumerations
enum	{ kLobDragFunctionG1 = 1 , kLobDragFunctionG2 = 2 , kLobDragFunctionG5 = 5 , kLobDragFunctionG6 = 6 , kLobDragFunctionG7 = 7 , kLobDragFunctionG8 = 8 }

enum	{ kLobAtmosphereReferenceArmyStandardMetro = 0 , kLobAtmosphereReferenceIcao }

enum	{ kLobClockAngleI = 1 , kLobClockAngleII = 2 , kLobClockAngleIII = 3 , kLobClockAngleIV = 4 , kLobClockAngleV = 5 , kLobClockAngleVI = 6 , kLobClockAngleVII = 7 , kLobClockAngleVIII = 8 , kLobClockAngleIX = 9 , kLobClockAngleX = 10 , kLobClockAngleXI = 11 , kLobClockAngleXII = 12 }

enum	{ kLobErrorNone = 0 , kLobErrorAirPressureOOR , kLobErrorAltitudeOfBarometerOOR , kLobErrorAltitudeOfFiringSiteOOR , kLobErrorAltitudeOfThermometerOOR , kLobErrorAzimuthOOR , kLobErrorBallisticCoefficientOOR , kLobErrorBallisticCoefficientRequired , kLobErrorBaseDiameterOOR , kLobErrorBcBandsInvalid , kLobErrorBcBandsNotMonotonic , kLobErrorBcBandsTooShort , kLobErrorDiameterOOR , kLobErrorHumidityOOR , kLobErrorInitialVelocityRequired , kLobErrorInternalError , kLobErrorLatitudeOOR , kLobErrorLengthOOR , kLobErrorMachDragTableInvalid , kLobErrorMachDragTableNotMonotonic , kLobErrorMachDragTableTooShort , kLobErrorMassOOR , kLobErrorMaximumTimeOOR , kLobErrorMeplatDiameterOOR , kLobErrorNoseLengthOOR , kLobErrorNotFormed , kLobErrorOgiveRtROOR , kLobErrorRangeAngleOOR , kLobErrorTailLengthOOR , kLobErrorWindHeadingOOR , kLobErrorZeroAngleOOR , kLobErrorZeroDataRequired , kLobErrorZeroDistanceOOR , kLobErrorZeroUnreachable , kLobErrorNumberOfErrors }

Functions
const char *	LobVersion (void)
	Gets the library version in major.minor.patch format.

void	LobBuilderInit (LobBuilder *pbuilder)
	Initializes a builder to default state. No-op if pbuilder is null.

void	LobBuilderDestroy (LobBuilder *pbuilder)
	Destroys a builder and releases resources. No-op if pbuilder is null.

void	LobBuilderCopy (LobBuilder dst, const LobBuilder src)
	Copies builder state from src to dst. No-op if either is null.

LobBuilder *	LobBuilderReset (LobBuilder *pbuilder)
	Resets a builder state by re-initializing. No-op if pbuilder is null.

LobBuilder *	LobBuilderBallisticCoefficientPsi (LobBuilder *pbuilder, double value)
	Sets the ballistic coefficient (Psi).

LobBuilder *	LobBuilderBCAtmosphere (LobBuilder *pbuilder, LobAtmosphereReferenceT type)
	Sets the atmosphere reference associated with ballistic coefficient.

LobBuilder *	LobBuilderBCDragFunction (LobBuilder *pbuilder, LobDragFunctionT type)
	Sets the drag function associated with ballistic coefficient.

LobBuilder *	LobBuilderDiameterInch (LobBuilder *pbuilder, double value)
	Sets the projectile diameter (caliber) in inches.

LobBuilder *	LobBuilderMeplatDiameterInch (LobBuilder *pbuilder, double value)
	Sets the projectile meplat diameter in inches.

LobBuilder *	LobBuilderBaseDiameterInch (LobBuilder *pbuilder, double value)
	Sets the projectile base diameter in inches.

LobBuilder *	LobBuilderLengthInch (LobBuilder *pbuilder, double value)
	Sets the projectile length in inches.

LobBuilder *	LobBuilderNoseLengthInch (LobBuilder *pbuilder, double value)
	Sets the projectile nose length in inches.

LobBuilder *	LobBuilderTailLengthInch (LobBuilder *pbuilder, double value)
	Sets the projectile tail length in inches.

LobBuilder *	LobBuilderOgiveRtR (LobBuilder *pbuilder, double value)
	Sets the Rt/R ratio of the projectile ogive.

LobBuilder *	LobBuilderSplineFitTable (LobBuilder pbuilder, const float pmachs, const float *pdrags, size_t size)
	Loads a custom Mach vs Drag table for the projectile.

LobBuilder *	LobBuilderBCVelocityBands (LobBuilder pbuilder, const float pfps, const float *pbcs, size_t size)
	Loads ballistic coefficients measured at multiple velocities.

LobBuilder *	LobBuilderMassGrains (LobBuilder *pbuilder, double value)
	Sets the projectile mass in grains.

LobBuilder *	LobBuilderInitialVelocityFps (LobBuilder *pbuilder, uint16_t value)
	Sets the initial velocity of the projectile in feet per second.

LobBuilder *	LobBuilderOpticHeightInches (LobBuilder *pbuilder, double value)
	Sets the height of the optic above the bore in inches.

LobBuilder *	LobBuilderTwistInchesPerTurn (LobBuilder *pbuilder, double value)
	Sets the twist rate of the barrel in inches per turn.

LobBuilder *	LobBuilderZeroAngleMOA (LobBuilder *pbuilder, double value)
	Sets the angle between the sight and launch angle used to achieve zero.

LobBuilder *	LobBuilderZeroDistanceYds (LobBuilder *pbuilder, double value)
	Sets the zero distance in yards.

LobBuilder *	LobBuilderZeroImpactHeightInches (LobBuilder *pbuilder, double value)
	Sets the zero impact height in inches.

LobBuilder *	LobBuilderAltitudeOfFiringSiteFt (LobBuilder *pbuilder, double value)
	Sets the altitude of the firing site in feet.

LobBuilder *	LobBuilderAirPressureInHg (LobBuilder *pbuilder, double value)
	Sets the air pressure in inches of mercury (inHg).

LobBuilder *	LobBuilderAltitudeOfBarometerFt (LobBuilder *pbuilder, double value)
	Sets the altitude of the location where air pressure was taken in feet.

LobBuilder *	LobBuilderTemperatureDegF (LobBuilder *pbuilder, double value)
	Sets the temperature in degrees Fahrenheit.

LobBuilder *	LobBuilderAltitudeOfThermometerFt (LobBuilder *pbuilder, double value)
	Sets the altitude of the location where temperature was taken in feet.

LobBuilder *	LobBuilderRelativeHumidityPercent (LobBuilder *pbuilder, double value)
	Sets the relative humidity at the firing site in percent.

LobBuilder *	LobBuilderWindHeading (LobBuilder *pbuilder, LobClockAngleT value)
	Sets the wind heading using a clock angle.

LobBuilder *	LobBuilderWindHeadingDeg (LobBuilder *pbuilder, double value)
	Sets the wind heading in degrees.

LobBuilder *	LobBuilderWindSpeedFps (LobBuilder *pbuilder, double value)
	Sets the wind speed in feet per second.

LobBuilder *	LobBuilderWindSpeedMph (LobBuilder *pbuilder, double value)
	Sets the wind speed in miles per hour.

LobBuilder *	LobBuilderAzimuthDeg (LobBuilder *pbuilder, double value)
	Sets the azimuth (bearing) of the target in degrees.

LobBuilder *	LobBuilderLatitudeDeg (LobBuilder *pbuilder, double value)
	Sets the latitude of the firing location in degrees.

LobBuilder *	LobBuilderRangeAngleDeg (LobBuilder *pbuilder, double value)
	Sets the range angle (inclination) to the target in degrees.

LobBuilder *	LobBuilderMinimumSpeed (LobBuilder *pbuilder, uint16_t value)
	Sets the minimum speed threshold for the solver.

LobBuilder *	LobBuilderMinimumEnergy (LobBuilder *pbuilder, uint16_t value)
	Sets the minimum energy threshold for the solver.

LobBuilder *	LobBuilderMaximumTime (LobBuilder *pbuilder, double value)
	Sets the maximum time of flight for the solver.

LobBuilder *	LobBuilderStepSize (LobBuilder *pbuilder, uint16_t value)
	Sets the step size for the numerical solver.

void	LobBuilderBuild (LobBuilder pbuilder, LobContext presult)
	Builds the LobContext object with the configured parameters.

size_t	LobSolve (const LobContext pctx, const uint32_t pranges, LobOutput *pouts, size_t size)
	Solves the exterior ballistics problem for a given set of ranges. Results contain a forward-solution.

size_t	LobFastInverse (const LobContext pctx, LobOutput pouts, size_t size)
	Converts forward-solution output to inverse-solution adjustments.

size_t	LobSolveInverse (const LobContext pctx, const uint32_t pranges, LobOutput *pouts, size_t size)
	Solves the exterior ballistics problem for a given set of ranges. Results contain an inverse-solution.

double	LobMoaToMil (double value)
	Converts minutes of angle (MOA) to milliradians (MIL).

double	LobMoaToDeg (double value)
	Converts minutes of angle (MOA) to degrees.

double	LobMoaToIphy (double value)
	Converts minutes of angle (MOA) to inches per hundred yards (IPHY).

double	LobMoaToInch (double value, double range_ft)
	Converts minutes of angle (MOA) to projected inches at a given range in feet.

double	LobMilToMoa (double value)
	Converts milliradians (MIL) to minutes of angle (MOA).

double	LobMilToDeg (double value)
	Converts milliradians (MIL) to degrees.

double	LobMilToIphy (double value)
	Converts milliradians (MIL) to inches per hundred yards (IPHY).

double	LobMilToInch (double value, double range_ft)
	Converts milliradians (MIL) to projected inches at a given range in feet.

double	LobDegToMoa (double value)
	Converts degrees to minutes of angle (MOA).

double	LobDegToMil (double value)
	Converts degrees to milliradians (MIL).

double	LobInchToMoa (double value, double range_ft)
	Inches of projection at a given range to minutes of angle (MOA).

double	LobInchToMil (double value, double range_ft)
	Inches of projection at a given range to milliradians (MIL).

double	LobInchToDeg (double value, double range_ft)
	Inches of projection at a given range to degrees.

double	LobJToFtLbs (double value)
	Converts joules to foot-pounds.

double	LobFtLbsToJ (double value)
	Converts foot-pounds to joules.

double	LobMToYd (double value)
	Converts meters to yards.

double	LobYdToFt (double value)
	Converts yards to feet.

double	LobMToFt (double value)
	Converts meters to feet.

double	LobFtToIn (double value)
	Converts feet to inches.

double	LobMmToIn (double value)
	Converts millimeters to inches.

double	LobCmToIn (double value)
	Converts centimeters to inches.

double	LobYdToM (double value)
	Converts yards to meters.

double	LobFtToM (double value)
	Converts feet to meters.

double	LobFtToYd (double value)
	Converts feet to yards.

double	LobInToMm (double value)
	Converts inches to millimeters.

double	LobInToCm (double value)
	Converts inches to centimeters.

double	LobInToFt (double value)
	Converts inches to feet.

double	LobPaToInHg (double value)
	Converts pascals to inches of mercury.

double	LobMbarToInHg (double value)
	Converts millibars to inches of mercury.

double	LobPsiToInHg (double value)
	Converts pounds per square inch (PSI) to inches of mercury.

double	LobLbsToGrain (double value)
	Converts pounds to grains.

double	LobGToGrain (double value)
	Converts grams to grains.

double	LobKgToGrain (double value)
	Converts kilograms to grains.

double	LobKgSqMToPmsi (double value)
	Converts kilograms per square meter to pounds mass per square inch.

double	LobFpsToMps (double value)
	Converts feet per second to meters per second.

double	LobMpsToFps (double value)
	Converts meters per second to feet per second.

double	LobKphToMph (double value)
	Converts kilometers per hour to miles per hour.

double	LobKnToMph (double value)
	Converts Knots to miles per hour.

double	LobMsToS (double value)
	Converts milliseconds to seconds.

double	LobUsToS (double value)
	Converts microseconds to seconds.

double	LobSToMs (double value)
	Converts seconds to milliseconds.

double	LobSToUs (double value)
	Converts seconds to microseconds.

double	LobDegCToDegF (double value)
	Converts degrees celsius to degrees fahrenheit.

Macro Definition Documentation

◆ LOB_BUILDER_BUFFER_SIZE

#define LOB_BUILDER_BUFFER_SIZE 272

The size in bytes of the builder buffer.

◆ LOB_SPLINE_SEGMENTS

#define LOB_SPLINE_SEGMENTS 15

The number of spline pieces comprising a drag function.

Typedef Documentation

◆ LobAtmosphereReferenceT

typedef uint8_t LobAtmosphereReferenceT

Atmosphere reference type.

◆ LobClockAngleT

typedef uint8_t LobClockAngleT

Clock angle positions for wind direction.

◆ LobDragFunctionT

typedef uint8_t LobDragFunctionT

Drag function type.

◆ LobErrorT

typedef uint8_t LobErrorT

Error codes returned by the builder.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
kLobClockAngleI	one o'clock
kLobClockAngleII	two o'clock
kLobClockAngleIII	three o'clock
kLobClockAngleIV	four o'clock
kLobClockAngleV	five o'clock
kLobClockAngleVI	six o'clock
kLobClockAngleVII	seven o'clock
kLobClockAngleVIII	eight o'clock
kLobClockAngleIX	nine o'clock
kLobClockAngleX	ten o'clock
kLobClockAngleXI	eleven o'clock
kLobClockAngleXII	twelve o'clock

◆ anonymous enum

anonymous enum

Enumerator
kLobAtmosphereReferenceArmyStandardMetro	Army Standard Metro.
kLobAtmosphereReferenceIcao	International Civil Aviation Organization (ICAO)

◆ anonymous enum

anonymous enum

Enumerator
kLobDragFunctionG1	G1 drag function.
kLobDragFunctionG2	G2 drag function.
kLobDragFunctionG5	G5 drag function.
kLobDragFunctionG6	G6 drag function.
kLobDragFunctionG7	G7 drag function.
kLobDragFunctionG8	G8 drag function.

◆ anonymous enum

anonymous enum

Enumerator
kLobErrorNone
kLobErrorAirPressureOOR
kLobErrorAltitudeOfBarometerOOR
kLobErrorAltitudeOfFiringSiteOOR
kLobErrorAltitudeOfThermometerOOR
kLobErrorAzimuthOOR
kLobErrorBallisticCoefficientOOR
kLobErrorBallisticCoefficientRequired
kLobErrorBaseDiameterOOR
kLobErrorBcBandsInvalid
kLobErrorBcBandsNotMonotonic
kLobErrorBcBandsTooShort
kLobErrorDiameterOOR
kLobErrorHumidityOOR
kLobErrorInitialVelocityRequired
kLobErrorInternalError
kLobErrorLatitudeOOR
kLobErrorLengthOOR
kLobErrorMachDragTableInvalid
kLobErrorMachDragTableNotMonotonic
kLobErrorMachDragTableTooShort
kLobErrorMassOOR
kLobErrorMaximumTimeOOR
kLobErrorMeplatDiameterOOR
kLobErrorNoseLengthOOR
kLobErrorNotFormed
kLobErrorOgiveRtROOR
kLobErrorRangeAngleOOR
kLobErrorTailLengthOOR
kLobErrorWindHeadingOOR
kLobErrorZeroAngleOOR
kLobErrorZeroDataRequired
kLobErrorZeroDistanceOOR
kLobErrorZeroUnreachable
kLobErrorNumberOfErrors	Note Total number of enumerated Errors

Function Documentation

◆ LobBuilderAirPressureInHg()

LobBuilder * LobBuilderAirPressureInHg	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the air pressure in inches of mercury (inHg).

Parameters

pbuilder	Pointer to the builder.
value	The air pressure in inHg.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderAltitudeOfBarometerFt()

LobBuilder * LobBuilderAltitudeOfBarometerFt	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the altitude of the location where air pressure was taken in feet.

Note: This only has an effect if the air pressure was taken from a site other than the firing site with a different altitude such as a nearby weather station.

Parameters

pbuilder	Pointer to the builder.
value	The altitude in feet.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderAltitudeOfFiringSiteFt()

LobBuilder * LobBuilderAltitudeOfFiringSiteFt	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the altitude of the firing site in feet.

Parameters

pbuilder	Pointer to the builder.
value	The altitude in feet.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderAltitudeOfThermometerFt()

LobBuilder * LobBuilderAltitudeOfThermometerFt	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the altitude of the location where temperature was taken in feet.

Note: This only has an effect if the temperature was taken from a site other than the firing site with a different altitude such as a nearby weather station.

Parameters

pbuilder	Pointer to the builder.
value	The altitude in feet.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderAzimuthDeg()

LobBuilder * LobBuilderAzimuthDeg	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the azimuth (bearing) of the target in degrees.

Note: Used for making coriolis effect corrections.

Parameters

pbuilder	Pointer to the builder.
value	The azimuth in degrees.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBallisticCoefficientPsi()

LobBuilder * LobBuilderBallisticCoefficientPsi	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the ballistic coefficient (Psi).

Parameters

pbuilder	Pointer to the builder.
value	The ballistic coefficient value.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBaseDiameterInch()

LobBuilder * LobBuilderBaseDiameterInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile base diameter in inches.

Parameters

pbuilder	Pointer to the builder.
value	The base diameter in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBCAtmosphere()

LobBuilder * LobBuilderBCAtmosphere	(	LobBuilder *	pbuilder,
		LobAtmosphereReferenceT	type )

extern

Sets the atmosphere reference associated with ballistic coefficient.

Parameters

pbuilder	Pointer to the builder.
type	The atmosphere reference type.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBCDragFunction()

LobBuilder * LobBuilderBCDragFunction	(	LobBuilder *	pbuilder,
		LobDragFunctionT	type )

extern

Sets the drag function associated with ballistic coefficient.

Note: Does not clear a table loaded via LobBuilderSplineFitTable or LobBuilderBCVelocityBands; those override the drag function at Build time. If both table types are configured, the last call wins regardless of order. Call LobBuilderReset to return to a standard drag function.

Parameters

pbuilder	Pointer to the builder.
type	The drag function type.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBCVelocityBands()

LobBuilder * LobBuilderBCVelocityBands	(	LobBuilder *	pbuilder,
		const float *	pfps,
		const float *	pbcs,
		size_t	size )

extern

Loads ballistic coefficients measured at multiple velocities.

A projectile's effective BC varies with velocity. Supplying BCs at several velocities tailors the drag function set via LobBuilderBCDragFunction to better fit the projectile's actual velocity-dependent drag. A constant BC across all bands reproduces the result of LobBuilderBallisticCoefficientPsi with that BC.

Note: The BCs use the same units as LobBuilderBallisticCoefficientPsi and respect the atmosphere reference set via LobBuilderBCAtmosphere.

Warning: The caller must keep pfps and pbcs valid until LobBuilderBuild is called. The builder copies no data; the pointers are referenced during Build().

Parameters

pbuilder	Pointer to the builder.
pfps	Pointer to an array of velocity values in feet per second.
pbcs	Pointer to an array of associated ballistic coefficients.
size	The number of velocity-bc pairs. Must be at least 2 and at most 16; velocities must be positive and strictly increasing, BCs positive, and the highest velocity below Mach 5.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderBuild()

void LobBuilderBuild	(	LobBuilder *	pbuilder,
		LobContext *	presult )

extern

Builds the LobContext object with the configured parameters.

Parameters

pbuilder	Pointer to the builder.
presult	Pointer to the LobContext to populate. Null pointers are ignored (the call is a no-op).

◆ LobBuilderCopy()

void LobBuilderCopy	(	LobBuilder *	dst,
		const LobBuilder *	src )

extern

Copies builder state from src to dst. No-op if either is null.

◆ LobBuilderDestroy()

void LobBuilderDestroy ( LobBuilder * pbuilder )

extern

Destroys a builder and releases resources. No-op if pbuilder is null.

◆ LobBuilderDiameterInch()

LobBuilder * LobBuilderDiameterInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile diameter (caliber) in inches.

Parameters

pbuilder	Pointer to the builder.
value	The diameter in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderInit()

void LobBuilderInit ( LobBuilder * pbuilder )

extern

Initializes a builder to default state. No-op if pbuilder is null.

◆ LobBuilderInitialVelocityFps()

LobBuilder * LobBuilderInitialVelocityFps	(	LobBuilder *	pbuilder,
		uint16_t	value )

extern

Sets the initial velocity of the projectile in feet per second.

Parameters

pbuilder	Pointer to the builder.
value	The initial velocity in fps.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderLatitudeDeg()

LobBuilder * LobBuilderLatitudeDeg	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the latitude of the firing location in degrees.

Note: Used for making coriolis effect corrections.

Parameters

pbuilder	Pointer to the builder.
value	The latitude in degrees.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderLengthInch()

LobBuilder * LobBuilderLengthInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile length in inches.

Parameters

pbuilder	Pointer to the builder.
value	The length in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderMassGrains()

LobBuilder * LobBuilderMassGrains	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile mass in grains.

Parameters

pbuilder	Pointer to the builder.
value	The mass in grains.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderMaximumTime()

LobBuilder * LobBuilderMaximumTime	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the maximum time of flight for the solver.

Parameters

pbuilder	Pointer to the builder.
value	The maximum time in seconds after which the solver will stop calculations.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderMeplatDiameterInch()

LobBuilder * LobBuilderMeplatDiameterInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile meplat diameter in inches.

Parameters

pbuilder	Pointer to the builder.
value	The meplat in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderMinimumEnergy()

LobBuilder * LobBuilderMinimumEnergy	(	LobBuilder *	pbuilder,
		uint16_t	value )

extern

Sets the minimum energy threshold for the solver.

Parameters

pbuilder	Pointer to the builder.
value	The minimum energy in foot-pounds (ft*lbf) at which the solver will stop calculations.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderMinimumSpeed()

LobBuilder * LobBuilderMinimumSpeed	(	LobBuilder *	pbuilder,
		uint16_t	value )

extern

Sets the minimum speed threshold for the solver.

Parameters

pbuilder	Pointer to the builder.
value	The minimum speed in feet per second (fps) at which the solver will stop calculations.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderNoseLengthInch()

LobBuilder * LobBuilderNoseLengthInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile nose length in inches.

Parameters

pbuilder	Pointer to the builder.
value	The nose length in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderOgiveRtR()

LobBuilder * LobBuilderOgiveRtR	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the Rt/R ratio of the projectile ogive.

Parameters

pbuilder	Pointer to the builder.
value	The Rt/R ratio.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderOpticHeightInches()

LobBuilder * LobBuilderOpticHeightInches	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the height of the optic above the bore in inches.

Parameters

pbuilder	Pointer to the builder.
value	The optic height in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderRangeAngleDeg()

LobBuilder * LobBuilderRangeAngleDeg	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the range angle (inclination) to the target in degrees.

Parameters

pbuilder	Pointer to the builder.
value	The range angle in degrees.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderRelativeHumidityPercent()

LobBuilder * LobBuilderRelativeHumidityPercent	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the relative humidity at the firing site in percent.

Parameters

pbuilder	Pointer to the builder.
value	The relative humidity in percent.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderReset()

LobBuilder * LobBuilderReset ( LobBuilder * pbuilder )

extern

Resets a builder state by re-initializing. No-op if pbuilder is null.

◆ LobBuilderSplineFitTable()

LobBuilder * LobBuilderSplineFitTable	(	LobBuilder *	pbuilder,
		const float *	pmachs,
		const float *	pdrags,
		size_t	size )

extern

Loads a custom Mach vs Drag table for the projectile.

This is a direct alternative to using a ballistic coefficient and a reference drag function.

Note: If the table does not span Mach 0..5 it is extrapolated; if extrapolation would produce invalid drag, Build returns kLobErrorMachDragTableInvalid — pad the table with explicit entries at 0 and/or 5.0 to define the desired edge behavior.

Warning: The caller must keep pmachs and pdrags valid until LobBuilderBuild is called. The builder copies no data; the pointers are referenced during Build().

Parameters

pbuilder	Pointer to the builder.
pmachs	Pointer to an array of mach values.
pdrags	Pointer to an array of associated drag values.
size	The number of mach-drag pairs in the table.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderStepSize()

LobBuilder * LobBuilderStepSize	(	LobBuilder *	pbuilder,
		uint16_t	value )

extern

Sets the step size for the numerical solver.

Note: If set to zero (the default) the solver uses a 1-yard step.

Parameters

pbuilder	Pointer to the builder.
value	The spatial step size in inches. 0 = default.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderTailLengthInch()

LobBuilder * LobBuilderTailLengthInch	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the projectile tail length in inches.

Parameters

pbuilder	Pointer to the builder.
value	The tail length in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderTemperatureDegF()

LobBuilder * LobBuilderTemperatureDegF	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the temperature in degrees Fahrenheit.

Parameters

pbuilder	Pointer to the builder.
value	The temperature in degrees F.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderTwistInchesPerTurn()

LobBuilder * LobBuilderTwistInchesPerTurn	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the twist rate of the barrel in inches per turn.

Note: Used to calculate adjustments for spin drift and aerodynamic jump.

Parameters

pbuilder	Pointer to the builder.
value	The twist rate in inches per turn.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderWindHeading()

LobBuilder * LobBuilderWindHeading	(	LobBuilder *	pbuilder,
		LobClockAngleT	value )

extern

Sets the wind heading using a clock angle.

Note: Twelve O'Clock is pure tailwind, Six O'Clock is a pure headwind.

Parameters

pbuilder	Pointer to the builder.
value	The wind heading as a clock angle.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderWindHeadingDeg()

LobBuilder * LobBuilderWindHeadingDeg	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the wind heading in degrees.

Note: 0 is pure tailwind, 180 is pure headwind.

Parameters

pbuilder	Pointer to the builder.
value	The wind heading in degrees.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderWindSpeedFps()

LobBuilder * LobBuilderWindSpeedFps	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the wind speed in feet per second.

Parameters

pbuilder	Pointer to the builder.
value	The wind speed in fps.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderWindSpeedMph()

LobBuilder * LobBuilderWindSpeedMph	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the wind speed in miles per hour.

Parameters

pbuilder	Pointer to the builder.
value	The wind speed in mph.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderZeroAngleMOA()

LobBuilder * LobBuilderZeroAngleMOA	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the angle between the sight and launch angle used to achieve zero.

Note: This is a portable zero value useful when firing conditions differ from zeroing conditions.

Parameters

pbuilder	Pointer to the builder.
value	The zero angle in MOA.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderZeroDistanceYds()

LobBuilder * LobBuilderZeroDistanceYds	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the zero distance in yards.

Parameters

pbuilder	Pointer to the builder.
value	The zero distance in yards.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobBuilderZeroImpactHeightInches()

LobBuilder * LobBuilderZeroImpactHeightInches	(	LobBuilder *	pbuilder,
		double	value )

extern

Sets the zero impact height in inches.

Note: This would be used if zeroing three inches high at 100 yards for example.

Parameters

pbuilder	Pointer to the builder.
value	The zero impact height in inches.

Returns: Pointer to the builder, or nullptr if pbuilder is null.

◆ LobCmToIn()

double LobCmToIn ( double value )

extern

Converts centimeters to inches.

Parameters

value Length in centimeters.

Returns: Equivalent length in inches.

◆ LobDegCToDegF()

double LobDegCToDegF ( double value )

extern

Converts degrees celsius to degrees fahrenheit.

Parameters

value Temperature in degrees celsius.

Returns: Equivalent temperature in degrees fahrenheit.

◆ LobDegToMil()

double LobDegToMil ( double value )

extern

Converts degrees to milliradians (MIL).

Parameters

value Angle in degrees.

Returns: Equivalent angle in MIL.

◆ LobDegToMoa()

double LobDegToMoa ( double value )

extern

Converts degrees to minutes of angle (MOA).

Parameters

value Angle in degrees.

Returns: Equivalent angle in MOA.

◆ LobFastInverse()

size_t LobFastInverse	(	const LobContext *	pctx,
		LobOutput *	pouts,
		size_t	size )

extern

Converts forward-solution output to inverse-solution adjustments.

Note: A one-step approximation. Only convert outputs whose forward solution reached the target range; fall-short trajectories yield meaningless results. Entries with non-finite elevation or deflection are skipped and not counted.

Parameters

pctx	Pointer to context parameters for the calculation.
pouts	Pointer to an array of forward-solution outputs to convert in place.
size	The number of outputs to convert.

Returns: The number of successful conversions, or 0 on invalid arguments. Entries with zero range are skipped and not counted.

◆ LobFpsToMps()

double LobFpsToMps ( double value )

extern

Converts feet per second to meters per second.

Parameters

value Speed in feet per second.

Returns: Equivalent speed in meters per second.

◆ LobFtLbsToJ()

double LobFtLbsToJ ( double value )

extern

Converts foot-pounds to joules.

Parameters

value Energy in foot-pounds.

Returns: Equivalent energy in joules.

◆ LobFtToIn()

double LobFtToIn ( double value )

extern

Converts feet to inches.

Parameters

value Length in feet.

Returns: Equivalent length in inches.

◆ LobFtToM()

double LobFtToM ( double value )

extern

Converts feet to meters.

Parameters

value Length in feet.

Returns: Equivalent length in meters.

◆ LobFtToYd()

double LobFtToYd ( double value )

extern

Converts feet to yards.

Parameters

value Length in feet.

Returns: Equivalent length in yards.

◆ LobGToGrain()

double LobGToGrain ( double value )

extern

Converts grams to grains.

Parameters

value Mass in grams.

Returns: Equivalent mass in grains.

◆ LobInchToDeg()

double LobInchToDeg	(	double	value,
		double	range_ft )

extern

Inches of projection at a given range to degrees.

Parameters

value	Projected inches.
range_ft	Range in feet.

Returns: Equivalent angle in degrees.

◆ LobInchToMil()

double LobInchToMil	(	double	value,
		double	range_ft )

extern

Inches of projection at a given range to milliradians (MIL).

Parameters

value	Projected inches.
range_ft	Range in feet.

Returns: Equivalent angle in MIL.

◆ LobInchToMoa()

double LobInchToMoa	(	double	value,
		double	range_ft )

extern

Inches of projection at a given range to minutes of angle (MOA).

Parameters

value	Projected inches.
range_ft	Range in feet.

Returns: Equivalent angle in MOA.

◆ LobInToCm()

double LobInToCm ( double value )

extern

Converts inches to centimeters.

Parameters

value Length in inches.

Returns: Equivalent length in centimeters.

◆ LobInToFt()

double LobInToFt ( double value )

extern

Converts inches to feet.

Parameters

value Length in inches.

Returns: Equivalent length in feet.

◆ LobInToMm()

double LobInToMm ( double value )

extern

Converts inches to millimeters.

Parameters

value Length in inches.

Returns: Equivalent length in millimeters.

◆ LobJToFtLbs()

double LobJToFtLbs ( double value )

extern

Converts joules to foot-pounds.

Parameters

value Energy in joules.

Returns: Equivalent energy in foot-pounds.

◆ LobKgSqMToPmsi()

double LobKgSqMToPmsi ( double value )

extern

Converts kilograms per square meter to pounds mass per square inch.

Parameters

value Sectional density in Kg/m^2.

Returns: Equivalent sectional density in lb/in^2.

◆ LobKgToGrain()

double LobKgToGrain ( double value )

extern

Converts kilograms to grains.

Parameters

value Mass in kilograms.

Returns: Equivalent mass in grains.

◆ LobKnToMph()

double LobKnToMph ( double value )

extern

Converts Knots to miles per hour.

Parameters

value Speed in Knots.

Returns: Equivalent speed in miles per hour.

◆ LobKphToMph()

double LobKphToMph ( double value )

extern

Converts kilometers per hour to miles per hour.

Parameters

value Speed in kilometers per hour.

Returns: Equivalent speed in miles per hour.

◆ LobLbsToGrain()

double LobLbsToGrain ( double value )

extern

Converts pounds to grains.

Parameters

value Mass in pounds.

Returns: Equivalent mass in grains.

◆ LobMbarToInHg()

double LobMbarToInHg ( double value )

extern

Converts millibars to inches of mercury.

Parameters

value Pressure in millibars.

Returns: Equivalent pressure in inches of mercury.

◆ LobMilToDeg()

double LobMilToDeg ( double value )

extern

Converts milliradians (MIL) to degrees.

Parameters

value Angle in MIL.

Returns: Equivalent angle in degrees.

◆ LobMilToInch()

double LobMilToInch	(	double	value,
		double	range_ft )

extern

Converts milliradians (MIL) to projected inches at a given range in feet.

Parameters

value	Angle in MIL.
range_ft	Range in feet.

Returns: Equivalent projected inches.

◆ LobMilToIphy()

double LobMilToIphy ( double value )

extern

Converts milliradians (MIL) to inches per hundred yards (IPHY).

Parameters

value Angle in MIL.

Returns: Equivalent angle in IPHY.

◆ LobMilToMoa()

double LobMilToMoa ( double value )

extern

Converts milliradians (MIL) to minutes of angle (MOA).

Parameters

value Angle in MIL.

Returns: Equivalent angle in MOA.

◆ LobMmToIn()

double LobMmToIn ( double value )

extern

Converts millimeters to inches.

Parameters

value Length in millimeters.

Returns: Equivalent length in inches.

◆ LobMoaToDeg()

double LobMoaToDeg ( double value )

extern

Converts minutes of angle (MOA) to degrees.

Parameters

value Angle in MOA.

Returns: Equivalent angle in degrees.

◆ LobMoaToInch()

double LobMoaToInch	(	double	value,
		double	range_ft )

extern

Converts minutes of angle (MOA) to projected inches at a given range in feet.

Parameters

value	Angle in MOA.
range_ft	Range in feet.

Returns: Equivalent projected inches.

◆ LobMoaToIphy()

double LobMoaToIphy ( double value )

extern

Converts minutes of angle (MOA) to inches per hundred yards (IPHY).

Parameters

value Angle in MOA.

Returns: Equivalent angle in IPHY.

◆ LobMoaToMil()

double LobMoaToMil ( double value )

extern

Converts minutes of angle (MOA) to milliradians (MIL).

Parameters

value Angle in MOA.

Returns: Equivalent angle in MIL.

◆ LobMpsToFps()

double LobMpsToFps ( double value )

extern

Converts meters per second to feet per second.

Parameters

value Speed in meters per second.

Returns: Equivalent speed in feet per second.

◆ LobMsToS()

double LobMsToS ( double value )

extern

Converts milliseconds to seconds.

Parameters

value Time in milliseconds.

Returns: Equivalent time in seconds.

◆ LobMToFt()

double LobMToFt ( double value )

extern

Converts meters to feet.

Parameters

value Length in meters.

Returns: Equivalent length in feet.

◆ LobMToYd()

double LobMToYd ( double value )

extern

Converts meters to yards.

Parameters

value Length in meters.

Returns: Equivalent length in yards.

◆ LobPaToInHg()

double LobPaToInHg ( double value )

extern

Converts pascals to inches of mercury.

Parameters

value Pressure in pascals.

Returns: Equivalent pressure in inches of mercury.

◆ LobPsiToInHg()

double LobPsiToInHg ( double value )

extern

Converts pounds per square inch (PSI) to inches of mercury.

Parameters

value Pressure in PSI.

Returns: Equivalent pressure in inches of mercury.

◆ LobSolve()

size_t LobSolve	(	const LobContext *	pctx,
		const uint32_t *	pranges,
		LobOutput *	pouts,
		size_t	size )

extern

Solves the exterior ballistics problem for a given set of ranges. Results contain a forward-solution.

Note: A forward-solution solves for the expected change in elevation and deflection (in inches) at a given range.

Parameters

pctx	Pointer to context parameters for the calculation.
pranges	Pointer to an array of ranges (in feet) to solve for.
pouts	Pointer to an array where the output results will be stored.
size	The number of ranges to solve for.

Returns: The number of successful solutions.

◆ LobSolveInverse()

size_t LobSolveInverse	(	const LobContext *	pctx,
		const uint32_t *	pranges,
		LobOutput *	pouts,
		size_t	size )

extern

Solves the exterior ballistics problem for a given set of ranges. Results contain an inverse-solution.

Note: An inverse-solution solves for the adjustments (in MOA) required to hit at a given range. Entries with zero range are counted but their adjustments are zeroed. Adjustments for ranges the projectile cannot reach (fall-short solutions) are not produced; solving stops at the first such entry. Unlike LobFastInverse, a fall-short entry is not silently given a meaningless adjustment.

Parameters

pctx	Pointer to context parameters for the calculation.
pranges	Pointer to an array of ranges (in feet) to solve for.
pouts	Pointer to an array where the output results will be stored.
size	The number of ranges to solve for.

Returns: The number of successful solutions.

◆ LobSToMs()

double LobSToMs ( double value )

extern

Converts seconds to milliseconds.

Parameters

value Time in seconds.

Returns: Equivalent time in milliseconds.

◆ LobSToUs()

double LobSToUs ( double value )

extern

Converts seconds to microseconds.

Parameters

value Time in seconds.

Returns: Equivalent time in microseconds.

◆ LobUsToS()

double LobUsToS ( double value )

extern

Converts microseconds to seconds.

Parameters

value Time in microseconds.

Returns: Equivalent time in seconds.

◆ LobVersion()

const char * LobVersion ( void )

extern

Gets the library version in major.minor.patch format.

◆ LobYdToFt()

double LobYdToFt ( double value )

extern

Converts yards to feet.

Parameters

value Length in yards.

Returns: Equivalent length in feet.

◆ LobYdToM()

double LobYdToM ( double value )

extern

Converts yards to meters.

Parameters

value Length in yards.

Returns: Equivalent length in meters.

Classes

Macros

Typedefs

Enumerations

Functions

Macro Definition Documentation

◆ LOB_BUILDER_BUFFER_SIZE

◆ LOB_SPLINE_SEGMENTS

Typedef Documentation

◆ LobAtmosphereReferenceT

◆ LobClockAngleT

◆ LobDragFunctionT

◆ LobErrorT

Enumeration Type Documentation

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

◆ anonymous enum

Function Documentation

◆ LobBuilderAirPressureInHg()

◆ LobBuilderAltitudeOfBarometerFt()

◆ LobBuilderAltitudeOfFiringSiteFt()

◆ LobBuilderAltitudeOfThermometerFt()

◆ LobBuilderAzimuthDeg()

◆ LobBuilderBallisticCoefficientPsi()

◆ LobBuilderBaseDiameterInch()

◆ LobBuilderBCAtmosphere()

◆ LobBuilderBCDragFunction()

◆ LobBuilderBCVelocityBands()

◆ LobBuilderBuild()

◆ LobBuilderCopy()

◆ LobBuilderDestroy()

◆ LobBuilderDiameterInch()

◆ LobBuilderInit()

◆ LobBuilderInitialVelocityFps()

◆ LobBuilderLatitudeDeg()

◆ LobBuilderLengthInch()

◆ LobBuilderMassGrains()

◆ LobBuilderMaximumTime()

◆ LobBuilderMeplatDiameterInch()

◆ LobBuilderMinimumEnergy()

◆ LobBuilderMinimumSpeed()

◆ LobBuilderNoseLengthInch()

◆ LobBuilderOgiveRtR()

◆ LobBuilderOpticHeightInches()

◆ LobBuilderRangeAngleDeg()

◆ LobBuilderRelativeHumidityPercent()

◆ LobBuilderReset()

◆ LobBuilderSplineFitTable()

◆ LobBuilderStepSize()

◆ LobBuilderTailLengthInch()

◆ LobBuilderTemperatureDegF()

◆ LobBuilderTwistInchesPerTurn()

◆ LobBuilderWindHeading()

◆ LobBuilderWindHeadingDeg()

◆ LobBuilderWindSpeedFps()

◆ LobBuilderWindSpeedMph()

◆ LobBuilderZeroAngleMOA()

◆ LobBuilderZeroDistanceYds()

◆ LobBuilderZeroImpactHeightInches()

◆ LobCmToIn()

◆ LobDegCToDegF()

◆ LobDegToMil()

◆ LobDegToMoa()

◆ LobFastInverse()

◆ LobFpsToMps()

◆ LobFtLbsToJ()

◆ LobFtToIn()

◆ LobFtToM()

◆ LobFtToYd()

◆ LobGToGrain()

◆ LobInchToDeg()

◆ LobInchToMil()

◆ LobInchToMoa()

◆ LobInToCm()

◆ LobInToFt()

◆ LobInToMm()

◆ LobJToFtLbs()

◆ LobKgSqMToPmsi()

◆ LobKgToGrain()