curve

The curve type models a linear, spline or gamma curve. More...

Data Structures
struct	stp_curve_point_t
	Point (x,y) for piecewise curve. More...
Typedefs
typedef struct stp_curve	stp_curve_t
	The curve opaque data type.
Enumerations
enum	stp_curve_type_t { STP_CURVE_TYPE_LINEAR, STP_CURVE_TYPE_SPLINE }
	Curve types. More...
enum	stp_curve_wrap_mode_t { STP_CURVE_WRAP_NONE, STP_CURVE_WRAP_AROUND }
	Wrapping mode. More...
enum	stp_curve_compose_t { STP_CURVE_COMPOSE_ADD, STP_CURVE_COMPOSE_MULTIPLY, STP_CURVE_COMPOSE_EXPONENTIATE }
	Composition types. More...
enum	stp_curve_bounds_t { STP_CURVE_BOUNDS_RESCALE, STP_CURVE_BOUNDS_CLIP, STP_CURVE_BOUNDS_ERROR }
	Behaviour when curve exceeds bounds. More...
Functions
stp_curve_t *	stp_curve_create (stp_curve_wrap_mode_t wrap)
	Create a new curve.
stp_curve_t *	stp_curve_create_copy (const stp_curve_t *curve)
	Copy and allocate a curve.
void	stp_curve_copy (stp_curve_t *dest, const stp_curve_t *source)
	Copy a curve.
stp_curve_t *	stp_curve_create_reverse (const stp_curve_t *curve)
	Reverse and allocate a curve.
void	stp_curve_reverse (stp_curve_t *dest, const stp_curve_t *source)
	Reverse a curve.
void	stp_curve_destroy (stp_curve_t *curve)
	Destroy an curve.
int	stp_curve_set_bounds (stp_curve_t *curve, double low, double high)
	Set the lower and upper bounds on a curve.
void	stp_curve_get_bounds (const stp_curve_t *curve, double *low, double *high)
	Get the lower and upper bounds on a curve.
stp_curve_wrap_mode_t	stp_curve_get_wrap (const stp_curve_t *curve)
	Get the wrapping mode.
int	stp_curve_is_piecewise (const stp_curve_t *curve)
	Determine whether the curve is piecewise.
void	stp_curve_get_range (const stp_curve_t *curve, double *low, double *high)
size_t	stp_curve_count_points (const stp_curve_t *curve)
	Get the number of allocated points in the curve.
int	stp_curve_set_interpolation_type (stp_curve_t *curve, stp_curve_type_t itype)
	Set the curve interpolation type.
stp_curve_type_t	stp_curve_get_interpolation_type (const stp_curve_t *curve)
	Get the curve interpolation type.
int	stp_curve_set_data (stp_curve_t *curve, size_t count, const double *data)
	Set all data points of the curve.
int	stp_curve_set_data_points (stp_curve_t *curve, size_t count, const stp_curve_point_t *data)
	Set all data points of the curve.
int	stp_curve_set_float_data (stp_curve_t *curve, size_t count, const float *data)
	Set the data points in a curve from float values.
int	stp_curve_set_long_data (stp_curve_t *curve, size_t count, const long *data)
	Set the data points in a curve from long values.
int	stp_curve_set_ulong_data (stp_curve_t *curve, size_t count, const unsigned long *data)
	Set the data points in a curve from unsigned long values.
int	stp_curve_set_int_data (stp_curve_t *curve, size_t count, const int *data)
	Set the data points in a curve from integer values.
int	stp_curve_set_uint_data (stp_curve_t *curve, size_t count, const unsigned int *data)
	Set the data points in a curve from unsigned integer values.
int	stp_curve_set_short_data (stp_curve_t *curve, size_t count, const short *data)
	Set the data points in a curve from short values.
int	stp_curve_set_ushort_data (stp_curve_t *curve, size_t count, const unsigned short *data)
	Set the data points in a curve from unsigned short values.
stp_curve_t *	stp_curve_get_subrange (const stp_curve_t *curve, size_t start, size_t count)
	Get a curve containing a subrange of data.
int	stp_curve_set_subrange (stp_curve_t *curve, const stp_curve_t *range, size_t start)
const double *	stp_curve_get_data (const stp_curve_t *curve, size_t *count)
	Get a pointer to the curve's raw data.
const stp_curve_point_t *	stp_curve_get_data_points (const stp_curve_t *curve, size_t *count)
	Get a pointer to the curve's raw data as points.
const float *	stp_curve_get_float_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as floats.
const long *	stp_curve_get_long_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as longs.
const unsigned long *	stp_curve_get_ulong_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as unsigned longs.
const int *	stp_curve_get_int_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as integers.
const unsigned int *	stp_curve_get_uint_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as unsigned integers.
const short *	stp_curve_get_short_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as shorts.
const unsigned short *	stp_curve_get_ushort_data (const stp_curve_t *curve, size_t *count)
	Get pointer to the curve's raw data as unsigned shorts.
const stp_sequence_t *	stp_curve_get_sequence (const stp_curve_t *curve)
	Get the underlying stp_sequence_t data structure which stp_curve_t is derived from.
int	stp_curve_set_gamma (stp_curve_t *curve, double f_gamma)
	Set the gamma of a curve.
double	stp_curve_get_gamma (const stp_curve_t *curve)
	Get the gamma value of the curve.
int	stp_curve_set_point (stp_curve_t *curve, size_t where, double data)
	Set a point along the curve.
int	stp_curve_get_point (const stp_curve_t *curve, size_t where, double *data)
	Get a point along the curve.
int	stp_curve_interpolate_value (const stp_curve_t *curve, double where, double *result)
	Interpolate a point along the curve.
int	stp_curve_resample (stp_curve_t *curve, size_t points)
	Resample a curve (change the number of points).
int	stp_curve_rescale (stp_curve_t *curve, double scale, stp_curve_compose_t mode, stp_curve_bounds_t bounds_mode)
	Rescale a curve (multiply all points by a scaling constant).
int	stp_curve_write (FILE *file, const stp_curve_t *curve)
	Write a curve to a file.
char *	stp_curve_write_string (const stp_curve_t *curve)
	Write a curve to a string.
stp_curve_t *	stp_curve_create_from_stream (FILE *fp)
	Create a curve from a stream.
stp_curve_t *	stp_curve_create_from_file (const char *file)
	Create a curve from a stream.
stp_curve_t *	stp_curve_create_from_string (const char *string)
	Create a curve from a string.
int	stp_curve_compose (stp_curve_t **retval, stp_curve_t *a, stp_curve_t *b, stp_curve_compose_t mode, int points)
	Compose two curves, creating a third curve.

---

Detailed Description

The curve type models a linear, spline or gamma curve.

curve "inherits" from the sequence data structure (implemented via containment), since the curve data is represented internally as a sequence of numbers, for linear and spline curves. Linear Piecewise Curves (LPCs) should be implemented in the future which represent a curve in a more compact format.

Various operations are supported, including interpolation and composition.

---

Typedef Documentation

typedef struct stp_curve stp_curve_t

The curve opaque data type.

---

Enumeration Type Documentation

enum stp_curve_bounds_t

Behaviour when curve exceeds bounds.

Enumerator:

STP_CURVE_BOUNDS_RESCALE	Rescale the bounds.
STP_CURVE_BOUNDS_CLIP	Clip the curve to the existing bounds.
STP_CURVE_BOUNDS_ERROR	Error if bounds are violated.

enum stp_curve_compose_t

Composition types.

Enumerator:

STP_CURVE_COMPOSE_ADD	Add composition.
STP_CURVE_COMPOSE_MULTIPLY	Multiply composition.
STP_CURVE_COMPOSE_EXPONENTIATE	Exponentiate composition.

enum stp_curve_type_t

Curve types.

Enumerator:

STP_CURVE_TYPE_LINEAR	Linear interpolation.
STP_CURVE_TYPE_SPLINE	Spline interpolation.

enum stp_curve_wrap_mode_t

Wrapping mode.

Enumerator:

STP_CURVE_WRAP_NONE	The curve does not wrap.
STP_CURVE_WRAP_AROUND	The curve wraps to its starting point.

---

Function Documentation

int stp_curve_compose	(	stp_curve_t **	retval,
		stp_curve_t *	a,
		stp_curve_t *	b,
		stp_curve_compose_t	mode,
		int	points
	)

Compose two curves, creating a third curve.

Only add and multiply composition is currently supported. If both curves are gamma curves with the same sign, and the operation is multiplication or division, the returned curve is a gamma curve with the appropriate number of points. Both a and b must have the same wraparound type.

Parameters:

	retval	a pointer to store the location of the newly-created output curve in.
	a	the first source curve.
	b	the second source curve.
	mode	the composition mode.
	points	the number of points in the output curve (must not exceed 1048576). It must be at least two, unless the curve is a gamma curve and the operation chosen is multiplication or division. If -1, the resulting number of points will be the least common multiplier of the number of points in the input and output curves (but will not exceed 1048576).

Returns:

FALSE if element-wise composition fails.

void stp_curve_copy	(	stp_curve_t *	dest,
		const stp_curve_t *	source
	)

Copy a curve.

Both dest and source must be valid curves previously created with stp_curve_create().

Parameters:

	dest	the destination curve.
	source	the source curve.

size_t stp_curve_count_points

(

const stp_curve_t *

curve

)

Get the number of allocated points in the curve.

Parameters:

curve

the curve to use.

Returns:

the number of points.

stp_curve_t* stp_curve_create

(

stp_curve_wrap_mode_t

wrap

)

Create a new curve.

Curves have y=lower..upper. The default bounds are 0..1. The default interpolation type is linear. There are no points allocated, and the gamma is defaulted to 1. The curve is a dense (equally-spaced) curve.

A wrapped curve has the same value at x=0 and x=1. The wrap mode of a curve cannot be changed except by routines that destroy the old curve entirely (e. g. stp_curve_copy, stp_curve_read).

Parameters:

wrap

the wrap mode of the curve.

Returns:

the newly created curve.

stp_curve_t* stp_curve_create_copy

(

const stp_curve_t *

curve

)

Copy and allocate a curve.

dest will be created, and then the contents of source will be copied into it. dest must not have been previously allocated with stp_curve_create().

Parameters:

curve

the source curve.

Returns:

the new copy of the curve.

stp_curve_t* stp_curve_create_from_file

(

const char *

file

)

Create a curve from a stream.

Warning:

NOTE that these calls are not thread-safe! These routines may manipulate the locale to achieve a safe representation.

Parameters:

file

the file to read.

Returns:

the newly created curve, or NULL if an error occured.

stp_curve_t* stp_curve_create_from_stream

(

FILE *

fp

)

Create a curve from a stream.

Warning:

NOTE that these calls are not thread-safe! These routines may manipulate the locale to achieve a safe representation.

Parameters:

fp

the stream to read.

Returns:

the newly created curve, or NULL if an error occured.

stp_curve_t* stp_curve_create_from_string

(

const char *

string

)

Create a curve from a string.

Warning:

NOTE that these calls are not thread-safe! These routines may manipulate the locale to achieve a safe representation.

Parameters:

string

the string to read.

Returns:

the newly created curve, or NULL if an error occured.

stp_curve_t* stp_curve_create_reverse

(

const stp_curve_t *

curve

)

Reverse and allocate a curve.

dest will be created, and then the contents of source will be copied into it. dest must not have been previously allocated with stp_curve_create().

Parameters:

curve

the source curve.

Returns:

the new copy of the curve.

void stp_curve_destroy

(

stp_curve_t *

curve

)

Destroy an curve.

It is an error to destroy the curve more than once.

Parameters:

curve

the curve to destroy.

void stp_curve_get_bounds	(	const stp_curve_t *	curve,
		double *	low,
		double *	high
	)

Get the lower and upper bounds on a curve.

Parameters:

	curve	the curve to use.
	low	a pointer to a double to store the lower bound in.
	high	a pointer to a double to store the upper bound in.

const double* stp_curve_get_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get a pointer to the curve's raw data.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This call also returns NULL if the curve is a piecewise curve.

const stp_curve_point_t* stp_curve_get_data_points	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get a pointer to the curve's raw data as points.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This call also returns NULL if the curve is a dense (equally-spaced) curve.

const float* stp_curve_get_float_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as floats.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

double stp_curve_get_gamma

(

const stp_curve_t *

curve

)

Get the gamma value of the curve.

Returns:

the gamma value. A value of 0 indicates that the curve does not have a valid gamma value.

const int* stp_curve_get_int_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as integers.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

stp_curve_type_t stp_curve_get_interpolation_type

(

const stp_curve_t *

curve

)

Get the curve interpolation type.

Parameters:

curve

the curve to use.

Returns:

the interpolation type.

const long* stp_curve_get_long_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as longs.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

int stp_curve_get_point	(	const stp_curve_t *	curve,
		size_t	where,
		double *	data
	)

Get a point along the curve.

Parameters:

	curve	the curve to use.
	where	the point to get.
	data	a pointer to a double to store the value of where in.

Returns:

FALSE if where is outside of the number of valid points. This also returns NULL if the curve is a piecewise curve.

void stp_curve_get_range	(	const stp_curve_t *	curve,
		double *	low,
		double *	high
	)

const stp_sequence_t* stp_curve_get_sequence

(

const stp_curve_t *

curve

)

Get the underlying stp_sequence_t data structure which stp_curve_t is derived from.

This can be used for fast access to the raw data.

Parameters:

curve

the curve to use.

Returns:

the stp_sequence_t. If the curve is a piecewise curve, the sequence returned is NULL;

const short* stp_curve_get_short_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as shorts.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

stp_curve_t* stp_curve_get_subrange	(	const stp_curve_t *	curve,
		size_t	start,
		size_t	count
	)

Get a curve containing a subrange of data.

If the start or count is invalid, the returned curve will compare equal to NULL (i. e. it will be a null pointer). start and count must not exceed the number of points in the curve, and count must be at least 2. The curve must be a dense (equally-spaced) curve

Parameters:

	curve	the curve to use.
	start	the start of the subrange.
	count	the number of point starting at start.

Returns:

a curve containing the subrange. The returned curve is non-wrapping.

const unsigned int* stp_curve_get_uint_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as unsigned integers.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

const unsigned long* stp_curve_get_ulong_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as unsigned longs.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

const unsigned short* stp_curve_get_ushort_data	(	const stp_curve_t *	curve,
		size_t *	count
	)

Get pointer to the curve's raw data as unsigned shorts.

Parameters:

	curve	the curve to use.
	count	a pointer to a size_t to store the curve size in.

Returns:

a pointer to the curve data. This data is not guaranteed to be valid beyond the next non-const curve call. If the curve is a pure gamma curve (no associated points), NULL is returned and the count is 0. This also returns NULL if the curve is a piecewise curve.

stp_curve_wrap_mode_t stp_curve_get_wrap

(

const stp_curve_t *

curve

)

Get the wrapping mode.

Parameters:

curve

the curve to use.

Returns:

the wrapping mode.

int stp_curve_interpolate_value	(	const stp_curve_t *	curve,
		double	where,
		double *	result
	)

Interpolate a point along the curve.

Parameters:

	curve	the curve to use.
	where	the point to interpolate.
	result	a pointer to double to store the value of where in. If interpolation would produce a value outside of the allowed range (as could happen with spline interpolation), the value is clipped to the range.

Returns:

FALSE if 'where' is less than 0 or greater than the number of points, an error is returned. Also returns FALSE if the curve is a piecewise curve.

int stp_curve_is_piecewise

(

const stp_curve_t *

curve

)

Determine whether the curve is piecewise.

Parameters:

curve

the curve to use.

Returns:

whether the curve is piecewise

int stp_curve_resample	(	stp_curve_t *	curve,
		size_t	points
	)

Resample a curve (change the number of points).

This does not destroy the gamma value of a curve. Points are interpolated as required; any interpolation that would place points outside of the bounds of the curve will be clipped to the bounds. The resulting curve is always dense (equally-spaced). This is the correct way to convert a piecewise curve to an equally-spaced curve.

Parameters:

	curve	the curve to use (must not exceed 1048576).
	points	the number of points.

Returns:

FALSE if the number of points is invalid (less than two, except that zero points is permitted for a gamma curve).

int stp_curve_rescale	(	stp_curve_t *	curve,
		double	scale,
		stp_curve_compose_t	mode,
		stp_curve_bounds_t	bounds_mode
	)

Rescale a curve (multiply all points by a scaling constant).

This also rescales the bounds. Note that this currently destroys the gamma property of the curve.

Parameters:

	curve	the curve to use.
	scale	the scaling factor.
	mode	the composition mode.
	bounds_mode	the bounds exceeding mode.

Returns:

FALSE if this would exceed floating point limits

void stp_curve_reverse	(	stp_curve_t *	dest,
		const stp_curve_t *	source
	)

Reverse a curve.

Both dest and source must be valid curves previously created with stp_curve_create().

Parameters:

	dest	the destination curve.
	source	the source curve.

int stp_curve_set_bounds	(	stp_curve_t *	curve,
		double	low,
		double	high
	)

Set the lower and upper bounds on a curve.

To change the bounds adjusting data as required, use stp_curve_rescale instead.

Parameters:

	curve	the curve to use.
	low	the lower bound.
	high	the upper bound.

Returns:

FALSE if any existing points on the curve are outside the bounds.

int stp_curve_set_data	(	stp_curve_t *	curve,
		size_t	count,
		const double *	data
	)

Set all data points of the curve.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of doubles (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_data_points	(	stp_curve_t *	curve,
		size_t	count,
		const stp_curve_point_t *	data
	)

Set all data points of the curve.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a piecewise curve.

Parameters:

	curve	the curve to use.
	count	the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of points (must be at least count in size). The first point must have X=0, and each point must have an X value at least .000001 greater than the previous point. If the curve is not a wraparound curve, the last point must have X=1.

Returns:

1 on success, 0 on failure.

int stp_curve_set_float_data	(	stp_curve_t *	curve,
		size_t	count,
		const float *	data
	)

Set the data points in a curve from float values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of floats (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_gamma	(	stp_curve_t *	curve,
		double	f_gamma
	)

Set the gamma of a curve.

This replaces all existing points along the curve. The bounds are set to 0..1. If the gamma value is positive, the function is increasing; if negative, the function is decreasing. Count must be either 0 or at least 2. If the count is zero, the gamma of the curve is set for interpolation purposes, but points cannot be assigned to. It is illegal to set gamma on a wrap-mode curve. The resulting curve is treated as a dense (equally-spaced) curve.

Parameters:

	curve	the curve to use.
	f_gamma	the gamma value to set.

Returns:

FALSE if the gamma value is illegal (0, infinity, or NaN), or if the curve wraps around.

int stp_curve_set_int_data	(	stp_curve_t *	curve,
		size_t	count,
		const int *	data
	)

Set the data points in a curve from integer values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of integers (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_interpolation_type	(	stp_curve_t *	curve,
		stp_curve_type_t	itype
	)

Set the curve interpolation type.

Parameters:

	curve	the curve to use.
	itype	the interpolation type.

Returns:

1 on success, or 0 if itype is invalid.

int stp_curve_set_long_data	(	stp_curve_t *	curve,
		size_t	count,
		const long *	data
	)

Set the data points in a curve from long values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of longs (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_point	(	stp_curve_t *	curve,
		size_t	where,
		double	data
	)

Set a point along the curve.

This call destroys any gamma value assigned to the curve.

Parameters:

	curve	the curve to use.
	where	the point to set.
	data	the value to set where to.

Returns:

FALSE if data is outside the valid bounds or if where is outside the number of valid points. This also returns NULL if the curve is a piecewise curve.

int stp_curve_set_short_data	(	stp_curve_t *	curve,
		size_t	count,
		const short *	data
	)

Set the data points in a curve from short values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of shorts (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_subrange	(	stp_curve_t *	curve,
		const stp_curve_t *	range,
		size_t	start
	)

int stp_curve_set_uint_data	(	stp_curve_t *	curve,
		size_t	count,
		const unsigned int *	data
	)

Set the data points in a curve from unsigned integer values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of unsigned integers (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_ulong_data	(	stp_curve_t *	curve,
		size_t	count,
		const unsigned long *	data
	)

Set the data points in a curve from unsigned long values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of unsigned longs (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_set_ushort_data	(	stp_curve_t *	curve,
		size_t	count,
		const unsigned short *	data
	)

Set the data points in a curve from unsigned short values.

If any of the data points fall outside the bounds, the operation is not performed and FALSE is returned. This creates a curve with equally-spaced points.

Parameters:

	curve	the curve to use.
	count	the number of the number of points (must be at least two and not more than 1048576).
	data	a pointer to an array of unsigned shorts (must be at least count in size).

Returns:

1 on success, 0 on failure.

int stp_curve_write	(	FILE *	file,
		const stp_curve_t *	curve
	)

Write a curve to a file.

The printable representation is guaranteed to contain only 7-bit printable ASCII characters, and is null-terminated. The curve will not contain any space, newline, single quote, or comma characters. Furthermore, a printed curve will be read back correctly in all locales. These calls are not guaranteed to provide more than 6 decimal places of precision or +/-0.5e-6 accuracy, whichever is less.

Warning:

NOTE that these calls are not thread-safe! These routines may manipulate the locale to achieve a safe representation.

Parameters:

	file	the file to write.
	curve	the curve to use.

Returns:

1 on success, 0 on failure.

char* stp_curve_write_string

(

const stp_curve_t *

curve

)

Write a curve to a string.

The printable representation is guaranteed to contain only 7-bit printable ASCII characters, and is null-terminated. The curve will not contain any space, newline, or comma characters. Furthermore, a printed curve will be read back correctly in all locales. These calls are not guaranteed to provide more than 6 decimal places of precision or +/-0.5e-6 accuracy, whichever is less.

Warning:

NOTE that these calls are not thread-safe! These routines may manipulate the locale to achieve a safe representation.

Parameters:

curve

the curve to use.

Returns:

a pointer to a string. This is allocated on the heap, and it is the caller's responsibility to free it.