libgutenprint-dev 5.2.11-1 / usr / include / gutenprint / curve.h

/*
 * "$Id: curve.h,v 1.2 2008/01/21 23:19:37 rlk Exp $"
 *
 *   libgimpprint curve functions.
 *
 *   Copyright 1997-2000 Michael Sweet (mike@easysw.com) and
 *	Robert Krawitz (rlk@alum.mit.edu)
 *
 *   This program 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 2 of the License, or (at your option)
 *   any later version.
 *
 *   This program 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 this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/**
 * @file gutenprint/curve.h
 * @brief Curve functions.
 */

#ifndef GUTENPRINT_CURVE_H
#define GUTENPRINT_CURVE_H

#include <stdio.h>
#include <stdlib.h>

#include <gutenprint/sequence.h>

#ifdef __cplusplus
extern "C" {
#endif


  /*
   * Curve code borrowed from GTK+, http://www.gtk.org/
   */

  /**
   * 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.
   *
   * @defgroup curve curve
   * @{
   */

struct stp_curve;
  /** The curve opaque data type. */
typedef struct stp_curve stp_curve_t;

  /** Curve types. */
typedef enum
{
  /** Linear interpolation. */
  STP_CURVE_TYPE_LINEAR,
  /** Spline interpolation. */
  STP_CURVE_TYPE_SPLINE
} stp_curve_type_t;

  /** Wrapping mode. */
typedef enum
{
  /** The curve does not wrap */
  STP_CURVE_WRAP_NONE,
  /** The curve wraps to its starting point. */
  STP_CURVE_WRAP_AROUND
} stp_curve_wrap_mode_t;

  /** Composition types. */
typedef enum
{
  /** Add composition. */
  STP_CURVE_COMPOSE_ADD,
  /** Multiply composition. */
  STP_CURVE_COMPOSE_MULTIPLY,
  /** Exponentiate composition. */
  STP_CURVE_COMPOSE_EXPONENTIATE
} stp_curve_compose_t;

  /** Behaviour when curve exceeds bounds. */
typedef enum
{
  /** Rescale the bounds. */
  STP_CURVE_BOUNDS_RESCALE,
  /** Clip the curve to the existing bounds. */
  STP_CURVE_BOUNDS_CLIP,
  /** Error if bounds are violated. */
  STP_CURVE_BOUNDS_ERROR
} stp_curve_bounds_t;

  /** Point (x,y) for piecewise curve. */
typedef struct
{
  /** Horizontal position. */
  double x;
  /** Vertical position. */
  double y;
} stp_curve_point_t;

/**
 * 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).
 * @param wrap the wrap mode of the curve.
 * @returns the newly created curve.
 */
extern stp_curve_t *stp_curve_create(stp_curve_wrap_mode_t wrap);

  /**
   * 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().
   * @param curve the source curve.
   * @returns the new copy of the curve.
   */
extern stp_curve_t *stp_curve_create_copy(const stp_curve_t *curve);

  /**
   * Copy a curve.
   * Both dest and source must be valid curves previously created with
   * stp_curve_create().
   * @param dest the destination curve.
   * @param source the source curve.
   */
extern void stp_curve_copy(stp_curve_t *dest, const stp_curve_t *source);

  /**
   * 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().
   * @param curve the source curve.
   * @returns the new copy of the curve.
   */
extern stp_curve_t *stp_curve_create_reverse(const stp_curve_t *curve);

  /**
   * Reverse a curve.
   * Both dest and source must be valid curves previously created with
   * stp_curve_create().
   * @param dest the destination curve.
   * @param source the source curve.
   */
extern void stp_curve_reverse(stp_curve_t *dest, const stp_curve_t *source);

  /**
   * Destroy an curve.
   * It is an error to destroy the curve more than once.
   * @param curve the curve to destroy.
   */
extern void stp_curve_destroy(stp_curve_t *curve);

/**
 * Set the lower and upper bounds on a curve.
 * To change the bounds adjusting data as required, use
 * stp_curve_rescale instead.
 * @param curve the curve to use.
 * @param low the lower bound.
 * @param high the upper bound.
 * @returns FALSE if any existing points on the curve are outside the
 * bounds.
 */
extern int stp_curve_set_bounds(stp_curve_t *curve, double low, double high);

/**
 * Get the lower and upper bounds on a curve.
 * @param curve the curve to use.
 * @param low a pointer to a double to store the lower bound in.
 * @param high a pointer to a double to store the upper bound in.
 */
extern void stp_curve_get_bounds(const stp_curve_t *curve,
				 double *low, double *high);

/**
 * Get the wrapping mode.
 * @param curve the curve to use.
 * @returns the wrapping mode.
 */
extern stp_curve_wrap_mode_t stp_curve_get_wrap(const stp_curve_t *curve);

/**
 * Determine whether the curve is piecewise
 * @param curve the curve to use.
 * @returns whether the curve is piecewise
 */
extern int stp_curve_is_piecewise(const stp_curve_t *curve);

/*
 * Get the range (lowest and highest value of points) in the curve.
 * This does not account for any interpolation that may place
 * intermediate points outside of the curve.
 * @param curve the curve to use.
 * @param low a pointer to double to store the lower limit in.
 * @param high a pointer to double to store the upper limit in.
 */
extern void stp_curve_get_range(const stp_curve_t *curve,
				double *low, double *high);

/**
 * Get the number of allocated points in the curve.
 * @param curve the curve to use.
 * @returns the number of points.
 */
extern size_t stp_curve_count_points(const stp_curve_t *curve);

/**
 * Set the curve interpolation type.
 * @param curve the curve to use.
 * @param itype the interpolation type.
 * @returns 1 on success, or 0 if itype is invalid.
 */
extern int stp_curve_set_interpolation_type(stp_curve_t *curve,
					    stp_curve_type_t itype);

/**
 * Get the curve interpolation type.
 * @param curve the curve to use.
 * @returns the interpolation type.
 */
extern stp_curve_type_t stp_curve_get_interpolation_type(const stp_curve_t *curve);

/**
 * 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.
 * @param curve the curve to use.
 * @param count the number of points (must be at least two and not
 * more than 1048576).
 * @param data a pointer to an array of doubles (must be at least
 * count in size).
 * @returns 1 on success, 0 on failure.
 */
extern 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 piecewise curve.
 * @param curve the curve to use.
 * @param count the number of points (must be at least two and not
 * more than 1048576).
 * @param 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.
 */
extern int stp_curve_set_data_points(stp_curve_t *curve, size_t count,
				     const stp_curve_point_t *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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of floats (must be at least
 * count in size).
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_float_data(stp_curve_t *curve,
				    size_t count, const float *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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of longs (must be at least
 * count in size).
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_long_data(stp_curve_t *curve,
				   size_t count, const 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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of unsigned longs (must be at
 * least count in size).
 * @returns 1 on success, 0 on failure.
 */
extern 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 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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of integers (must be at least
 * count in size).
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_int_data(stp_curve_t *curve,
				  size_t count, const 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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of unsigned integers (must be at
 * least count in size).
 * @returns 1 on success, 0 on failure.
 */
extern 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 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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of shorts (must be at least
 * count in size).
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_short_data(stp_curve_t *curve,
				    size_t count, const 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.
 * @param curve the curve to use.
 * @param count the number of the number of points (must be at least
 * two and not more than 1048576).
 * @param data a pointer to an array of unsigned shorts (must be at
 * least count in size).
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_ushort_data(stp_curve_t *curve,
				     size_t count, const unsigned short *data);

/**
 * 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
 * @param curve the curve to use.
 * @param start the start of the subrange.
 * @param count the number of point starting at start.
 * @returns a curve containing the subrange.  The returned curve is
 * non-wrapping.
 */
extern stp_curve_t *stp_curve_get_subrange(const stp_curve_t *curve,
					   size_t start, size_t count);

/*
 * Set part of a curve to the range in another curve.  The data in the
 * range must fit within both the bounds and the number of points in
 * the first curve.  The curve must be a dense (equally-spaced) curve.
 * @param curve the curve to use (destination).
 * @param range the source curve.
 * @param start the starting point in the destination range.
 * @param returns 1 on success, 0 on failure.
 */
extern int stp_curve_set_subrange(stp_curve_t *curve, const stp_curve_t *range,
				  size_t start);

/**
 * Get a pointer to the curve's raw data.
 * @param curve the curve to use.
 * @param 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.
 */
extern const double *stp_curve_get_data(const stp_curve_t *curve, size_t *count);

/**
 * Get a pointer to the curve's raw data as points.
 * @param curve the curve to use.
 * @param 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.
 */
extern const stp_curve_point_t *stp_curve_get_data_points(const stp_curve_t *curve, size_t *count);


/**
 * Get pointer to the curve's raw data as floats.
 * @param curve the curve to use.
 * @param 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.
 */
extern const float *stp_curve_get_float_data(const stp_curve_t *curve,
					     size_t *count);

/**
 * Get pointer to the curve's raw data as longs.
 * @param curve the curve to use.
 * @param 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.
 */
extern const long *stp_curve_get_long_data(const stp_curve_t *curve,
					   size_t *count);

/**
 * Get pointer to the curve's raw data as unsigned longs.
 * @param curve the curve to use.
 * @param 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.
 */
extern 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 integers.
 * @param curve the curve to use.
 * @param 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.
 */
extern const int *stp_curve_get_int_data(const stp_curve_t *curve,
					 size_t *count);

/**
 * Get pointer to the curve's raw data as unsigned integers.
 * @param curve the curve to use.
 * @param 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.
 */
extern 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 shorts.
 * @param curve the curve to use.
 * @param 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.
 */
extern const short *stp_curve_get_short_data(const stp_curve_t *curve,
					     size_t *count);

/**
 * Get pointer to the curve's raw data as unsigned shorts.
 * @param curve the curve to use.
 * @param 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.
 */
extern const unsigned short *stp_curve_get_ushort_data(const stp_curve_t *curve,
						       size_t *count);

/**
 * 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.
 * @param curve the curve to use.
 * @returns the stp_sequence_t.  If the curve is a piecewise curve, the
 * sequence returned is NULL;
 */
extern const stp_sequence_t *stp_curve_get_sequence(const stp_curve_t *curve);

/**
 * 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.
 * @param curve the curve to use.
 * @param 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.
 */
extern int stp_curve_set_gamma(stp_curve_t *curve, double f_gamma);

/**
 * 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.
 */
extern double stp_curve_get_gamma(const stp_curve_t *curve);

/**
 * Set a point along the curve.
 * This call destroys any gamma value assigned to the curve.
 * @param curve the curve to use.
 * @param where the point to set.
 * @param 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.
 */
extern int stp_curve_set_point(stp_curve_t *curve, size_t where, double data);

/**
 * Get a point along the curve.
 * @param curve the curve to use.
 * @param where the point to get.
 * @param 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.
 */
extern int stp_curve_get_point(const stp_curve_t *curve, size_t where,
			       double *data);

/**
 * Interpolate a point along the curve.
 * @param curve the curve to use.
 * @param where the point to interpolate.
 * @param 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.
 */
extern int stp_curve_interpolate_value(const stp_curve_t *curve,
				       double where, double *result);

/**
 * 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.
 * @param curve the curve to use (must not exceed 1048576).
 * @param 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).
 */
extern int stp_curve_resample(stp_curve_t *curve, size_t points);

/**
 * 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.
 * @param curve the curve to use.
 * @param scale the scaling factor.
 * @param mode the composition mode.
 * @param bounds_mode the bounds exceeding mode.
 * @returns FALSE if this would exceed floating point limits
 */
extern int stp_curve_rescale(stp_curve_t *curve, double scale,
			     stp_curve_compose_t mode,
			     stp_curve_bounds_t bounds_mode);

/**
 * 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.
 * @param file the file to write.
 * @param curve the curve to use.
 * @returns 1 on success, 0 on failure.
 */
extern int stp_curve_write(FILE *file, 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.
 * @param 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.
 */
extern char *stp_curve_write_string(const stp_curve_t *curve);

/**
 * 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.
 * @param fp the stream to read.
 * @returns the newly created curve, or NULL if an error occured.
 */
extern 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.
 * @param file the file to read.
 * @returns the newly created curve, or NULL if an error occured.
 */
extern stp_curve_t *stp_curve_create_from_file(const char* file);

/**
 * 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.
 * @param string the string to read.
 * @returns the newly created curve, or NULL if an error occured.
 */
extern stp_curve_t *stp_curve_create_from_string(const char* string);

/**
 * 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.
 * @param retval a pointer to store the location of the newly-created
 * output curve in.
 * @param a the first source curve.
 * @param b the second source curve.
 * @param mode the composition mode.
 * @param 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.
 */
extern int stp_curve_compose(stp_curve_t **retval,
			     stp_curve_t *a, stp_curve_t *b,
			     stp_curve_compose_t mode, int points);

  /** @} */

#ifdef __cplusplus
  }
#endif

#endif /* GUTENPRINT_CURVE_H */
/*
 * End of "$Id: curve.h,v 1.2 2008/01/21 23:19:37 rlk Exp $".
 */