nurbsCurveResult.I

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/**
 * PANDA 3D SOFTWARE
 * Copyright (c) Carnegie Mellon University.  All rights reserved.
 *
 * All use of this software is subject to the terms of the revised BSD
 * license.  You should have received a copy of this license along
 * with this source code in a file named "LICENSE."
 *
 * @file nurbsCurveResult.I
 * @author drose
 * @date 2002-12-04
 */

/**
 *
 */
INLINE NurbsCurveResult::
~NurbsCurveResult() {
}

/**
 * Returns the first legal value of t on the curve.  Usually this is 0.0.
 */
INLINE PN_stdfloat NurbsCurveResult::
get_start_t() const {
  return _basis.get_start_t();
}

/**
 * Returns the last legal value of t on the curve.
 */
INLINE PN_stdfloat NurbsCurveResult::
get_end_t() const {
  return _basis.get_end_t();
}

/**
 * Computes the point on the curve corresponding to the indicated value in
 * parametric time.  Returns true if the t value is valid, false otherwise.
 */
INLINE bool NurbsCurveResult::
eval_point(PN_stdfloat t, LVecBase3 &point) {
  int segment = find_segment(t);
  if (segment == -1) {
    return false;
  }

  eval_segment_point(segment, _basis.scale_t(segment, t), point);
  return true;
}

/**
 * Computes the tangent to the curve at the indicated point in parametric
 * time.  This tangent vector will not necessarily be normalized, and could be
 * zero.  See also eval_point().
 */
INLINE bool NurbsCurveResult::
eval_tangent(PN_stdfloat t, LVecBase3 &tangent) {
  int segment = find_segment(t);
  if (segment == -1) {
    return false;
  }

  eval_segment_tangent(segment, _basis.scale_t(segment, t), tangent);
  return true;
}

/**
 * Evaluates the curve in n-dimensional space according to the extended
 * vertices associated with the curve in the indicated dimension.
 */
INLINE PN_stdfloat NurbsCurveResult::
eval_extended_point(PN_stdfloat t, int d) {
  int segment = find_segment(t);
  if (segment == -1) {
    return 0.0f;
  }

  return eval_segment_extended_point(segment, _basis.scale_t(segment, t), d);
}

/**
 * Simultaneously performs eval_extended_point on a contiguous sequence of
 * dimensions.  The dimensions evaluated are d through (d + num_values - 1);
 * the results are filled into the num_values elements in the indicated result
 * array.
 */
INLINE bool NurbsCurveResult::
eval_extended_points(PN_stdfloat t, int d, PN_stdfloat result[], int num_values) {
  int segment = find_segment(t);
  if (segment == -1) {
    return false;
  }

  eval_segment_extended_points(segment, _basis.scale_t(segment, t), d,
                               result, num_values);
  return true;
}

/**
 * Returns the number of piecewise continuous segments within the curve.  This
 * number is usually not important unless you plan to call
 * eval_segment_point().
 */
INLINE int NurbsCurveResult::
get_num_segments() const {
  return _basis.get_num_segments();
}

/**
 * Accepts a t value in the range [0, 1], and assumed to be relative to the
 * indicated segment (as in eval_segment_point()), and returns the
 * corresponding t value in the entire curve (as in eval_point()).
 */
INLINE PN_stdfloat NurbsCurveResult::
get_segment_t(int segment, PN_stdfloat t) const {
  return t * (_basis.get_to(segment) - _basis.get_from(segment)) + _basis.get_from(segment);
}

/**
 * Returns the number of sample points generated by the previous call to
 * adaptive_sample().
 */
INLINE int NurbsCurveResult::
get_num_samples() const {
  return (int)_adaptive_result.size();
}

/**
 * Returns the t value of the nth sample point generated by the previous call
 * to adaptive_sample().
 */
INLINE PN_stdfloat NurbsCurveResult::
get_sample_t(int n) const {
  nassertr(n >= 0 && n < (int)_adaptive_result.size(), 0.0f);
  return _adaptive_result[n]._t;
}

/**
 * Returns the point on the curve of the nth sample point generated by the
 * previous call to adaptive_sample().
 *
 * For tangents, or extended points, you should use get_sample_t() and pass it
 * into eval_tangent() or eval_extended_point().
 */
INLINE const LPoint3 &NurbsCurveResult::
get_sample_point(int n) const {
  nassertr(n >= 0 && n < (int)_adaptive_result.size(), LPoint3::zero());
  return _adaptive_result[n]._point;
}

/**
 * Accepts a t value in the range [0, 1], and assumed to be relative to the
 * indicated segment (as in eval_segment_point()), and returns the
 * corresponding t value in the entire curve (as in eval_point()).
 */
INLINE NurbsCurveResult::AdaptiveSample::
AdaptiveSample(PN_stdfloat t, const LPoint3 &point) :
  _t(t),
  _point(point)
{
}