Removing dimension from get_curvature in ABI.

docs/abi/curve.rst

@@ -266,7 +266,6 @@ Procedures
                   bool *not_implemented);
 
 .. c:function:: void get_curvature(int *num_nodes, \
-                                   int *dimension, \
                                    double *nodes, \
                                    double *tangent_vec, \
                                    double *s, \
@@ -275,18 +274,21 @@ Procedures
    Get the curvature of a B |eacute| zier curve at a point. See
    :func:`._get_curvature` for more details.
 
+   .. note::
+
+      This **only** computes curvature for plane curves (i.e. curves
+      in :math:`\mathbf{R}^2`). An equivalent notion of curvature exists for
+      space curves, but support for that is not implemented here.
+
    :param int* num_nodes:
       **[Input]** The number of control points :math:`N` of a
       B |eacute| zier curve.
-   :param int* dimension:
-      **[Input]** The dimension :math:`D` such that the curve lies in
-      :math:`\mathbf{R}^D`.
    :param double* nodes:
       **[Input]** The actual control points of the curve as a
-      :math:`D \times N` array. This should be laid out in Fortran order,
-      with :math:`D N` total values.
+      :math:`2 \times N` array. This should be laid out in Fortran order,
+      with :math:`2 N` total values.
    :param double* tangent_vec:
-      **[Input]** The hodograph :math:`B'(s)` as a :math:`D \times 1` array.
+      **[Input]** The hodograph :math:`B'(s)` as a :math:`2 \times 1` array.
       Note that this could be computed once :math:`s` and :math:`B` are known,
       but this allows the caller to re-use an already computed tangent vector.
    :param double* s:

src/bezier/_curve.pxd

@@ -41,7 +41,7 @@ cdef extern from "bezier/curve.h":
     void elevate_nodes_curve(
         int *num_nodes, int *dimension, double *nodes, double *elevated)
     void get_curvature(
-        int *num_nodes, int *dimension, double *nodes, double *tangent_vec,
+        int *num_nodes, double *nodes, double *tangent_vec,
         double *s, double *curvature)
     void reduce_pseudo_inverse(
         int *num_nodes, int *dimension, double *nodes, double *reduced,

src/bezier/_speedup.pyx

@@ -278,15 +278,15 @@ def elevate_nodes(double[::1, :] nodes):
 
 
 def get_curvature(double[::1, :] nodes, double[::1, :] tangent_vec, double s):
-    cdef int num_nodes, dimension
+    cdef int num_nodes
     cdef double curvature
 
-    dimension, num_nodes = np.shape(nodes)
-    # NOTE: We don't check that ``np.shape(tangent_vec) == (dimension, 1)``.
+    # NOTE: We don't check that there are 2 rows.
+    _, num_nodes = np.shape(nodes)
+    # NOTE: We don't check that ``np.shape(tangent_vec) == (2, 1)``.
 
     bezier._curve.get_curvature(
         &num_nodes,
-        &dimension,
         &nodes[0, 0],
         &tangent_vec[0, 0],
         &s,

src/bezier/curve.f90

@@ -570,17 +570,21 @@ subroutine elevate_nodes( &
   end subroutine elevate_nodes
 
   subroutine get_curvature( &
-       num_nodes, dimension_, nodes, tangent_vec, s, curvature) &
+       num_nodes, nodes, tangent_vec, s, curvature) &
        bind(c, name='get_curvature')
 
-    integer(c_int), intent(in) :: num_nodes, dimension_
-    real(c_double), intent(in) :: nodes(dimension_, num_nodes)
-    real(c_double), intent(in) :: tangent_vec(dimension_, 1)
+    ! NOTE: This **only** computes curvature for plane curves (i.e. curves
+    !       in R^2). An equivalent notion of curvature exists for space
+    !       curves, but support for that is not implemented here.
+
+    integer(c_int), intent(in) :: num_nodes
+    real(c_double), intent(in) :: nodes(2, num_nodes)
+    real(c_double), intent(in) :: tangent_vec(2, 1)
     real(c_double), intent(in) :: s
     real(c_double), intent(out) :: curvature
     ! Variables outside of signature.
-    real(c_double) :: work(dimension_, num_nodes - 1)
-    real(c_double) :: concavity(dimension_, 1)
+    real(c_double) :: work(2, num_nodes - 1)
+    real(c_double) :: concavity(2, 1)
 
     if (num_nodes == 2) then
        curvature = 0
@@ -596,7 +600,7 @@ subroutine get_curvature( &
 
     ! NOTE: The degree being evaluated is ``degree - 2 == num_nodes - 3``.
     call evaluate_multi( &
-         num_nodes - 2, dimension_, work(:, :num_nodes - 2), 1, [s], concavity)
+         num_nodes - 2, 2, work(:, :num_nodes - 2), 1, [s], concavity)
     ! B''(s) = d (d - 1) D(s) where D(s) is defined by the "double hodograph".
     concavity = concavity * (num_nodes - 1) * (num_nodes - 2)
 

src/bezier/include/bezier/curve.h

@@ -43,7 +43,7 @@ void locate_point_curve(
 void elevate_nodes_curve(
     int *num_nodes, int *dimension, double *nodes, double *elevated);
 void get_curvature(
-    int *num_nodes, int *dimension, double *nodes, double *tangent_vec,
+    int *num_nodes, double *nodes, double *tangent_vec,
     double *s, double *curvature);
 void reduce_pseudo_inverse(
     int *num_nodes, int *dimension, double *nodes, double *reduced,

src/bezier/surface_intersection.f90

@@ -582,12 +582,12 @@ subroutine classify_tangent_intersection( &
     !       parallel and we don't handle that case.
     num_nodes = size(edges_first(intersection_%index_first)%nodes, 2)
     call get_curvature( &
-         num_nodes, 2, edges_first(intersection_%index_first)%nodes, &
+         num_nodes, edges_first(intersection_%index_first)%nodes, &
          tangent_s, intersection_%s, curvature1)
 
     num_nodes = size(edges_second(intersection_%index_second)%nodes, 2)
     call get_curvature( &
-         num_nodes, 2, edges_second(intersection_%index_second)%nodes, &
+         num_nodes, edges_second(intersection_%index_second)%nodes, &
          tangent_t, intersection_%t, curvature2)
 
     if (dot_prod < 0.0_dp) then

tests/fortran/test_curve.f90

@@ -574,7 +574,7 @@ subroutine test_get_curvature(success)
     call evaluate_hodograph( &
          s_val, 2, 2, nodes1, tangent_vec)
     call get_curvature( &
-         2, 2, nodes1, tangent_vec, s_val, curvature)
+         2, nodes1, tangent_vec, s_val, curvature)
     case_success = (curvature == 0.0_dp)
     call print_status(name, case_id, case_success, success)
 
@@ -586,7 +586,7 @@ subroutine test_get_curvature(success)
     call evaluate_hodograph( &
          s_val, 3, 2, nodes2, tangent_vec)
     call get_curvature( &
-         3, 2, nodes2, tangent_vec, s_val, curvature)
+         3, nodes2, tangent_vec, s_val, curvature)
     case_success = (curvature == 0.0_dp)
     call print_status(name, case_id, case_success, success)
 
@@ -598,7 +598,7 @@ subroutine test_get_curvature(success)
     call evaluate_hodograph( &
          s_val, 3, 2, nodes2, tangent_vec)
     call get_curvature( &
-         3, 2, nodes2, tangent_vec, s_val, curvature)
+         3, nodes2, tangent_vec, s_val, curvature)
     case_success = (curvature == -4.0_dp)
     call print_status(name, case_id, case_success, success)