Operator Reference

draw_nurbs_interpT_draw_nurbs_interpDrawNurbsInterpDrawNurbsInterpdraw_nurbs_interp (Operator)

draw_nurbs_interpT_draw_nurbs_interpDrawNurbsInterpDrawNurbsInterpdraw_nurbs_interp — Interactive drawing of a NURBS curve using interpolation.

Warning

This operator does not work in an HDevelop graphics window opened with dev_open_window.

Signature

Herror T_draw_nurbs_interp(Hobject* ContOut, const Htuple WindowHandle, const Htuple Rotate, const Htuple Move, const Htuple Scale, const Htuple KeepRatio, const Htuple Degree, Htuple* ControlRows, Htuple* ControlCols, Htuple* Knots, Htuple* Rows, Htuple* Cols, Htuple* Tangents)

void DrawNurbsInterp(HObject* ContOut, const HTuple& WindowHandle, const HTuple& Rotate, const HTuple& Move, const HTuple& Scale, const HTuple& KeepRatio, const HTuple& Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents)

void HXLDCont::DrawNurbsInterp(const HWindow& WindowHandle, const HString& Rotate, const HString& Move, const HString& Scale, const HString& KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents)

void HXLDCont::DrawNurbsInterp(const HWindow& WindowHandle, const char* Rotate, const char* Move, const char* Scale, const char* KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents)

void HXLDCont::DrawNurbsInterp(const HWindow& WindowHandle, const wchar_t* Rotate, const wchar_t* Move, const wchar_t* Scale, const wchar_t* KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents)   ( Windows only)

HXLDCont HWindow::DrawNurbsInterp(const HString& Rotate, const HString& Move, const HString& Scale, const HString& KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents) const

HXLDCont HWindow::DrawNurbsInterp(const char* Rotate, const char* Move, const char* Scale, const char* KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents) const

HXLDCont HWindow::DrawNurbsInterp(const wchar_t* Rotate, const wchar_t* Move, const wchar_t* Scale, const wchar_t* KeepRatio, Hlong Degree, HTuple* ControlRows, HTuple* ControlCols, HTuple* Knots, HTuple* Rows, HTuple* Cols, HTuple* Tangents) const   ( Windows only)

static void HOperatorSet.DrawNurbsInterp(out HObject contOut, HTuple windowHandle, HTuple rotate, HTuple move, HTuple scale, HTuple keepRatio, HTuple degree, out HTuple controlRows, out HTuple controlCols, out HTuple knots, out HTuple rows, out HTuple cols, out HTuple tangents)

void HXLDCont.DrawNurbsInterp(HWindow windowHandle, string rotate, string move, string scale, string keepRatio, int degree, out HTuple controlRows, out HTuple controlCols, out HTuple knots, out HTuple rows, out HTuple cols, out HTuple tangents)

HXLDCont HWindow.DrawNurbsInterp(string rotate, string move, string scale, string keepRatio, int degree, out HTuple controlRows, out HTuple controlCols, out HTuple knots, out HTuple rows, out HTuple cols, out HTuple tangents)

def draw_nurbs_interp(window_handle: HHandle, rotate: str, move: str, scale: str, keep_ratio: str, degree: int) -> Tuple[HObject, Sequence[float], Sequence[float], Sequence[float], Sequence[float], Sequence[float], Sequence[float]]

Description

draw_nurbs_interpdraw_nurbs_interpDrawNurbsInterpDrawNurbsInterpdraw_nurbs_interp returns the contour ContOutContOutContOutcontOutcont_out of a NURBS curve of degree DegreeDegreeDegreedegreedegree, which has been created interactively by the user in the window WindowHandleWindowHandleWindowHandlewindowHandlewindow_handle using interpolation. That means, that the user specifies a set of points and the operator computes the parameters of a NURBS curve that includes this points. By contrast, using the Operator draw_nurbsdraw_nurbsDrawNurbsDrawNurbsdraw_nurbs it is possible to create a NURBS curve by drawing its control polygon.

In addition to ContOutContOutContOutcontOutcont_out, the control information of the curve (ControlRowsControlRowsControlRowscontrolRowscontrol_rows, ControlColsControlColsControlColscontrolColscontrol_cols, and KnotsKnotsKnotsknotsknots), the interpolation points (RowsRowsRowsrowsrows, ColsColsColscolscols) specified by the user and the tangents at the first and the last point (TangentsTangentsTangentstangentstangents) are returned. TangentsTangentsTangentstangentstangents consists of four values. The first two values correspond to the y (row) and the x (column) value of the tangent at the start of the curve and the second two values to the tangent at the end of the curve, respectively.

The weight vector is not returned because it consists of equal entries. As a consequence, one can use 'auto'"auto""auto""auto""auto" as weight vector if the control information is used in a subsequent call to the operator gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldgen_contour_nurbs_xld. For more information on NURBS see the documentation of gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldgen_contour_nurbs_xld.

Directly after calling draw_nurbs_interpdraw_nurbs_interpDrawNurbsInterpDrawNurbsInterpdraw_nurbs_interp, you can add interpolation points by clicking with the left mouse button in the window at the desired positions. If enough points are specified (at least DegreeDegreeDegreedegreedegree-1), a NURBS curve that goes through all specified points (in the order of their generation) is computed and displayed.

When there are three points or more, the first and the last point will be marked with an additional square. By clicking on them you can close the curve or open it again. You delete the point appended last by pressing the Ctrl key.

The tangents (i.e. the first derivative of the curve) of the first and the last point are displayed as lines. They can be modified by dragging their ends using the mouse.

Existing points can be moved by dragging them with the mouse. Further new points on the curve can be inserted by a left click on the desired position on the curve.

By pressing the Shift key, you can switch into the transformation mode. In this mode you can rotate, move, and scale the curve as a whole, but only if you set the parameters RotateRotateRotaterotaterotate, MoveMoveMovemovemove, and ScaleScaleScalescalescale, respectively, to 'true'"true""true""true""true". Instead of the pick points and the two tangents, 3 symbols are displayed with the curve: a cross in the middle and an arrow to the right if RotateRotateRotaterotaterotate is set to 'true'"true""true""true""true", and a double-headed arrow to the upper right if ScaleScaleScalescalescale is set to 'true'"true""true""true""true".

You can

  • move the curve by clicking the left mouse button on the cross in the center and then dragging it to the new position,

  • rotate it by clicking with the left mouse button on the arrow and then dragging it, till the curve has the right direction, and

  • scale it by dragging the double arrow. To keep the ratio, the parameter KeepRatioKeepRatioKeepRatiokeepRatiokeep_ratio has to be set to 'true'"true""true""true""true".

By pressing the Shift key again you can switch back to the edit mode. Pressing the right mouse button terminates the procedure.

The appearance of the curve while drawing is determined by the line width, size, and color set via the operators set_colorset_colorSetColorSetColorset_color, set_coloredset_coloredSetColoredSetColoredset_colored, set_line_widthset_line_widthSetLineWidthSetLineWidthset_line_width, and set_line_styleset_line_styleSetLineStyleSetLineStyleset_line_style. The tangents and all handles are displayed in the second color set by set_colorset_colorSetColorSetColorset_color or set_coloredset_coloredSetColoredSetColoredset_colored. Their line width is fixed to 1 and their line style is fixed to a drawn-through line.

Attention

In contrast to draw_nurbsdraw_nurbsDrawNurbsDrawNurbsdraw_nurbs, each point specified by the user influences the whole curve. Thus, if one point is moved, the whole curve can and will change. To minimize this effects, it is recommended to use a small degree (3-5) and to place the points such that they are approximately equally spaced. In general, uneven degrees will perform slightly better than even degrees.

Execution Information

  • Multithreading type: reentrant (runs in parallel with non-exclusive operators).
  • Multithreading scope: global (may be called from any thread).
  • Processed without parallelization.

Parameters

ContOutContOutContOutcontOutcont_out (output_object)  xld_cont objectHXLDContHObjectHObjectHobject *

Contour of the curve.

WindowHandleWindowHandleWindowHandlewindowHandlewindow_handle (input_control)  window HWindow, HTupleHHandleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)

Window handle.

RotateRotateRotaterotaterotate (input_control)  string HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Enable rotation?

Default: 'true' "true" "true" "true" "true"

List of values: 'false'"false""false""false""false", 'true'"true""true""true""true"

MoveMoveMovemovemove (input_control)  string HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Enable moving?

Default: 'true' "true" "true" "true" "true"

List of values: 'false'"false""false""false""false", 'true'"true""true""true""true"

ScaleScaleScalescalescale (input_control)  string HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Enable scaling?

Default: 'true' "true" "true" "true" "true"

List of values: 'false'"false""false""false""false", 'true'"true""true""true""true"

KeepRatioKeepRatioKeepRatiokeepRatiokeep_ratio (input_control)  string HTuplestrHTupleHtuple (string) (string) (HString) (char*)

Keep ratio while scaling?

Default: 'true' "true" "true" "true" "true"

List of values: 'false'"false""false""false""false", 'true'"true""true""true""true"

DegreeDegreeDegreedegreedegree (input_control)  integer HTupleintHTupleHtuple (integer) (int / long) (Hlong) (Hlong)

The degree p of the NURBS curve. Reasonable values are 3 to 5.

Default: 3

Suggested values: 2, 3, 4, 5

Restriction: Degree >= 2 && Degree <= 9

ControlRowsControlRowsControlRowscontrolRowscontrol_rows (output_control)  coordinates.y-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Row coordinates of the control polygon.

ControlColsControlColsControlColscontrolColscontrol_cols (output_control)  coordinates.x-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Column coordinates of the control polygon.

KnotsKnotsKnotsknotsknots (output_control)  real-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Knot vector.

RowsRowsRowsrowsrows (output_control)  coordinates.y-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Row coordinates of the points specified by the user.

ColsColsColscolscols (output_control)  coordinates.x-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Column coordinates of the points specified by the user.

TangentsTangentsTangentstangentstangents (output_control)  real-array HTupleSequence[float]HTupleHtuple (real) (double) (double) (double)

Tangents specified by the user.

Result

draw_nurbs_interpdraw_nurbs_interpDrawNurbsInterpDrawNurbsInterpdraw_nurbs_interp returns 2 ( H_MSG_TRUE) , if the window is valid. If necessary, an exception is raised.

Possible Predecessors

open_windowopen_windowOpenWindowOpenWindowopen_window

Possible Successors

set_coloredset_coloredSetColoredSetColoredset_colored, set_line_widthset_line_widthSetLineWidthSetLineWidthset_line_width, set_drawset_drawSetDrawSetDrawset_draw, set_insertset_insertSetInsertSetInsertset_insert

Alternatives

draw_xlddraw_xldDrawXldDrawXlddraw_xld, draw_nurbsdraw_nurbsDrawNurbsDrawNurbsdraw_nurbs

See also

draw_nurbs_interp_moddraw_nurbs_interp_modDrawNurbsInterpModDrawNurbsInterpModdraw_nurbs_interp_mod, draw_nurbsdraw_nurbsDrawNurbsDrawNurbsdraw_nurbs, gen_contour_nurbs_xldgen_contour_nurbs_xldGenContourNurbsXldGenContourNurbsXldgen_contour_nurbs_xld

Module

Foundation