draw_ellipseT_draw_ellipseDrawEllipseDrawEllipse (Operator)

Name

draw_ellipseT_draw_ellipseDrawEllipseDrawEllipse — Interactive drawing of an ellipse.

Signature

draw_ellipse( : : WindowHandle : Row, Column, Phi, Radius1, Radius2)

Herror T_draw_ellipse(const Htuple WindowHandle, Htuple* Row, Htuple* Column, Htuple* Phi, Htuple* Radius1, Htuple* Radius2)

void DrawEllipse(const HTuple& WindowHandle, HTuple* Row, HTuple* Column, HTuple* Phi, HTuple* Radius1, HTuple* Radius2)

void HWindow::DrawEllipse(double* Row, double* Column, double* Phi, double* Radius1, double* Radius2) const

static void HOperatorSet.DrawEllipse(HTuple windowHandle, out HTuple row, out HTuple column, out HTuple phi, out HTuple radius1, out HTuple radius2)

void HWindow.DrawEllipse(out double row, out double column, out double phi, out double radius1, out double radius2)

Description

draw_ellipsedraw_ellipseDrawEllipseDrawEllipseDrawEllipse returns the parameter for any orientated ellipse, which has been created interactively by the user in the window.

The created ellipse is described by its center, RowRowRowRowrow and ColumnColumnColumnColumncolumn, its orientation, PhiPhiPhiPhiphi, and its two half axes, Radius1Radius1Radius1Radius1radius1 and Radius2Radius2Radius2Radius2radius2.

To create an ellipse you have to determine the center of the ellipse with the left mouse button. Keeping the button pressed determines the length (Radius1Radius1Radius1Radius1radius1) and the orientation (PhiPhiPhiPhiphi) of the first half axis. In doing so a temporary default length for the second half axis is assumed, which may be modified afterwards on demand. After another mouse click in the center of the created ellipse you can move it. A mouse click close to a vertex “grips” it to modify the length of the appropriate half axis. You may modify the orientation only, if a vertex of the first half axis is gripped.

Pressing the right mouse button terminates the procedure. On macOS draw_ellipsedraw_ellipseDrawEllipseDrawEllipseDrawEllipse can also be terminated by pressing the escape key. After terminating the procedure the ellipse is not visible in the window any longer.

Attention

If used in a buffer window, mouse events have to be supplied by the application, while the draw operator must be run in another thread.

Execution Information

Parameters

WindowHandleWindowHandleWindowHandleWindowHandlewindowHandle (input_control)  window HWindow, HTupleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)

Window handle.

RowRowRowRowrow (output_control)  ellipse.center.y HTupleHTupleHtuple (real) (double) (double) (double)

Row index of the center.

ColumnColumnColumnColumncolumn (output_control)  ellipse.center.x HTupleHTupleHtuple (real) (double) (double) (double)

Column index of the center.

PhiPhiPhiPhiphi (output_control)  ellipse.angle.rad HTupleHTupleHtuple (real) (double) (double) (double)

Orientation of the first half axis in radians.

Radius1Radius1Radius1Radius1radius1 (output_control)  ellipse.radius1 HTupleHTupleHtuple (real) (double) (double) (double)

First half axis.

Radius2Radius2Radius2Radius2radius2 (output_control)  ellipse.radius2 HTupleHTupleHtuple (real) (double) (double) (double)

Second half axis.

Example (HDevelop)

read_image(Image,'monkey')
draw_ellipse(WindowHandle,Row,Column,Phi,Radius1,Radius2)
gen_ellipse(Ellipse,Row,Column,Phi,Radius1,Radius2)
reduce_domain(Image,Ellipse,GrayEllipse)
sobel_amp(GrayEllipse,Sobel,'sum_abs',3)
dev_display(Sobel)

Example (C)

read_image(&Image,"monkey");
draw_ellipse(WindowHandle,&Row,&Column,&Phi,&Radius1,&Radius2);
gen_ellipse(&Ellipse,Row,Column,Phi,Radius1,Radius2);
reduce_domain(Image,Ellipse,&GrayEllipse);
sobel_amp(GrayEllipse,&Sobel,"sum_abs",3);
disp_image(Sobel,WindowHandle);

Example (HDevelop)

read_image(Image,'monkey')
draw_ellipse(WindowHandle,Row,Column,Phi,Radius1,Radius2)
gen_ellipse(Ellipse,Row,Column,Phi,Radius1,Radius2)
reduce_domain(Image,Ellipse,GrayEllipse)
sobel_amp(GrayEllipse,Sobel,'sum_abs',3)
dev_display(Sobel)

Example (HDevelop)

read_image(Image,'monkey')
draw_ellipse(WindowHandle,Row,Column,Phi,Radius1,Radius2)
gen_ellipse(Ellipse,Row,Column,Phi,Radius1,Radius2)
reduce_domain(Image,Ellipse,GrayEllipse)
sobel_amp(GrayEllipse,Sobel,'sum_abs',3)
dev_display(Sobel)

Example (HDevelop)

read_image(Image,'monkey')
draw_ellipse(WindowHandle,Row,Column,Phi,Radius1,Radius2)
gen_ellipse(Ellipse,Row,Column,Phi,Radius1,Radius2)
reduce_domain(Image,Ellipse,GrayEllipse)
sobel_amp(GrayEllipse,Sobel,'sum_abs',3)
dev_display(Sobel)

Result

draw_ellipsedraw_ellipseDrawEllipseDrawEllipseDrawEllipse returns 2 (H_MSG_TRUE), if the window is valid and the needed drawing mode (see set_insertset_insertSetInsertSetInsertSetInsert) is available. If necessary, an exception is raised.

Possible Predecessors

open_windowopen_windowOpenWindowOpenWindowOpenWindow

Possible Successors

reduce_domainreduce_domainReduceDomainReduceDomainReduceDomain, disp_regiondisp_regionDispRegionDispRegionDispRegion, set_coloredset_coloredSetColoredSetColoredSetColored, set_line_widthset_line_widthSetLineWidthSetLineWidthSetLineWidth, set_drawset_drawSetDrawSetDrawSetDraw, set_insertset_insertSetInsertSetInsertSetInsert

Alternatives

draw_ellipse_moddraw_ellipse_modDrawEllipseModDrawEllipseModDrawEllipseMod, draw_circledraw_circleDrawCircleDrawCircleDrawCircle, draw_regiondraw_regionDrawRegionDrawRegionDrawRegion

See also

gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipse, draw_rectangle1draw_rectangle1DrawRectangle1DrawRectangle1DrawRectangle1, draw_rectangle2draw_rectangle2DrawRectangle2DrawRectangle2DrawRectangle2, draw_polygondraw_polygonDrawPolygonDrawPolygonDrawPolygon, set_insertset_insertSetInsertSetInsertSetInsert

Module

Foundation