draw_ellipseDrawEllipseDrawEllipsedraw_ellipseT_draw_ellipse🔗

Short description🔗

draw_ellipseDrawEllipseDrawEllipsedraw_ellipseT_draw_ellipse — Interactive drawing of an ellipse.

Signature🔗

draw_ellipse( window WindowHandle, out ellipse.center.y Row, out ellipse.center.x Column, out ellipse.angle.rad Phi, out ellipse.radius1 Radius1, out ellipse.radius2 Radius2 )

Description🔗

draw_ellipseDrawEllipse 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, Rowrowrow and Columncolumncolumn, its orientation, Phiphiphi, and its two half axes, Radius1radius1radius_1 and Radius2radius2radius_2.

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 (Radius1radius1radius_1) and the orientation (Phiphiphi) 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. 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🔗

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🔗

WindowHandlewindowHandlewindow_handle (input_control) window → (handle)HTuple (HHandle)HWindow, HTuple (IntPtr)HHandleHtuple (handle)

Window handle.

Rowrowrow (output_control) ellipse.center.y → (real)HTuple (double)HTuple (double)floatHtuple (double)

Row index of the center.

Columncolumncolumn (output_control) ellipse.center.x → (real)HTuple (double)HTuple (double)floatHtuple (double)

Column index of the center.

Phiphiphi (output_control) ellipse.angle.rad → (real)HTuple (double)HTuple (double)floatHtuple (double)

Orientation of the first half axis in radians.

Radius1radius1radius_1 (output_control) ellipse.radius1 → (real)HTuple (double)HTuple (double)floatHtuple (double)

First half axis.

Radius2radius2radius_2 (output_control) ellipse.radius2 → (real)HTuple (double)HTuple (double)floatHtuple (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)

(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)\;

Result🔗

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

Combinations with other operators🔗

Combinations

Possible predecessors

open_windowOpenWindow

Possible successors

reduce_domainReduceDomain, disp_regionDispRegion, set_coloredSetColored, set_line_widthSetLineWidth, set_drawSetDraw

Alternatives

draw_ellipse_modDrawEllipseMod, draw_circleDrawCircle, draw_regionDrawRegion

Module🔗

Foundation