draw_ellipseT_draw_ellipseDrawEllipseDrawEllipsedraw_ellipse (Operator)
Name
draw_ellipseT_draw_ellipseDrawEllipseDrawEllipsedraw_ellipse — Interactive drawing of an ellipse.
Signature
def draw_ellipse(window_handle: HHandle) -> Tuple[float, float, float, float, float]
Description
draw_ellipsedraw_ellipseDrawEllipseDrawEllipseDrawEllipsedraw_ellipse 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, RowRowRowRowrowrow and
ColumnColumnColumnColumncolumncolumn, its orientation, PhiPhiPhiPhiphiphi, and its two half axes,
Radius1Radius1Radius1Radius1radius1radius_1 and Radius2Radius2Radius2Radius2radius2radius_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 (Radius1Radius1Radius1Radius1radius1radius_1)
and the orientation (PhiPhiPhiPhiphiphi) 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_ellipseDrawEllipseDrawEllipseDrawEllipsedraw_ellipse 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
- Multithreading type: reentrant (runs in parallel with non-exclusive operators).
- Multithreading scope: global (may be called from any thread).
- Processed without parallelization.
Parameters
WindowHandleWindowHandleWindowHandleWindowHandlewindowHandlewindow_handle (input_control) window → HWindow, HTupleHHandleHTupleHtuple (handle) (IntPtr) (HHandle) (handle)
Window handle.
RowRowRowRowrowrow (output_control) ellipse.center.y → HTuplefloatHTupleHtuple (real) (double) (double) (double)
Row index of the center.
ColumnColumnColumnColumncolumncolumn (output_control) ellipse.center.x → HTuplefloatHTupleHtuple (real) (double) (double) (double)
Column index of the center.
PhiPhiPhiPhiphiphi (output_control) ellipse.angle.rad → HTuplefloatHTupleHtuple (real) (double) (double) (double)
Orientation of the first half axis in radians.
Radius1Radius1Radius1Radius1radius1radius_1 (output_control) ellipse.radius1 → HTuplefloatHTupleHtuple (real) (double) (double) (double)
First half axis.
Radius2Radius2Radius2Radius2radius2radius_2 (output_control) ellipse.radius2 → HTuplefloatHTupleHtuple (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_ellipseDrawEllipseDrawEllipseDrawEllipsedraw_ellipse returns 2 (H_MSG_TRUE), if the window is valid and the
needed drawing mode (see set_insertset_insertSetInsertSetInsertSetInsertset_insert) is available.
If necessary, an exception is raised.
Possible Predecessors
open_windowopen_windowOpenWindowOpenWindowOpenWindowopen_window
Possible Successors
reduce_domainreduce_domainReduceDomainReduceDomainReduceDomainreduce_domain,
disp_regiondisp_regionDispRegionDispRegionDispRegiondisp_region,
set_coloredset_coloredSetColoredSetColoredSetColoredset_colored,
set_line_widthset_line_widthSetLineWidthSetLineWidthSetLineWidthset_line_width,
set_drawset_drawSetDrawSetDrawSetDrawset_draw,
set_insertset_insertSetInsertSetInsertSetInsertset_insert
Alternatives
draw_ellipse_moddraw_ellipse_modDrawEllipseModDrawEllipseModDrawEllipseModdraw_ellipse_mod,
draw_circledraw_circleDrawCircleDrawCircleDrawCircledraw_circle,
draw_regiondraw_regionDrawRegionDrawRegionDrawRegiondraw_region
See also
gen_ellipsegen_ellipseGenEllipseGenEllipseGenEllipsegen_ellipse,
draw_rectangle1draw_rectangle1DrawRectangle1DrawRectangle1DrawRectangle1draw_rectangle1,
draw_rectangle2draw_rectangle2DrawRectangle2DrawRectangle2DrawRectangle2draw_rectangle2,
draw_polygondraw_polygonDrawPolygonDrawPolygonDrawPolygondraw_polygon,
set_insertset_insertSetInsertSetInsertSetInsertset_insert
Module
Foundation