Create an ellipse.
The operator ::gen_ellipse generates one or more ellipses with the center (Row, Column), the orientation Phi and the half-radii Radius1 and Radius2. The angle is indicated in arc measure according to the x axis in mathematically positive direction. More than one region can be created by passing tuples of parameter values.
The center must be located within the image coordinates. The coordinate system runs from (0,0) (upper left corner) to (Width-1,Height-1). See ::get_system and ::reset_obj_db in this context. If the ellipse reaches beyond the edge of the image it is clipped to the current image format according to the value of the system flag 'clip_region' (::set_system).
|
Ellipse (output_object) |
region(-array) -> Hobject * : HRegion(Array) |
| Created ellipse(s). | |
|
Row (input_control) |
ellipse.center.y(-array) -> HTuple.double / long |
| Line index of center. | |
| Default value: 200.0 | |
| Suggested values: 0.0, 10.0, 20.0, 50.0, 100.0, 256.0, 300.0, 400.0 | |
| Typical range of values: 1.0 <= Row <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Column (input_control) |
ellipse.center.x(-array) -> HTuple.double / long |
| Column index of center. | |
| Default value: 200.0 | |
| Suggested values: 0.0, 10.0, 20.0, 50.0, 100.0, 256.0, 300.0, 400.0 | |
| Typical range of values: 1.0 <= Column <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
|
Phi (input_control) |
ellipse.angle.rad(-array) -> HTuple.double / long |
| Orientation of the longer radius (Radius1). | |
| Default value: 0.0 | |
| Suggested values: -1.178097, -0.785398, -0.392699, 0.0, 0.392699, 0.785398, 1.178097 | |
| Typical range of values: -1.178097 <= Phi <= 1.178097 (lin) | |
| Minimum increment: 0.01 | |
|
Recommended increment: 0.1 | |
|
Radius1 (input_control) |
ellipse.radius1(-array) -> HTuple.double / long |
| Longer radius. | |
| Default value: 100.0 | |
| Suggested values: 2.0, 5.0, 10.0, 20.0, 50.0, 100.0, 256.0, 300.0, 400.0 | |
| Typical range of values: 1.0 <= Radius1 <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
| Restriction: Radius1 > 0 | |
|
Radius2 (input_control) |
ellipse.radius2(-array) -> HTuple.double / long |
| Shorter radius. | |
| Default value: 60.0 | |
| Suggested values: 1.0, 2.0, 4.0, 5.0, 10.0, 20.0, 50.0, 100.0, 256.0, 300.0, 400.0 | |
| Typical range of values: 1.0 <= Radius2 <= 1024.0 (lin) | |
| Minimum increment: 1.0 | |
|
Recommended increment: 10.0 | |
| Restriction: (Radius2 > 0) && (Radius2 <= Radius1) | |
open_window(0,0,-1,-1,"root","visible","",&WindowHandle);
set_insert(WindowHandle,"xor");
do {
get_mbutton(WindowHandle,&Row,&Column,&Button);
gen_ellipse(&Ellipse,(double)Row,(double)Column,Column / 300.0,
(Row % 100)+1.0,(Column % 50) + 1.0);
disp_region(Ellipse,WindowHandle);
clear_obj(Ellipse);
} while(Button != 1);Runtime complexity: O(Radius1 * 2)
Storage complexity (byte): O(Radius1 * 8)
If the parameter values are correct, the operator ::gen_ellipse returns the value H_MSG_TRUE. Otherwise an exception handling is raised. The clipping according to the current image format is set via the operator ::set_system('clip_region',<'true'/'false'>).
::paint_region, ::reduce_domain
::gen_circle, ::gen_region_polygon_filled, ::draw_ellipse
::disp_ellipse, ::set_shape, ::smallest_circle, ::reduce_domain
Region processing
