Create an ellipse.
The operator ellipse generates one mor 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 in this connection get_system and init_horus. 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) -> object |
Created ellipse(s). |
Row (input_control) |
ellipse.center.y(-array) -> real / integer |
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 | |
Range of values: 1.0 <= Row <= 1024.0 (lin) | |
Minimum increment: 1.0 | |
Recommended increment: 10.0 |
Column (input_control) |
ellipse.center.x(-array) -> real / integer |
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 | |
Range of values: 1.0 <= Column <= 1024.0 (lin) | |
Minimum increment: 1.0 | |
Recommended increment: 10.0 |
Phi (input_control) |
ellipse.angle.rad(-array) -> real / integer |
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 | |
Range of values: -1.178097 <= Phi <= 1.178097 (lin) | |
Minimum increment: 0.01 | |
Recommended increment: 0.1 |
Radius1 (input_control) |
ellipse.radius1(-array) -> real / integer |
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 | |
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) -> real / integer |
Kürzerer 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 | |
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','':) > set_insert(::'xor':) > repeat(:::) > get_mbutton(:::Row,Column,Button) > ellipse(:Ellipse:Row,Column,Column / 300.0, (Row mod 100)+1,(Column mod 50) + 1:) > disp_region(Ellipse:::) > clear(Ellipse:::) > until(::Button = 1:).
Runtime complexity: O(Radius1 * 2) Storage complexity (byte): O(Radius1 * 8)
If the parameter values are correct, the operator ellipse returns the value TRUE. Otherwise an exception is raised. The clipping of the current image format is set via the operator set_system(::'clip_region',<true/false>:).
circle, store_filled_polygon, draw_ellipse
disp_ellipse, set_shape, smallest_circle, reduce_domain