PathBezier2D class¶

What class is this?¶

The PathBezier2D class is the class to set a 2D bezier curve on a path.

Mainly, the Path class constructor or draw_path interfaces use this setting.

Basic usage¶

The PathBezier2D class constructor requires the control_x, control_y, dest_x, and dest_y arguments.

The control_x and control_y are the coordinates to determine the control point of the bezier curve.

The dest_x and dest_y are the bezier curve’s destination coordinates.

import apysc as ap

ap.Stage(
    background_color=ap.Color("#333"),
    stage_width=200,
    stage_height=150,
    stage_elem_id="stage",
)
path: ap.Path = ap.Path(
    path_data_list=[
        ap.PathMoveTo(x=50, y=100),
        ap.PathBezier2D(
            control_x=100,
            control_y=25,
            dest_x=150,
            dest_y=100,
        ),
    ],
    line_color=ap.Color("#0af"),
    line_thickness=5,
)

ap.save_overall_html(dest_dir_path="path_bezier_2d_basic_usage_1/")

In the following example, the magenta circle shows the control point.

Similarly, the cyan circle shows the destination point.

import apysc as ap

ap.Stage(
    background_color=ap.Color("#333"),
    stage_width=200,
    stage_height=150,
    stage_elem_id="stage",
)

CONTROL_X: float = 100
CONTROL_Y: float = 25
DEST_X: float = 150
DEST_Y: float = 100
path: ap.Path = ap.Path(
    path_data_list=[
        ap.PathMoveTo(x=50, y=100),
        ap.PathBezier2D(
            control_x=CONTROL_X,
            control_y=CONTROL_Y,
            dest_x=DEST_X,
            dest_y=DEST_Y,
        ),
    ],
    line_color=ap.Color("#fff"),
    line_thickness=5,
)

RADIUS: int = 5
magenta_circle: ap.Circle = ap.Circle(
    x=CONTROL_X,
    y=CONTROL_Y,
    radius=RADIUS,
    fill_color=ap.Color("#f0a"),
)
cyan_circle: ap.Circle = ap.Circle(
    x=DEST_X,
    y=DEST_Y,
    radius=RADIUS,
    fill_color=ap.Color("#0af"),
)

ap.save_overall_html(dest_dir_path="path_bezier_2d_basic_usage_2/")

Relative position setting¶

The constructor’s relative optional argument changes its behavior.

For example, if you set True to its argument, coordinates become relative.

The default setting is False, and it becomes absolute.

A criteria point is a starting point, not a control point.

The following example sets the relative setting and draws the bezier curve.

Since it uses the relative setting, the control_y parameter becomes the minus value, and the dest_y becomes zero:

import apysc as ap

ap.Stage(
    background_color=ap.Color("#333"),
    stage_width=200,
    stage_height=150,
    stage_elem_id="stage",
)

path: ap.Path = ap.Path(
    path_data_list=[
        ap.PathMoveTo(x=50, y=100),
        ap.PathBezier2D(
            control_x=50, control_y=-75, dest_x=100, dest_y=0, relative=True
        ),
    ],
    line_color=ap.Color("#0af"),
    line_thickness=5,
)

ap.save_overall_html(dest_dir_path="path_bezier_2d_relative/")

PathBezier2D class constructor API¶

Note: the document build script generates and updates this API document section automatically. Maybe this section is duplicated compared with previous sections.

[Interface signature] __init__(self, control_x: Union[float, apysc._type.number.Number], control_y: Union[float, apysc._type.number.Number], dest_x: Union[float, apysc._type.number.Number], dest_y: Union[float, apysc._type.number.Number], *, relative: Union[bool, apysc._type.boolean.Boolean] = False, variable_name_suffix: str = '') -> None

[Interface summary]

Path data class for the SVG’s 2D bezier curve (Q).

[Parameters]

• control_x: float or Number

  • X-coordinate of the bezier’s control point.

• control_y: float or Number

  • Y-coordinate of the bezier’s control point.

• dest_x: float or Number

  • X-coordinate of the destination point.

• dest_y: float or Number

  • Y-coordinate of the destination point.

• relative: bool or Boolean, default False

  • A boolean value indicates whether the path coordinates are relative or not (absolute).

• variable_name_suffix: str, default “”

  • A JavaScript variable name suffix string. This setting is sometimes useful for JavaScript debugging.

[Examples]

>>> import apysc as ap
>>> stage: ap.Stage = ap.Stage()
>>> sprite: ap.Sprite = ap.Sprite()
>>> sprite.graphics.line_style(color=ap.Color("#fff"), thickness=3)
>>> path: ap.Path = sprite.graphics.draw_path(
...     path_data_list=[
...         ap.PathMoveTo(x=0, y=50),
...         ap.PathBezier2D(control_x=50, control_y=0, dest_x=100, dest_y=50),
...     ]
... )

[References]

• Path class

• Graphics draw_path interface

• PathBezier2DContinual class