godot/doc/classes/PathFollow2D.xml
Guillaume Turri ea9dff87ae
Add error checks for bad configuration in PathFollow2D/3D set_progress_ratio
When a PathFollow is badly configured it's possible to have code that
call get_progress_ratio just after set_progress_ratio does not return
the value just set, which may be confusing for developer (ie that
    myPathFollow2D.set_progress_ratio(0.5)
    myPathFollow2D.get_progress_ratio()
does not return 0.5)

This commit makes ensures the developer has useful error messages in
such case, to make it easier to troubleshot it.
2024-09-04 18:07:49 +02:00

39 lines
3.1 KiB
XML

<?xml version="1.0" encoding="UTF-8" ?>
<class name="PathFollow2D" inherits="Node2D" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
<brief_description>
Point sampler for a [Path2D].
</brief_description>
<description>
This node takes its parent [Path2D], and returns the coordinates of a point within it, given a distance from the first vertex.
It is useful for making other nodes follow a path, without coding the movement pattern. For that, the nodes must be children of this node. The descendant nodes will then move accordingly when setting the [member progress] in this node.
</description>
<tutorials>
</tutorials>
<members>
<member name="cubic_interp" type="bool" setter="set_cubic_interpolation" getter="get_cubic_interpolation" default="true">
If [code]true[/code], the position between two cached points is interpolated cubically, and linearly otherwise.
The points along the [Curve2D] of the [Path2D] are precomputed before use, for faster calculations. The point at the requested offset is then calculated interpolating between two adjacent cached points. This may present a problem if the curve makes sharp turns, as the cached points may not follow the curve closely enough.
There are two answers to this problem: either increase the number of cached points and increase memory consumption, or make a cubic interpolation between two points at the cost of (slightly) slower calculations.
</member>
<member name="h_offset" type="float" setter="set_h_offset" getter="get_h_offset" default="0.0">
The node's offset along the curve.
</member>
<member name="loop" type="bool" setter="set_loop" getter="has_loop" default="true">
If [code]true[/code], any offset outside the path's length will wrap around, instead of stopping at the ends. Use it for cyclic paths.
</member>
<member name="progress" type="float" setter="set_progress" getter="get_progress" default="0.0">
The distance along the path, in pixels. Changing this value sets this node's position to a point within the path.
</member>
<member name="progress_ratio" type="float" setter="set_progress_ratio" getter="get_progress_ratio" default="0.0">
The distance along the path as a number in the range 0.0 (for the first vertex) to 1.0 (for the last). This is just another way of expressing the progress within the path, as the offset supplied is multiplied internally by the path's length.
It can be set or get only if the [PathFollow2D] is the child of a [Path2D] which is part of the scene tree, and that this [Path2D] has a [Curve2D] with a non-zero length. Otherwise, trying to set this field will print an error, and getting this field will return [code]0.0[/code].
</member>
<member name="rotates" type="bool" setter="set_rotates" getter="is_rotating" default="true">
If [code]true[/code], this node rotates to follow the path, with the +X direction facing forward on the path.
</member>
<member name="v_offset" type="float" setter="set_v_offset" getter="get_v_offset" default="0.0">
The node's offset perpendicular to the curve.
</member>
</members>
</class>