<?xml version="1.0" encoding="UTF-8" ?>
<class name="Curve2D" inherits="Resource" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
	<brief_description>
		Describes a Bézier curve in 2D space.
	</brief_description>
	<description>
		This class describes a Bézier curve in 2D space. It is mainly used to give a shape to a [Path2D], but can be manually sampled for other purposes.
		It keeps a cache of precalculated points along the curve, to speed up further calculations.
	</description>
	<tutorials>
	</tutorials>
	<methods>
		<method name="add_point">
			<return type="void" />
			<param index="0" name="position" type="Vector2" />
			<param index="1" name="in" type="Vector2" default="Vector2(0, 0)" />
			<param index="2" name="out" type="Vector2" default="Vector2(0, 0)" />
			<param index="3" name="index" type="int" default="-1" />
			<description>
				Adds a point with the specified [param position] relative to the curve's own position, with control points [param in] and [param out]. Appends the new point at the end of the point list.
				If [param index] is given, the new point is inserted before the existing point identified by index [param index]. Every existing point starting from [param index] is shifted further down the list of points. The index must be greater than or equal to [code]0[/code] and must not exceed the number of existing points in the line. See [member point_count].
			</description>
		</method>
		<method name="clear_points">
			<return type="void" />
			<description>
				Removes all points from the curve.
			</description>
		</method>
		<method name="get_baked_length" qualifiers="const">
			<return type="float" />
			<description>
				Returns the total length of the curve, based on the cached points. Given enough density (see [member bake_interval]), it should be approximate enough.
			</description>
		</method>
		<method name="get_baked_points" qualifiers="const">
			<return type="PackedVector2Array" />
			<description>
				Returns the cache of points as a [PackedVector2Array].
			</description>
		</method>
		<method name="get_closest_offset" qualifiers="const">
			<return type="float" />
			<param index="0" name="to_point" type="Vector2" />
			<description>
				Returns the closest offset to [param to_point]. This offset is meant to be used in [method sample_baked].
				[param to_point] must be in this curve's local space.
			</description>
		</method>
		<method name="get_closest_point" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="to_point" type="Vector2" />
			<description>
				Returns the closest point on baked segments (in curve's local space) to [param to_point].
				[param to_point] must be in this curve's local space.
			</description>
		</method>
		<method name="get_point_in" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="idx" type="int" />
			<description>
				Returns the position of the control point leading to the vertex [param idx]. The returned position is relative to the vertex [param idx]. If the index is out of bounds, the function sends an error to the console, and returns [code](0, 0)[/code].
			</description>
		</method>
		<method name="get_point_out" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="idx" type="int" />
			<description>
				Returns the position of the control point leading out of the vertex [param idx]. The returned position is relative to the vertex [param idx]. If the index is out of bounds, the function sends an error to the console, and returns [code](0, 0)[/code].
			</description>
		</method>
		<method name="get_point_position" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="idx" type="int" />
			<description>
				Returns the position of the vertex [param idx]. If the index is out of bounds, the function sends an error to the console, and returns [code](0, 0)[/code].
			</description>
		</method>
		<method name="remove_point">
			<return type="void" />
			<param index="0" name="idx" type="int" />
			<description>
				Deletes the point [param idx] from the curve. Sends an error to the console if [param idx] is out of bounds.
			</description>
		</method>
		<method name="sample" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="idx" type="int" />
			<param index="1" name="t" type="float" />
			<description>
				Returns the position between the vertex [param idx] and the vertex [code]idx + 1[/code], where [param t] controls if the point is the first vertex ([code]t = 0.0[/code]), the last vertex ([code]t = 1.0[/code]), or in between. Values of [param t] outside the range ([code]0.0 &lt;= t &lt;= 1.0[/code]) give strange, but predictable results.
				If [param idx] is out of bounds it is truncated to the first or last vertex, and [param t] is ignored. If the curve has no points, the function sends an error to the console, and returns [code](0, 0)[/code].
			</description>
		</method>
		<method name="sample_baked" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="offset" type="float" default="0.0" />
			<param index="1" name="cubic" type="bool" default="false" />
			<description>
				Returns a point within the curve at position [param offset], where [param offset] is measured as a pixel distance along the curve.
				To do that, it finds the two cached points where the [param offset] lies between, then interpolates the values. This interpolation is cubic if [param cubic] is set to [code]true[/code], or linear if set to [code]false[/code].
				Cubic interpolation tends to follow the curves better, but linear is faster (and often, precise enough).
			</description>
		</method>
		<method name="sample_baked_with_rotation" qualifiers="const">
			<return type="Transform2D" />
			<param index="0" name="offset" type="float" default="0.0" />
			<param index="1" name="cubic" type="bool" default="false" />
			<description>
				Similar to [method sample_baked], but returns [Transform2D] that includes a rotation along the curve, with [member Transform2D.origin] as the point position and the [member Transform2D.x] vector pointing in the direction of the path at that point. Returns an empty transform if the length of the curve is [code]0[/code].
				[codeblock]
				var baked = curve.sample_baked_with_rotation(offset)
				# The returned Transform2D can be set directly.
				transform = baked
				# You can also read the origin and rotation separately from the returned Transform2D.
				position = baked.get_origin()
				rotation = baked.get_rotation()
				[/codeblock]
			</description>
		</method>
		<method name="samplef" qualifiers="const">
			<return type="Vector2" />
			<param index="0" name="fofs" type="float" />
			<description>
				Returns the position at the vertex [param fofs]. It calls [method sample] using the integer part of [param fofs] as [code]idx[/code], and its fractional part as [code]t[/code].
			</description>
		</method>
		<method name="set_point_in">
			<return type="void" />
			<param index="0" name="idx" type="int" />
			<param index="1" name="position" type="Vector2" />
			<description>
				Sets the position of the control point leading to the vertex [param idx]. If the index is out of bounds, the function sends an error to the console. The position is relative to the vertex.
			</description>
		</method>
		<method name="set_point_out">
			<return type="void" />
			<param index="0" name="idx" type="int" />
			<param index="1" name="position" type="Vector2" />
			<description>
				Sets the position of the control point leading out of the vertex [param idx]. If the index is out of bounds, the function sends an error to the console. The position is relative to the vertex.
			</description>
		</method>
		<method name="set_point_position">
			<return type="void" />
			<param index="0" name="idx" type="int" />
			<param index="1" name="position" type="Vector2" />
			<description>
				Sets the position for the vertex [param idx]. If the index is out of bounds, the function sends an error to the console.
			</description>
		</method>
		<method name="tessellate" qualifiers="const">
			<return type="PackedVector2Array" />
			<param index="0" name="max_stages" type="int" default="5" />
			<param index="1" name="tolerance_degrees" type="float" default="4" />
			<description>
				Returns a list of points along the curve, with a curvature controlled point density. That is, the curvier parts will have more points than the straighter parts.
				This approximation makes straight segments between each point, then subdivides those segments until the resulting shape is similar enough.
				[param max_stages] controls how many subdivisions a curve segment may face before it is considered approximate enough. Each subdivision splits the segment in half, so the default 5 stages may mean up to 32 subdivisions per curve segment. Increase with care!
				[param tolerance_degrees] controls how many degrees the midpoint of a segment may deviate from the real curve, before the segment has to be subdivided.
			</description>
		</method>
		<method name="tessellate_even_length" qualifiers="const">
			<return type="PackedVector2Array" />
			<param index="0" name="max_stages" type="int" default="5" />
			<param index="1" name="tolerance_length" type="float" default="20.0" />
			<description>
				Returns a list of points along the curve, with almost uniform density. [param max_stages] controls how many subdivisions a curve segment may face before it is considered approximate enough. Each subdivision splits the segment in half, so the default 5 stages may mean up to 32 subdivisions per curve segment. Increase with care!
				[param tolerance_length] controls the maximal distance between two neighboring points, before the segment has to be subdivided.
			</description>
		</method>
	</methods>
	<members>
		<member name="bake_interval" type="float" setter="set_bake_interval" getter="get_bake_interval" default="5.0">
			The distance in pixels between two adjacent cached points. Changing it forces the cache to be recomputed the next time the [method get_baked_points] or [method get_baked_length] function is called. The smaller the distance, the more points in the cache and the more memory it will consume, so use with care.
		</member>
		<member name="point_count" type="int" setter="set_point_count" getter="get_point_count" default="0">
			The number of points describing the curve.
		</member>
	</members>
</class>
