Curve2D

Inherits:Resource<Reference<Object

Describes a Bézier curve in 2D space.

Description

This class describes a Bézier curve in 2D space. It is mainly used to give a shape to aPath2D, but can be manually sampled for other purposes.

It keeps a cache of precalculated points along the curve, to speed up further calculations.

Properties

float

bake_interval

5.0

Methods

void

add_point(Vector2 position,Vector2 in=Vector2( 0, 0 ),Vector2 out=Vector2( 0, 0 ),int at_position=-1)

void

clear_points()

float

get_baked_length()const

PoolVector2Array

get_baked_points()const

float

get_closest_offset(Vector2 to_point)const

Vector2

get_closest_point(Vector2 to_point)const

int

get_point_count()const

Vector2

get_point_in(int idx)const

Vector2

get_point_out(int idx)const

Vector2

get_point_position(int idx)const

Vector2

interpolate(int idx,float t)const

Vector2

interpolate_baked(float offset,bool cubic=false)const

Vector2

interpolatef(float fofs)const

void

remove_point(int idx)

void

set_point_in(int idx,Vector2 position)

void

set_point_out(int idx,Vector2 position)

void

set_point_position(int idx,Vector2 position)

PoolVector2Array

tessellate(int max_stages=5,float tolerance_degrees=4)const

Property Descriptions

Default

5.0

Setter

set_bake_interval(value)

Getter

get_bake_interval()

The distance in pixels between two adjacent cached points. Changing it forces the cache to be recomputed the next time theget_baked_points orget_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.

Method Descriptions

Adds a point to a curve atposition relative to theCurve2D's position, with control pointsin andout.

Ifat_position is given, the point is inserted before the point numberat_position, moving that point (and every point after) after the inserted point. Ifat_position is not given, or is an illegal value (at_position<0 orat_position>=[methodget_point_count]), the point will be appended at the end of the point list.


  • voidclear_points()

Removes all points from the curve.


Returns the total length of the curve, based on the cached points. Given enough density (seebake_interval), it should be approximate enough.


Returns the cache of points as aPoolVector2Array.


Returns the closest offset toto_point. This offset is meant to be used ininterpolate_baked.

to_point must be in this curve's local space.


Returns the closest baked point (in curve's local space) toto_point.

to_point must be in this curve's local space.


Returns the number of points describing the curve.


Returns the position of the control point leading to the vertexidx. The returned position is relative to the vertexidx. If the index is out of bounds, the function sends an error to the console, and returns(0,0).


Returns the position of the control point leading out of the vertexidx. The returned position is relative to the vertexidx. If the index is out of bounds, the function sends an error to the console, and returns(0,0).


Returns the position of the vertexidx. If the index is out of bounds, the function sends an error to the console, and returns(0,0).


Returns the position between the vertexidx and the vertexidx+1, wheret controls if the point is the first vertex (t=0.0), the last vertex (t=1.0), or in between. Values oft outside the range (0.0>=t<=1) give strange, but predictable results.

Ifidx is out of bounds it is truncated to the first or last vertex, andt is ignored. If the curve has no points, the function sends an error to the console, and returns(0,0).


Returns a point within the curve at positionoffset, whereoffset is measured as a pixel distance along the curve.

To do that, it finds the two cached points where theoffset lies between, then interpolates the values. This interpolation is cubic ifcubic is set totrue, or linear if set tofalse.

Cubic interpolation tends to follow the curves better, but linear is faster (and often, precise enough).


Returns the position at the vertexfofs. It callsinterpolate using the integer part offofs asidx, and its fractional part ast.


  • voidremove_point(int idx)

Deletes the pointidx from the curve. Sends an error to the console ifidx is out of bounds.


Sets the position of the control point leading to the vertexidx. If the index is out of bounds, the function sends an error to the console. The position is relative to the vertex.


Sets the position of the control point leading out of the vertexidx. If the index is out of bounds, the function sends an error to the console. The position is relative to the vertex.


Sets the position for the vertexidx. If the index is out of bounds, the function sends an error to the console.


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.

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!

tolerance_degrees controls how many degrees the midpoint of a segment may deviate from the real curve, before the segment has to be subdivided.