Curve2D

Describes a Bézier curve in 2D space.

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

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

• bake_interval

The distance in pixels between two adjacent cached points. Changing it forces the cache to be recomputed the next time the get_baked_points or function is called. The smaller the distance, the more points in the cache and the more memory it will consume, so use with care.

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

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

Removes all points from the curve.

• get_baked_length ( ) const

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

• get_baked_points ( ) const

Returns the cache of points as a PoolVector2Array.

• get_closest_offset ( Vector2 to_point ) const

Returns the closest offset to to_point. This offset is meant to be used in .

to_point must be in this curve’s local space.

• Vector2 get_closest_point ( to_point ) const

Returns the closest baked point (in curve’s local space) to to_point.

to_point must be in this curve’s local space.

• int get_point_count ( ) const

Returns the number of points describing the curve.

• get_point_in ( int idx ) const

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

• get_point_out ( int idx ) const

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

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

• interpolate ( int idx, t ) const

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

If idx is out of bounds it is truncated to the first or last vertex, and t is ignored. If the curve has no points, the function sends an error to the console, and returns .

• Vector2 interpolate_baked ( offset, bool cubic=false ) const

Returns a point within the curve at position offset, where offset is measured as a pixel distance along the curve.

To do that, it finds the two cached points where the offset lies between, then interpolates the values. This interpolation is cubic if cubic is set to true, or linear if set to false.

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

• interpolatef ( float fofs ) const

Returns the position at the vertex fofs. It calls using the integer part of fofs as idx, and its fractional part as t.

• void remove_point ( int idx )

Deletes the point idx from the curve. Sends an error to the console if idx is out of bounds.

• void set_point_in ( idx, Vector2 position )

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

• void set_point_out ( idx, Vector2 position )

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

• void set_point_position ( idx, Vector2 position )

Sets the position for the vertex idx. 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.

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