Curve2D

    Category: Core

    Describes a Bezier curve in 2D space.

    Properties

    Description

    This class describes a Bezier 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 further calculations up.

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

    Method Descriptions

    Adds a point to a curve, at , with control points in and out.

    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.

    • void clear_points ( )

    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

    to_point must be in this curve’s local space.

    • get_closest_point ( Vector2 to_point ) const

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

    to_point must be in this curve’s local space.

    • get_point_count ( ) const

    Returns the number of points describing the curve.

    • Vector2 get_point_in ( idx ) const

    Returns 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, and returns (0, 0).

    Returns 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, and returns .

    • Vector2 get_point_position ( idx ) const

    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).

    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 (0, 0).

    • interpolate_baked ( float offset, cubic=false ) const

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

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

    • Vector2 interpolatef ( fofs ) const

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

    • void remove_point ( idx )

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

    • void set_point_in ( int idx, 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.

    • void set_point_out ( int idx, 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.

    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.

    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.