note_arc

A NoteArc draws a Bezier curve arc that connects a special note (drumroll, balloon, or kusudama) from its hit position back along the note lane, giving the player a visual path to follow. player keeps active instances in draw_arc_list and removes them when is_finished() returns true.

NoteArc

Construction

NoteArc(NoteType note_type, double current_ms, PlayerNum player_num, bool big, bool is_balloon,
        float start_x = 0, float start_y = 0);

Parameter	Description
note_type	Note type; selects the arc colour
current_ms	Song timestamp when the arc begins
player_num	Which player; affects the arc's screen position
big	Whether the note is a big note (thicker arc)
is_balloon	Whether this is a balloon arc (different shape)
start_x/y	Optional custom start position for the arc origin

Public members

Member	Type	Description
note_type	NoteType	Type of note this arc belongs to
is_big	bool	Whether this is a big-note arc

Private members

Member	Type	Description
is_balloon	bool	Balloon arcs use a different curve shape
arc_points	int	Number of points sampled along the Bezier curve
arc_duration	int	Duration over which the arc travels (ms)
current_progress	float	Normalised progress (0–1) along the arc
start_ms	double	Timestamp when the arc started
start_x/y	float	Arc origin (note head position)
end_x/y	float	Arc destination (judgment zone)
control_x/y	float	Bezier control point; determines the curve shape
arc_points_cache	const vector<pair<int,int>>*	Pointer into the static cache of pre-computed pixel coordinates
_arc_points_cache	static unordered_map<CacheKey, ...>	Class-level cache keyed by arc geometry; avoids re-computation

CacheKey

A struct that uniquely identifies an arc by its six geometry floats and point count. It is hashed and compared via CacheKeyHash and operator== for use in the static cache.

Methods

void update(double current_ms);

Advances current_progress based on elapsed time since start_ms.

void draw(float y, ray::Shader mask_shader);

Iterates the cached Bezier points and draws each segment of the arc. The mask_shader is applied for rainbow balloon arcs.

bool is_finished() const;

Returns true when current_progress >= 1.0.