donner::editor::RopeSimulation Class Reference

Small fixed-endpoint Verlet rope simulation used by source reference connectors. More...

#include "donner/editor/RopeSimulation.h"

Public Member Functions
	RopeSimulation ()=default
	Construct an empty rope simulation.
void	reset (std::span< const Vector2d > route, const RopeSimulationOptions &options)
	Reset this rope by sampling route into evenly spaced simulated particles.
void	resetCatenary (const Vector2d &start, const Vector2d &end, const RopeSimulationOptions &options)
	Reset this rope to a catenary between fixed endpoints.
void	applyImpulse (const Vector2d &impulse)
	Add an instantaneous velocity impulse to interior rope particles.
void	applyBottomImpulse (const Vector2d &impulse, double normalizedWidth)
	Add a localized velocity impulse centered on the lowest interior particle.
void	update (const Vector2d &start, const Vector2d &end, double deltaTimeSeconds, double scrollDeltaY, double timeSeconds, std::uint32_t phaseSeed, bool frozen, const RopeSimulationOptions &options)
	Advance the rope by one frame.
std::span< const Vector2d >	points () const
	Return the simulated particle positions.
bool	empty () const
	Return true when this rope has no particles.
bool	needsAnimation () const
	Return true when this rope still needs timed animation frames.
Path	toPath (const RopeSimulationOptions &options) const
	Convert the current rope body into a Bézier path.
Vector2d	endTangent () const
	Return the final segment tangent for orienting an arrowhead.

Detailed Description

Small fixed-endpoint Verlet rope simulation used by source reference connectors.

Member Function Documentation

applyBottomImpulse()

void donner::editor::RopeSimulation::applyBottomImpulse	(	const Vector2d &	impulse,
		double	normalizedWidth )

Add a localized velocity impulse centered on the lowest interior particle.

Parameters

impulse	Screen-space velocity displacement at the catenary bottom.
normalizedWidth	Sine-normalized falloff width in [0, 1].

applyImpulse()

void donner::editor::RopeSimulation::applyImpulse

(

const Vector2d &

impulse

)

Add an instantaneous velocity impulse to interior rope particles.

Parameters

impulse

Screen-space velocity displacement applied with a sine envelope.

reset()

void donner::editor::RopeSimulation::reset	(	std::span< const Vector2d >	route,
		const RopeSimulationOptions &	options )

Reset this rope by sampling route into evenly spaced simulated particles.

Parameters

route	Polyline route from fixed start to fixed end.
options	Simulation options controlling segment count and smoothing.

resetCatenary()

void donner::editor::RopeSimulation::resetCatenary	(	const Vector2d &	start,
		const Vector2d &	end,
		const RopeSimulationOptions &	options )

Reset this rope to a catenary between fixed endpoints.

The resulting rest lengths come from the sampled catenary, so gravity and distance constraints settle toward the same hanging-curve family instead of a pre-routed polyline. The rope starts asleep with zero velocity; callers may wake it with applyBottomImpulse or endpoint motion.

Parameters

start	Fixed rope start point in screen coordinates.
end	Fixed rope end point in screen coordinates.
options	Simulation options controlling slack and segment count.

update()

void donner::editor::RopeSimulation::update	(	const Vector2d &	start,
		const Vector2d &	end,
		double	deltaTimeSeconds,
		double	scrollDeltaY,
		double	timeSeconds,
		std::uint32_t	phaseSeed,
		bool	frozen,
		const RopeSimulationOptions &	options )

Advance the rope by one frame.

Parameters

start	Fixed rope start point in screen coordinates.
end	Fixed rope end point in screen coordinates.
deltaTimeSeconds	Frame delta time in seconds.
scrollDeltaY	Source-pane vertical scroll delta since the previous frame.
timeSeconds	Monotonic UI time in seconds, used for idle sway phase.
phaseSeed	Stable per-rope seed used to desynchronize idle sway.
frozen	If true, skip integration and keep the rope body stable for interaction.
options	Simulation options.

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The documentation for this class was generated from the following file:

• donner/editor/RopeSimulation.h