classdef spring < handle
properties
particle_1
particle_2
rest
strength
damping
graphics_handle
end
methods
function Spring = spring (Particle_System, particle_1, particle_2, rest, strength, damping)
%SPRING Spring object constructor.
%
% Examples
%
% S = SPRING (PS, P1, P2) creates spring S between two
% particles P1 and P2 with default properties:
% rest (length): 1
% strength: 1
% damping: 0
% and appends it to the particle system PS
%
% S = SPRING (PS, P1, P2, R, S, D) creates spring S between
% two particles P1 and P2 with the following properties:
% rest (length): R
% strength: S
% damping: D
% and appends it to the particle system PS
% Copyright 2008-2008, buchholz.hs-bremen.de
if nargin == 3
rest = 1;
strength = 1;
damping = 0;
end
Spring.particle_1 = particle_1;
Spring.particle_2 = particle_2;
Spring.rest = rest;
Spring.strength = strength;
Spring.damping = damping;
Spring.append (Particle_System);
end
function delete (Spring)
%DELETE Delete spring.
%
% Example
%
% DELETE (S) deletes the spring S.
% Copyright 2008-2008 buchholz.hs-bremen.de
if ishandle (Spring.graphics_handle)
delete (Spring.graphics_handle)
end
end
function update_graphics_position (Spring)
%UPDATE_GRAPHICS_POSITION Update the graphical spring representation.
%
% Example
%
% UPDATE_GRAPHICS_POSITION (S) updates the position of the
% graphical representation of the spring S.
% Copyright 2008-2008 buchholz.hs-bremen.de
spring_position(1, 1:3) = Spring.particle_1.position;
spring_position(2, 1:3) = Spring.particle_2.position;
set (Spring.graphics_handle, ...
'xdata', spring_position(:, 1), ...
'ydata', spring_position(:, 2), ...
'zdata', spring_position(:, 3));
end
end
methods (Access = 'private')
function append (Spring, Particle_System)
%APPEND Append spring to particle system.
%
% Example
%
% APPEND (S, PS) appends the spring S to the
% particle system PS.
% Copyright 2008-2008 buchholz.hs-bremen.de
figure (Particle_System.graphics_handle)
spring_position(1, 1:3) = Spring.particle_1.position;
spring_position(2, 1:3) = Spring.particle_2.position;
Spring.graphics_handle = ...
line (...
spring_position(:, 1), ...
spring_position(:, 2), ...
spring_position(:, 3), ...
'linewidth', 1, ...
'linestyle', '-', ...
'color', [0 0 1]);
Particle_System.springs = [Particle_System.springs, Spring];
end
end
end
