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authorKarl Berry <karl@freefriends.org>2015-08-08 22:54:29 +0000
committerKarl Berry <karl@freefriends.org>2015-08-08 22:54:29 +0000
commit531d43fafa269c546d587eaca6cd14adcd11914f (patch)
tree1883933af984c60254e6d9d1bd955a76748cb827 /Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/force/jedi/forcetypes/ForcePullToPoint.lua
parent877e963d44f039783cb9227d90c911866c780961 (diff)
pgf (8aug15)
git-svn-id: svn://tug.org/texlive/trunk@38079 c570f23f-e606-0410-a88d-b1316a301751
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diff --git a/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/force/jedi/forcetypes/ForcePullToPoint.lua b/Master/texmf-dist/tex/generic/pgf/graphdrawing/lua/pgf/gd/force/jedi/forcetypes/ForcePullToPoint.lua
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+-- Copyright 2014 by Ida Bruhns
+--
+-- This file may be distributed and/or modified
+--
+-- 1. under the LaTeX Project Public License and/or
+-- 2. under the GNU Public License
+--
+-- See the file doc/generic/pgf/licenses/LICENSE for more information
+
+--- This is a subclass of ForceTemplate, which is used to implement forces
+-- that work on individual vertices and pulls them to a specific point on the
+-- canvas. This point is given by the |desired at| option. The forces depend
+-- on the canvas position of the vertices relative to the canvas point it is
+-- pulled to.
+
+
+-- Imports
+local ForceTemplate = require "pgf.gd.force.jedi.base.ForceTemplate"
+local lib = require "pgf.gd.lib"
+local Preprocessing = require "pgf.gd.force.jedi.base.Preprocessing"
+
+-- Localize math functions
+local max = math.max
+local sqrt = math.sqrt
+local min = math.min
+
+-- Implementation starts here:
+
+local ForcePullToPoint = lib.class { base_class = ForceTemplate }
+
+function ForcePullToPoint:constructor ()
+ ForceTemplate.constructor(self)
+ self.p = {}
+end
+
+-- This force class works on individual vertices and depends on their
+-- current position as well as the point it is desired at. Thus all vertices
+-- where the |desired at| option is set are added to the table |p| together
+-- with the point where they are wanted.
+--
+-- @param v The vertices of the graph we are trying to find a layout for.
+
+function ForcePullToPoint:preprocess(v)
+ for _,vertex in ipairs(v) do
+ if vertex.options then
+ local da = vertex.options["desired at"]
+ if da then
+ self.p[vertex]= {da}
+ end
+ end
+ end
+end
+
+
+-- Applying the force to the vertices andadding the effect to the passed net
+-- force array
+--
+-- @param data The parameters needed to aplly the force: The options table,
+-- the current time stamp, an array containing the summed up net
+-- forces
+
+function ForcePullToPoint:applyTo(data)
+ -- locals for speed
+ local cap = self.force.cap
+ local net_forces = data.net_forces
+ local t_max = self.options["maximum time"]
+ local t_now = data.t_now
+ local p = self.p
+ local time_fun = self.force.time_fun
+
+ -- Evaluate time function
+ local time_factor = time_fun(t_max, t_now)
+ if time_factor == 0 then
+ return
+ end
+
+ for v, point in pairs(p) do
+ -- dereference
+ local p1 = v.pos
+ local p2 = point[1]
+
+ -- calculate distance between vertex and centroid
+ local x = p1.x - p2.x
+ local y = p1.y - p2.y
+ local d = max(sqrt(x*x+y*y),0.1)
+
+ -- Include time function
+ local h = d * time_factor
+
+ -- scale effect according to direction
+ local f = x * h
+ local g = y * h
+
+ -- cap effect if necessary
+ if cap then
+ if f <= 0 then
+ x = max(-cap, f)
+ else
+ x = min(cap, f)
+ end
+
+ if g <= 0 then
+ y = max(-cap, g)
+ else
+ y = min(cap, g)
+ end
+ else
+ x = f
+ y = g
+ end
+
+ -- add calculated effect to net forces
+ local c1 = net_forces[v]
+ c1.x = c1.x - x
+ c1.y = c1.y - y
+ end
+end
+
+return ForcePullToPoint \ No newline at end of file