Moving objects by scripts

The objective is to add scripts to Meclib widgets, which allow the control of the sketch by interactively dragging control points. Here is a jsfiddle example

The general procedure is as follows

• create Meclib objects

  [
    [ "grid", "", "", 0, 6, 0, 5, 40],
    [ "fix12", "A", [1, 1], 0],
    [ "fix12", "B", [5, 1], 0],
    [ "bar", "", [1,1], [3,3]],
    [ "bar", "", [5,1], [3,3]],
    [ "force", "F", [3,3], [3,4 ]]
  ]
  

• Create shortcuts for objects you want to control

  var B = objects[2]; 
  var A = objects[1];
  var AC = objects[3];
  var CB = objects[4];
  var F = objects[5];
  

• Create interactive control points. Here we copy the positions from the meclib objects, XY() is an internal meclib function

  var pA = board.create("point", XY(A.p1), {fixed:false});
  var pB = board.create("point", XY(B.p1), {fixed:false});
  var pC = board.create("point", XY(AC.p2), {fixed:false});
  var pF = board.create("point", XY(F.p2), {fixed:false});
  

• Create callbacks for the control points

  pA.on('drag', function(e) { A.p1.moveTo(XY(pA)); AC.p1.moveTo(XY(pA)); });
  pB.on('drag', function(e) { B.p1.moveTo(XY(pB)); CB.p1.moveTo(XY(pB)); });
  pC.on('drag', function(e) { AC.p2.moveTo(XY(pC)); CB.p2.moveTo(XY(pC)); F.p1.moveTo(XY(pC));});
  pF.on('drag', function(e) { F.p2.moveTo(XY(pF)); });
  

Interactivity legend:

• "Switch": object can be activated or deactivated by double-click.
• "Move": object or it's control points can be dragged around with the mouse.
• "Delete": object can be deleted by double-click (if active)
• "Generate": object can generate "force" or "moment" objects by dragging sample objects with the mouse.

Return value: only relevant for interactive input

Not all objects are meant to be animated, as it depends on the purpose of their functionalities.

Restrictions:

• "beam": works only for single part beams. Multipart beams would be controlled by a list of points p[0], p[1], ...

Work in progress:

• dashpot (p1,p2) (done)
• dim (p1,p2)
• dir (p1,p2) (done)
• disp (p1,p2) (done)
• fixXX (refactoring) (done)
• line (x, y vectors)?
• polygon (p.vertex[i])?
• rope (p1,p2) center points
• springc (p1, p2)
• springt (p1, p2)

Objects with generic control

• bar (p1, p2)
• circle (pc)
• force (p1, p2)
• label (p1)
• mass (p1)
• moment (p1, p2, p3)
• node (p1)
• point (p1)
• rot (p1, p2, p3)

The input for the images in the table are found here

Object	Interactivity	Return value in names	Example	moveTo( ) points
"angle", "angle1", "angle2"		label string		p1 (center), p2, p3
"axes"
"bar"	Switch	"show" or list of load indices if hidden		p1, p2
"beam"	Switch	state
"circle"	Switch	state		p1 (circle midpoint)
"circle2p"	Move	[x1,y1],[x2,y2]
"crosshair"	Move	[x,y] (scaled)
"dashpot"	Switch	"show" or list of load indices if hidden		p1, p2
"dim"		label string
"dir"		label string		p1, p2
"disp"		label string		p1, p2
"fix1", "fix12", "fix123", "fix13"	Switch	"show" or list of load indices if hidden		p1
"force"	Move, delete	expression		p1, p2
"forceGen"	Generate	0
"frame"		0
"grid"		0
"label"		0		p1
"line"		0
"line2p"	Move	[x1,y1],[x2,y2]
"mass"		0		p1
"moment"	Move, delete	expression
"momentGen"	Generate	0
"node"		label string		p1
"point"		label string		p1
"polygon"	Switch	state		p1 (polygon midpoint)
"q"	Switch	"show" or list of load indices if hidden
"rope"	Switch	"show" or list of load indices if hidden
"rot"		label string
"spline"	Move	expression f(x)
"springc"	Switch	"show" or list of load indices if hidden		p1, p2
"springt"	Switch	"show" or list of load indices if hidden		p1, p2
"wall"	Switch	"show" or list of load indices if hidden