changes.md

Final concept

Library mec2.js does not depend on other modules (except g2.js). It particularly does not depend on the DOM.

public API

model

{
    id: String
    nodes: Array
    constraints: Array
    loads: Array
​    shapes: Array
​
    state: Object { valid: Boolean, direc: Number, … }
​    timer: Object { t: Number, dt: Number }

    dof: Number
    isActive: Boolean

    init()
    pose()
    reset()
    stop()
    tick(dt:Number)
    draw(g:Object)
}

node

{
    id: String
    base: Boolean
    m: Number
    x: Number
    xt: Number
    xtt: Number
    y: Number
    yt: Number
    ytt: Number

    Qx: Number
    Qy: Number
}

constraint

{
    id: String
    p1: Node
    p2: Node
    ori: Object
    len: Object
    r: Number
    rt: Number
    rtt: Number
    w: Number
    wt: Number
    wtt: Number

    type: String
    dof: Number
    force: Number
    moment: Number
}

load

{
    id: String
    type: String
}

depending on its load.type loads become one of these objects:

load.force

{
    id: String
    type: 'force'

    p: Node
    value: Number
    wref: Constraint
    w0: Number
    mode: String

    len: Number
    force: Number
    Qx: Number
    Qy: Number
}

load.spring

{
    id: String
    type: 'spring'

    p1: Node
    p2: Node
    k: Number
    len0: Constraint

    Qx: Number
    Qy: Number
}

shape

{
    type: String
}

depending on its shape.type shapes become one of these objects:

shape.fix

{
    type: 'fix'
    p: Node
    w0: Number
}

shape.flt

{
    type: 'flt'
    p: Node
    w0: Number
}

shape.slider

{
    type: 'slider'
    p: Node
    wref: Constraint
    w0: Number
}

shape.bar

{
    type: 'bar'
    p1: Node
    p2: Node
}

shape.beam

{
    type: 'beam'
    p: Node
    wref: Constraint
    len: Number
}

shape.wheel

{
    type: 'wheel'
    p: Node
    wref: Constraint
    w0: Number
    r: Number
}

shape.poly

{
    type: 'poly'
    pts: Object | Array
    p: Node
    wref: Constraint
    fill: web color
    stroke: web color
}

shape.img

{
    type: 'img'
    uri: String
    p: Node | Object
    b: Number
    h: Number
    sx: Number
    sy: Number
    sb: Number
    sh: Number
    xoff: Number
    yoff: Number
    wref: Constraint
    w0: Number
    scl: Number
}

Changes 20/12/18

• Moved everything graphics related (flags, colors) to mec.core.show.
• Model now get e reference to their environment in model.env by passing it as a second parameter when extending (e.g. mec.model.extend(this.model,this);). When an evnironment is set, mec.core.show is copied as a property for that instance. If no environment is passed, mec.core.show is used.

Changes 28/08/18

• Add mec.core.linkage for constraint and node graphics-flags.
• Models now store label-flags in an model.graphics object that additionally has a member linkage of type object containing flags from mec.core.linkage.
• Fixed some bugs and added some missing properties in asJSON methods.

Changes 16/08/18

• Add mec.shape.poly for supporting polygonial shapes.
• Add mec.aly.r, mec.aly.rt and mec.aly.rtt to mec.core.js.

Changes 14/08/18

• Add idloc property to mec.constraint. Value is
  • left positiv (default)
  • right negativ
  • numeric value [-1 .. 1]

Changes 13/08/18

• Draw references bug resolved.
• *.toJSON removed.

Changes 11/08/18

• add stroke property to mec.trace elements.
• changed source to current mec.labels convention.
• introduce mec.labels structure with previous defaults for setting per JSON model.
• depricate mec.showNodeLabels, mec.showConstraintLabels , mec.showLoadLabels.
• decouple element prototype extension and initialization.
• static mec.aly.* for processing view.info added.
• view.info added.
• model.elementById added.

Changes 10/08/18

• trace view added.
• apply internal constraint forces to its nodes.
• minor vector view bugs removed.
• Elements as well as the model itself now have a asJSON() method, which returns a formatted JSON string. toJSON() will probably be removed in the future.

Changes 09/08/18

• view container added to model.
• vector view implemented.

Changes 08/08/18

• Bug removed in mec.model.isActive. The negated result was returned. (Changes in app required !)
• Bug removed in mec.model.hasActiveDrives.

Changes 07/08/18

• Add mec.load.spring.
• Remove hilite bug with mec.load.force.
• Add mec.gravity = {x:0,y:-10,active:false} as default gravity vector and mode to mec.cor.js. This is in order to switch gravity comfortable on and off, without affecting its vector.
• Added a toJSON method to model and to all element types. model.toJSON() invokes .toJSON() on each element in the model returns a canonical JSON-representation of the model
• Implemented a global darkmode flag (default false) for darker canvas backgrounds. Most colors are now centralized as getters in mec.core.
• Added a different shading for elements when they are selected and not just hovered over.

Changes 06/08/18

• Rename model.hasDependencies() to the semantic more correct model.hasDependents().
• Add model.dependentsOf(elem) to get a dictionary object of all dependents.
• Add model.purgeElements(elems) to purge all elements in a dictionary object.
• Add a new function mec.toZero(a,eps) to mec.core.js. If amount of a is smaller than eps the result is 0 else a.
• Avoid constraint masses to get infinite.

Changes 05/08/18

• Rename model.pos() and model.vel() to model.posStep() and model.velStep().
• Rename constraint.pos() and constraint.vel() to constraint.posStep() and constraint.velStep().
• Change constraint.type from object member to getter.
• Eliminate ambiguity of shape.bar definition by defining {type:'bar',p1,p2} and new shape.beam by {type:'beam',p,wref,len}
• Split mec.load into mec.load and mec.load.force, to add other load types easier later.

Changes 04/08/18

• Adding a static type to drive functions, which is for velocity-less actuating positions.
• model.dirty flag isn't used anymore. It's flagged as depricated.

Changes 03/08/18

• Commenting the requirement for app to provide a cartesian getter (see mec.microapp.js)
• Rename tickTimer's tick method to timerTick in mixin.js to avoid collision with app's own new tick method (should have no other side effects).
• Rename app.step method to app.tick in mec.microapp.js.
• Adding key event handler to mec.microapp.js for using escape key or others for anything.
• Adding state to app to be compatible with Jan's (modifying mec.microapp.js when required). It has one of the values [created,initialized,active,idle, input].
• Triggering new app.pause method when pressing Escape key.
• Accepting mec.model.gravity values as falsy, not necessarily of type boolean.
• Throwing nodes by dragging, giving them an initial velocity, is deactivated at current. Has to be investigated further.
• When releasing the pointer after dragging, the node always has zero velocity.
• Implement isSleeping getter for model and node to indicate significant motion.
• Automatically change app.state from active to idle in app.tick(), if model.isSleeping === true.
• New model.isActive getter is testing, if there are any active drives in constraints or if some nodes are moving (see example mec.5r.drive)
• drives with different start times are working now (see example mec.somecranks)
• drives in constraints get additional boolean bounce property (see example mec.crank).
• drives in constraints get additional integer repeat property (see example mec.crank).