I've written a wrapper class around RaphaelElement. It has a property elem which stores the corresponding Element and the two convenience methods setPos and getPos. Moreover there's a position member with the two entries x and y.
Therefore getPos() merely returns the position. setPos accepts a new position as a parameter and has to update the coordinates of elem.
Unfortunately there is no information what type of RaphaelElement will be stored in elem, it could be a circle as well as a rectangle. Right now the code inside setPos looks like this:
//position is the parameter, this.pos is the member
this.pos = position;
this.elem.attr("x",this.pos.x);
this.elem.attr("y",this.pos.y);
this.elem.attr("cx", this.pos.x);
this.elem.attr("cy", this.pos.y);
This feels like a dirty workaround. It works with both circles and rectangles, but on a rectangle there's no attribute "cx" or "cy" and on a circle both "x" and "y" don't exist.
I browsed the documentation for a better way to modify the position of a RaphaelElement and found the method transform. But there's a problem: I haven't found a way to give "absolute" new coordinates to transform. It only offers means to translate, rotate or scale. If I have to change the position by applying a translation from my current position to the new position, then I have to append a new translation to the transformation string. I fear that it might grow VERY long. Moreover, I would have to evaluate an increasingly long string to get my current position.
It certainly is possible to move my Elements by appending new translations to the transformation but I would like to be able to either set the new position directly or to "apply" or "finalise" a transformation, so that it's string doesn't grow infinitely.
The consolidate method on a TransformList will convert a list of transforms into a single matrix. You could call this after you've added your translation.
Alternatively you could call getItem on the transformList which will give you an SVGTransform object and you can call setTranslate on that which would set the new position directly. You'd need to be careful that there is a transform and create one if there isn't.
Related
I'm think I'm having a similar issue as this in that I can not work out (or know if it exists) whereby I can get access to the scaling applied to a given object (in my instance, a raster).
I need to know this so I can animate the scaling via Tween.js.
Anyone have any ideas or know if indeed it is possible to find out the current scaling applied to a raster (or any) object?
I thought it was an issue with Rasters so I tried tweening the scale property of a Path and then a Group and I couldn't get access to the values in order to animate it.
Because I am using Tween.js I can not simply use the object.scale(value) function.
UPDATE
I even tried applying an arbitrary (animated) number to the scale function and it failed to work... i.e.:
object.scale( 0 );
object.arbitraryNumber = 0;
createjs.Tween.get( object )
.to( { arbitraryNumber:1 } , 1000, createjs.Ease.getPowInOut(2) )
.addEventListener( "change", function( event ) {
event.target.target.scale( event.target.target.arbitraryNumber);
} );
Although this did not work, when the same approach was applied to the x position of the object, it animated fine.
Is there anything that needs to be flagged in order to update scaling of an object?
When calling Item.scale() method on each frame with values from 0 to 1, you are actually scaling down item exponentially because each call scales the item relatively to the previous value.
What you want to do is animate the Item.scaling property instead.
You also have to know that by default, PaperJS use global coordinates system and apply every transformations directly to points.
You can change this behavior by setting Item.applyMatrix property to false.
Doing this, scale change will affect item matrix instead of affecting points coordinates and you will be able to animate it as you expect.
Here is simple Sketch of a scale animation:
var circle = new Path.Circle(view.center, 50);
circle.fillColor = 'orange';
circle.applyMatrix = false;
function onFrame(event)
{
circle.scaling = Math.sin(1 + event.count * 0.05);
}
You should be able to transpose this example to your Tween.js context easily.
I have questions please correct me, I dint't find anything about this after some research, You can point me to an answer if one exist. To be specific this is continuation of another post.
After applying a transformation matrix to the container element there is no dragging animation. I figured it out after reading the documentation:
transformMatrix Matrix2D
Inherited from DisplayObject: transformMatrix:318
If set, defines the transformation for this display object, overriding all other transformation properties (x, y, rotation, scale, skew).
Default: null
for dragging I used x and y proprieties of the target object
dragger.on("pressmove", function (evt) {
evt.currentTarget.x = evt.stageX;
evt.currentTarget.y = evt.stageY;
canvasElement.update();
});
so now I think I have to change the matrix values to make dragging animation. Or there is another solution?
Here is the fiddle with the container with transformation matrix.
Right. If you apply a transformMatrix it overrides the other transformation properties. The most obvious solution, looking at your code is to just not use a matrix, and set the x and y properties.
https://jsfiddle.net/n55jk201/11/
The other option would be to use Matrix2D.translate(), or set tx/ty on the matrix directly:
https://jsfiddle.net/n55jk201/12/
Obviously there's a lot of code cleanup you could do, but hopefully that conveys the general idea.
By using the simple array app.selection[x], you can apply a transformation to any object in the selection, independently. But how do I apply a transformation to the entire selection together?
For example: inside InDesign, I can select two side-by-side objects and flip them horizontally, causing them to switch places and flip.
Inside a script, I can target each object in the selection, but they will not switch places; they will remain in the same place and flip.
for ( var x = 0; x < app.selection.length; x++ ){
app.selection[x].absoluteFlip = Flip.HORIZONTAL;
}
I could possibly group the selection, apply a transformation, then ungroup when finished, but this seems like unnecessary bulk that could slow down the code. I can easily do it manually inside InDesign, so it should follow that there's some way to access app.selection as a single object instead of an array. Does such an object exist?
Not really a solution, but it's worth noting that I don't think absoluteFlip is the action being performed, but a state indicating if the item has ben flipped. It's writable so you can set the state, but I think what's happening when using the menu to flip is flipItem: http://jongware.mit.edu/idcs6js/pc_PageItem.html#flipItem,
in which you can set "around" coordinates.
Now getting the origin of the selection box isn't straightforward for some reason (or maybe it is but I don't know how), but you can either use first object coordinates to set the origin so you can flip it around different coordinates depending on order of selection. Or you can sort the array to find left most coordinates (or whichever is needed), like this:
var selection_array = app.selection;
selection_array.sort(function(a, b){return a.visibleBounds[1]-b.visibleBounds[1]})
var flip_origin = [selection_array[0].visibleBounds[1],selection_array[0].visibleBounds[0]]
for(i=0;i<app.selection.length;i++){
app.selection[i].flipItem(Flip.HORIZONTAL, flip_origin);
}
Not sure it's easier or faster than grouping and ungrouping though.
Consider resize. It has a "individual/global" parameter :
void resize (in: varies, from: varies, by: ResizeMethods, values: Array of varies[, resizeIndividually: bool=true][, consideringRulerUnits: bool=false])
Resize the page item.
In Three.JS, I am capable of rotating an object about its origin. If I were to do this with a line, for instance, the line rotates, but the positions of its vertices are not updated with their new locations. Is there some way to apply the rotation matrix to the position of the vertices to find the new position of the point? Say I rotate a line with points at (0,0,0) and (0,100,100) by 45° on the x, 20° on the y, and 100° on the z. How would I go about finding the actual position of the vertices with respect to the entire scene.
Thanks
yes, 'entire scene' means world position.
THREE.Vector3() has a applyMatrix4() method,
you can do the same things that the shader does so in order to project a vertex into world space you would do this
yourPoint.applyMatrix4(yourObject.matrixWorld);
to project that into camera space you can apply this next
yourPoint.applyMatrix4(camera.matrixWorld);
to get an actual screen position in -1 to 1
yourPoint.applyMatrix4(camera.projectionMatrix);
you would access your point like this
var yourPoint = yourObject.geometry.vertices[0]; //first vertex
also, rather than doing this three times, you can just combine the matrices. Didnt test this, but something along the lines of this. Might go the other way:
var neededPVMmatrix = new THREE.Matrix4().multiplyMatrices(yourObject.matrixWorld, camera.matrixWorld);
neededPVMmatrix.multiplyMatrices(neededPVMmatrix, camera.projectionMatrix);
if you need a good tutorial on what this does under the hood i recommend this
Alteredq posted everything there is to know about three.js matrices here
edit
One thing to note though, if you want just the rotation, not the translation, you need to use the upper 3x3 portion which is the rotation matrix, of the models world matrix. This might be slightly more complicated. I forgot what three.js gives you, but i think the normalMatrix would do the trick, or perhaps you can convert your THREE.Vector3() to THREE.Vector4(), and set .w to 0, this will prevent any translation from being applied.
edit2
if you want to move the line point in your example, instead of applying it to the particle, apply it to
var yourVertexWorldPosition = new THREE.Vector3().clone(geo.vertices[1]); //this is your second line point, to whatever you set it in your init function
yourVertexWorldPosition.applyMatrix4();//this transforms the new vector into world space based on the matrix you provide (line.matrixWorld)
I have a small project (to learn SVG) running (using javascript).
I would like to be able to track a point in a shape with its own user coordinate system. My idea is to find the coordinates of the point within the shape, then create an SVGPoint, so that I can pass on that element. I have seen the method create SVGPoint in examples, but it seems it is used in the context of the 'SVG_root' (that is, document.documentElement.createSVGPoint() works).
When I use (in Firefox)
inSvgObj.createSVGPoint()
where inSVGObj is a element, the web console says "TypeError: inSvgObj.createSVGPoint is not a function". Is it possible to create an SVG point within the to subsequently set with values representing coordinates in that 's user coordinate system?
EDIT (after considernig Robert Longson's answer):
Given that SVGPoint is created only within an "SVG root" and that I have been unable to find a way to move that to within another element, I have found more convenient to use a different svg element type: SVGMatrix. In case it helps someone (as I have spent some time trying to deal with this),It is possible to manipulate analogue values inside an SVG Point by creating an SVGMatrix that would work as a simulated point (for the purposes of coordinates. To that endthe methods .createSVGMatrix(), getCTM() and.multiply() (this last from SVGMatrix) are used. To illustrate that, I will include a (js) function that takes 4 arguments: x-coordinate in user coordinate system (ucs) to transform, y-coordinate is that ucs, object whose ucs is the want we want to transform and an object in the ucs we want to transform to; and returns am object with thrre poperties the x-coordinate in the transformed ucs, its y-coordinate and 1 (for consistency with SVG Recommendations).
function coorUcsAToUcsB(ucsAx,ucsAy,svgObjUcsA,svgObjUcsB){
var ctmUcsA=svgObjUcsA.getCTM();
var ctmUcsB=svgObjUcsB.getCTM().inverse();
var mtx=document.getElementsByTagName('svg')[0].createSVGMatrix();
mtx.e=ucsAx;
mtx.f=ucsAy;
var simulSvgP=ctmUcsB.multiply(ctmUcsA.multiply(mtx)); //1
return {"x":simulSvgP.e,"y":simulSvgP.f,"z":1};
}
//1 this line creates an svg matrix with 1st and 2nd column at 0, 3rd with coordinates of ucsB from the analogue svg matrix with coordinates in ucsA - it takes the coordinates in ucsA to viewport's cs and from there to coordinates in ucsB. For the matrix operation explanation, see this.
Any comments, in particular having overlooked a existing method that does the same or any drawbacks, will be more than welcome.
You create the SVG Point using the root element creation but once you've done that you can set whatever values in it you want. When you assign those values to an object the object will interpret them in its coordinate system.