apply all transform matrices - javascript

I am looking for a possibly fast way to apply all transform matrices of a given svg-graphic. In other words: the algorithm should remove all "transform" attributes and transform all coordinates of the graphic to absolute coordinates.
Is their any library that can do this, or is their any SVGDomInterface method that coulld do that?
EDIT::
If I call the consolidate method like this:
$.each( svg.find( 'path' ), function( i ){
this.transform.baseVal.consolidate();
});
nothing happens, if i call it like this:
$.each( svg.find( 'path' ), function( i ){
this.transform.animVal.consolidate();
});
i get this error:
So, how should i use the "consolidate" method, on which elements shall I call it?
Greetings
philipp

Here's a jsFiddle with some javascript library code (based in part on Raphael.js) to bake the transforms into all paths' data:
http://jsfiddle.net/ecmanaut/2Wez8/
(Not sure what's up with Opera here, though; it's usually best in class on SVG. I may be stumbling in some way the other browsers are more forgiving about.)

The consolidate method only reduces the list of matrices to a single matrix. And the error you get on the animVal example is because you are not allowed to modify the animated values (consolidate destructively modifies the transform list).
To answer your question, no there's no existing method in SVG DOM that applies the transforms by modifying the values of paths etc. There are options in Inkscape (and Illustrator too IIRC) for applying transforms like that.
If you're looking for a library or utility that does this you can try SVG Cleaner.

SVG Cleaner didn't seem to apply all transforms for me, but Inkscape does. Here's the command line I use when I need to apply one:
inkscape copy-of-file.svg --select=id-of-node \
--verb=EditCut --verb=EditPaste \
--verb=FileSave --verb=FileClose
Assuming you have "Transforms -> Store transformation" set to "Optimized" in inkscape's prefs (I believe it is on by default), this will apply it and produce the wanted result. Be sure you operate on a copy of your input file, as the operation replaces your original file!
If you are running this on a mac, you may want to first do this in your shell:
alias inkscape=/Applications/Inkscape.app/Contents/Resources/bin/inkscape

Better use EditPasteInPlace instead of EditPaste. EditPaste pastes at the mouse location, which is not the location of the node.

In order to retreive the path relative to some other, parent DOM node (e.g. the SVG root container), you can use the technique here.
It uses SVG.getTransformToElement which calculates the transform between a parent and some node on the SVG tree. The returned object contains methods to return the inverse of the transform, etc, to do practical things with it.
How to determine size of Raphael object after scaling & rotating it?
I dont know exactly what you are trying to achieve, but this has the power to do it.

Related

How to apply transformation to selection in Illustrator by scripting

I managed to select every thing I want in Illustrator with a ExtendScript Toolkit javascript code: lots of things (text, path, symbols, ...) in several layers. Now I want to resize them the same way, then move them.
I know how to apply a transformation to one object by code, but I want to avoid looping on each element because it would be very very long and transformation would be applied from the anchor point of each element, so my drawings wouldn't be cohesive.
So, I am looking for a way to do like in Illustrator UI: right click > transform > scale. Is there any UI command like this I could access from code (javascript)?
There are at least three ways to do this:
Record AI Actions that perform required transformations, and then play these Actions (by DoScript) from your script
Group selected objects and apply required transformations to the group as #Dane proposed. You need to backup the Layer object property to allow objects to be restored in original layers, as shown in VBA example below:
For i = Index_Lo To Index_Hi
Call Layers_Backup.Add(Item:=SelectedItems(i).Layer, Key:=Format(i))
Call SelectedItems(i).Move(Temp_Group, AiElementPlacement.aiPlaceAtEnd)
Next i
Call Temp_Group.Resize(scaleX:=120, scaleY:=120, changeLineWidths:=120)
For i = Index_Lo To Index_Hi
Call SelectedItems(i).Move(Layers_Backup(Format(i)), AiElementPlacement.aiPlaceAtEnd)
Next i
Call Windows API functions (like PostMessage (..., WM_COMMAND, ..., ...), SendDlgItemMessage, FindWindowEx etc) to show, fill and execute required AI transformations dialog boxes
IMHO, item #1 is the easiest to implement while item#2 is the most reliable
So I dont know if you can get away with not looping in some form or other. that said, if you dont mind putting your selection in to a group, it might be faster to loop through your selection adding to a group which might be faster than looping and through the selection and scale and moving each element. With the group object you can then do groupObject.scale() and .translate().
Here is a snippet i took from a script of mine.
#target "illustrator"
var aiApp = app.activeDocument;
var aSelection = aiApp.selection;
var aGroup = app.activeDocument.groupItems.add();
for (i=0; i < aSelection.length; i++){
aSelection[i].move( aGroup, ElementPlacement.INSIDE);
aSelection[i].move( aGroup, ElementPlacement.PLACEATEND);
}
//moves up 700 points and scales by 200
aGroup.translate(0,700)
aGroup.resize(200, 200, true , true, true, true, 200)

getPointAtLength with SVG not working correctly

I have a huge SVG file and all of its data is in one single element. It's something like this:
<path d="M724 1541c133,-400 36,-222 334,-520 76,-75 440,-37 557,-37 145,291 111,
-32 111,445 0,344 -3,260 483,260 457,0 177,-111 409,-111 0,-62 0,-124 0,-186
-368,0 190,-111 -409,-111 -143,0 2,40 -148,223 ... huge SVG "/>
I am converting this huge SVG to polylines using the function "getPointAtLength"as this guy answered my question: https://stackoverflow.com/a/39405746/2934699
The problem is this: this SVG is not a continuous one, it has some shapes (rectangles, circles...) which are not connected. But when I use the method of the link above all my shapes get connected. Is there someway to solve this problem?
There are two possible approaches I can think of to solve your problem.
1. Quick and dirty
As you loop through the path, calculate the distance from the last path point. If that distance exceeds some limit, you can consider that you have stepped into a new subpath. So begin a new polyline.
2. More accurate but trickier
Preprocess the path using the mypath.pathSegList property. That call returns a list of the path commands in the path.
Then loop through the pathSegList and take note of where each move command is. These mark the start of each subpath
As you loop through flattening the path, call the mypath.getPathSegAtLength() function. It returns the index of the pathseg entry at that length.
Compare that with the data you recorded in step 1 to see if you have moved into a new subpath
If you have, start a new polyline (or polygon)
One complication is that Chrome has deprecated support for the pathSegList property, and have instead moved to the new SVG2 API for this (mypath.getPathData()). Fortunately there is a polyfill for Chrome to add back support for the old API. Or you can switch to the new API and use a different polyfill so that the new API works on older browsers.
You can find details on the two polyfills here

InDesign extendScript: How do I transform the entire selection?

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.

Create SVGPoint inside an element with user coordinate

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.

Faster SVG Path manipulation

So I want to make a drawing tool using SVG, I'm using a rather naive approach to change the d attribute of my Path:
$("div#drawarea").bind("mousemove", function(ev) {
ev.preventDefault();
ev.stopPropagation();
var pX= (ev.pageX - this.offsetLeft);
var pY= (ev.pageY - this.offsetTop);
$path.attr("d", $path.attr("d") + " L" +pX+ "," + pY); //using jquery-svg here to change the d attribute
});
As you can see I do this on the mousemove function. The code works but it becomes unresponsive when the mouse is moving fast creating numerous straight lines when I actually want it to be smooth lines. I think this is happening because the numerous string concatenations I'm doing on the mousemove event (the d attribute on the path can become quite big when the click has been held for long, thousands of characters long in fact).
I'm wondering if there is any native way to add new values at the end of a path instead of manipulating the d attribute directly. I checked the jquery-svg sourcecode and it seems that the library also uses the naive string concatenation mode internally so using its methods would not wield any benefit.
Also I'm wondering if this is the case or if the browser just limits the amount of mousemove events (once every X milliseconds?) that can be triggered and so no performance optimizations would improve this.
Use the SVG pathseg DOM methods. You have to write more complicated code but the browser doesn't have to reparse the whole path attribute. Firefox for instance does take advantage of this and it's quite likely other broswers also.
In case someone else stumbeld upon the quesion of what is the fastes way to update an SVG-Path data attribute (for realtime applications), I run a small test on that:
http://jsperf.com/svg-path-test
Yes, setting it as string means that it needs to be parsed, which isn't the case for the DOM SVG interface but the first method is still much faster. Maybee the interface updates the DOM with each point added, slowing down the whole process.

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