Hi Ruben,
I'm fairly certain that getExtentOfChar works properly. We have a fairly
complete test of it in "samples/tests/spec/scripting/text_content.svg" I added
some hkern examples to the SVG font that test includes and getExtentOfChar
worked correctly in that context. In looking at that test one thing that
occurred to me is the possibility that the coordinate system you are adding the
rectangles is slightly different from the texts coordinate system (note that
getExtentOfChar returns box in the text element not in the coordinate system of
the parent of the text which is likely where you are appending the rect). You
might want to adopt the code that test uses to display it's rectangles for your
rectangle display.
BTW it's expected that the boxes don't overlap that doesn't indicate that
the kerning is being ignored.
The extent boxes for horizontal text are adjusted to just touch each other so
they can be used for hit detection. If text selection works correctly for that
text then getExtentOfChar should work.
As for the issue with getting the extent of a single space char I suspect
the issue is that we are required to remove
leading and trailing spaces from text elements in the normal case. I think you
need to set the "xml:space" attribute
to "preserve".
I would strong recommend that you try and get the 'getExtentOfChar' approach
to work for you as that is a much better solution than dropping support for all
the nice text features in SVG. It also seems to me like if you can't
getExtentOfChar to work properly then it likely means you don't really
understand your coordinate systems which will likely lead to similar issues
down the road with your own solution eventually.
Thomas
On Nov 7, 2012, at 9:34 AM, rm <ruben.malc...@googlemail.com> wrote:
>
>
> hi,
>
> i am having font kerning issues.
>
> what i do is this: i dynamically convert a TTF font to an SVG font. in the
> SVG font, there's all kinds of kerning hints. then i link to that svg font
> from my svg as follows:
>
>
> Element fontface = getSvg().createElementNS(svgNS,
> SVGConstants.SVG_FONT_FACE_TAG);
> fontface.setAttributeNS(null, "font-family", fontname);
>
> Element fontfacesrc = getSvg().createElementNS(svgNS,
> SVGConstants.SVG_FONT_FACE_SRC_TAG);
> Element fontfaceuri = getSvg().createElementNS(svgNS,
> SVGConstants.SVG_FONT_FACE_URI_TAG);
> fontfaceuri.setAttributeNS(svgNS, "xlink:href",
> uri+"#"+fontname);
>
> Element fontfaceformat =
> getSvg().createElementNS(svgNS, SVGConstants.SVG_FONT_FACE_FORMAT_TAG);
> fontfaceformat.setAttributeNS(svgNS, "string", "svg");
>
> fontfaceuri.appendChild(fontfaceformat);
> fontfacesrc.appendChild(fontfaceuri);
> fontface.appendChild(fontfacesrc);
> defs.appendChild(fontface);
>
>
> and then i create my textnode like this:
>
>
> Element text = svg.createElementNS(
> svgNS,
> SVG12Constants.SVG_TEXT_TAG);
>
> svg.getDocumentElement().appendChild(text);
>
> set the font face etc in the style att:
>
> text.setAttributeNS(
> null,
> SVGConstants.SVG_STYLE_ATTRIBUTE,
> "font-size:"+fontSize+fontUnit+";"+
> "font-family:"+fontName+";"+
> "font-style:normal;"+
> "font-variant:normal;"+
> "font-weight:normal;"+
> "fill:#000000;"+
> "stroke:none"
> );
>
>
> and append the text content:
>
> Node fpText =
> text.getOwnerDocument().createTextNode(textContent);
> text.appendChild(fpText);
>
>
> now, if i get draw a bounding box for each character:
>
>
> SVGOMTextElement te = (SVGOMTextElement)text;
>
> for(int i=0;i<textContent.length();i++) {
> SVGRect rect = te.getExtentOfChar(i);
>
> Element e = svg.createElement("rect");
> e.setAttributeNS(null, "x", rect.getX()+"");
> e.setAttributeNS(null, "y", rect.getY()+"");
> e.setAttributeNS(null, "width",
> (rect.getWidth()-6)+"");
> e.setAttributeNS(null, "height",
> rect.getHeight()+"");
> e.setAttributeNS(null, "style",
> "fill:none;fill-opacity:1;stroke:#0000ff;stroke-width:6;stroke-opacity:1;stroke-dasharray:9,9;stroke-dashoffset:0");
> svg.appendChild(e);
> }
>
>
> i get a bunch of boxes that have the correct sizes, but don't honour the
> kerning hints -
> basically, with each box exactly touching the previous one. the glyphs
> themselves are, however,
> laid out including the kerning. in the attachment, this is especially obvious
> in the AT
> combination. text bounding box and getComputedLength() are also too wide.
>
> it would be ok for me to switch kerning off completely, but setting
> kerning="0" does not work
> (or i misunderstand it's purpose), and WITH kerning, i cannot correctly
> calculate the position
> and rotation.
>
> any help, anyone?
>
> thanks!
>
> .rm
>
>
>
>
> <Untitled-1.jpg>
>
