Fractured Arabic words using ANGLE FOLLOW

[jackeycheung]

If a layer uses ANGLE FOLLOW to render labels that are in Arabic, the rendered labels have tiny gaps between each joined characters.

-- Stephen Woodbridge wrotes --

OK, this is great. I think I learned something new then. With ANGLE AUTO you can ask GD to draw the whole string at the specified angle. But there is not equivalent function in GD for ANGLE FOLLOW. The only way we can do that is one character at a time, changing the insertion point and angle of each character.

I know Thomas has put a lot of effort into make the AGG render well integrated with mapserver. It would probably be a good idea to document this issue and the fact that the outlinecolor is what is causing in a bug. ​http://trac.osgeo.org/mapserver/ If you do not have an OSGeo userid, follow the link to get one first.

Thank you for your patience and Thank you, Tanya, for your excellent observations on this issue.

-- end of quote --

[jackeycheung]

Lables generated with ANGLE AUTO

[jackeycheung]

Lables generated with ANGLE FOLLOW

[jackeycheung]

Lables generated with ANGLE FOLLOW without OUTLINE

[tbonfort]

applied a two-pass rendering on angle follow labels in r9432:

• first pass draws all outlines and shadows
• second pass draws the actual text

this should correct the fractured text that was occuring, and also helps readability on labels with high curvature

this is an AGG only fix (for now?)

[tbonfort]

pushing off to 6.0 when applied to all renderers

[tbonfort]

the two-pass rendering is done at a higher level, so this should be fixed for all renderers. performance-wise this is not optimal, see #3611 for a possible workaround.