- From: Henri Sivonen <hsivonen@iki.fi>
- Date: Thu, 10 May 2007 17:39:05 +0300
On May 9, 2007, at 22:51, Philip Taylor wrote: > The common graphics APIs (at least > Cairo, Quartz and java.awt.Graphics, and any SVG implementation) all > have dashes specified by passing an array of dash lengths (alternating > on/off), so that should be alright as long as you define what units > it's measured in and what happens when you specify an odd number of > values and how errors are handled and what happens if you update the > array later. Na?vely, one might expect the right answer to be "Do whatever Adobe's PostScript implementation does." Has anyone tested if the expected <canvas> back end libraries (Quartz 2D, Cairo, whatever they call the 2D stuff under WPF, Java 2D) follow PostScript faithfully in the case of dashed strokes? > But after that, what does it do when stroking multiple subpaths, in > terms of offsetting the dashes? "Each subpath of a path is treated independently; the dash pattern is restarted and the offset reapplied at the beginning of each subpath." ? PostScript Language Reference, 3rd ed. p. 667 > How does it interact with lineCap/lineJoin? "Dashed strokes wrap around curves and corners in the same way as solid strokes. The ends of each dash are treated with the current line cap, and corners within a dash are treated with the current line join." ? PostScript Language Reference, 3rd ed. p. 666 -- Henri Sivonen hsivonen at iki.fi http://hsivonen.iki.fi/
Received on Thursday, 10 May 2007 07:39:05 UTC