Re: Drawing a sequence of line segments
ax487 <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
*bump* I actually put quite some work into the pastebin example. Doesn't anyone have an idea how to interpolate between the full redraw and the lazy variant? On 29.05.2014 13:16, ax487 wrote: > Hello all, > > I am using cairo to draw a stroke, that is a sequence of line segments, > onto a canvas, which is represented as a cairo_surface_t* internally. > The canvas is used in a Gtk+ application, the stroke is extended > whenever the mouse moves. Obviously, the redraw needs to be fast enough > such that there is no visible lag. A minimal example is here: > http://pastebin.com/RtaPajcU > I have tried the following approaches: > > 1: Redraw the entire stroke whenever the mouse moves. This works > correctly apart from the fact that there is a lag which increases as > more points are drawn. > > 2: Only draw the stroke between the last two points whenever the mouse > moves. This is noticeably faster but the drawing is incorrect: Pixels > are repeatedly overdrawn so the alpha value increases along certain > paths of the stroke. > > I would like to go for fast and correct. Any ideas? > > ax487 > -- cairo mailing list [email protected] http://lists.cairographics.org/mailman/listinfo/cairo