Drawing a sequence of line segments
ax487 <[email protected]>
| Newsgroups | gmane.comp.lib.cairo |
|---|---|
| Message-ID | <[email protected]> |
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