On Sun, 2017-03-19 at 22:12 +0000, Marcin Kolny wrote: > I'd like to write very simple application for drawing lines.
You can restrict all drawing operations to a rectangle enclosing your line. For each move with button pressed, fill that rectangle with background color and then draw the line with foreground color. Or, you may save the old line start and end points and paint that old line with background color before drawing the new line. I think there is not much benefit for using an temporary surface for this use case. For more complicated graphics it can become a bit slow indeed -- I once tried it for my schematics editor -- there I used a bounding box for all the graphical elements, when one element is moved, I had to draw its background and then all other elements overlapping with that background element. Using OpenGl may be faster and easier, because you can fast just redraw all. I think GTK3 now has a gl-area widget. The problem with Gl is that it is basically more for drawing triangles than for drawing lines... _______________________________________________ gtk-app-devel-list mailing list gtk-app-devel-list@gnome.org https://mail.gnome.org/mailman/listinfo/gtk-app-devel-list
