Merge lp:~inkscape+alexander/inkscape/angle into lp:~inkscape.dev/inkscape/trunk

[Alexander Brock]

When selecting exactly two nodes the status line shows the angle relative to the x-axis, e.g.:

"2 of 65 nodes selected, angle: 65.09°."

[Martin Owens (doctormo)]

It would be nice if the angle calculation were split out into the more core of the code. Having it all here in the text generation for the node tool makes it a little more inflexible if we ever choose to make the selected nodes do something with the angle (for instance align, or display the angle on the screen and etc)

Can you move the core of the calculation out?

[Alexander Brock (brock-alexander)]

On 08/06/15 16:55, Martin Owens wrote:
> It would be nice if the angle calculation were split out into the more core of the code. Having it all here in the text generation for the node tool makes it a little more inflexible if we ever choose to make the selected nodes do something with the angle (for instance align, or display the angle on the screen and etc)
>
> Can you move the core of the calculation out?

I don't exactly know where the core of Inkscape is, in which file should
the calculation be done?
Which part should be moved to the core exactly? Should I write a
function which takes two Geom::Point and returns the angle in ° like that?

double getAngle(const Geom::Point& a, const Geom::Point& b) {
   const Geom::Point difference = b-a;
   double angle = Geom::atan2(difference);
   if (angle < 0) {
         angle += 2*M_PI;
   }
   angle *= 180.0/M_PI;
}

[Krzysztof Kosinski (tweenk)]

What you actually want to compute is the angle between a line going from a to b and the X axis. Therefore, you should use Geom::rad_to_deg(Geom::Line(a, b).angle()).

Also please read this document, because your variable names do not match coding style.
https://inkscape.org/en/develop/coding-style/

review: Needs Fixing

[lp:~inkscape+alexander/inkscape/angle]

14197. By Alexander Brock on 2015-06-10

Compute angle in [0,180[ and adhere to style guide

14198. By Alexander Brock on 2015-06-10

Change function call to one line

[Alexander Brock (brock-alexander)]

> What you actually want to compute is the angle between a line going from a to
> b and the X axis. Therefore, you should use Geom::rad_to_deg(Geom::Line(a,
> b).angle()).

Makes sense, I changed that.

> Also please read this document, because your variable names do not match
> coding style.
> https://inkscape.org/en/develop/coding-style/

I changed it, better now?

[Alexander Brock (brock-alexander)]

I'd like to gently nudge someone to comment / merge :-)

[Krzysztof Kosinski (tweenk)]

Looks okay now, merged.

review: Approve

[Alexander Brock (brock-alexander)]

On 24/06/15 22:56, Krzysztof Kosinski wrote:
> Looks okay now, merged.

Thank you very much :-)

=== modified file 'src/ui/tools/node-tool.cpp'
--- src/ui/tools/node-tool.cpp	2015-05-30 18:27:42 +0000
+++ src/ui/tools/node-tool.cpp	2015-06-10 00:56:17 +0000
@@ -665,9 +665,25 @@
     unsigned total = this->_selected_nodes->allPoints().size();
 
     if (sz != 0) {
-        char *nodestring = g_strdup_printf(
-            ngettext("<b>%u of %u</b> node selected.", "<b>%u of %u</b> nodes selected.", total),
-            sz, total);
+        char *nodestring; 
+        if (sz == 2) {
+            Inkscape::UI::ControlPointSelection::Set &selection_nodes = this->_selected_nodes->allPoints();
+            std::vector<Geom::Point> positions;
+            for (Inkscape::UI::ControlPointSelection::Set::iterator i = selection_nodes.begin(); i != selection_nodes.end(); ++i) {
+                if ((*i)->selected()) {
+                    Inkscape::UI::Node *n = dynamic_cast<Inkscape::UI::Node *>(*i);
+                    positions.push_back(n->position());
+                }
+            }
+            g_assert(positions.size() == 2);
+            const double angle = Geom::rad_to_deg(Geom::Line(positions[0], positions[1]).angle());
+            nodestring = g_strdup_printf("<b>%u of %u</b> nodes selected, angle: %.2f°.", sz, total, angle);
+        }
+        else {
+            nodestring = g_strdup_printf(
+                ngettext("<b>%u of %u</b> node selected.", "<b>%u of %u</b> nodes selected.", total),
+                sz, total);
+        }
 
         if (this->_last_over) {
             // TRANSLATORS: The %s below is where the "%u of %u nodes selected" sentence gets put