Merge branch 'master' of git+ssh://jneem@git.sv.gnu.org/srv/git/lilypond

[lilypond.git] / lily / prob-scheme.cc

diff --git a/lily/prob-scheme.cc b/lily/prob-scheme.cc
index c22c88bc729ab57a1c189ce10def62f0c730fdd7..a9838bb4353be12aafaea4ef3a315bbf19f477d3 100644 (file)
--- a/lily/prob-scheme.cc
+++ b/lily/prob-scheme.cc
@@ -7,6 +7,7 @@
 */
 
 #include "prob.hh"
+#include "skyline.hh"
 
 LY_DEFINE (ly_prob_set_property_x, "ly:prob-set-property!",
           2, 1, 0, (SCM obj, SCM sym, SCM value),
@@ -83,3 +84,28 @@ LY_DEFINE(ly_paper_system_p, "ly:paper-system?",
 {
   return ly_prob_type_p (obj, ly_symbol2scm ("paper-system"));
 }
+
+LY_DEFINE (ly_paper_system_minimum_distance, "ly:paper-system-minimum-distance",
+          2, 0, 0, (SCM sys1, SCM sys2),
+          "Measure the minimum distance between these two paper-systems "
+          "using their stored skylines if possible and falling back to "
+          "their extents otherwise.")
+{
+  Real ret = 0;
+  Prob *p1 = unsmob_prob (sys1);
+  Prob *p2 = unsmob_prob (sys2);
+  Skyline_pair *sky1 = Skyline_pair::unsmob (p1->get_property ("skylines"));
+  Skyline_pair *sky2 = Skyline_pair::unsmob (p2->get_property ("skylines"));
+
+  if (sky1 && sky2)
+    ret = (*sky1)[DOWN].distance ((*sky2)[UP]);
+  else
+    {
+      Stencil *s1 = unsmob_stencil (p1->get_property ("stencil"));
+      Stencil *s2 = unsmob_stencil (p2->get_property ("stencil"));
+      Interval iv1 = s1->extent (Y_AXIS);
+      Interval iv2 = s2->extent (Y_AXIS);
+      ret = iv2[UP] - iv1[DOWN];
+    }
+  return scm_from_double (ret);
+}