X-Git-Url: https://git.donarmstrong.com/?p=xournal.git;a=blobdiff_plain;f=src%2Fxo-shapes.c;h=5631c0d87300720e2654e1657076a4a725545bcb;hp=01f9073d24c9430f5902bfc810e963b78a484e63;hb=b471a5e1ffc9ad87400f079679fdf261875d513e;hpb=4d39b1b77c637b56b4f094e39328b3394cefa4dc

diff --git a/src/xo-shapes.c b/src/xo-shapes.c
index 01f9073..5631c0d 100644
--- a/src/xo-shapes.c
+++ b/src/xo-shapes.c
@@ -69,28 +69,34 @@ inline double center_y(struct Inertia s)
 
 inline double I_xx(struct Inertia s)
 {
+  if (s.mass <= 0.) return 0.;
   return (s.sxx - s.sx*s.sx/s.mass)/s.mass;
 }
 
 inline double I_xy(struct Inertia s)
 {
+  if (s.mass <= 0.) return 0.;
   return (s.sxy - s.sx*s.sy/s.mass)/s.mass;
 }
 
 inline double I_yy(struct Inertia s)
 {
+  if (s.mass <= 0.) return 0.;
   return (s.syy - s.sy*s.sy/s.mass)/s.mass;
 }
 
 inline double I_rad(struct Inertia s)
 {
-  return sqrt(I_xx(s)+I_yy(s));
+  double ixx = I_xx(s), iyy = I_yy(s);
+  if (ixx+iyy <= 0.) return 0.;
+  return sqrt(ixx+iyy);
 }
 
 inline double I_det(struct Inertia s)
 {
-  if (s.mass == 0.) return 0.;
   double ixx = I_xx(s), iyy = I_yy(s), ixy = I_xy(s);
+  if (s.mass <= 0.) return 0.;
+  if (ixx+iyy <= 0.) return 0.;
   return 4*(ixx*iyy-ixy*ixy)/(ixx+iyy)/(ixx+iyy);
 }