Review validity ranges for angle parameters

Documentation has been updated accordingly.

src/orange/orangeinp/ConvexRegion.cc

@@ -358,7 +358,7 @@ void InfWedge::output(JsonPimpl* j) const
 // PARALLELEPIPED
 //---------------------------------------------------------------------------//
 /*!
- * Construct with a 3-vector of half-edges and three angles (in radians).
+ * Construct with a 3-vector of half-edges and three angles.
  */
 Parallelepiped::Parallelepiped(Real3 const& half_projs,
                                Turn alpha,
@@ -373,13 +373,13 @@ Parallelepiped::Parallelepiped(Real3 const& half_projs,
                        << to_char(ax) << " axis: " << hpr_[to_int(ax)]);
     }
 
-    CELER_VALIDATE(alpha_ >= zero_quantity() && alpha_ < Turn{0.25},
+    CELER_VALIDATE(alpha_ > -Turn{0.25} && alpha_ < Turn{0.25},
                    << "invalid angle " << alpha_.value()
-                   << " [turns]: must be in the range [0, 0.25]");
+                   << " [turns]: must be in the range (-0.25, 0.25)");
 
     CELER_VALIDATE(theta_ >= zero_quantity() && theta_ < Turn{0.25},
                    << "invalid angle " << theta_.value()
-                   << " [turns]: must be in the range [0, 0.25]");
+                   << " [turns]: must be in the range [0, 0.25)");
 
     CELER_VALIDATE(phi_ >= zero_quantity() && phi_ < Turn{1.},
                    << "invalid angle " << phi_.value()

src/orange/orangeinp/ConvexRegion.hh

@@ -237,18 +237,20 @@ class InfWedge final : public ConvexRegionInterface
  * A parallelepiped is a shape having 3 pairs of parallel faces out of
  * which one is parallel with the XY plane (Z faces). All faces are
  * parallelograms in the general case. The Z faces have 2 edges parallel
- * with the X-axis.
+ * with the X-axis. Note that all angle parameters are expressed in terms
+ * of fractions of a 360deg turn.
  *
  * The shape has the center in the origin and it is defined by:
  *
- *   - `dX, dY, dZ:` half-lengths of the projections of the edges on X, Y
- *     and Z. The lower Z face is positioned at `-dZ`, while the upper at
- * `+dZ`.
+ *   - `halfedges:` a 3-vector (dY, dY, dZ) with half-lengths of the
+ * projections of the edges on X, Y, Z. The lower Z face is positioned at
+ * `-dZ`, and the upper one at `+dZ`.
  *   - `alpha:` angle between the segment defined by the centers of the
- *     X-parallel edges and Y axis `[-90,90]` in degrees;
+ *     X-parallel edges and Y axis. Validity range is `(-1/4, 1/4)`;
  *   - `theta:` polar angle of the shape's main axis, e.g. the segment defined
- *     by the centers of the Z faces;
- *   - `phi:` azimuthal angle of the shape's main axis (explained above).
+ *     by the centers of the Z faces. Validity range is `[0, 1/4)`;
+ *   - `phi:` azimuthal angle of the shape's main axis (as explained above).
+ *     Validity range is `[0, 1)`.
  */
 class Parallelepiped final : public ConvexRegionInterface
 {