Changeset 260

Timestamp:

12/06/14 01:16:34 (10 years ago)

Author:

Maciej Komosinski

Message:

Added docs for quadrant and octant literals

File:

• cpp/frams/model/geometry/geometryutils.h (modified) (2 diffs)

cpp/frams/model/geometry/geometryutils.h

@@ -11 +11 @@
 #include <frams/util/list.h>
 
-//binary literals standardized in C++14
+
+/*Binary literals like 0b010 are standardized only in C++14. We use macros as they are compatible with older compilers too.
+
+3-bit numbers are used when iterating through octants in a 3D space. Example: when creating points that cover the surface
+of an ellipsoid, the points are only created for the positive octant (x, y, and z coordinates are positive). Points in
+the remaining 7 octants are created by reflecting points from the positive octant through the appropriate planes defined by
+pairs of axes.
+
+2-bit numbers are used for 2D. Example: cylinders are aligned along the x axis so that both bases are parallel to
+the yz plane. When points are created along the edge of the base (these will be used later to create points along the side
+of the cylinder), only y and z axes are important, so quadrants of the 2D are sufficient. Just as in the 3D example above,
+only points for the positive quadrant, QuadrantYZ, are created, and points of the remaining quadrants are created by reflection.
+QuadrantXY and QuadrantZX enumerations are never used and are provided only for completeness.
+*/
 #define b000 0
 #define b01 1
@@ -19 +32 @@
 #define b100 4
 #define b110 6
+
+
 
 namespace CuboidFaces