Update documentation.

Author: cgyurgyik

Grid3D.h

@@ -6,6 +6,12 @@
 
 // Represents a 3 dimensional grid sub-divided with voxels. Provides necessary information to perform
 // traversal over the grid system.
+//
+// Requires:
+//   min_bound < max_bound
+//   num_x_voxels > 0
+//   num_y_voxels > 0
+//   num_z_voxels > 0
 struct Grid3D {
 public:
     [[nodiscard]] constexpr Grid3D(const BoundVec3& min_bound, const BoundVec3& max_bound, size_t num_x_voxels,

amanatidesWooAlgorithm.cpp

@@ -8,6 +8,7 @@
 // the grid between tMin and tMax. This version causes an additional efficiency penalty,
 // but takes into account the negative zero case.
 // tMin and tMax are then updated to incorporate the new intersection values.
+// Returns true if the ray intersects the grid, and false otherwise.
 // See: http://www.cs.utah.edu/~awilliam/box/box.pdf
 [[no discard]] bool rayBoxIntersection(const Ray& ray, const Grid3D& grid, value_type& tMin, value_type& tMax,
                         value_type t0, value_type t1) noexcept {
@@ -50,10 +51,10 @@
 }
 
 void amanatidesWooAlgorithm(const Ray& ray, const Grid3D& grid, value_type t0, value_type t1) noexcept {
-    value_type tMin; // Modified in rayBoxIntersection.
-    value_type tMax; // Modified in rayBoxIntersection.
-    const bool ray_has_intersected = rayBoxIntersection(ray, grid, tMin, tMax, t0, t1);
-    if (!ray_has_intersected) return;
+    value_type tMin;
+    value_type tMax;
+    const bool ray_intersects_grid = rayBoxIntersection(ray, grid, tMin, tMax, t0, t1);
+    if (!ray_intersects_grid) return;
 
     tMin = MAX(tMin, t0);
     tMax = MAX(tMax, t1);

amanatidesWooAlgorithm.h

@@ -4,11 +4,17 @@
 #include "Ray.h"
 #include "Grid3D.h"
 
-// Provides a basis for Amanatides & Woo's "A Fast Voxel Traversal Algorithm for Ray Tracing."
+// Implements the algorithm presented in Amanatides & Woo's "A Fast Voxel Traversal Algorithm for Ray Tracing."
 // See: https://www.researchgate.net/publication/2611491_A_Fast_Voxel_Traversal_Algorithm_for_Ray_Tracing
 // If the ray origin is outside the voxel grid, uses a safer version of Smit's ray box intersection algorithm
 // to determine intersection. The bounds [t0, t1] determine the begin and end time for which the ray travels.
-//
+// The algorithm occurs in two phases, initialization and traversal.
+// Requires:
+//     t0 > t1
+//     0.0 <= t0 <= 1.0
+//     0.0 <= t1 <= 1.0
+//     To encapsulate entire ray traversal, set t0 = 0.0, t1 = 1.0
+//     'grid' encapsulates a valid voxel grid system.
 // Notes: Assumes that indices for voxel coordinates begin at 1.
 void amanatidesWooAlgorithm(const Ray& ray, const Grid3D& grid, value_type t0, value_type t1) noexcept;