From 312d0390018a922f781ed81c7e5da3d451779745 Mon Sep 17 00:00:00 2001
From: josh <josh@stepbro.wtf>
Date: Fri, 31 May 2024 15:19:45 -0400
Subject: [PATCH] Implement Vector3::FromScalar() RandomDir() RandomSphere()
 RandomBox()

---
 include/J3ML/LinearAlgebra/Vector3.h | 22 +++++++++++++++++++++-
 src/J3ML/LinearAlgebra/Vector3.cpp   | 25 +++++++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/include/J3ML/LinearAlgebra/Vector3.h b/include/J3ML/LinearAlgebra/Vector3.h
index 6123547..300ab8f 100644
--- a/include/J3ML/LinearAlgebra/Vector3.h
+++ b/include/J3ML/LinearAlgebra/Vector3.h
@@ -5,6 +5,10 @@
 #include <cstddef>
 #include <cstdlib>
 #include <J3ML/LinearAlgebra/Angle2D.h>
+#include <J3ML/Algorithm/RNG.h>
+
+
+using namespace J3ML::Algorithm;
 
 namespace J3ML::LinearAlgebra {
 
@@ -95,7 +99,23 @@ public:
     /// Constructs a new Vector3 with the value (scalar, scalar, scalar).
     explicit Vector3(float scalar);
 
+    /// Generates a new Vector3 by fillings its entries by the given scalar.
+    /// @see Vector3::Vector3(float scalar), SetFromScalar()
+    static Vector3 FromScalar(float scalar);
 
+    /// Generates a direction vector of the given length.
+    /** The returned vector points at a uniformly random direction.
+        @see RandomSphere(), RandomBox() */
+    static Vector3 RandomDir(RNG& rng, float length = 1.f);
+    static Vector3 RandomSphere(RNG& rng, const Vector3& center, float radius);
+    static Vector3 RandomBox(RNG& rng, float xmin, float xmax, float ymin, float ymax, float zmin, float zmax);
+    static Vector3 RandomBox(RNG& rng, const Vector3& min, const Vector3 &max);
+
+    static Vector3 RandomBox(RNG& rng, float min, float max);
+
+
+    static inline Vector3 RandomGeneral(RNG& rng, float minElem, float maxElem) { return RandomBox(rng, minElem, maxElem); }
+public:
     /// Casts this float3 to a C array.
     /** This function does not allocate new memory or make a copy of this Vector3. This function simply
             returns a C pointer view to this data structure. Use ptr()[0] to access the x component of this float3,
@@ -172,7 +192,7 @@ public:
     float MinElement() const;
     static float MinElement(const Vector3& of);
 
-    // Normalizes this Vector3.
+    /// Normalizes this Vector3.
     /** In the case of failure, this vector is set to (1, 0, 0), so calling this function will never result in an
 		unnormalized vector.
 		@note If this function fails to normalize the vector, no error message is printed, the vector is set to (1,0,0) and
diff --git a/src/J3ML/LinearAlgebra/Vector3.cpp b/src/J3ML/LinearAlgebra/Vector3.cpp
index 108eca9..3392eec 100644
--- a/src/J3ML/LinearAlgebra/Vector3.cpp
+++ b/src/J3ML/LinearAlgebra/Vector3.cpp
@@ -2,6 +2,7 @@
 #include <algorithm>
 #include <cassert>
 #include <cmath>
+#include <J3ML/Geometry/Sphere.h>
 
 namespace J3ML::LinearAlgebra {
 
@@ -529,5 +530,29 @@ namespace J3ML::LinearAlgebra {
                c.IsNormalized(epsilon*epsilon);
     }
 
+    Vector3 Vector3::FromScalar(float scalar) {
+        return {scalar, scalar, scalar};
+    }
+
+    Vector3 Vector3::RandomDir(RNG &rng, float length) {
+        return Sphere(Vector3::FromScalar(0.f), length).RandomPointOnSurface(rng);
+    }
+
+    Vector3 Vector3::RandomSphere(RNG &rng, const Vector3 &center, float radius) {
+        return Sphere(center, radius).RandomPointInside(rng);
+    }
+
+    Vector3 Vector3::RandomBox(RNG &rng, const Vector3& min, const Vector3& max) {
+        return AABB(min, max).RandomPointInside(rng);
+    }
+
+    Vector3 Vector3::RandomBox(RNG &rng, float min, float max) {
+        return RandomBox(rng, {min,min,min}, {max,max,max});
+    }
+
+    Vector3 Vector3::RandomBox(RNG &rng, float xmin, float xmax, float ymin, float ymax, float zmin, float zmax) {
+        return RandomBox(rng, {xmin,ymin,zmin}, {xmax,ymax,zmax});
+    }
+
 
 }
\ No newline at end of file