Merge topic 'perlin-noise-updates'

a200592f4 Fix type conversions in PerlinNoise source
4204e4455 Add changelog for perline noise generator
8f6705450 Allow automatic seed for perlin noise

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !2650

docs/changelog/perlin-noise.md

@@ -0,0 +1,13 @@
+# Perlin Noise source
+
+A new source, `vtkm::source::PerlinNoise`, has been added. As the name
+would imply, this source generates a pseudo-random [Perlin
+noise](https://en.wikipedia.org/wiki/Perlin_noise) field.
+
+The field is defined on a 3D grid of specified dimensions. A seed value can
+also be specified to enforce consistent results in, for example, test code.
+If a seed is not specified, one will be created based on the current system
+time.
+
+Perlin noise is useful for testing purposes as it can create non-trivial
+geometry at pretty much any scale.

vtkm/source/PerlinNoise.cxx

@@ -15,12 +15,11 @@
 #include <vtkm/source/PerlinNoise.h>
 #include <vtkm/worklet/WorkletMapTopology.h>
 
-namespace vtkm
+#include <time.h>
-{
+
-namespace source
+namespace
-{
-namespace perlin
 {
+
 struct PerlinNoiseWorklet : public vtkm::worklet::WorkletVisitPointsWithCells
 {
   using ControlSignature = void(CellSetIn, FieldInPoint, WholeArrayIn, FieldOut noise);
@@ -39,9 +38,9 @@ struct PerlinNoiseWorklet : public vtkm::worklet::WorkletVisitPointsWithCells
     vtkm::Id xi = static_cast<vtkm::Id>(pos[0]) % this->Repeat;
     vtkm::Id yi = static_cast<vtkm::Id>(pos[1]) % this->Repeat;
     vtkm::Id zi = static_cast<vtkm::Id>(pos[2]) % this->Repeat;
-    vtkm::FloatDefault xf = pos[0] - xi;
+    vtkm::FloatDefault xf = static_cast<vtkm::FloatDefault>(pos[0] - xi);
-    vtkm::FloatDefault yf = pos[1] - yi;
+    vtkm::FloatDefault yf = static_cast<vtkm::FloatDefault>(pos[1] - yi);
-    vtkm::FloatDefault zf = pos[2] - zi;
+    vtkm::FloatDefault zf = static_cast<vtkm::FloatDefault>(pos[2] - zi);
     vtkm::FloatDefault u = this->Fade(xf);
     vtkm::FloatDefault v = this->Fade(yf);
     vtkm::FloatDefault w = this->Fade(zf);
@@ -158,7 +157,7 @@ private:
     rng.seed(this->Seed);
     std::uniform_int_distribution<vtkm::Id> distribution(0, this->TableSize - 1);
 
-    vtkm::cont::ArrayHandle<vtkm::FloatDefault> perms;
+    vtkm::cont::ArrayHandle<vtkm::Id> perms;
     perms.Allocate(this->TableSize);
     auto permsPortal = perms.WritePortal();
     for (auto i = 0; i < permsPortal.GetNumberOfValues(); ++i)
@@ -175,9 +174,37 @@ private:
 
   vtkm::IdComponent TableSize;
   vtkm::Id Seed;
-  vtkm::cont::ArrayHandle<vtkm::FloatDefault> Permutations;
+  vtkm::cont::ArrayHandle<vtkm::Id> Permutations;
 };
-} // namespace perlin
+
+} // anonymous namespace
+
+namespace vtkm
+{
+namespace source
+{
+
+PerlinNoise::PerlinNoise(vtkm::Id3 dims)
+  : PerlinNoise(dims, vtkm::Vec3f(0), static_cast<vtkm::IdComponent>(time(NULL)))
+{
+}
+
+PerlinNoise::PerlinNoise(vtkm::Id3 dims, vtkm::IdComponent seed)
+  : PerlinNoise(dims, vtkm::Vec3f(0), seed)
+{
+}
+
+PerlinNoise::PerlinNoise(vtkm::Id3 dims, vtkm::Vec3f origin)
+  : PerlinNoise(dims, origin, static_cast<vtkm::IdComponent>(time(NULL)))
+{
+}
+
+PerlinNoise::PerlinNoise(vtkm::Id3 dims, vtkm::Vec3f origin, vtkm::IdComponent seed)
+  : Dims(dims)
+  , Origin(origin)
+  , Seed(seed)
+{
+}
 
 vtkm::cont::DataSet PerlinNoise::Execute() const
 {
@@ -198,7 +225,7 @@ vtkm::cont::DataSet PerlinNoise::Execute() const
 
   auto tableSize = static_cast<vtkm::IdComponent>(
     vtkm::Max(this->Dims[0], vtkm::Max(this->Dims[1], this->Dims[2])));
-  perlin::PerlinNoiseField noiseGenerator(tableSize, this->Seed);
+  PerlinNoiseField noiseGenerator(tableSize, this->Seed);
   noiseGenerator.SetOutputFieldName("perlinnoise");
   dataSet = noiseGenerator.Execute(dataSet);
 

vtkm/source/PerlinNoise.h

@@ -30,19 +30,10 @@ class VTKM_SOURCE_EXPORT PerlinNoise final : public vtkm::source::Source
 {
 public:
   ///Construct a PerlinNoise with Cell Dimensions
-  VTKM_CONT
+  VTKM_CONT PerlinNoise(vtkm::Id3 dims);
-  PerlinNoise(vtkm::Id3 dims, vtkm::IdComponent seed)
+  VTKM_CONT PerlinNoise(vtkm::Id3 dims, vtkm::IdComponent seed);
-    : PerlinNoise(dims, vtkm::Vec3f(0), seed)
+  VTKM_CONT PerlinNoise(vtkm::Id3 dims, vtkm::Vec3f origin);
-  {
+  VTKM_CONT PerlinNoise(vtkm::Id3 dims, vtkm::Vec3f origin, vtkm::IdComponent seed);
-  }
-
-  VTKM_CONT
-  PerlinNoise(vtkm::Id3 dims, vtkm::Vec3f origin, vtkm::IdComponent seed)
-    : Dims(dims)
-    , Origin(origin)
-    , Seed(seed)
-  {
-  }
 
   vtkm::IdComponent GetSeed() const { return this->Seed; }