1 files changed, 121 insertions, 0 deletions
diff --git a/Source/Initialization/InjectorPosition.H b/Source/Initialization/InjectorPosition.H
new file mode 100644
index 000000000..e74345ae5
--- /dev/null
+++ b/Source/Initialization/InjectorPosition.H
@@ -0,0 +1,121 @@
+#ifndef INJECTOR_POSITION_H_
+#define INJECTOR_POSITION_H_
+
+#include <AMReX_Gpu.H>
+#include <AMReX_Dim3.H>
+#include <AMReX_Utility.H>
+
+struct InjectorPositionRandom
+{
+    AMREX_GPU_HOST_DEVICE
+    amrex::XDim3
+    getPositionUnitBox (int i_part, int ref_fac=1) const noexcept
+    {
+        return amrex::XDim3{amrex::Random(), amrex::Random(), amrex::Random()};
+    }
+};
+
+struct InjectorPositionRegular
+{
+    InjectorPositionRegular (amrex::Dim3 const& a_ppc) noexcept : ppc(a_ppc) {}
+
+    AMREX_GPU_HOST_DEVICE
+    amrex::XDim3
+    getPositionUnitBox (int i_part, int ref_fac=1) const noexcept
+    {
+        int nx = ref_fac*ppc.x;
+        int ny = ref_fac*ppc.y;
+#if (AMREX_SPACEDIM == 3)
+        int nz = ref_fac*ppc.z;
+#else
+        int nz = 1;
+#endif
+        int ix_part = i_part/(ny*nz);  // written this way backward compatibility
+        int iz_part = (i_part-ix_part*(ny*nz)) / ny;
+        int iy_part = (i_part-ix_part*(ny*nz)) - ny*iz_part;
+        return amrex::XDim3{(0.5+ix_part)/nx, (0.5+iy_part)/ny, (0.5+iz_part) / nz};
+    }
+private:
+    amrex::Dim3 ppc;
+};
+
+struct InjectorPosition
+    : public amrex::Gpu::Managed
+{
+    InjectorPosition (InjectorPositionRandom* t,
+                      amrex::Real a_xmin, amrex::Real a_xmax,
+                      amrex::Real a_ymin, amrex::Real a_ymax,
+                      amrex::Real a_zmin, amrex::Real a_zmax)
+        : type(Type::random),
+          object(t),
+          xmin(a_xmin), xmax(a_xmax),
+          ymin(a_ymin), ymax(a_ymax),
+          zmin(a_zmin), zmax(a_zmax)
+    { }
+
+    InjectorPosition (InjectorPositionRegular* t,
+                      amrex::Real a_xmin, amrex::Real a_xmax,
+                      amrex::Real a_ymin, amrex::Real a_ymax,
+                      amrex::Real a_zmin, amrex::Real a_zmax,
+                      amrex::Dim3 const& a_ppc)
+        : type(Type::regular),
+          object(t, a_ppc),
+          xmin(a_xmin), xmax(a_xmax),
+          ymin(a_ymin), ymax(a_ymax),
+          zmin(a_zmin), zmax(a_zmax)
+    { }
+
+    InjectorPosition (InjectorPosition const&) = delete;
+    InjectorPosition (InjectorPosition&&) = delete;
+    void operator= (InjectorPosition const&) = delete;
+    void operator= (InjectorPosition &&) = delete;
+
+    std::size_t sharedMemoryNeeded () const noexcept { return 0; }
+
+    bool useRandom () const noexcept;
+
+    AMREX_GPU_HOST_DEVICE
+    amrex::XDim3
+    getPositionUnitBox (int i_part, int ref_fac=1) const noexcept
+    {
+        switch (type)
+        {
+        case Type::regular:
+        {
+            return object.regular.getPositionUnitBox(i_part, ref_fac);
+        }
+        default:
+        {
+            return object.random.getPositionUnitBox(i_part, ref_fac);
+        }
+        };
+    }
+
+    AMREX_GPU_HOST_DEVICE
+    bool
+    insideBounds (amrex::Real x, amrex::Real y, amrex::Real z) const noexcept
+    {
+        return (x < xmax and x >= xmin and
+                y < ymax and y >= ymin and
+                z < zmax and z >= zmin);
+    }
+
+private:
+    enum struct Type { random, regular };
+    Type type;
+
+    union Object {
+        Object (InjectorPositionRandom*) noexcept : random() {}
+        Object (InjectorPositionRegular*, amrex::Dim3 const& a_ppc) noexcept
+            : regular(a_ppc) {}
+        InjectorPositionRandom random;
+        InjectorPositionRegular regular;
+    };
+    Object object;
+
+    amrex::Real xmin, xmax;
+    amrex::Real ymin, ymax;
+    amrex::Real zmin, zmax;
+};
+
+#endif