Particles: initial support for events and actions

The following nodes work now (although things can still be improved of course):
Particle Birth Event, Praticle Time Step Event, Set Particle Attribute and Execute Condition.

Multiple Set Particle Attribute nodes can be chained using the "Execute" sockets.
They will be executed from left to right.

1 files changed, 40 insertions, 0 deletions

diff --git a/source/blender/functions/FN_spans.hh b/source/blender/functions/FN_spans.hh
index c50c92cd16d..a81f3ea3633 100644
--- a/source/blender/functions/FN_spans.hh
+++ b/source/blender/functions/FN_spans.hh
@@ -209,6 +209,20 @@ template<typename T> struct VSpanBase {
     return false;
   }
 
+  bool is_full_array() const
+  {
+    switch (category_) {
+      case VSpanCategory::Single:
+        return virtual_size_ == 1;
+      case VSpanCategory::FullArray:
+        return true;
+      case VSpanCategory::FullPointerArray:
+        return false;
+    }
+    BLI_assert(false);
+    return false;
+  }
+
   bool is_empty() const
   {
     return this->virtual_size_ == 0;
@@ -285,6 +299,22 @@ template<typename T> class VSpan : public VSpanBase<T> {
     BLI_assert(false);
     return *this->data_.single.data;
   }
+
+  const T &as_single_element() const
+  {
+    BLI_assert(this->is_single_element());
+    return (*this)[0];
+  }
+
+  Span<T> as_full_array() const
+  {
+    BLI_assert(this->is_full_array());
+    if (this->virtual_size_ == 0) {
+      return Span<T>();
+    }
+    const T *data = &(*this)[0];
+    return Span<T>(data, this->virtual_size_);
+  }
 };
 
 /**
@@ -395,6 +425,16 @@ class GVSpan : public VSpanBase<void> {
     return (*this)[0];
   }
 
+  GSpan as_full_array() const
+  {
+    BLI_assert(this->is_full_array());
+    if (this->virtual_size_ == 0) {
+      return GSpan(*this->type_);
+    }
+    const void *data = (*this)[0];
+    return GSpan(*this->type_, data, this->virtual_size_);
+  }
+
   void materialize_to_uninitialized(void *dst) const
   {
     this->materialize_to_uninitialized(IndexRange(virtual_size_), dst);