Particles: Create a simulation state for every Particle Simulation node

Every Particle Simulation node has a name (or a path when it is in a node group).
This name has to be used in the Simulation modifier on a point cloud to see
the particles.

Caching has been disabled for now, because it was holding back development
a bit. To reset the simulation, go back to frame 1.

Currently, there is no way to influence the simulation. There are just some
randomly moving points. Changing that is the next step.

1 files changed, 38 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index eab7326868b..20648970bd1 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1639,6 +1639,40 @@ static void rna_SimulationModifier_simulation_update(Main *bmain, Scene *scene,
   rna_Modifier_dependency_update(bmain, scene, ptr);
 }
 
+static void rna_SimulationModifier_data_path_get(PointerRNA *ptr, char *value)
+{
+  SimulationModifierData *smd = ptr->data;
+
+  if (smd->data_path) {
+    strcpy(value, smd->data_path);
+  }
+  else {
+    value[0] = '\0';
+  }
+}
+
+static int rna_SimulationModifier_data_path_length(PointerRNA *ptr)
+{
+  SimulationModifierData *smd = ptr->data;
+  return smd->data_path ? strlen(smd->data_path) : 0;
+}
+
+static void rna_SimulationModifier_data_path_set(PointerRNA *ptr, const char *value)
+{
+  SimulationModifierData *smd = ptr->data;
+
+  if (smd->data_path) {
+    MEM_freeN(smd->data_path);
+  }
+
+  if (value[0]) {
+    smd->data_path = BLI_strdup(value);
+  }
+  else {
+    smd->data_path = NULL;
+  }
+}
+
 /**
  * Special set callback that just changes the first bit of the expansion flag.
  * This way the expansion state of all the sub-panels is not changed by RNA.
@@ -6859,6 +6893,10 @@ static void rna_def_modifier_simulation(BlenderRNA *brna)
   RNA_def_property_update(prop, 0, "rna_SimulationModifier_simulation_update");
 
   prop = RNA_def_property(srna, "data_path", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_funcs(prop,
+                                "rna_SimulationModifier_data_path_get",
+                                "rna_SimulationModifier_data_path_length",
+                                "rna_SimulationModifier_data_path_set");
   RNA_def_property_ui_text(
       prop, "Data Path", "Identifier of the simulation component that should be accessed");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");