[Bf-blender-cvs] [5114a48fd7c] functions: correct usage of attribute offsets that are not available

[Jacques Lucke]

Commit: 5114a48fd7c048cbd9521e340b1e9bef03090aa8
Author: Jacques Lucke
Date:   Thu Jul 11 10:15:56 2019 +0200
Branches: functions
https://developer.blender.org/rB5114a48fd7c048cbd9521e340b1e9bef03090aa8

correct usage of attribute offsets that are not available

===================================================================

M	source/blender/simulations/bparticles/actions.cpp
M	source/blender/simulations/bparticles/attributes.hpp
M	source/blender/simulations/bparticles/emitters.cpp

===================================================================

diff --git a/source/blender/simulations/bparticles/actions.cpp b/source/blender/simulations/bparticles/actions.cpp
index 073df6faf83..8cc736687da 100644
--- a/source/blender/simulations/bparticles/actions.cpp
+++ b/source/blender/simulations/bparticles/actions.cpp
@@ -25,8 +25,8 @@ class ChangeDirectionAction : public Action {
   {
     ParticleSet particles = interface.particles();
     auto velocities = particles.attributes().get_float3("Velocity");
-    auto position_offsets = interface.attribute_offsets().get_float3("Position");
-    auto velocity_offsets = interface.attribute_offsets().get_float3("Velocity");
+    auto position_offsets = interface.attribute_offsets().try_get_float3("Position");
+    auto velocity_offsets = interface.attribute_offsets().try_get_float3("Velocity");
 
     auto caller = m_compute_inputs.get_caller(particles.attributes(), interface.event_info());
 
@@ -40,8 +40,13 @@ class ChangeDirectionAction : public Action {
       float3 direction = fn_out.get<float3>(0);
 
       velocities[pindex] = direction;
-      position_offsets[pindex] = direction * interface.remaining_time_in_step(pindex);
-      velocity_offsets[pindex] = float3(0);
+
+      if (position_offsets.has_value()) {
+        position_offsets.value()[pindex] = direction * interface.remaining_time_in_step(pindex);
+      }
+      if (velocity_offsets.has_value()) {
+        velocity_offsets.value()[pindex] = float3(0);
+      }
     }
 
     m_post_action->execute(interface);
diff --git a/source/blender/simulations/bparticles/attributes.hpp b/source/blender/simulations/bparticles/attributes.hpp
index 295a3676372..830e2435308 100644
--- a/source/blender/simulations/bparticles/attributes.hpp
+++ b/source/blender/simulations/bparticles/attributes.hpp
@@ -9,12 +9,14 @@
 #include "BLI_range.hpp"
 #include "BLI_small_set_vector.hpp"
 #include "BLI_array_allocator.hpp"
+#include "BLI_optional.hpp"
 
 namespace BParticles {
 
 using BLI::ArrayAllocator;
 using BLI::ArrayRef;
 using BLI::float3;
+using BLI::Optional;
 using BLI::Range;
 using BLI::SmallSetVector;
 using BLI::SmallVector;
@@ -130,6 +132,24 @@ class AttributesInfo {
     return m_indices.index(name.to_std_string());
   }
 
+  /**
+   * Get the index corresponding to an attribute with the given name and type.
+   * Returns -1 when the attribute does not exist.
+   */
+  bool attribute_index_try(StringRef name, AttributeType type) const
+  {
+    int index = this->attribute_index_try(name);
+    if (index == -1) {
+      return -1;
+    }
+    else if (this->type_of((uint)index) == type) {
+      return index;
+    }
+    else {
+      return -1;
+    }
+  }
+
   /**
    * Get the index corresponding to an attribute name.
    * Asserts when the attribute does not exist.
@@ -323,7 +343,8 @@ class AttributeArrays {
   void init_default(StringRef name);
 
   /**
-   * Get access do the underlying attribute arrays.
+   * Get access to the underlying attribute arrays.
+   * Asserts when the attribute does not exists.
    */
   ArrayRef<uint8_t> get_byte(uint index) const;
   ArrayRef<uint8_t> get_byte(StringRef name);
@@ -332,6 +353,14 @@ class AttributeArrays {
   ArrayRef<float3> get_float3(uint index) const;
   ArrayRef<float3> get_float3(StringRef name);
 
+  /**
+   * Get access to the arrays.
+   * Does not assert when the attribute does not exist.
+   */
+  Optional<ArrayRef<uint8_t>> try_get_byte(StringRef name);
+  Optional<ArrayRef<float>> try_get_float(StringRef name);
+  Optional<ArrayRef<float3>> try_get_float3(StringRef name);
+
   /**
    * Get a continuous slice of the attribute arrays.
    */
@@ -463,6 +492,39 @@ inline ArrayRef<float3> AttributeArrays::get_float3(StringRef name)
   return this->get_float3(this->attribute_index(name));
 }
 
+inline Optional<ArrayRef<uint8_t>> AttributeArrays::try_get_byte(StringRef name)
+{
+  int index = this->info().attribute_index_try(name, AttributeType::Byte);
+  if (index == -1) {
+    return {};
+  }
+  else {
+    return this->get_byte((uint)index);
+  }
+}
+
+inline Optional<ArrayRef<float>> AttributeArrays::try_get_float(StringRef name)
+{
+  int index = this->info().attribute_index_try(name, AttributeType::Float);
+  if (index == -1) {
+    return {};
+  }
+  else {
+    return this->get_float((uint)index);
+  }
+}
+
+inline Optional<ArrayRef<float3>> AttributeArrays::try_get_float3(StringRef name)
+{
+  int index = this->info().attribute_index_try(name, AttributeType::Float3);
+  if (index == -1) {
+    return {};
+  }
+  else {
+    return this->get_float3((uint)index);
+  }
+}
+
 inline AttributeArrays AttributeArrays::slice(uint start, uint size) const
 {
   return AttributeArrays(m_core, m_start + start, size);
diff --git a/source/blender/simulations/bparticles/emitters.cpp b/source/blender/simulations/bparticles/emitters.cpp
index 1c2ca82695c..c416782c4ba 100644
--- a/source/blender/simulations/bparticles/emitters.cpp
+++ b/source/blender/simulations/bparticles/emitters.cpp
@@ -33,6 +33,7 @@ class PointEmitter : public Emitter {
     auto target = interface.particle_allocator().request(m_particle_type_name, 1);
     target.set_float3("Position", {m_point});
     target.set_float3("Velocity", {float3{-1, -1, 0}});
+    target.fill_float("Size", 0.01f);
     target.fill_float("Birth Time", interface.time_span().end());
   }
 };