Alembic export: separated "writing Alembic mesh" from "writing mesh object"

I moved most of the `AbcMeshWriter` code to a new class
`AbcGenericMeshWriter`. The latter is an abstract class and does not
make any assumptions about the type of Blender object being written.
This makes it possible to write metaballs, curves, nurbs surfaces, etc.
as mesh to Alembic files.

The `AbcMeshWriter` class now is the concrete implementation of
`AbcGenericMeshWriter` for writing mesh objects.

Reviewers: sergey

Differential Revision: https://developer.blender.org/D4213

1 files changed, 51 insertions, 25 deletions

diff --git a/source/blender/alembic/intern/abc_mesh.cc b/source/blender/alembic/intern/abc_mesh.cc
index 9cc5edc505b..229f788f87c 100644
--- a/source/blender/alembic/intern/abc_mesh.cc
+++ b/source/blender/alembic/intern/abc_mesh.cc
@@ -289,10 +289,10 @@ static ModifierData *get_liquid_sim_modifier(Scene *scene, Object *ob)
 
 /* ************************************************************************** */
 
-AbcMeshWriter::AbcMeshWriter(Object *ob,
-                             AbcTransformWriter *parent,
-                             uint32_t time_sampling,
-                             ExportSettings &settings)
+AbcGenericMeshWriter::AbcGenericMeshWriter(Object *ob,
+                                           AbcTransformWriter *parent,
+                                           uint32_t time_sampling,
+                                           ExportSettings &settings)
     : AbcObjectWriter(ob, time_sampling, settings, parent)
 {
 	m_is_animated = isAnimated();
@@ -329,22 +329,15 @@ AbcMeshWriter::AbcMeshWriter(Object *ob,
 	}
 }
 
-AbcMeshWriter::~AbcMeshWriter()
+AbcGenericMeshWriter::~AbcGenericMeshWriter()
 {
 	if (m_subsurf_mod) {
 		m_subsurf_mod->mode &= ~eModifierMode_DisableTemporary;
 	}
 }
 
-bool AbcMeshWriter::isAnimated() const
+bool AbcGenericMeshWriter::isAnimated() const
 {
-	/* Check if object has shape keys. */
-	Mesh *me = static_cast<Mesh *>(m_object->data);
-
-	if (me->key) {
-		return true;
-	}
-
 	/* Test modifiers. */
 	ModifierData *md = static_cast<ModifierData *>(m_object->modifiers.first);
 
@@ -356,15 +349,15 @@ bool AbcMeshWriter::isAnimated() const
 		md = md->next;
 	}
 
-	return me->adt != NULL;
+	return false;
 }
 
-void AbcMeshWriter::setIsAnimated(bool is_animated)
+void AbcGenericMeshWriter::setIsAnimated(bool is_animated)
 {
 	m_is_animated = is_animated;
 }
 
-void AbcMeshWriter::do_write()
+void AbcGenericMeshWriter::do_write()
 {
 	/* We have already stored a sample for this object. */
 	if (!m_first_frame && !m_is_animated)
@@ -389,7 +382,7 @@ void AbcMeshWriter::do_write()
 	}
 }
 
-void AbcMeshWriter::writeMesh(struct Mesh *mesh)
+void AbcGenericMeshWriter::writeMesh(struct Mesh *mesh)
 {
 	std::vector<Imath::V3f> points, normals;
 	std::vector<int32_t> poly_verts, loop_counts;
@@ -455,7 +448,7 @@ void AbcMeshWriter::writeMesh(struct Mesh *mesh)
 	writeArbGeoParams(mesh);
 }
 
-void AbcMeshWriter::writeSubD(struct Mesh *mesh)
+void AbcGenericMeshWriter::writeSubD(struct Mesh *mesh)
 {
 	std::vector<float> crease_sharpness;
 	std::vector<Imath::V3f> points;
@@ -506,7 +499,7 @@ void AbcMeshWriter::writeSubD(struct Mesh *mesh)
 }
 
 template <typename Schema>
-void AbcMeshWriter::writeFaceSets(struct Mesh *me, Schema &schema)
+void AbcGenericMeshWriter::writeFaceSets(struct Mesh *me, Schema &schema)
 {
 	std::map< std::string, std::vector<int32_t> > geo_groups;
 	getGeoGroups(me, geo_groups);
@@ -520,17 +513,18 @@ void AbcMeshWriter::writeFaceSets(struct Mesh *me, Schema &schema)
 	}
 }
 
-Mesh *AbcMeshWriter::getFinalMesh(bool &r_needsfree)
+Mesh *AbcGenericMeshWriter::getFinalMesh(bool &r_needsfree)
 {
 	/* We don't want subdivided mesh data */
 	if (m_subsurf_mod) {
 		m_subsurf_mod->mode |= eModifierMode_DisableTemporary;
 	}
 
+	r_needsfree = false;
+
 	Scene *scene = DEG_get_evaluated_scene(m_settings.depsgraph);
 	Object *ob_eval = DEG_get_evaluated_object(m_settings.depsgraph, m_object);
-	struct Mesh *mesh = mesh_get_eval_final(m_settings.depsgraph, scene, ob_eval, CD_MASK_MESH);
-	r_needsfree = false;
+	struct Mesh *mesh = getEvaluatedMesh(scene, ob_eval, r_needsfree);
 
 	if (m_subsurf_mod) {
 		m_subsurf_mod->mode &= ~eModifierMode_DisableTemporary;
@@ -568,7 +562,7 @@ Mesh *AbcMeshWriter::getFinalMesh(bool &r_needsfree)
 	return mesh;
 }
 
-void AbcMeshWriter::writeArbGeoParams(struct Mesh *me)
+void AbcGenericMeshWriter::writeArbGeoParams(struct Mesh *me)
 {
 	if (m_is_liquid) {
 		/* We don't need anything more for liquid meshes. */
@@ -585,7 +579,7 @@ void AbcMeshWriter::writeArbGeoParams(struct Mesh *me)
 	}
 }
 
-void AbcMeshWriter::getVelocities(struct Mesh *mesh, std::vector<Imath::V3f> &vels)
+void AbcGenericMeshWriter::getVelocities(struct Mesh *mesh, std::vector<Imath::V3f> &vels)
 {
 	const int totverts = mesh->totvert;
 
@@ -609,7 +603,7 @@ void AbcMeshWriter::getVelocities(struct Mesh *mesh, std::vector<Imath::V3f> &ve
 	}
 }
 
-void AbcMeshWriter::getGeoGroups(
+void AbcGenericMeshWriter::getGeoGroups(
         struct Mesh *mesh,
         std::map<std::string, std::vector<int32_t> > &geo_groups)
 {
@@ -651,6 +645,38 @@ void AbcMeshWriter::getGeoGroups(
 	}
 }
 
+
+AbcMeshWriter::AbcMeshWriter(Object *ob,
+                             AbcTransformWriter *parent,
+                             uint32_t time_sampling,
+                             ExportSettings &settings)
+    : AbcGenericMeshWriter(ob, parent, time_sampling, settings)
+{}
+
+AbcMeshWriter::~AbcMeshWriter()
+{}
+
+struct Mesh *AbcMeshWriter::getEvaluatedMesh(struct Scene *scene_eval, struct Object *ob_eval,
+                                             bool &UNUSED(r_needsfree))
+{
+	return mesh_get_eval_final(m_settings.depsgraph, scene_eval, ob_eval, CD_MASK_MESH);
+}
+
+
+bool AbcMeshWriter::isAnimated() const
+{
+	Mesh *me = static_cast<Mesh *>(m_object->data);
+	if (me->key != NULL) {
+		return true;
+	}
+	if (me->adt != NULL) {
+		return true;
+	}
+
+	return AbcGenericMeshWriter::isAnimated();
+}
+
+
 /* ************************************************************************** */
 
 /* Some helpers for mesh generation */