1 files changed, 142 insertions, 0 deletions
diff --git a/intern/cycles/blender/object_cull.cpp b/intern/cycles/blender/object_cull.cpp
new file mode 100644
index 00000000000..c2493be26dd
--- /dev/null
+++ b/intern/cycles/blender/object_cull.cpp
@@ -0,0 +1,142 @@
+/*
+ * Copyright 2011-2016 Blender Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cstdlib>
+
+#include "scene/camera.h"
+
+#include "blender/object_cull.h"
+#include "blender/util.h"
+
+CCL_NAMESPACE_BEGIN
+
+BlenderObjectCulling::BlenderObjectCulling(Scene *scene, BL::Scene &b_scene)
+    : use_scene_camera_cull_(false),
+      use_camera_cull_(false),
+      camera_cull_margin_(0.0f),
+      use_scene_distance_cull_(false),
+      use_distance_cull_(false),
+      distance_cull_margin_(0.0f)
+{
+  if (b_scene.render().use_simplify()) {
+    PointerRNA cscene = RNA_pointer_get(&b_scene.ptr, "cycles");
+
+    use_scene_camera_cull_ = scene->camera->get_camera_type() != CAMERA_PANORAMA &&
+                             !b_scene.render().use_multiview() &&
+                             get_boolean(cscene, "use_camera_cull");
+    use_scene_distance_cull_ = scene->camera->get_camera_type() != CAMERA_PANORAMA &&
+                               !b_scene.render().use_multiview() &&
+                               get_boolean(cscene, "use_distance_cull");
+
+    camera_cull_margin_ = get_float(cscene, "camera_cull_margin");
+    distance_cull_margin_ = get_float(cscene, "distance_cull_margin");
+
+    if (distance_cull_margin_ == 0.0f) {
+      use_scene_distance_cull_ = false;
+    }
+  }
+}
+
+void BlenderObjectCulling::init_object(Scene *scene, BL::Object &b_ob)
+{
+  if (!use_scene_camera_cull_ && !use_scene_distance_cull_) {
+    return;
+  }
+
+  PointerRNA cobject = RNA_pointer_get(&b_ob.ptr, "cycles");
+
+  use_camera_cull_ = use_scene_camera_cull_ && get_boolean(cobject, "use_camera_cull");
+  use_distance_cull_ = use_scene_distance_cull_ && get_boolean(cobject, "use_distance_cull");
+
+  if (use_camera_cull_ || use_distance_cull_) {
+    /* Need to have proper projection matrix. */
+    scene->camera->update(scene);
+  }
+}
+
+bool BlenderObjectCulling::test(Scene *scene, BL::Object &b_ob, Transform &tfm)
+{
+  if (!use_camera_cull_ && !use_distance_cull_) {
+    return false;
+  }
+
+  /* Compute world space bounding box corners. */
+  float3 bb[8];
+  BL::Array<float, 24> boundbox = b_ob.bound_box();
+  for (int i = 0; i < 8; ++i) {
+    float3 p = make_float3(boundbox[3 * i + 0], boundbox[3 * i + 1], boundbox[3 * i + 2]);
+    bb[i] = transform_point(&tfm, p);
+  }
+
+  bool camera_culled = use_camera_cull_ && test_camera(scene, bb);
+  bool distance_culled = use_distance_cull_ && test_distance(scene, bb);
+
+  return ((camera_culled && distance_culled) || (camera_culled && !use_distance_cull_) ||
+          (distance_culled && !use_camera_cull_));
+}
+
+/* TODO(sergey): Not really optimal, consider approaches based on k-DOP in order
+ * to reduce number of objects which are wrongly considered visible.
+ */
+bool BlenderObjectCulling::test_camera(Scene *scene, float3 bb[8])
+{
+  Camera *cam = scene->camera;
+  const ProjectionTransform &worldtondc = cam->worldtondc;
+  float3 bb_min = make_float3(FLT_MAX, FLT_MAX, FLT_MAX),
+         bb_max = make_float3(-FLT_MAX, -FLT_MAX, -FLT_MAX);
+  bool all_behind = true;
+  for (int i = 0; i < 8; ++i) {
+    float3 p = bb[i];
+    float4 b = make_float4(p.x, p.y, p.z, 1.0f);
+    float4 c = make_float4(
+        dot(worldtondc.x, b), dot(worldtondc.y, b), dot(worldtondc.z, b), dot(worldtondc.w, b));
+    p = float4_to_float3(c / c.w);
+    if (c.z < 0.0f) {
+      p.x = 1.0f - p.x;
+      p.y = 1.0f - p.y;
+    }
+    if (c.z >= -camera_cull_margin_) {
+      all_behind = false;
+    }
+    bb_min = min(bb_min, p);
+    bb_max = max(bb_max, p);
+  }
+  if (all_behind) {
+    return true;
+  }
+  return (bb_min.x >= 1.0f + camera_cull_margin_ || bb_min.y >= 1.0f + camera_cull_margin_ ||
+          bb_max.x <= -camera_cull_margin_ || bb_max.y <= -camera_cull_margin_);
+}
+
+bool BlenderObjectCulling::test_distance(Scene *scene, float3 bb[8])
+{
+  float3 camera_position = transform_get_column(&scene->camera->get_matrix(), 3);
+  float3 bb_min = make_float3(FLT_MAX, FLT_MAX, FLT_MAX),
+         bb_max = make_float3(-FLT_MAX, -FLT_MAX, -FLT_MAX);
+
+  /* Find min & max points for x & y & z on bounding box */
+  for (int i = 0; i < 8; ++i) {
+    float3 p = bb[i];
+    bb_min = min(bb_min, p);
+    bb_max = max(bb_max, p);
+  }
+
+  float3 closest_point = max(min(bb_max, camera_position), bb_min);
+  return (len_squared(camera_position - closest_point) >
+          distance_cull_margin_ * distance_cull_margin_);
+}
+
+CCL_NAMESPACE_END