From 3f688f92d343f74ca41f4ab026a340c71932a497 Mon Sep 17 00:00:00 2001
From: Brad Davis <bdavis@saintandreas.org>
Date: Mon, 14 Sep 2015 16:09:13 -0700
Subject: [PATCH] Don't do an O(N^2) operation on cluster matrices

---
 libraries/render-utils/src/Model.cpp | 31 +++++++++++++++++++++++-----
 libraries/render-utils/src/Model.h   |  1 +
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 4c9279c8fd..cfbcd0599a 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -798,7 +798,7 @@ namespace render {
             return payload->model->renderPart(args, payload->meshIndex, payload->partIndex, payload->transparent);
         }
     }
-
+    
    /* template <> const model::MaterialKey& shapeGetMaterialKey(const MeshPartPayload::Pointer& payload) {
         return payload->model->getPartMaterial(payload->meshIndex, payload->partIndex);
     }*/
@@ -829,6 +829,9 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
         auto renderData = MeshPartPayload::Pointer(renderItem);
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
         pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+            data.model->_needsUpdateClusterMatrices = true;
+        });
         _renderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
@@ -838,6 +841,9 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
         auto renderData = MeshPartPayload::Pointer(renderItem);
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
         pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+            data.model->_needsUpdateClusterMatrices = true;
+        });
         _renderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
@@ -860,6 +866,9 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
         renderPayload->addStatusGetters(statusGetters);
         pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+            data.model->_needsUpdateClusterMatrices = true;
+        });
         _renderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
@@ -870,6 +879,9 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
         renderPayload->addStatusGetters(statusGetters);
         pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+            data.model->_needsUpdateClusterMatrices = true;
+        });
         _renderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
@@ -1293,11 +1305,15 @@ void Model::simulateInternal(float deltaTime) {
     updateRig(deltaTime, parentTransform);
 }
 void Model::updateClusterMatrices() {
+    if (!_needsUpdateClusterMatrices) {
+        return;
+    }
+    _needsUpdateClusterMatrices = false;
     const FBXGeometry& geometry = _geometry->getFBXGeometry();
     glm::mat4 zeroScale(glm::vec4(0.0f, 0.0f, 0.0f, 0.0f),
-                        glm::vec4(0.0f, 0.0f, 0.0f, 0.0f),
-                        glm::vec4(0.0f, 0.0f, 0.0f, 0.0f),
-                        glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
+        glm::vec4(0.0f, 0.0f, 0.0f, 0.0f),
+        glm::vec4(0.0f, 0.0f, 0.0f, 0.0f),
+        glm::vec4(0.0f, 0.0f, 0.0f, 1.0f));
     auto cauterizeMatrix = _rig->getJointTransform(geometry.neckJointIndex) * zeroScale;
 
     glm::mat4 modelToWorld = glm::mat4_cast(_rotation);
@@ -1803,13 +1819,15 @@ bool Model::initWhenReady(render::ScenePointer scene) {
         segregateMeshGroups();
 
         render::PendingChanges pendingChanges;
-
         foreach (auto renderItem, _transparentRenderItems) {
             auto item = scene->allocateID();
             auto renderData = MeshPartPayload::Pointer(renderItem);
             auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
             _renderItems.insert(item, renderPayload);
             pendingChanges.resetItem(item, renderPayload);
+            pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+                data.model->_needsUpdateClusterMatrices = true;
+            });
         }
 
         foreach (auto renderItem, _opaqueRenderItems) {
@@ -1818,6 +1836,9 @@ bool Model::initWhenReady(render::ScenePointer scene) {
             auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderData);
             _renderItems.insert(item, renderPayload);
             pendingChanges.resetItem(item, renderPayload);
+            pendingChanges.updateItem<MeshPartPayload>(item, [&](MeshPartPayload& data) {
+                data.model->_needsUpdateClusterMatrices = true;
+            });
         }
         scene->enqueuePendingChanges(pendingChanges);
 
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index 348e5cf549..93b98da8b5 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -497,6 +497,7 @@ private:
     QMap<render::ItemID, render::PayloadPointer> _renderItems;
     bool _readyWhenAdded = false;
     bool _needsReload = true;
+    bool _needsUpdateClusterMatrices = true;
 
 protected:
     RigPointer _rig;