From 313ba87fce2788ed441c3d3d377f828564e7b91c Mon Sep 17 00:00:00 2001
From: SamGondelman <samuel_gondelman@brown.edu>
Date: Mon, 1 Aug 2016 14:47:20 -0700
Subject: [PATCH] fade on texture load

---
 libraries/render-utils/src/MeshPartPayload.cpp | 15 +++++----------
 libraries/render-utils/src/MeshPartPayload.h   |  7 +++++--
 libraries/render-utils/src/Model.cpp           |  4 ++++
 3 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/libraries/render-utils/src/MeshPartPayload.cpp b/libraries/render-utils/src/MeshPartPayload.cpp
index da9ba50271..99fedefc99 100644
--- a/libraries/render-utils/src/MeshPartPayload.cpp
+++ b/libraries/render-utils/src/MeshPartPayload.cpp
@@ -329,8 +329,6 @@ ModelMeshPartPayload::ModelMeshPartPayload(Model* model, int _meshIndex, int par
 
     updateTransform(transform, offsetTransform);
     initCache();
-
-    _fadeStartTime = usecTimestampNow();
 }
 
 void ModelMeshPartPayload::initCache() {
@@ -357,7 +355,7 @@ void ModelMeshPartPayload::initCache() {
 float ModelMeshPartPayload::calcFadeRatio() const {
     const float FADE_TIME = 0.5f;
     float t =  std::min(((float)(usecTimestampNow() - _fadeStartTime)) / ((float)(FADE_TIME * USECS_PER_SECOND)), 1.0f);
-    return -0.5f * (cosf(M_PI*t) - 1.0f);
+    return -(cosf(M_PI_2*t) - 1.0f);
 }
 
 void ModelMeshPartPayload::notifyLocationChanged() {
@@ -495,9 +493,9 @@ void ModelMeshPartPayload::bindMesh(gpu::Batch& batch) const {
         batch.setInputStream(2, _drawMesh->getVertexStream().makeRangedStream(2));
     }
 
-    // TODO: Get rid of that extra call
-    if (!_hasColorAttrib) {
-        batch._glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
+    float fadeRatio = calcFadeRatio();
+    if (!_hasColorAttrib || fadeRatio < 1.0f) {
+        batch._glColor4f(1.0f, 1.0f, 1.0f, fadeRatio);
     }
 }
 
@@ -528,7 +526,7 @@ void ModelMeshPartPayload::bindTransform(gpu::Batch& batch, const ShapePipeline:
 void ModelMeshPartPayload::render(RenderArgs* args) const {
     PerformanceTimer perfTimer("ModelMeshPartPayload::render");
 
-    if (!_model->_readyWhenAdded || !_model->_isVisible) {
+    if (!_model->_readyWhenAdded || !_model->_isVisible || !_hasStartedFade) {
         return; // bail asap
     }
 
@@ -552,9 +550,6 @@ void ModelMeshPartPayload::render(RenderArgs* args) const {
     // apply material properties
     bindMaterial(batch, locations);
 
-    // model fading
-    batch._glColor4f(1.0f, 1.0f, 1.0f, calcFadeRatio());
-
     if (args) {
         args->_details._materialSwitches++;
     }
diff --git a/libraries/render-utils/src/MeshPartPayload.h b/libraries/render-utils/src/MeshPartPayload.h
index d5c59a7967..4be6132122 100644
--- a/libraries/render-utils/src/MeshPartPayload.h
+++ b/libraries/render-utils/src/MeshPartPayload.h
@@ -83,6 +83,9 @@ public:
 
     // Entity fade in
     float calcFadeRatio() const;
+    void startFade() { _fadeStartTime = usecTimestampNow(); }
+    bool hasStartedFade() { return _hasStartedFade; }
+    void setHasStartedFade(bool hasStartedFade) { _hasStartedFade = hasStartedFade; }
 
     // Render Item interface
     render::ItemKey getKey() const override;
@@ -104,8 +107,8 @@ public:
     bool _isBlendShaped{ false };
 
 private:
-    quint64 _fadeStartTime { usecTimestampNow() };
-    bool _hasFadeStarted { false };
+    quint64 _fadeStartTime { 0 };
+    bool _hasStartedFade { false };
 };
 
 namespace render {
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index b04a1d8023..cc7178587f 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -207,6 +207,10 @@ void Model::updateRenderItems() {
         render::PendingChanges pendingChanges;
         foreach (auto itemID, self->_modelMeshRenderItems.keys()) {
             pendingChanges.updateItem<ModelMeshPartPayload>(itemID, [modelTransform, modelMeshOffset, deleteGeometryCounter](ModelMeshPartPayload& data) {
+                if (!data.hasStartedFade() && data._model && data._model->isLoaded() && data._model->getGeometry()->areTexturesLoaded()) {
+                    data.startFade();
+                    data.setHasStartedFade(true);
+                }
                 // Ensure the model geometry was not reset between frames
                 if (data._model && data._model->isLoaded() && deleteGeometryCounter == data._model->_deleteGeometryCounter) {
                     // lazy update of cluster matrices used for rendering.  We need to update them here, so we can correctly update the bounding box.