From df9791faaff2ca75b1e9dc36ab3500c983e1f8d7 Mon Sep 17 00:00:00 2001
From: Philip Rideout <philiprideout@gmail.com>
Date: Thu, 14 Mar 2019 09:59:55 -0700
Subject: [PATCH] gltf_viewer: add stats and view controls.

---
 libs/gltfio/include/gltfio/SimpleViewer.h | 49 +++++++++++++++++------
 samples/app/FilamentApp.cpp               |  2 +
 samples/app/FilamentApp.h                 |  3 ++
 samples/gltf_viewer.cpp                   |  8 ++++
 4 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/libs/gltfio/include/gltfio/SimpleViewer.h b/libs/gltfio/include/gltfio/SimpleViewer.h
index 24b4abd6df..744e44dc98 100644
--- a/libs/gltfio/include/gltfio/SimpleViewer.h
+++ b/libs/gltfio/include/gltfio/SimpleViewer.h
@@ -102,6 +102,11 @@ public:
      */
     int getSidebarWidth() const { return mSidebarWidth; }
 
+    /**
+     * Allows clients to inject custom UI.
+     */
+    void setUiCallback(std::function<void()> callback) { mCustomUI = callback; }
+
     static constexpr int INITIAL_SIDEBAR_WIDTH = 350;
 
 private:
@@ -116,6 +121,7 @@ private:
     utils::NameComponentManager* mNames = nullptr;
     Animator* mAnimator = nullptr;
     filament::IndirectLight* mIndirectLight = nullptr;
+    std::function<void()> mCustomUI;
 
     // Properties that can be changed from the UI.
     int mCurrentAnimation = 1;
@@ -125,6 +131,9 @@ private:
     bool mShowWireframe = false;
     bool mEnableSunlight = true;
     bool mEnableDithering = true;
+    bool mEnablePrepass = true;
+    bool mEnableFxaa = true;
+    bool mEnableMsaa = true;
     int mSidebarWidth = INITIAL_SIDEBAR_WIDTH;
 };
 
@@ -318,21 +327,35 @@ void SimpleViewer::updateUserInterface() {
     ImGui::SetNextWindowSizeConstraints(ImVec2(20, height), ImVec2(width, height));
 
     ImGui::Begin("Filament", nullptr, ImGuiWindowFlags_NoTitleBar);
+    if (mCustomUI) {
+        mCustomUI();
+    }
+
     if (ImGui::CollapsingHeader("View")) {
         ImGui::Checkbox("Dithering", &mEnableDithering);
-        auto mode = mEnableDithering ? View::Dithering::TEMPORAL : View::Dithering::NONE;
-        mView->setDithering(mode);
+        ImGui::Checkbox("Depth prepass", &mEnablePrepass);
+        ImGui::Checkbox("FXAA", &mEnableFxaa);
+        ImGui::Checkbox("MSAA 4x", &mEnableMsaa);
     }
+
+    mView->setDepthPrepass(
+            mEnablePrepass ? View::DepthPrepass::ENABLED : View::DepthPrepass::DISABLED);
+    mView->setDithering(mEnableDithering ? View::Dithering::TEMPORAL : View::Dithering::NONE);
+    mView->setAntiAliasing(mEnableFxaa ? View::AntiAliasing::FXAA : View::AntiAliasing::NONE);
+    mView->setSampleCount(mEnableMsaa ? 4 : 1);
+
     if (ImGui::CollapsingHeader("Light")) {
         ImGui::SliderFloat("IBL intensity", &mIblIntensity, 0.0f, 100000.0f);
         ImGui::SliderAngle("IBL rotation", &mIblRotation);
         ImGui::Checkbox("Sunlight", &mEnableSunlight);
-        if (mEnableSunlight) {
-            mScene->addEntity(mSunlight);
-        } else {
-            mScene->remove(mSunlight);
-        }
     }
+
+    if (mEnableSunlight) {
+        mScene->addEntity(mSunlight);
+    } else {
+        mScene->remove(mSunlight);
+    }
+
     if (ImGui::CollapsingHeader("Model", ImGuiTreeNodeFlags_DefaultOpen)) {
         if (mAnimator->getAnimationCount() > 0) {
             intptr_t animationsNodeId = -1;
@@ -343,13 +366,15 @@ void SimpleViewer::updateUserInterface() {
             }
         }
         ImGui::Checkbox("Wireframe", &mShowWireframe);
-        if (mShowWireframe) {
-            mScene->addEntity(mAsset->getWireframe());
-        } else {
-            mScene->remove(mAsset->getWireframe());
-        }
         treeNode(mAsset->getRoot());
     }
+
+    if (mShowWireframe) {
+        mScene->addEntity(mAsset->getWireframe());
+    } else {
+        mScene->remove(mAsset->getWireframe());
+    }
+
     mSidebarWidth = ImGui::GetWindowWidth();
     ImGui::End();
 
diff --git a/samples/app/FilamentApp.cpp b/samples/app/FilamentApp.cpp
index c81c456271..200d2d2de9 100644
--- a/samples/app/FilamentApp.cpp
+++ b/samples/app/FilamentApp.cpp
@@ -365,6 +365,8 @@ void FilamentApp::run(const Config& config, SetupCallback setupCallback,
                 renderer->render(view->getView());
             }
             renderer->endFrame();
+        } else {
+            ++mSkippedFrames;
         }
 
         if (postRender) {
diff --git a/samples/app/FilamentApp.h b/samples/app/FilamentApp.h
index 035b8770c1..dfa2474305 100644
--- a/samples/app/FilamentApp.h
+++ b/samples/app/FilamentApp.h
@@ -80,6 +80,8 @@ public:
 
     void setSidebarWidth(int width) { mSidebarWidth = width; }
 
+    size_t getSkippedFrameCount() const { return mSkippedFrames; }
+
     FilamentApp(const FilamentApp& rhs) = delete;
     FilamentApp(FilamentApp&& rhs) = delete;
     FilamentApp& operator=(const FilamentApp& rhs) = delete;
@@ -208,6 +210,7 @@ private:
     AnimCallback mAnimation;
     DropCallback mDropHandler;
     int mSidebarWidth = 0;
+    size_t mSkippedFrames = 0;
 };
 
 #endif // TNT_FILAMENT_SAMPLE_FILAMENTAPP_H
diff --git a/samples/gltf_viewer.cpp b/samples/gltf_viewer.cpp
index 5258dfefd3..767e1982e9 100644
--- a/samples/gltf_viewer.cpp
+++ b/samples/gltf_viewer.cpp
@@ -199,6 +199,14 @@ int main(int argc, char** argv) {
 
         loadResources(filename);
 
+        app.viewer->setUiCallback([&app, scene] () {
+            if (ImGui::CollapsingHeader("Stats")) {
+                ImGui::Text("%zu entities in the asset", app.asset->getEntityCount());
+                ImGui::Text("%zu renderables (excluding UI)", scene->getRenderableCount());
+                ImGui::Text("%zu skipped frames", FilamentApp::get().getSkippedFrameCount());
+            }
+        });
+
         // Leave FXAA enabled but we also enable MSAA for a nice result. The wireframe looks
         // much better with MSAA enabled.
         view->setSampleCount(4);