From b234fc525d070d85ccfc68c49dff3a4e3c32d965 Mon Sep 17 00:00:00 2001
From: Martin Dobias <wonder.sk@gmail.com>
Date: Thu, 10 Aug 2017 22:35:10 +0200
Subject: [PATCH] Correctly working "zoom full" + more robust near/far plane
 config

---
 src/3d/cameracontroller.cpp   |  8 ++++----
 src/3d/cameracontroller.h     |  2 +-
 src/3d/scene.cpp              | 30 ++++++++++++++++++++++++++++--
 src/3d/scene.h                |  2 ++
 src/app/3d/qgs3dmapcanvas.cpp |  4 +++-
 5 files changed, 38 insertions(+), 8 deletions(-)

diff --git a/src/3d/cameracontroller.cpp b/src/3d/cameracontroller.cpp
index a63edae11ab..7ac3ab3808d 100644
--- a/src/3d/cameracontroller.cpp
+++ b/src/3d/cameracontroller.cpp
@@ -240,12 +240,12 @@ void CameraController::frameTriggered( float dt )
   }
 }
 
-void CameraController::resetView()
+void CameraController::resetView( float distance )
 {
-  setCameraData( 0, 0, 1000 );
+  setCameraData( 0, 0, distance );
   // a basic setup to make frustum depth range long enough that it does not cull everything
-  mCamera->setNearPlane( 1 );
-  mCamera->setFarPlane( 10000 );
+  mCamera->setNearPlane( distance / 2 );
+  mCamera->setFarPlane( distance * 2 );
 
   emit cameraChanged();
 }
diff --git a/src/3d/cameracontroller.h b/src/3d/cameracontroller.h
index 14d96b16385..ec4d4a9c026 100644
--- a/src/3d/cameracontroller.h
+++ b/src/3d/cameracontroller.h
@@ -29,7 +29,7 @@ class _3D_EXPORT CameraController : public Qt3DCore::QEntity
     void frameTriggered( float dt );
 
     //! Move camera back to the initial position (looking down towards origin of world's coordinates)
-    void resetView();
+    void resetView( float distance );
 
   signals:
     void cameraChanged();
diff --git a/src/3d/scene.cpp b/src/3d/scene.cpp
index 484e2d4fe48..0e32e06ec70 100644
--- a/src/3d/scene.cpp
+++ b/src/3d/scene.cpp
@@ -58,7 +58,7 @@ Scene::Scene( const Map3D &map, Qt3DExtras::QForwardRenderer *defaultFrameGraph,
   mCameraController = new CameraController( this ); // attaches to the scene
   mCameraController->setViewport( viewportRect );
   mCameraController->setCamera( camera );
-  mCameraController->resetView();
+  mCameraController->resetView( 1000 );
 
   // create terrain entity
 
@@ -147,6 +147,13 @@ Scene::Scene( const Map3D &map, Qt3DExtras::QForwardRenderer *defaultFrameGraph,
   onCameraChanged();
 }
 
+void Scene::viewZoomFull()
+{
+  QgsRectangle extent = mMap.terrainGenerator()->extent();
+  float side = qMax( extent.width(), extent.height() );
+  mCameraController->resetView( side );  // assuming FOV being 45 degrees
+}
+
 SceneState _sceneState( CameraController *cameraController )
 {
   Qt3DRender::QCamera *camera = cameraController->camera();
@@ -187,6 +194,13 @@ void Scene::onCameraChanged()
     float far = 0;
 
     QList<ChunkNode *> activeNodes = mTerrain->getActiveNodes();
+
+    // it could be that there are no active nodes - they could be all culled or because root node
+    // is not yet loaded - we still need at least something to understand bounds of our scene
+    // so lets use the root node
+    if ( activeNodes.isEmpty() )
+      activeNodes << mTerrain->getRootNode();
+
     Q_FOREACH ( ChunkNode *node, activeNodes )
     {
       // project each corner of bbox to camera coordinates
@@ -206,14 +220,26 @@ void Scene::onCameraChanged()
           far = dst;
       }
     }
-    //qDebug() << "near/far" << near << far;
     if ( near < 1 )
       near = 1;  // does not really make sense to use negative far plane (behind camera)
 
+    if ( near == 1e9 && far == 0 )
+    {
+      // the update didn't work out... this should not happen
+      // well at least temprarily use some conservative starting values
+      qDebug() << "oops... this should not happen! couldn't determine near/far plane. defaulting to 1...1e9";
+      near = 1;
+      far = 1e9;
+    }
+
     // set near/far plane - with some tolerance in front/behind expected near/far planes
     camera->setFarPlane( far * 2 );
     camera->setNearPlane( near / 2 );
   }
+  else
+    qDebug() << "no terrain - not setting near/far plane";
+
+  //qDebug() << "camera near/far" << mCameraController->camera()->nearPlane() << mCameraController->camera()->farPlane();
 }
 
 void Scene::onFrameTriggered( float dt )
diff --git a/src/3d/scene.h b/src/3d/scene.h
index f19fdda0fcd..f6f404add10 100644
--- a/src/3d/scene.h
+++ b/src/3d/scene.h
@@ -39,6 +39,8 @@ class _3D_EXPORT Scene : public Qt3DCore::QEntity
     CameraController *cameraController() { return mCameraController; }
     Terrain *terrain() { return mTerrain; }
 
+    void viewZoomFull();
+
   private slots:
     void onCameraChanged();
     void onFrameTriggered( float dt );
diff --git a/src/app/3d/qgs3dmapcanvas.cpp b/src/app/3d/qgs3dmapcanvas.cpp
index 8e07c3d64dc..9c6ff826d96 100644
--- a/src/app/3d/qgs3dmapcanvas.cpp
+++ b/src/app/3d/qgs3dmapcanvas.cpp
@@ -55,9 +55,11 @@ void Qgs3DMapCanvas::setMap( Map3D *map )
 
   delete mMap;
   mMap = map;
+
+  resetView();
 }
 
 void Qgs3DMapCanvas::resetView()
 {
-  mScene->cameraController()->resetView();
+  mScene->viewZoomFull();
 }