Preserve depth buffer between 3D layers + optimize render order (#9931)

Port of https://github.com/mapbox/mapbox-gl-js/pull/5101: adds a new render pass `Pass3D` before any other rendering wherein we render layers with 3D passes (fill-extrusion layers) to offscreen framebuffers, sharing a depth renderbuffer between those layers in order to render 3D space correctly. Those framebuffers are saved on the RenderLayers and copied back to the map during the translucent pass. Rendering to offscreen framebuffers before we do any clear + draw means we can avoid expensive framebuffer restores.

2 files changed, 5 insertions, 5 deletions

diff --git a/platform/qt/src/qmapboxgl.cpp b/platform/qt/src/qmapboxgl.cpp
index c7c4cf1e4a..e79c6af56a 100644
--- a/platform/qt/src/qmapboxgl.cpp
+++ b/platform/qt/src/qmapboxgl.cpp
@@ -1505,7 +1505,7 @@ QMapboxGLPrivate::QMapboxGLPrivate(QMapboxGL *q, const QMapboxGLSettings &settin
                                              static_cast<mbgl::GLContextMode>(settings.contextMode())),
             *this);
     connect(frontend.get(), SIGNAL(updated()), this, SLOT(invalidate()));
-    
+
     mapObj = std::make_unique<mbgl::Map>(
             *frontend,
             *this, sanitizedSize(size),
@@ -1528,18 +1528,18 @@ QMapboxGLPrivate::~QMapboxGLPrivate()
 {
 }
 
-mbgl::Size QMapboxGLPrivate::framebufferSize() const {
+mbgl::Size QMapboxGLPrivate::getFramebufferSize() const {
     return sanitizedSize(fbSize);
 }
 
 void QMapboxGLPrivate::updateAssumedState() {
     assumeFramebufferBinding(fbObject);
-    assumeViewport(0, 0, framebufferSize());
+    assumeViewport(0, 0, getFramebufferSize());
 }
 
 void QMapboxGLPrivate::bind() {
     setFramebufferBinding(fbObject);
-    setViewport(0, 0, framebufferSize());
+    setViewport(0, 0, getFramebufferSize());
 }
 
 void QMapboxGLPrivate::invalidate()
diff --git a/platform/qt/src/qmapboxgl_p.hpp b/platform/qt/src/qmapboxgl_p.hpp
index 7b0dd8c192..eb86870c10 100644
--- a/platform/qt/src/qmapboxgl_p.hpp
+++ b/platform/qt/src/qmapboxgl_p.hpp
@@ -20,10 +20,10 @@ public:
     explicit QMapboxGLPrivate(QMapboxGL *, const QMapboxGLSettings &, const QSize &size, qreal pixelRatio);
     virtual ~QMapboxGLPrivate();
 
-    mbgl::Size framebufferSize() const;
 
     // mbgl::RendererBackend implementation.
     void bind() final;
+    mbgl::Size getFramebufferSize() const final;
     void updateAssumedState() final;
     void activate() final {}
     void deactivate() final {}