Merge branch 'master' into new-labelling

Conflicts:
	src/mbgl/map/tile_parser.cpp
	src/mbgl/map/tile_parser.hpp
	src/mbgl/renderer/painter.hpp
	src/mbgl/renderer/painter_symbol.cpp
	src/mbgl/renderer/symbol_bucket.cpp
	src/mbgl/renderer/symbol_bucket.hpp
	src/mbgl/text/collision.cpp
	src/mbgl/text/collision.hpp
	src/mbgl/text/placement.cpp

1 files changed, 15 insertions, 1 deletions

diff --git a/src/mbgl/renderer/bucket.hpp b/src/mbgl/renderer/bucket.hpp
index a7b0f61a3b..711fc42384 100644
--- a/src/mbgl/renderer/bucket.hpp
+++ b/src/mbgl/renderer/bucket.hpp
@@ -1,6 +1,7 @@
 #ifndef MBGL_RENDERER_BUCKET
 #define MBGL_RENDERER_BUCKET
 
+#include <mbgl/renderer/render_pass.hpp>
 #include <mbgl/util/noncopyable.hpp>
 #include <mbgl/util/mat4.hpp>
 
@@ -12,10 +13,23 @@ class TileID;
 
 class Bucket : private util::noncopyable {
 public:
+    // As long as this bucket has a Prepare render pass, this function is getting called. Typically,
+    // this only happens once when the bucket is being rendered for the first time.
+    virtual void upload() = 0;
+
+    // Every time this bucket is getting rendered, this function is called. This happens either
+    // once or twice (for Opaque and Transparent render passes).
     virtual void render(Painter&, const StyleLayer&, const TileID&, const mat4&) = 0;
-    virtual bool hasData() const = 0;
+
     virtual ~Bucket() {}
 
+    inline bool needsUpload() const {
+        return !uploaded;
+    }
+
+protected:
+    bool uploaded = false;
+
 };
 
 }