[core] Switch from background to foreground placement

 - Background placement code now just generates static symbol buffers
 - Don't render GeometryTiles until their symbols are loaded. This is necessary for the CrossTileSymbolIndex to successfully prevent flicker.
 - SymbolInstances are transferred to SymbolBucket for use on foreground during collision detection
 - Symbols are sorted on foreground by sorting their index buffer but leaving vertex buffers intact (only works within one segment)
 - Vertical glyphs are generated at same time as horizontal glyphs. `reprojectLineLabels` chooses which one to use at render time and hides the other.
 - Icons are now always represented with a single collision box, even if they're placed along a line (this means their rotation alignment may be wrong, but the approach of representing them with multiple collision boxes wasn't very accurate either).
 - Generate vertices for new debug collision boxes and collision circles
 - Only add symbols within tile boundaries (reduces work, avoids double-draw)
 - Update symbol_projection.cpp to support line label projection calls from CollisionIndex.

1 files changed, 6 insertions, 1 deletions

diff --git a/src/mbgl/renderer/renderer_impl.hpp b/src/mbgl/renderer/renderer_impl.hpp
index 720e01ed53..e4cc893d07 100644
--- a/src/mbgl/renderer/renderer_impl.hpp
+++ b/src/mbgl/renderer/renderer_impl.hpp
@@ -11,6 +11,7 @@
 #include <mbgl/map/transform_state.hpp>
 #include <mbgl/map/zoom_history.hpp>
 #include <mbgl/text/glyph_manager_observer.hpp>
+#include <mbgl/text/placement.hpp>
 
 #include <memory>
 #include <string>
@@ -31,6 +32,7 @@ class Scheduler;
 class GlyphManager;
 class ImageManager;
 class LineAtlas;
+class CrossTileSymbolIndex;
 
 class Renderer::Impl : public GlyphManagerObserver,
                        public RenderSourceObserver{
@@ -56,7 +58,7 @@ public:
 
 private:
     bool isLoaded() const;
-    bool hasTransitions() const;
+    bool hasTransitions(TimePoint) const;
 
     RenderSource* getRenderSource(const std::string& id) const;
 
@@ -108,6 +110,9 @@ private:
     std::unordered_map<std::string, std::unique_ptr<RenderLayer>> renderLayers;
     RenderLight renderLight;
 
+    std::unique_ptr<CrossTileSymbolIndex> crossTileSymbolIndex;
+    std::unique_ptr<Placement> placement;
+
     bool contextLost = false;
 };