1 files changed, 91 insertions, 0 deletions
diff --git a/src/mbgl/text/placement.hpp b/src/mbgl/text/placement.hpp
new file mode 100644
index 0000000000..bcc20f15a4
--- /dev/null
+++ b/src/mbgl/text/placement.hpp
@@ -0,0 +1,91 @@
+#pragma once
+
+#include <string>
+#include <unordered_map>
+#include <mbgl/util/chrono.hpp>
+#include <mbgl/text/collision_index.hpp>
+#include <mbgl/layout/symbol_projection.hpp>
+#include <unordered_set>
+
+namespace mbgl {
+
+class RenderSymbolLayer;
+class SymbolBucket;
+
+class OpacityState {
+public:
+    OpacityState(bool placed, bool offscreen);
+    OpacityState(const OpacityState& prevOpacityState, float increment, bool placed);
+    bool isHidden() const;
+    float opacity;
+    bool placed;
+};
+
+class JointOpacityState {
+public:
+    JointOpacityState(bool placedIcon, bool placedText, bool offscreen);
+    JointOpacityState(const JointOpacityState& prevOpacityState, float increment, bool placedIcon, bool placedText);
+    bool isHidden() const;
+    OpacityState icon;
+    OpacityState text;
+};
+
+class JointPlacement {
+public:
+    JointPlacement(bool text_, bool icon_, bool offscreen_)
+        : text(text_), icon(icon_), offscreen(offscreen_)
+    {}
+
+    const bool text;
+    const bool icon;
+    // offscreen = outside viewport, but within CollisionIndex::viewportPadding px of the edge
+    // Because these symbols aren't onscreen yet, we can skip the "fade in" animation,
+    // and if a subsequent viewport change brings them into view, they'll be fully
+    // visible right away.
+    const bool offscreen;
+};
+
+class Placement {
+public:
+    Placement(const TransformState&, MapMode mapMode);
+    void placeLayer(RenderSymbolLayer&, const mat4&, bool showCollisionBoxes);
+    bool commit(const Placement& prevPlacement, TimePoint);
+    void updateLayerOpacities(RenderSymbolLayer&);
+    JointOpacityState getOpacity(uint32_t crossTileSymbolID) const;
+    float symbolFadeChange(TimePoint now) const;
+    bool hasTransitions(TimePoint now) const;
+
+    const CollisionIndex& getCollisionIndex() const;
+
+    bool stillRecent(TimePoint now) const;
+    void setRecent(TimePoint now);
+    void setStale();
+private:
+
+    void placeLayerBucket(
+            SymbolBucket&,
+            const mat4& posMatrix,
+            const mat4& textLabelPlaneMatrix,
+            const mat4& iconLabelPlaneMatrix,
+            const float scale,
+            const float pixelRatio,
+            const bool showCollisionBoxes,
+            std::unordered_set<uint32_t>& seenCrossTileIDs,
+            const bool holdingForFade);
+
+    void updateBucketOpacities(SymbolBucket&, std::set<uint32_t>&);
+
+    CollisionIndex collisionIndex;
+
+    TransformState state;
+    MapMode mapMode;
+    TimePoint commitTime;
+
+    std::unordered_map<uint32_t, JointPlacement> placements;
+    std::unordered_map<uint32_t, JointOpacityState> opacities;
+
+    TimePoint recentUntil;
+    bool stale = false;
+};
+
+} // namespace mbgl