[core] only update the render order array when there are changes to tiles

4 files changed, 31 insertions, 22 deletions

diff --git a/src/mbgl/map/map_context.cpp b/src/mbgl/map/map_context.cpp
index 8935457ca5..9f803c87c9 100644
--- a/src/mbgl/map/map_context.cpp
+++ b/src/mbgl/map/map_context.cpp
@@ -242,7 +242,11 @@ bool MapContext::renderSync(const TransformState& state, const FrameData& frame)
     // Cleanup OpenGL objects that we abandoned since the last render call.
     glObjectStore.performCleanup();
 
-    if (!painter) painter = std::make_unique<Painter>(data);
+    if (!painter) {
+        painter = std::make_unique<Painter>(data);
+        painter->updateRenderOrder(*style);
+    }
+
     painter->render(*style, transformState, frame);
 
     if (data.mode == MapMode::Still) {
@@ -314,6 +318,10 @@ void MapContext::setSprite(const std::string& name, std::shared_ptr<const Sprite
 void MapContext::onTileDataChanged() {
     assert(util::ThreadContext::currentlyOn(util::ThreadType::Map));
 
+    if (painter) {
+        painter->updateRenderOrder(*style);
+    }
+
     updateFlags |= Update::Repaint;
     asyncUpdate->send();
 }
diff --git a/src/mbgl/map/source.cpp b/src/mbgl/map/source.cpp
index a6fd9665bb..569109a998 100644
--- a/src/mbgl/map/source.cpp
+++ b/src/mbgl/map/source.cpp
@@ -527,9 +527,14 @@ bool Source::update(MapData& data,
 }
 
 void Source::updateTilePtrs() {
-    tilePtrs.clear();
+    std::vector<Tile*> newPtrs;
     for (const auto& pair : tiles) {
-        tilePtrs.push_back(pair.second.get());
+        newPtrs.push_back(pair.second.get());
+    }
+
+    if (tilePtrs != newPtrs) {
+        tilePtrs.swap(newPtrs);
+        emitTileLoaded(true);
     }
 }
 
diff --git a/src/mbgl/renderer/painter.cpp b/src/mbgl/renderer/painter.cpp
index b947ff24a0..788e290f63 100644
--- a/src/mbgl/renderer/painter.cpp
+++ b/src/mbgl/renderer/painter.cpp
@@ -146,9 +146,6 @@ void Painter::render(const Style& style, TransformState state_, const FrameData&
     resize();
     changeMatrix();
 
-    // Figure out what buckets we have to draw and what order we have to draw them in.
-    const auto order = determineRenderOrder(style);
-
     // - UPLOAD PASS -------------------------------------------------------------------------------
     // Uploads all required buffers and images before we do any actual rendering.
     {
@@ -167,7 +164,6 @@ void Painter::render(const Style& style, TransformState state_, const FrameData&
         }
     }
 
-
     // - CLIPPING MASKS ----------------------------------------------------------------------------
     // Draws the clipping masks to the stencil buffer.
     {
@@ -241,6 +237,8 @@ void Painter::renderPass(RenderPass pass_,
                          GLsizei i, int8_t increment) {
     pass = pass_;
 
+    const double zoom = state.getZoom();
+
     MBGL_DEBUG_GROUP(pass == RenderPass::Opaque ? "opaque" : "translucent");
 
     if (debug::renderTree) {
@@ -254,6 +252,13 @@ void Painter::renderPass(RenderPass pass_,
         currentLayer = i;
         const auto& item = *it;
         if (item.bucket && item.tile) {
+            // Skip this layer if it's outside the range of min/maxzoom.
+            // This may occur when there /is/ a bucket created for this layer, but the min/max-zoom
+            // is set to a fractional value, or value that is larger than the source maxzoom.
+            if (item.layer.minZoom > zoom ||
+                item.layer.maxZoom <= zoom) {
+                continue;
+            }
             if (item.layer.hasRenderPass(pass)) {
                 MBGL_DEBUG_GROUP(item.layer.id + " - " + std::string(item.tile->id));
                 prepareTile(*item.tile);
@@ -270,8 +275,8 @@ void Painter::renderPass(RenderPass pass_,
     }
 }
 
-std::vector<RenderItem> Painter::determineRenderOrder(const Style& style) {
-    std::vector<RenderItem> order;
+void Painter::updateRenderOrder(const Style& style) {
+    order.clear();
 
     for (const auto& layerPtr : style.layers) {
         const auto& layer = *layerPtr;
@@ -300,15 +305,6 @@ std::vector<RenderItem> Painter::determineRenderOrder(const Style& style) {
             continue;
         }
 
-        // Skip this layer if it's outside the range of min/maxzoom.
-        // This may occur when there /is/ a bucket created for this layer, but the min/max-zoom
-        // is set to a fractional value, or value that is larger than the source maxzoom.
-        const double zoom = state.getZoom();
-        if (layer.minZoom > zoom ||
-            layer.maxZoom <= zoom) {
-            continue;
-        }
-
         const auto& tiles = source->getTiles();
         for (auto tile : tiles) {
             assert(tile);
@@ -341,8 +337,6 @@ std::vector<RenderItem> Painter::determineRenderOrder(const Style& style) {
             }
         }
     }
-
-    return order;
 }
 
 void Painter::renderBackground(const BackgroundLayer& layer) {
diff --git a/src/mbgl/renderer/painter.hpp b/src/mbgl/renderer/painter.hpp
index 8f63388461..28008c5ac5 100644
--- a/src/mbgl/renderer/painter.hpp
+++ b/src/mbgl/renderer/painter.hpp
@@ -134,13 +134,13 @@ public:
 
     bool needsAnimation() const;
 
+    void updateRenderOrder(const Style& style);
+
 private:
     void setup();
     void setupShaders();
     mat4 translatedMatrix(const mat4& matrix, const std::array<float, 2> &translation, const TileID &id, TranslateAnchorType anchor);
 
-    std::vector<RenderItem> determineRenderOrder(const Style& style);
-
     template <class Iterator>
     void renderPass(RenderPass,
                     Iterator it, Iterator end,
@@ -198,6 +198,8 @@ private:
     float depthRangeSize;
     const float depthEpsilon = 1.0f / (1 << 16);
 
+    std::vector<RenderItem> order;
+
 public:
     FrameHistory frameHistory;