[core] Store SegmentVectors in ephemeral render objects

We used some shared SegmentVectors, e.g. for drawing raster or background tiles.
In longer running maps, this lead to resource accumulation. By storing the SegmentVectors
and the contained gfx::DrawScope objects, we ensure that resources get released
when the associated render objects vanish.

1 files changed, 4 insertions, 5 deletions

diff --git a/src/mbgl/renderer/layers/render_line_layer.cpp b/src/mbgl/renderer/layers/render_line_layer.cpp
index 588cf6286c..90bb38b9f9 100644
--- a/src/mbgl/renderer/layers/render_line_layer.cpp
+++ b/src/mbgl/renderer/layers/render_line_layer.cpp
@@ -23,7 +23,7 @@ using namespace style;
 
 namespace {
 
-inline const LineLayer::Impl& impl(const Immutable<style::Layer::Impl>& impl) {
+inline const LineLayer::Impl& impl_cast(const Immutable<style::Layer::Impl>& impl) {
     assert(impl->getTypeInfo() == LineLayer::Impl::staticTypeInfo());
     return static_cast<const LineLayer::Impl&>(*impl);
 }
@@ -32,14 +32,13 @@ inline const LineLayer::Impl& impl(const Immutable<style::Layer::Impl>& impl) {
 
 RenderLineLayer::RenderLineLayer(Immutable<style::LineLayer::Impl> _impl)
     : RenderLayer(makeMutable<LineLayerProperties>(std::move(_impl))),
-      unevaluated(impl(baseImpl).paint.untransitioned()),
-      colorRamp({256, 1}) {
-}
+      unevaluated(impl_cast(baseImpl).paint.untransitioned()),
+      colorRamp({256, 1}) {}
 
 RenderLineLayer::~RenderLineLayer() = default;
 
 void RenderLineLayer::transition(const TransitionParameters& parameters) {
-    unevaluated = impl(baseImpl).paint.transitioned(parameters, std::move(unevaluated));
+    unevaluated = impl_cast(baseImpl).paint.transitioned(parameters, std::move(unevaluated));
     updateColorRamp();
 }