[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, 23 insertions, 20 deletions

diff --git a/src/mbgl/renderer/layers/render_raster_layer.cpp b/src/mbgl/renderer/layers/render_raster_layer.cpp
index 8a1a8a6c28..047333d5e5 100644
--- a/src/mbgl/renderer/layers/render_raster_layer.cpp
+++ b/src/mbgl/renderer/layers/render_raster_layer.cpp
@@ -16,7 +16,7 @@ using namespace style;
 
 namespace {
 
-inline const RasterLayer::Impl& impl(const Immutable<style::Layer::Impl>& impl) {
+inline const RasterLayer::Impl& impl_cast(const Immutable<style::Layer::Impl>& impl) {
     assert(impl->getTypeInfo() == RasterLayer::Impl::staticTypeInfo());
     return static_cast<const RasterLayer::Impl&>(*impl);
 }
@@ -25,13 +25,12 @@ inline const RasterLayer::Impl& impl(const Immutable<style::Layer::Impl>& impl)
 
 RenderRasterLayer::RenderRasterLayer(Immutable<style::RasterLayer::Impl> _impl)
     : RenderLayer(makeMutable<RasterLayerProperties>(std::move(_impl))),
-      unevaluated(impl(baseImpl).paint.untransitioned()) {
-}
+      unevaluated(impl_cast(baseImpl).paint.untransitioned()) {}
 
 RenderRasterLayer::~RenderRasterLayer() = default;
 
 void RenderRasterLayer::transition(const TransitionParameters& parameters) {
-    unevaluated = impl(baseImpl).paint.transitioned(parameters, std::move(unevaluated));
+    unevaluated = impl_cast(baseImpl).paint.transitioned(parameters, std::move(unevaluated));
 }
 
 void RenderRasterLayer::evaluate(const PropertyEvaluationParameters& parameters) {
@@ -153,14 +152,14 @@ void RenderRasterLayer::render(PaintParameters& parameters) {
         size_t i = 0;
         for (const auto& matrix_ : imageData->matrices) {
             draw(matrix_,
-                *bucket.vertexBuffer,
-                *bucket.indexBuffer,
-                bucket.segments,
-                RasterProgram::TextureBindings{
-                    textures::image0::Value{ bucket.texture->getResource(), filter },
-                    textures::image1::Value{ bucket.texture->getResource(), filter },
-                },
-                bucket.drawScopeID + std::to_string(i++));
+                 *bucket.vertexBuffer,
+                 *bucket.indexBuffer,
+                 bucket.segments,
+                 RasterProgram::TextureBindings{
+                     textures::image0::Value{bucket.texture->getResource(), filter},
+                     textures::image1::Value{bucket.texture->getResource(), filter},
+                 },
+                 std::to_string(i++));
         }
     } else if (renderTiles) {
         for (const RenderTile& tile : *renderTiles) {
@@ -174,28 +173,32 @@ void RenderRasterLayer::render(PaintParameters& parameters) {
                 continue;
 
             assert(bucket.texture);
-            if (bucket.vertexBuffer && bucket.indexBuffer && !bucket.segments.empty()) {
+            if (bucket.vertexBuffer && bucket.indexBuffer) {
                 // Draw only the parts of the tile that aren't drawn by another tile in the layer.
                 draw(parameters.matrixForTile(tile.id, true),
                      *bucket.vertexBuffer,
                      *bucket.indexBuffer,
                      bucket.segments,
                      RasterProgram::TextureBindings{
-                         textures::image0::Value{ bucket.texture->getResource(), filter },
-                         textures::image1::Value{ bucket.texture->getResource(), filter },
+                         textures::image0::Value{bucket.texture->getResource(), filter},
+                         textures::image1::Value{bucket.texture->getResource(), filter},
                      },
-                     bucket.drawScopeID);
+                     "image");
             } else {
                 // Draw the full tile.
+                if (bucket.segments.empty()) {
+                    // Copy over the segments so that we can create our own DrawScopes.
+                    bucket.segments = parameters.staticData.rasterSegments();
+                }
                 draw(parameters.matrixForTile(tile.id, true),
                      *parameters.staticData.rasterVertexBuffer,
                      *parameters.staticData.quadTriangleIndexBuffer,
-                     parameters.staticData.rasterSegments,
+                     bucket.segments,
                      RasterProgram::TextureBindings{
-                         textures::image0::Value{ bucket.texture->getResource(), filter },
-                         textures::image1::Value{ bucket.texture->getResource(), filter },
+                         textures::image0::Value{bucket.texture->getResource(), filter},
+                         textures::image1::Value{bucket.texture->getResource(), filter},
                      },
-                     bucket.drawScopeID);
+                     "image");
             }
         }
     }