Bug/stencil tiles (#1871)

include/mbgl/renderer/layer_group.hpp

@@ -13,10 +13,12 @@ namespace mbgl {
 class LayerGroupBase;
 class PaintParameters;
 class RenderOrchestrator;
+class RenderTile;
 class RenderTree;
 class TileLayerGroup;
 
 using LayerGroupBasePtr = std::shared_ptr<LayerGroupBase>;
+using RenderTiles = std::shared_ptr<const std::vector<std::reference_wrapper<const RenderTile>>>;
 
 namespace gfx {
 class Context;
@@ -127,9 +129,15 @@ class TileLayerGroup : public LayerGroupBase {
 
     std::size_t clearDrawables() override;
 
+    void setStencilTiles(RenderTiles);
+
 protected:
     struct Impl;
     std::unique_ptr<Impl> impl;
+
+    // When stencil clipping is enabled for the layer, this is the set
+    // of tile IDs that need to be rendered to the stencil buffer.
+    RenderTiles stencilTiles;
 };
 
 /**

src/mbgl/gl/layer_group_gl.cpp

@@ -62,31 +62,26 @@ void TileLayerGroupGL::render(RenderOrchestrator&, PaintParameters& parameters)
         const auto debugGroupClip = parameters.encoder->createDebugGroup(label_clip.c_str());
 #endif
 
-        // Collect the tile IDs relevant to stenciling and update the stencil buffer, if necessary.
-        std::set<UnwrappedTileID> tileIDs;
-        visitDrawables([&](const gfx::Drawable& drawable) {
-            if (!drawable.getEnabled() || !drawable.hasRenderPass(parameters.pass)) {
-                return;
-            }
-            if (drawable.getIs3D()) {
-                features3d = true;
-                if (drawable.getEnableStencil()) {
-                    stencil3d = true;
+        // If we're using stencil clipping, we need to handle 3D features separately
+        if (stencilTiles && !stencilTiles->empty()) {
+            visitDrawables([&](const gfx::Drawable& drawable) {
+                if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
+                    features3d = true;
+                    if (drawable.getEnableStencil()) {
+                        stencil3d = true;
+                    }
                 }
-            }
-            if (!features3d && drawable.getEnableStencil() && drawable.getTileID()) {
-                tileIDs.emplace(drawable.getTileID()->toUnwrapped());
-            }
-        });
+            });
+        }
 
         // If we're doing 3D stenciling and have any features
         // to draw, set up the single-value stencil mask.
         // If we're doing 2D stenciling and have any drawables with tile IDs,
         // render each tile into the stencil buffer with a different value.
         if (features3d) {
             stencilMode3d = stencil3d ? parameters.stencilModeFor3D() : gfx::StencilMode::disabled();
-        } else if (!tileIDs.empty()) {
-            parameters.renderTileClippingMasks(tileIDs);
+        } else if (stencilTiles && !stencilTiles->empty()) {
+            parameters.renderTileClippingMasks(stencilTiles);
         }
     }
 

src/mbgl/mtl/tile_layer_group.cpp

@@ -55,37 +55,25 @@ void TileLayerGroup::render(RenderOrchestrator&, PaintParameters& parameters) {
     bool stencil3d = false;
     gfx::StencilMode stencilMode3d;
 
-    // Collect the tile IDs relevant to stenciling and update the stencil buffer, if necessary.
-    std::set<UnwrappedTileID> tileIDs;
-    std::size_t numEnabled = 0;
-    visitDrawables([&](const gfx::Drawable& drawable) {
-        if (!drawable.getEnabled() || !drawable.hasRenderPass(parameters.pass)) {
-            return;
-        }
-        numEnabled += 1;
-        if (drawable.getIs3D()) {
-            features3d = true;
-            if (drawable.getEnableStencil()) {
-                stencil3d = true;
+    // If we're using stencil clipping, we need to handle 3D features separately
+    if (stencilTiles && !stencilTiles->empty()) {
+        visitDrawables([&](const gfx::Drawable& drawable) {
+            if (drawable.getEnabled() && drawable.getIs3D() && drawable.hasRenderPass(parameters.pass)) {
+                features3d = true;
+                if (drawable.getEnableStencil()) {
+                    stencil3d = true;
+                }
             }
-        }
-        if (!features3d && drawable.getEnableStencil() && drawable.getTileID()) {
-            tileIDs.emplace(drawable.getTileID()->toUnwrapped());
-        }
-    });
-
-    if (!numEnabled) {
-        return;
+        });
     }
 
 #if !defined(NDEBUG)
     const auto debugGroupRender = parameters.encoder->createDebugGroup(getName() + "-render");
 #endif
 
-    // If we're doing 3D stenciling and have any features
-    // to draw, set up the single-value stencil mask.
-    // If we're doing 2D stenciling and have any drawables with tile IDs,
-    // render each tile into the stencil buffer with a different value.
+    // If we're doing 3D stenciling and have any features to draw, set up the single-value stencil mask.
+    // If we're doing 2D stenciling and have any drawables with tile IDs, render each tile into the stencil buffer with
+    // a different value.
     MTLDepthStencilStatePtr stateWithStencil, stateWithoutStencil;
     if (features3d) {
         const auto depthMode = parameters.depthModeFor3D();
@@ -95,8 +83,8 @@ void TileLayerGroup::render(RenderOrchestrator&, PaintParameters& parameters) {
             encoder->setStencilReferenceValue(stencilMode3d.ref);
         }
         stateWithoutStencil = context.makeDepthStencilState(depthMode, gfx::StencilMode::disabled(), renderable);
-    } else if (!tileIDs.empty()) {
-        parameters.renderTileClippingMasks(tileIDs);
+    } else if (stencilTiles && !stencilTiles->empty()) {
+        parameters.renderTileClippingMasks(stencilTiles);
     }
 
     visitDrawables([&](gfx::Drawable& drawable) {

src/mbgl/renderer/layers/render_background_layer.cpp

@@ -204,10 +204,6 @@ void RenderBackgroundLayer::prepare(const LayerPrepareParameters& params) {
         addPatternIfNeeded(evaluated.get<BackgroundPattern>().from.id(), params);
         addPatternIfNeeded(evaluated.get<BackgroundPattern>().to.id(), params);
     }
-
-#if MLN_DRAWABLE_RENDERER
-    updateRenderTileIDs();
-#endif // MLN_DRAWABLE_RENDERER
 }
 
 #if MLN_DRAWABLE_RENDERER
@@ -290,9 +286,11 @@ void RenderBackgroundLayer::update(gfx::ShaderRegistry& shaders,
 
     std::unique_ptr<gfx::DrawableBuilder> builder;
 
-    tileLayerGroup->visitDrawables([&](gfx::Drawable& drawable) -> bool {
-        // Has this tile dropped out of the cover set?
-        return (!drawable.getTileID() || hasRenderTile(*drawable.getTileID()));
+    // Remove drawables for tiles that are no longer in the cover set.
+    // (Note that `RenderTiles` is empty, and this layer does not use it)
+    tileLayerGroup->removeDrawablesIf([&](gfx::Drawable& drawable) -> bool {
+        return drawable.getTileID() &&
+               (std::find(tileCover.begin(), tileCover.end(), *drawable.getTileID()) == tileCover.end());
     });
 
     // For each tile in the cover set, add a tile drawable if one doesn't already exist.

src/mbgl/renderer/layers/render_fill_extrusion_layer.cpp

@@ -347,6 +347,8 @@ void RenderFillExtrusionLayer::update(gfx::ShaderRegistry& shaders,
         return;
     }
 
+    tileLayerGroup->setStencilTiles(renderTiles);
+
     std::unordered_set<StringIdentity> propertiesAsUniforms;
     for (const RenderTile& tile : *renderTiles) {
         const auto& tileID = tile.getOverscaledTileID();
@@ -448,7 +450,6 @@ void RenderFillExtrusionLayer::update(gfx::ShaderRegistry& shaders,
             if (auto builder = context.createDrawableBuilder(layerPrefix + "depth")) {
                 builder->setShader(shader);
                 builder->setIs3D(true);
-                builder->setEnableStencil(false);
                 builder->setEnableColor(false);
                 builder->setRenderPass(drawPass);
                 builder->setCullFaceMode(gfx::CullFaceMode::backCCW());

src/mbgl/renderer/layers/render_fill_layer.cpp

@@ -364,6 +364,8 @@ void RenderFillLayer::update(gfx::ShaderRegistry& shaders,
         return tileID && !hasRenderTile(*tileID);
     });
 
+    tileLayerGroup->setStencilTiles(renderTiles);
+
     std::unordered_set<StringIdentity> propertiesAsUniforms;
     for (const RenderTile& tile : *renderTiles) {
         const auto& tileID = tile.getOverscaledTileID();
@@ -559,11 +561,13 @@ void RenderFillLayer::update(gfx::ShaderRegistry& shaders,
 
             if (!fillBuilder && fillShader) {
                 if (auto builder = context.createDrawableBuilder(layerPrefix + "fill")) {
+                    // Only write opaque fills to the depth buffer, matching `fillRenderPass` in legacy rendering
+                    const bool opaque = (evaluated.get<FillColor>().constantOr(Color()).a >= 1.0f &&
+                                         evaluated.get<FillOpacity>().constantOr(0) >= 1.0f);
+
                     commonInit(*builder);
-                    builder->setDepthType((renderPass == RenderPass::Opaque) ? gfx::DepthMaskType::ReadWrite
-                                                                             : gfx::DepthMaskType::ReadOnly);
-                    builder->setColorMode(renderPass == RenderPass::Translucent ? gfx::ColorMode::alphaBlended()
-                                                                                : gfx::ColorMode::unblended());
+                    builder->setDepthType(opaque ? gfx::DepthMaskType::ReadWrite : gfx::DepthMaskType::ReadOnly);
+                    builder->setColorMode(opaque ? gfx::ColorMode::unblended() : gfx::ColorMode::alphaBlended());
                     builder->setSubLayerIndex(1);
                     builder->setRenderPass(renderPass);
                     fillBuilder = std::move(builder);

src/mbgl/renderer/layers/render_heatmap_layer.cpp

@@ -435,7 +435,6 @@ void RenderHeatmapLayer::update(gfx::ShaderRegistry& shaders,
         heatmapBuilder->setEnableDepth(false);
         heatmapBuilder->setColorMode(gfx::ColorMode::additive());
         heatmapBuilder->setCullFaceMode(gfx::CullFaceMode::disabled());
-        heatmapBuilder->setEnableStencil(false);
         heatmapBuilder->setRenderPass(renderPass);
         heatmapBuilder->setVertexAttributes(std::move(heatmapVertexAttrs));
         heatmapBuilder->setRawVertices({}, vertexCount, gfx::AttributeDataType::Short2);
@@ -509,7 +508,6 @@ void RenderHeatmapLayer::update(gfx::ShaderRegistry& shaders,
     heatmapTextureBuilder->setEnableDepth(false);
     heatmapTextureBuilder->setColorMode(gfx::ColorMode::alphaBlended());
     heatmapTextureBuilder->setCullFaceMode(gfx::CullFaceMode::disabled());
-    heatmapTextureBuilder->setEnableStencil(false);
     heatmapTextureBuilder->setRenderPass(renderPass);
     heatmapTextureBuilder->setVertexAttributes(std::move(textureVertexAttrs));
     heatmapTextureBuilder->setRawVertices({}, textureVertexCount, gfx::AttributeDataType::Short2);

src/mbgl/renderer/layers/render_line_layer.cpp

@@ -461,6 +461,8 @@ void RenderLineLayer::update(gfx::ShaderRegistry& shaders,
         builder->setSegments(gfx::Triangles(), bucket.sharedTriangles, bucket.segments.data(), bucket.segments.size());
     };
 
+    tileLayerGroup->setStencilTiles(renderTiles);
+
     std::unordered_set<StringIdentity> propertiesAsUniforms;
     for (const RenderTile& tile : *renderTiles) {
         const auto& tileID = tile.getOverscaledTileID();

src/mbgl/renderer/layers/render_symbol_layer.cpp

@@ -1055,7 +1055,6 @@ void RenderSymbolLayer::update(gfx::ShaderRegistry& shaders,
 
     std::unique_ptr<gfx::DrawableBuilder> collisionBuilder = context.createDrawableBuilder(layerCollisionPrefix);
     collisionBuilder->setSubLayerIndex(0);
-    collisionBuilder->setEnableStencil(false);
     collisionBuilder->setEnableDepth(false);
     collisionBuilder->setRenderPass(passes);
     collisionBuilder->setCullFaceMode(gfx::CullFaceMode::disabled());
@@ -1316,7 +1315,6 @@ void RenderSymbolLayer::update(gfx::ShaderRegistry& shaders,
                 if (!builder) {
                     builder = context.createDrawableBuilder(layerPrefix);
                     builder->setSubLayerIndex(0);
-                    builder->setEnableStencil(false);
                     builder->setRenderPass(passes);
                     builder->setCullFaceMode(gfx::CullFaceMode::disabled());
                     builder->setDepthType(gfx::DepthMaskType::ReadOnly);

src/mbgl/renderer/paint_parameters.cpp

@@ -101,7 +101,9 @@ using GetTileIDFunc = const UnwrappedTileID& (*)(const typename TIter::value_typ
 
 using TileMaskIDMap = std::map<UnwrappedTileID, int32_t>;
 
-// `std::includes` adapted to extract tile IDs from arbitrary collection iterators
+// `std::includes` adapted to extract tile IDs from arbitrary collection iterators.
+// This is needed because, although it accepts iterators of different types, they must be:
+// "...such that an object of type InputIt can be dereferenced and then implicitly converted to both of them.​"
 template <class I1, class I2>
 bool includes(I1 beg1, const I1 end1, I2 beg2, const I2 end2, const GetTileIDFunc<I2>& unwrap) {
     for (; beg2 != end2; ++beg1) {
@@ -118,25 +120,20 @@ bool includes(I1 beg1, const I1 end1, I2 beg2, const I2 end2, const GetTileIDFun
     return true;
 }
 
+const UnwrappedTileID& unwrap(const RenderTiles::element_type::value_type& iter) {
+    return iter.get().id;
+}
+
 // Check whether the given set of tile IDs is a subset of the ones already rendered
-template <typename TIter>
-bool tileIDsCovered(TIter beg, TIter end, GetTileIDFunc<TIter>& unwrap, const TileMaskIDMap& idMap) {
-    if (idMap.size() < static_cast<std::size_t>(std::distance(beg, end))) {
+bool tileIDsCovered(const RenderTiles& tiles, const TileMaskIDMap& idMap) {
+    if (idMap.size() < tiles->size()) {
         return false;
     }
-    assert(std::is_sorted(beg, end, [=](const auto& a, const auto& b) { return unwrap(a) < unwrap(b); }));
-    return includes(idMap.cbegin(), idMap.cend(), beg, end, unwrap);
+    assert(std::is_sorted(
+        tiles->begin(), tiles->end(), [=](const auto& a, const auto& b) { return unwrap(a) < unwrap(b); }));
+    return includes(idMap.cbegin(), idMap.cend(), tiles->cbegin(), tiles->cend(), &unwrap);
 }
 
-#if MLN_LEGACY_RENDERER
-const UnwrappedTileID& unwrapRenderTiles(const RenderTiles::element_type::value_type& iter) {
-    return iter.get().id;
-}
-#else  // !MLN_LEGACY_RENDERER
-const UnwrappedTileID& unwrapIdentity(const UnwrappedTileID& value) {
-    return value;
-}
-#endif // MLN_LEGACY_RENDERER
 } // namespace
 
 void PaintParameters::clearStencil() {
@@ -164,35 +161,13 @@ void PaintParameters::clearStencil() {
 #endif
 }
 
-#if MLN_LEGACY_RENDERER
 void PaintParameters::renderTileClippingMasks(const RenderTiles& renderTiles) {
-    renderTileClippingMasks((*renderTiles).cbegin(), (*renderTiles).cend(), &unwrapRenderTiles);
-}
-#else  // !MLN_LEGACY_RENDERER
-void PaintParameters::renderTileClippingMasks(const std::set<UnwrappedTileID>& tileIDs) {
-    renderTileClippingMasks(tileIDs.cbegin(), tileIDs.cend(), &unwrapIdentity);
-}
-#endif // MLN_LEGACY_RENDERER
-
-void PaintParameters::clearTileClippingMasks() {
-    if (!tileClippingMaskIDs.empty()) {
-        clearStencil();
-    }
-}
-
-template <typename TIter>
-void PaintParameters::renderTileClippingMasks(TIter beg, TIter end, GetTileIDFunc<TIter> unwrap) {
-    if (!renderPass) {
-        assert(false);
-        return;
-    }
-
-    if (tileIDsCovered(beg, end, unwrap, tileClippingMaskIDs)) {
-        // The current stencil mask is for this source already; no need to draw another one.
+    // If the current stencil mask covers this source already, there's no need to draw another one.
+    if (!renderTiles || !renderPass || tileIDsCovered(renderTiles, tileClippingMaskIDs)) {
         return;
     }
 
-    const auto count = std::distance(beg, end);
+    const auto count = renderTiles->size();
     if (nextStencilID + count > maxStencilValue) {
         // we'll run out of fresh IDs so we need to clear and start from scratch
         clearStencil();
@@ -201,8 +176,8 @@ void PaintParameters::renderTileClippingMasks(TIter beg, TIter end, GetTileIDFun
 #if MLN_RENDER_BACKEND_METAL
     // Assign a stencil ID and build a UBO for each tile in the set
     std::vector<shaders::ClipUBO> tileUBOs;
-    for (auto i = beg; i != end; ++i) {
-        const auto& tileID = unwrap(*i);
+    for (const auto& tileRef : *renderTiles) {
+        const auto& tileID = tileRef.get().id;
 
         const int32_t stencilID = nextStencilID;
         const auto result = tileClippingMaskIDs.insert(std::make_pair(tileID, stencilID));
@@ -215,7 +190,7 @@ void PaintParameters::renderTileClippingMasks(TIter beg, TIter end, GetTileIDFun
         }
 
         if (tileUBOs.empty()) {
-            tileUBOs.reserve(std::distance(beg, end));
+            tileUBOs.reserve(count);
         }
 
         tileUBOs.emplace_back(shaders::ClipUBO{/*.matrix=*/util::cast<float>(matrixForTile(tileID)),
@@ -248,8 +223,8 @@ void PaintParameters::renderTileClippingMasks(TIter beg, TIter end, GetTileIDFun
     const style::Properties<>::PossiblyEvaluated properties{};
     const ClippingMaskProgram::Binders paintAttributeData(properties, 0);
 
-    for (auto i = beg; i != end; ++i) {
-        const auto& tileID = unwrap(*i);
+    for (const auto& tileRef : *renderTiles) {
+        const auto& tileID = tileRef.get().id;
 
         const int32_t stencilID = nextStencilID;
         const auto result = tileClippingMaskIDs.insert(std::make_pair(tileID, stencilID));

src/mbgl/renderer/paint_parameters.hpp

@@ -95,14 +95,7 @@ class PaintParameters {
 
     // Stencil handling
 public:
-#if MLN_LEGACY_RENDERER
     void renderTileClippingMasks(const RenderTiles&);
-#else
-    void renderTileClippingMasks(const std::set<UnwrappedTileID>&);
-#endif // MLN_LEGACY_RENDERER
-
-    /// Clear any tile masks and the stencil buffer, if necessary
-    void clearTileClippingMasks();
 
     /// Clear the stencil buffer, even if there are no tile masks (for 3D)
     void clearStencil();

src/mbgl/renderer/sources/render_tile_source.cpp

@@ -68,7 +68,6 @@ void TileSourceRenderItem::updateDebugDrawables(DebugLayerGroupMap& debugLayerGr
     builder->setEnableDepth(false);
     builder->setColorMode(gfx::ColorMode::unblended());
     builder->setCullFaceMode(gfx::CullFaceMode::disabled());
-    builder->setEnableStencil(false);
     builder->setVertexAttrNameId(idVertexAttribName);
 
     // add or get the layer group for a debug type

src/mbgl/renderer/tile_layer_group.cpp

@@ -142,4 +142,8 @@ std::size_t TileLayerGroup::clearDrawables() {
     return count;
 }
 
+void TileLayerGroup::setStencilTiles(RenderTiles tiles) {
+    stencilTiles = std::move(tiles);
+}
+
 } // namespace mbgl