[core] don't hide icons if text is an empty string

src/mbgl/layout/symbol_instance.cpp

@@ -12,6 +12,8 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
                                const SymbolLayoutProperties::Evaluated& layout,
                                const float layoutTextSize,
                                const uint32_t index_,
+                               const bool hasText_,
+                               const bool hasIcon_,
                                const float textBoxScale,
                                const float textPadding,
                                const SymbolPlacementType textPlacement,
@@ -27,8 +29,10 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
     anchor(anchor_),
     line(line_),
     index(index_),
-    hasText(shapedTextOrientations.first || shapedTextOrientations.second),
-    hasIcon(shapedIcon),
+    hasText(hasText_),
+    hasIcon(hasIcon_),
+    hasTextData(shapedTextOrientations.first || shapedTextOrientations.second),
+    hasIconData(shapedIcon),
 
     // Create the collision features that will be used to check whether this symbol instance can be placed
     textCollisionFeature(line_, anchor, shapedTextOrientations.first, textBoxScale, textPadding, textPlacement, indexedFeature, overscaling),

src/mbgl/layout/symbol_instance.hpp

@@ -20,6 +20,8 @@ class SymbolInstance {
                    const style::SymbolLayoutProperties::Evaluated&,
                    const float layoutTextSize,
                    const uint32_t index,
+                   const bool hasText,
+                   const bool hasIcon,
                    const float textBoxScale,
                    const float textPadding,
                    style::SymbolPlacementType textPlacement,
@@ -38,6 +40,8 @@ class SymbolInstance {
     uint32_t index;
     bool hasText;
     bool hasIcon;
+    bool hasTextData;
+    bool hasIconData;
     SymbolQuads horizontalGlyphQuads;
     SymbolQuads verticalGlyphQuads;
     optional<SymbolQuad> iconQuad;

src/mbgl/layout/symbol_layout.cpp

@@ -323,6 +323,7 @@ void SymbolLayout::addFeature(const std::size_t index,
             symbolInstances.emplace_back(anchor, line, shapedTextOrientations, shapedIcon,
                     layout.evaluate(zoom, feature), layoutTextSize,
                     symbolInstances.size(),
+                    bool(feature.text), bool(feature.icon),
                     textBoxScale, textPadding, textPlacement, textOffset,
                     iconBoxScale, iconPadding, iconOffset,
                     glyphPositionMap, indexedFeature, index, feature.text.value_or(std::u16string()), overscaling);
@@ -428,14 +429,14 @@ std::unique_ptr<SymbolBucket> SymbolLayout::place(const bool showCollisionBoxes)
 
     for (SymbolInstance &symbolInstance : bucket->symbolInstances) {
 
-        const bool hasText = symbolInstance.hasText;
-        const bool hasIcon = symbolInstance.hasIcon;
+        const bool hasTextData = symbolInstance.hasTextData;
+        const bool hasIconData = symbolInstance.hasIconData;
 
         const auto& feature = features.at(symbolInstance.featureIndex);
 
         // Insert final placement into collision tree and add glyphs/icons to buffers
 
-        if (hasText) {
+        if (hasTextData) {
             const Range<float> sizeData = bucket->textSizeBinder->getVertexSizeData(feature);
             bucket->text.placedSymbols.emplace_back(symbolInstance.anchor.point, symbolInstance.anchor.segment, sizeData.min, sizeData.max,
                     symbolInstance.textOffset, symbolInstance.writingModes, symbolInstance.line, CalculateTileDistances(symbolInstance.line, symbolInstance.anchor));
@@ -474,7 +475,7 @@ std::unique_ptr<SymbolBucket> SymbolLayout::place(const bool showCollisionBoxes)
             }
         }
 
-        if (hasIcon) {
+        if (hasIconData) {
             if (symbolInstance.iconQuad) {
                 const Range<float> sizeData = bucket->iconSizeBinder->getVertexSizeData(feature);
                 bucket->icon.placedSymbols.emplace_back(symbolInstance.anchor.point, symbolInstance.anchor.segment, sizeData.min, sizeData.max,

src/mbgl/text/placement.cpp

@@ -108,8 +108,8 @@ void Placement::placeLayerBucket(
                 continue;
             }
 
-            bool placeText = false;
-            bool placeIcon = false;
+            bool placeText = symbolInstance.hasText;
+            bool placeIcon = symbolInstance.hasIcon;
             bool offscreen = true;
 
             if (symbolInstance.placedTextIndex) {
@@ -149,11 +149,11 @@ void Placement::placeLayerBucket(
                 placeIcon = placeText && placeIcon;
             }
 
-            if (placeText) {
+            if (placeText && symbolInstance.hasTextData) {
                 collisionIndex.insertFeature(symbolInstance.textCollisionFeature, bucket.layout.get<style::TextIgnorePlacement>());
             }
 
-            if (placeIcon) {
+            if (placeIcon && symbolInstance.hasIconData) {
                 collisionIndex.insertFeature(symbolInstance.iconCollisionFeature, bucket.layout.get<style::IconIgnorePlacement>());
             }
 
@@ -249,7 +249,7 @@ void Placement::updateBucketOpacities(SymbolBucket& bucket, std::set<uint32_t>&
 
         seenCrossTileIDs.insert(symbolInstance.crossTileID);
 
-        if (symbolInstance.hasText) {
+        if (symbolInstance.hasTextData) {
             auto opacityVertex = SymbolOpacityAttributes::vertex(opacityState.text.placed, opacityState.text.opacity);
             for (size_t i = 0; i < symbolInstance.horizontalGlyphQuads.size() * 4; i++) {
                 bucket.text.opacityVertices.emplace_back(opacityVertex);
@@ -264,7 +264,7 @@ void Placement::updateBucketOpacities(SymbolBucket& bucket, std::set<uint32_t>&
                 bucket.text.placedSymbols[*symbolInstance.placedVerticalTextIndex].hidden = opacityState.isHidden();
             }
         }
-        if (symbolInstance.hasIcon) {
+        if (symbolInstance.hasIconData) {
             auto opacityVertex = SymbolOpacityAttributes::vertex(opacityState.icon.placed, opacityState.icon.opacity);
             if (symbolInstance.iconQuad) {
                 bucket.icon.opacityVertices.emplace_back(opacityVertex);

test/text/cross_tile_symbol_index.test.cpp

@@ -11,7 +11,7 @@ SymbolInstance makeSymbolInstance(float x, float y, std::u16string key) {
     style::SymbolLayoutProperties::Evaluated layout_;
     IndexedSubfeature subfeature(0, "", "", 0);
     Anchor anchor(x, y, 0, 0);
-    return {anchor, line, shaping, {}, layout_, 0, 0, 0, 0, style::SymbolPlacementType::Point, {{0, 0}}, 0, 0, {{0, 0}}, gpm, subfeature, 0, key, 0 };
+    return {anchor, line, shaping, {}, layout_, 0, 0, true, false, 0, 0, style::SymbolPlacementType::Point, {{0, 0}}, 0, 0, {{0, 0}}, gpm, subfeature, 0, key, 0 };
 }