[core] Single line optimization for variable label placement

8 files changed, 50 insertions, 33 deletions

diff --git a/platform/node/test/ignores.json b/platform/node/test/ignores.json
index 11dff4d716..060f4935a6 100644
--- a/platform/node/test/ignores.json
+++ b/platform/node/test/ignores.json
@@ -149,8 +149,8 @@
   "render-tests/symbol-sort-key/text-expression": "https://github.com/mapbox/mapbox-gl-native/issues/14028",
   "render-tests/symbol-sort-key/text-placement": "https://github.com/mapbox/mapbox-gl-native/issues/14028",
   "render-tests/fill-opacity/opaque-fill-over-symbol-layer": "skip - port https://github.com/mapbox/mapbox-gl-js/pull/7612",
-  "render-tests/text-variable-anchor/pitched-rotated-debug": "skip - fails on gl-native due to worse accuracy at collision detection (float vs double) - needs issue",
-  "render-tests/text-variable-anchor/rotated-offset": "skip - fails on gl-native due to worse accuracy at collision detection (float vs double) - needs issue",
+  "render-tests/text-variable-anchor/pitched-rotated-debug": "https://github.com/mapbox/mapbox-gl-native/issues/14211",
+  "render-tests/text-variable-anchor/rotated-offset": "https://github.com/mapbox/mapbox-gl-native/issues/14211",
   "render-tests/text-variable-anchor/remember-last-placement": "skip - fails on gl-native, as symbol index is not functional at static map mode - needs issue",
   "render-tests/geojson/clustered-properties": "https://github.com/mapbox/mapbox-gl-native/issues/14043",
   "render-tests/remove-feature-state/composite-expression": "https://github.com/mapbox/mapbox-gl-native/issues/12413",
diff --git a/src/mbgl/layout/symbol_instance.cpp b/src/mbgl/layout/symbol_instance.cpp
index fddaaf7c2d..0197df1066 100644
--- a/src/mbgl/layout/symbol_instance.cpp
+++ b/src/mbgl/layout/symbol_instance.cpp
@@ -54,26 +54,37 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
     iconOffset(iconOffset_),
     key(key_),
     textBoxScale(textBoxScale_),
-    radialTextOffset(radialTextOffset_) {
+    radialTextOffset(radialTextOffset_),
+    singleLine(shapedTextOrientations.singleLine) {
 
     // Create the quads used for rendering the icon and glyphs.
     if (shapedIcon) {
         iconQuad = getIconQuad(*shapedIcon, layout, layoutTextSize, shapedTextOrientations.horizontal);
     }
-
-    if (shapedTextOrientations.right) {
+    
+    bool singleLineInitialized = false;
+    const auto initHorizontalGlyphQuads = [&] (SymbolQuads& quads, const Shaping& shaping) {
         writingModes |= WritingModeType::Horizontal;
-        rightJustifiedGlyphQuads = getGlyphQuads(shapedTextOrientations.right, textOffset, layout, textPlacement, positions);
+        if (!singleLine) {
+            quads = getGlyphQuads(shaping, textOffset, layout, textPlacement, positions);
+            return;
+        }
+        if (!singleLineInitialized) {
+            rightJustifiedGlyphQuads = getGlyphQuads(shaping, textOffset, layout, textPlacement, positions);
+            singleLineInitialized = true;
+        }
+    };
+    
+    if (shapedTextOrientations.right) {
+        initHorizontalGlyphQuads(rightJustifiedGlyphQuads, shapedTextOrientations.right);
     }
 
     if (shapedTextOrientations.center) {
-        writingModes |= WritingModeType::Horizontal;
-        centerJustifiedGlyphQuads = getGlyphQuads(shapedTextOrientations.center, textOffset, layout, textPlacement, positions);
+        initHorizontalGlyphQuads(centerJustifiedGlyphQuads, shapedTextOrientations.center);
     }
 
     if (shapedTextOrientations.left) {
-        writingModes |= WritingModeType::Horizontal;
-        leftJustifiedGlyphQuads = getGlyphQuads(shapedTextOrientations.left, textOffset, layout, textPlacement, positions);
+        initHorizontalGlyphQuads(leftJustifiedGlyphQuads, shapedTextOrientations.left);
     }
 
     if (shapedTextOrientations.vertical) {
diff --git a/src/mbgl/layout/symbol_instance.hpp b/src/mbgl/layout/symbol_instance.hpp
index 44d81ae1e5..5169b16adb 100644
--- a/src/mbgl/layout/symbol_instance.hpp
+++ b/src/mbgl/layout/symbol_instance.hpp
@@ -18,6 +18,7 @@ struct ShapedTextOrientations {
     Shaping& right = horizontal; 
     Shaping center;
     Shaping left;
+    bool singleLine = false;
 };
 
 class SymbolInstance {
@@ -45,14 +46,15 @@ public:
                    float radialTextOffset);
 
     optional<size_t> getDefaultHorizontalPlacedTextIndex() const;
-
     Anchor anchor;
     GeometryCoordinates line;
     bool hasText;
     bool hasIcon;
+    // Note: When singleLine == true, only `rightJustifiedGlyphQuads` is populated.
     SymbolQuads rightJustifiedGlyphQuads;
     SymbolQuads centerJustifiedGlyphQuads;
     SymbolQuads leftJustifiedGlyphQuads;
+
     SymbolQuads verticalGlyphQuads;
 
     optional<SymbolQuad> iconQuad;
@@ -72,6 +74,7 @@ public:
     optional<size_t> placedIconIndex;
     float textBoxScale;
     float radialTextOffset;
+    bool singleLine;
     uint32_t crossTileID = 0;
 };
 
diff --git a/src/mbgl/layout/symbol_layout.cpp b/src/mbgl/layout/symbol_layout.cpp
index f691d406f1..d1c50d7773 100644
--- a/src/mbgl/layout/symbol_layout.cpp
+++ b/src/mbgl/layout/symbol_layout.cpp
@@ -312,7 +312,6 @@ void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions
                         justifications.push_back(getAnchorJustification(anchor));
                     }
                 }
-
                 for (TextJustifyType justification: justifications) {
                     Shaping& shapingForJustification = shapingForTextJustifyType(shapedTextOrientations, justification);
                     if (shapingForJustification) {
@@ -323,8 +322,11 @@ void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions
                     Shaping shaping = applyShaping(*feature.formattedText, WritingModeType::Horizontal, SymbolAnchorType::Center, justification);
                     if (shaping) {
                         shapingForJustification = std::move(shaping);
+                        if (shaping.lineCount == 1u) {
+                            shapedTextOrientations.singleLine = true;
+                            break;
+                        }
                     }
-                    // TODO: use 'singleLine' optimization.
                 }
             } else {
                 if (textJustify == TextJustifyType::Auto) {
@@ -547,9 +549,9 @@ void SymbolLayout::createBucket(const ImagePositions&, std::unique_ptr<FeatureIn
     auto bucket = std::make_shared<SymbolBucket>(layout, layerPaintProperties, textSize, iconSize, zoom, sdfIcons, iconsNeedLinear, sortFeaturesByY, bucketLeaderID, std::move(symbolInstances), tilePixelRatio);
 
     for (SymbolInstance &symbolInstance : bucket->symbolInstances) {
-
         const bool hasText = symbolInstance.hasText;
         const bool hasIcon = symbolInstance.hasIcon;
+        const bool singleLine = symbolInstance.singleLine;
 
         const auto& feature = features.at(symbolInstance.layoutFeatureIndex);
 
@@ -557,16 +559,23 @@ void SymbolLayout::createBucket(const ImagePositions&, std::unique_ptr<FeatureIn
 
         if (hasText && feature.formattedText) {
             optional<std::size_t> lastAddedSection;
-            if (!symbolInstance.rightJustifiedGlyphQuads.empty()) {
-                lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedRightTextIndex, symbolInstance.rightJustifiedGlyphQuads, lastAddedSection);
-            }
-            if (!symbolInstance.centerJustifiedGlyphQuads.empty()) {
-                lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedCenterTextIndex, symbolInstance.centerJustifiedGlyphQuads, lastAddedSection);
-            }
-            if (!symbolInstance.leftJustifiedGlyphQuads.empty()) {
-                lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedLeftTextIndex, symbolInstance.leftJustifiedGlyphQuads, lastAddedSection);
+            if (singleLine) {
+                optional<std::size_t> placedTextIndex;
+                lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, placedTextIndex, symbolInstance.rightJustifiedGlyphQuads, lastAddedSection);
+                symbolInstance.placedRightTextIndex = placedTextIndex;
+                symbolInstance.placedCenterTextIndex = placedTextIndex;
+                symbolInstance.placedLeftTextIndex = placedTextIndex;
+            } else {
+                if (!symbolInstance.rightJustifiedGlyphQuads.empty()) {
+                    lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedRightTextIndex, symbolInstance.rightJustifiedGlyphQuads, lastAddedSection);
+                }
+                if (!symbolInstance.centerJustifiedGlyphQuads.empty()) {
+                    lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedCenterTextIndex, symbolInstance.centerJustifiedGlyphQuads, lastAddedSection);
+                }
+                if (!symbolInstance.leftJustifiedGlyphQuads.empty()) {
+                    lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, symbolInstance.writingModes, symbolInstance.placedLeftTextIndex, symbolInstance.leftJustifiedGlyphQuads, lastAddedSection);
+                }
             }
-
             if (symbolInstance.writingModes & WritingModeType::Vertical) {
                 lastAddedSection = addSymbolGlyphQuads(*bucket, symbolInstance, feature, WritingModeType::Vertical, symbolInstance.placedVerticalTextIndex, symbolInstance.verticalGlyphQuads, lastAddedSection);
             }
diff --git a/src/mbgl/renderer/buckets/symbol_bucket.cpp b/src/mbgl/renderer/buckets/symbol_bucket.cpp
index 38342b44ee..68f683c8d6 100644
--- a/src/mbgl/renderer/buckets/symbol_bucket.cpp
+++ b/src/mbgl/renderer/buckets/symbol_bucket.cpp
@@ -224,11 +224,11 @@ void SymbolBucket::sortFeatures(const float angle) {
             addPlacedSymbol(text.triangles, text.placedSymbols[*symbolInstance.placedRightTextIndex]);
         }
 
-        if (symbolInstance.placedCenterTextIndex) {
+        if (symbolInstance.placedCenterTextIndex && !symbolInstance.singleLine) {
             addPlacedSymbol(text.triangles, text.placedSymbols[*symbolInstance.placedCenterTextIndex]);
         }
 
-        if (symbolInstance.placedLeftTextIndex) {
+        if (symbolInstance.placedLeftTextIndex && !symbolInstance.singleLine) {
             addPlacedSymbol(text.triangles, text.placedSymbols[*symbolInstance.placedLeftTextIndex]);
         }
 
diff --git a/src/mbgl/style/conversion/constant.cpp b/src/mbgl/style/conversion/constant.cpp
index 1942779aaa..0fcaab433b 100644
--- a/src/mbgl/style/conversion/constant.cpp
+++ b/src/mbgl/style/conversion/constant.cpp
@@ -147,11 +147,6 @@ optional<std::vector<float>> Converter<std::vector<float>>::operator()(const Con
     return result;
 }
 
-
-namespace {
-
-}  // namespace
-
 optional<std::vector<std::string>> Converter<std::vector<std::string>>::operator()(const Convertible& value, Error& error) const {
     if (!isArray(value)) {
         error.message = "value must be an array";
diff --git a/src/mbgl/text/placement.cpp b/src/mbgl/text/placement.cpp
index 9d0fcf7b32..f6c4ac1eb6 100644
--- a/src/mbgl/text/placement.cpp
+++ b/src/mbgl/text/placement.cpp
@@ -464,14 +464,14 @@ void Placement::updateBucketOpacities(SymbolBucket& bucket, std::set<uint32_t>&
                 PlacedSymbol& placed = bucket.text.placedSymbols[*symbolInstance.placedRightTextIndex];
                 placed.hidden = opacityState.isHidden();
             }
-            if (symbolInstance.placedCenterTextIndex) {
+            if (symbolInstance.placedCenterTextIndex && !symbolInstance.singleLine) {
                 for (size_t i = 0; i < symbolInstance.centerJustifiedGlyphQuads.size() * 4; i++) {
                     bucket.text.opacityVertices.emplace_back(opacityVertex);
                 }
                 PlacedSymbol& placed = bucket.text.placedSymbols[*symbolInstance.placedCenterTextIndex];
                 placed.hidden = opacityState.isHidden();
             }
-            if (symbolInstance.placedLeftTextIndex) {
+            if (symbolInstance.placedLeftTextIndex && !symbolInstance.singleLine) {
                 for (size_t i = 0; i < symbolInstance.leftJustifiedGlyphQuads.size() * 4; i++) {
                     bucket.text.opacityVertices.emplace_back(opacityVertex);
                 }
diff --git a/src/mbgl/text/shaping.cpp b/src/mbgl/text/shaping.cpp
index 348c2ddccc..ba21b97389 100644
--- a/src/mbgl/text/shaping.cpp
+++ b/src/mbgl/text/shaping.cpp
@@ -363,7 +363,6 @@ const Shaping getShaping(const TaggedString& formattedString,
                          const style::TextJustifyType textJustify,
                          const float spacing,
                          const Point<float>& translate,
-                         //const float verticalHeight,
                          const WritingModeType writingMode,
                          BiDi& bidi,
                          const GlyphMap& glyphs) {