[core] Enable text-offset with variable label placement

platform/android/CHANGELOG.md

@@ -7,6 +7,7 @@ Mapbox welcomes participation and contributions from everyone.  If you'd like to
  - Introduce `clusterProperties` option for aggregated cluster properties. [#15425](https://github.com/mapbox/mapbox-gl-native/pull/15425)
  - Expose the `CameraPosition#padding` field and associated utility camera position builders. This gives a choice to set a persisting map padding immediately during a transition instead of setting it lazily `MapboxMap#setPadding`, which required scheduling additional transition to be applied. This also deprecates `MapboxMap#setPadding` as there should be no need for a lazy padding setter. [#15444](https://github.com/mapbox/mapbox-gl-native/pull/15444)
  - Add number-format expression that allows to format a number to a string, with configurations as minimal/maximal fraction and locale/currency. [#15424](https://github.com/mapbox/mapbox-gl-native/pull/15424)
+ - Enable using of `text-offset` option together with `text-variable-anchor` (if `text-radial-offset` option is not provided). If used with `text-variable-anchor`, input values will be taken as absolute values. Offsets along the x- and y-axis will be applied automatically based on the anchor position. [#15542](https://github.com/mapbox/mapbox-gl-native/pull/15542)
 
  ### Performance improvements
  - Mark used offline region resources in batches. [#15521](https://github.com/mapbox/mapbox-gl-native/pull/15521)

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java

@@ -2296,7 +2296,7 @@ public static PropertyValue<Expression> textJustify(Expression value) {
   }
 
   /**
-   * Radial offset of text, in the direction of the symbol's anchor. Useful in combination with {@link PropertyFactory#textVariableAnchor}, which doesn't support the two-dimensional {@link PropertyFactory#textOffset}.
+   * Radial offset of text, in the direction of the symbol's anchor. Useful in combination with {@link PropertyFactory#textVariableAnchor}, which defaults to using the two-dimensional {@link PropertyFactory#textOffset} if present.
    *
    * @param value a Float value
    * @return property wrapper around Float
@@ -2306,7 +2306,7 @@ public static PropertyValue<Float> textRadialOffset(Float value) {
   }
 
   /**
-   * Radial offset of text, in the direction of the symbol's anchor. Useful in combination with {@link PropertyFactory#textVariableAnchor}, which doesn't support the two-dimensional {@link PropertyFactory#textOffset}.
+   * Radial offset of text, in the direction of the symbol's anchor. Useful in combination with {@link PropertyFactory#textVariableAnchor}, which defaults to using the two-dimensional {@link PropertyFactory#textOffset} if present.
    *
    * @param value a Float value
    * @return property wrapper around Float
@@ -2316,7 +2316,7 @@ public static PropertyValue<Expression> textRadialOffset(Expression value) {
   }
 
   /**
-   * To increase the chance of placing high-priority labels on the map, you can provide an array of {@link Property.TEXT_ANCHOR} locations: the render will attempt to place the label at each location, in order, before moving onto the next label. Use `text-justify: auto` to choose justification based on anchor position. To apply an offset, use the {@link PropertyFactory#textRadialOffset} instead of the two-dimensional {@link PropertyFactory#textOffset}.
+   * To increase the chance of placing high-priority labels on the map, you can provide an array of {@link Property.TEXT_ANCHOR} locations: the render will attempt to place the label at each location, in order, before moving onto the next label. Use `text-justify: auto` to choose justification based on anchor position. To apply an offset, use the {@link PropertyFactory#textRadialOffset} or the two-dimensional {@link PropertyFactory#textOffset}.
    *
    * @param value a String[] value
    * @return property wrapper around String[]
@@ -2326,7 +2326,7 @@ public static PropertyValue<String[]> textVariableAnchor(String[] value) {
   }
 
   /**
-   * To increase the chance of placing high-priority labels on the map, you can provide an array of {@link Property.TEXT_ANCHOR} locations: the render will attempt to place the label at each location, in order, before moving onto the next label. Use `text-justify: auto` to choose justification based on anchor position. To apply an offset, use the {@link PropertyFactory#textRadialOffset} instead of the two-dimensional {@link PropertyFactory#textOffset}.
+   * To increase the chance of placing high-priority labels on the map, you can provide an array of {@link Property.TEXT_ANCHOR} locations: the render will attempt to place the label at each location, in order, before moving onto the next label. Use `text-justify: auto` to choose justification based on anchor position. To apply an offset, use the {@link PropertyFactory#textRadialOffset} or the two-dimensional {@link PropertyFactory#textOffset}.
    *
    * @param value a String[] value
    * @return property wrapper around String[]
@@ -2476,7 +2476,7 @@ public static PropertyValue<Expression> textTransform(Expression value) {
   }
 
   /**
-   * Offset distance of text from its anchor. Positive values indicate right and down, while negative values indicate left and up.
+   * Offset distance of text from its anchor. Positive values indicate right and down, while negative values indicate left and up. If used with text-variable-anchor, input values will be taken as absolute values. Offsets along the x- and y-axis will be applied automatically based on the anchor position.
    *
    * @param value a Float[] value
    * @return property wrapper around Float[]
@@ -2486,7 +2486,7 @@ public static PropertyValue<Float[]> textOffset(Float[] value) {
   }
 
   /**
-   * Offset distance of text from its anchor. Positive values indicate right and down, while negative values indicate left and up.
+   * Offset distance of text from its anchor. Positive values indicate right and down, while negative values indicate left and up. If used with text-variable-anchor, input values will be taken as absolute values. Offsets along the x- and y-axis will be applied automatically based on the anchor position.
    *
    * @param value a Float[] value
    * @return property wrapper around Float[]

platform/darwin/src/MGLSymbolStyleLayer.h

@@ -1404,8 +1404,7 @@ MGL_EXPORT
  ems downward. Set this property to `nil` to reset it to the default value.
 
  This property is only applied to the style if `text` is non-`nil`, and
- `textRadialOffset` is set to `nil`, and `textVariableAnchor` is set to `nil`.
- Otherwise, it is ignored.
+ `textRadialOffset` is set to `nil`. Otherwise, it is ignored.
 
  You can set this property to an expression containing any of the following:
 
@@ -1428,8 +1427,7 @@ MGL_EXPORT
  ems upward. Set this property to `nil` to reset it to the default value.
 
  This property is only applied to the style if `text` is non-`nil`, and
- `textRadialOffset` is set to `nil`, and `textVariableAnchor` is set to `nil`.
- Otherwise, it is ignored.
+ `textRadialOffset` is set to `nil`. Otherwise, it is ignored.
 
  You can set this property to an expression containing any of the following:
 
@@ -1521,8 +1519,8 @@ MGL_EXPORT
 
 /**
  Radial offset of text, in the direction of the symbol's anchor. Useful in
- combination with `textVariableAnchor`, which doesn't support the
- two-dimensional `textOffset`.
+ combination with `textVariableAnchor`, which defaults to using the
+ two-dimensional `textOffset` if present.
 
  This property is measured in ems.
 
@@ -1634,8 +1632,7 @@ MGL_EXPORT
  provide an array of `textAnchor` locations: the render will attempt to place
  the label at each location, in order, before moving onto the next label. Use
  `textJustify: auto` to choose justification based on anchor position. To apply
- an offset, use the `textRadialOffset` instead of the two-dimensional
- `textOffset`.
+ an offset, use the `textRadialOffset` or the two-dimensional `textOffset`.
 
  This property is only applied to the style if `text` is non-`nil`, and
  `symbolPlacement` is set to an expression that evaluates to or

platform/ios/CHANGELOG.md

@@ -8,6 +8,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 * Fixed a bug with annotation view positions after camera transitions. ([#15122](https://github.com/mapbox/mapbox-gl-native/pull/15122/))
 * Fixed a rendering issue of `collisionBox` when `text-translate` or `icon-translate` is enabled. ([#15467](https://github.com/mapbox/mapbox-gl-native/pull/15467))
 * Fixed an issue where the scale bar text would become illegible if iOS 13 dark mode was enabled. ([#15524](https://github.com/mapbox/mapbox-gl-native/pull/15524))
+ * Enable using of `text-offset` option together with `text-variable-anchor` (if `text-radial-offset` option is not provided). If used with `text-variable-anchor`, input values will be taken as absolute values. Offsets along the x- and y-axis will be applied automatically based on the anchor position. ([#15542](https://github.com/mapbox/mapbox-gl-native/pull/15542))
 
  ### Performance improvements
 

src/mbgl/layout/symbol_instance.cpp

@@ -87,7 +87,7 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
                                const float overscaling,
                                const float iconRotation,
                                const float textRotation,
-                               float radialTextOffset_,
+                               const std::array<float, 2>& variableTextOffset_,
                                bool allowVerticalPlacement,
                                const SymbolContent iconType) :
     sharedData(std::move(sharedData_)),
@@ -104,7 +104,7 @@ SymbolInstance::SymbolInstance(Anchor& anchor_,
     iconOffset(iconOffset_),
     key(std::move(key_)),
     textBoxScale(textBoxScale_),
-    radialTextOffset(radialTextOffset_),
+    variableTextOffset(variableTextOffset_),
     singleLine(shapedTextOrientations.singleLine) {
     // 'hasText' depends on finding at least one glyph in the shaping that's also in the GlyphPositionMap
     if(!sharedData->empty()) symbolContent |= SymbolContent::Text;

src/mbgl/layout/symbol_instance.hpp

@@ -83,7 +83,7 @@ class SymbolInstance {
                    const float overscaling,
                    const float iconRotation,
                    const float textRotation,
-                   float radialTextOffset,
+                   const std::array<float, 2>& variableTextOffset,
                    bool allowVerticalPlacement,
                    const SymbolContent iconType = SymbolContent::None);
 
@@ -130,7 +130,7 @@ class SymbolInstance {
     optional<size_t> placedIconIndex;
     optional<size_t> placedVerticalIconIndex;
     float textBoxScale;
-    float radialTextOffset;
+    std::array<float, 2> variableTextOffset;
     bool singleLine;
     uint32_t crossTileID = 0;
 };

src/mbgl/layout/symbol_layout.cpp

@@ -91,11 +91,13 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
       pixelRatio(parameters.pixelRatio),
       tileSize(util::tileSize * overscaling),
       tilePixelRatio(float(util::EXTENT) / tileSize),
-      textSize(toSymbolLayerProperties(layers.at(0)).layerImpl().layout.get<TextSize>()),
-      iconSize(toSymbolLayerProperties(layers.at(0)).layerImpl().layout.get<IconSize>()),
       layout(createLayout(toSymbolLayerProperties(layers.at(0)).layerImpl().layout, zoom)) {
     const SymbolLayer::Impl& leader = toSymbolLayerProperties(layers.at(0)).layerImpl();
 
+    textSize = leader.layout.get<TextSize>();
+    iconSize = leader.layout.get<IconSize>();
+    textRadialOffset = leader.layout.get<TextRadialOffset>();
+
     const bool hasText = has<TextField>(*layout) && has<TextFont>(*layout);
     const bool hasIcon = has<IconImage>(*layout);
 
@@ -235,29 +237,27 @@ Shaping& shapingForTextJustifyType(ShapedTextOrientations& shapedTextOrientation
     }
 }
 
-}  // namespace
-
-// static
-Point<float> SymbolLayout::evaluateRadialOffset(SymbolAnchorType anchor, float radialOffset) {
-    Point<float> result{};
+std::array<float, 2> evaluateRadialOffset(style::SymbolAnchorType anchor, float radialOffset) { 
+    std::array<float, 2> result{{0.0f, 0.0f}};
+    if (radialOffset < 0.0f) radialOffset = 0.0f; // Ignore negative offset.
     // solve for r where r^2 + r^2 = radialOffset^2
     const float sqrt2 = 1.41421356237f;
     const float hypotenuse = radialOffset / sqrt2;
 
     switch (anchor) {
     case SymbolAnchorType::TopRight:
     case SymbolAnchorType::TopLeft:
-        result.y = hypotenuse - baselineOffset;
+        result[1] = hypotenuse - baselineOffset;
         break;
     case SymbolAnchorType::BottomRight:
     case SymbolAnchorType::BottomLeft:
-        result.y = -hypotenuse + baselineOffset;
+        result[1] = -hypotenuse + baselineOffset;
         break;
     case SymbolAnchorType::Bottom:
-        result.y = -radialOffset + baselineOffset;
+        result[1] = -radialOffset + baselineOffset;
         break;
     case SymbolAnchorType::Top:
-        result.y = radialOffset - baselineOffset;
+        result[1] = radialOffset - baselineOffset;
         break;
     default:
         break;
@@ -266,17 +266,17 @@ Point<float> SymbolLayout::evaluateRadialOffset(SymbolAnchorType anchor, float r
     switch (anchor) {
     case SymbolAnchorType::TopRight:
     case SymbolAnchorType::BottomRight:
-        result.x = -hypotenuse;
+        result[0] = -hypotenuse;
         break;
     case SymbolAnchorType::TopLeft:
     case SymbolAnchorType::BottomLeft:
-        result.x = hypotenuse;
+        result[0] = hypotenuse;
         break;
     case SymbolAnchorType::Left:
-        result.x = radialOffset;
+        result[0] = radialOffset;
         break;
     case SymbolAnchorType::Right:
-        result.x = -radialOffset;
+        result[0] = -radialOffset;
         break;
     default:
         break;
@@ -285,6 +285,54 @@ Point<float> SymbolLayout::evaluateRadialOffset(SymbolAnchorType anchor, float r
     return result;
 }
 
+} // namespace
+
+// static
+std::array<float, 2> SymbolLayout::evaluateVariableOffset(style::SymbolAnchorType anchor, std::array<float, 2> offset) {
+    if (offset[1] == INVALID_OFFSET_VALUE) {
+        return evaluateRadialOffset(anchor, offset[0]);
+    }
+    std::array<float, 2> result{{0.0f, 0.0f}};
+    offset[0] = std::abs(offset[0]);
+    offset[1] = std::abs(offset[1]);
+
+    switch (anchor) {
+    case SymbolAnchorType::TopRight:
+    case SymbolAnchorType::TopLeft:
+    case SymbolAnchorType::Top:
+        result[1] = offset[1] - baselineOffset;
+        break;
+    case SymbolAnchorType::BottomRight:
+    case SymbolAnchorType::BottomLeft:
+    case SymbolAnchorType::Bottom:
+        result[1] = -offset[1] + baselineOffset;
+        break;
+    case SymbolAnchorType::Center:
+    case SymbolAnchorType::Left:
+    case SymbolAnchorType::Right:
+        break;
+    }
+
+    switch (anchor) {
+    case SymbolAnchorType::TopRight:
+    case SymbolAnchorType::BottomRight:
+    case SymbolAnchorType::Right:
+        result[0] = -offset[0];
+        break;
+    case SymbolAnchorType::TopLeft:
+    case SymbolAnchorType::BottomLeft:
+    case SymbolAnchorType::Left:
+        result[0] = offset[0];
+        break;
+    case SymbolAnchorType::Center:
+    case SymbolAnchorType::Top:
+    case SymbolAnchorType::Bottom:
+        break;
+    }
+
+    return result;
+}
+
 void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions& glyphPositions,
                            const ImageMap& imageMap, const ImagePositions& imagePositions) {
     const bool isPointPlacement = layout->get<SymbolPlacement>() == SymbolPlacementType::Point;
@@ -296,7 +344,7 @@ void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions
 
         ShapedTextOrientations shapedTextOrientations;
         optional<PositionedIcon> shapedIcon;
-        Point<float> textOffset;
+        std::array<float, 2> textOffset{{0.0f, 0.0f}};
 
         // if feature has text, shape the text
         if (feature.formattedText) {
@@ -320,18 +368,18 @@ void SymbolLayout::prepareSymbols(const GlyphMap& glyphMap, const GlyphPositions
                 return result;
             };
             const std::vector<style::TextVariableAnchorType> variableTextAnchor = layout->evaluate<TextVariableAnchor>(zoom, feature);
-            const float radialOffset = layout->evaluate<TextRadialOffset>(zoom, feature);
             const SymbolAnchorType textAnchor = layout->evaluate<TextAnchor>(zoom, feature); 
             if (variableTextAnchor.empty()) {
                 // Layers with variable anchors use the `text-radial-offset` property and the [x, y] offset vector
                 // is calculated at placement time instead of layout time
+                const float radialOffset = layout->evaluate<TextRadialOffset>(zoom, feature);
                 if (radialOffset > 0.0f) {
                     // The style spec says don't use `text-offset` and `text-radial-offset` together
                     // but doesn't actually specify what happens if you use both. We go with the radial offset.
                     textOffset = evaluateRadialOffset(textAnchor, radialOffset * util::ONE_EM);
                 } else {
-                    textOffset = { layout->evaluate<TextOffset>(zoom, feature)[0] * util::ONE_EM,
-                                   layout->evaluate<TextOffset>(zoom, feature)[1] * util::ONE_EM};
+                    textOffset = {{layout->evaluate<TextOffset>(zoom, feature)[0] * util::ONE_EM,
+                                   layout->evaluate<TextOffset>(zoom, feature)[1] * util::ONE_EM}};
                 }
             }
             TextJustifyType textJustify = textAlongLine ? TextJustifyType::Center : layout->evaluate<TextJustify>(zoom, feature);
@@ -435,14 +483,13 @@ void SymbolLayout::addFeature(const std::size_t layoutFeatureIndex,
                               const ShapedTextOrientations& shapedTextOrientations,
                               optional<PositionedIcon> shapedIcon,
                               const GlyphPositions& glyphPositions,
-                              Point<float> offset,
+                              std::array<float, 2> textOffset,
                               const SymbolContent iconType) {
     const float minScale = 0.5f;
     const float glyphSize = 24.0f;
 
     const float layoutTextSize = layout->evaluate<TextSize>(zoom + 1, feature);
     const float layoutIconSize = layout->evaluate<IconSize>(zoom + 1, feature);
-    const std::array<float, 2> textOffset = {{ offset.x, offset.y }};
 
     const std::array<float, 2> iconOffset = layout->evaluate<IconOffset>(zoom, feature);
 
@@ -462,7 +509,15 @@ void SymbolLayout::addFeature(const std::size_t layoutFeatureIndex,
     const float textMaxAngle = layout->get<TextMaxAngle>() * util::DEG2RAD;
     const float iconRotation = layout->evaluate<IconRotate>(zoom, feature);
     const float textRotation = layout->evaluate<TextRotate>(zoom, feature);
-    const float radialTextOffset = layout->evaluate<TextRadialOffset>(zoom, feature) * util::ONE_EM;
+    std::array<float, 2> variableTextOffset;
+    if (!textRadialOffset.isUndefined()) {
+        variableTextOffset = {{layout->evaluate<TextRadialOffset>(zoom, feature) * util::ONE_EM,
+                               INVALID_OFFSET_VALUE}};
+    } else {
+        variableTextOffset = {{layout->evaluate<TextOffset>(zoom, feature)[0] * util::ONE_EM,
+                               layout->evaluate<TextOffset>(zoom, feature)[1] * util::ONE_EM}};
+    }
+
     const SymbolPlacementType textPlacement = layout->get<TextRotationAlignment>() != AlignmentType::Map
                                                   ? SymbolPlacementType::Point
                                                   : layout->get<SymbolPlacement>();
@@ -503,7 +558,7 @@ void SymbolLayout::addFeature(const std::size_t layoutFeatureIndex,
                     iconBoxScale, iconPadding, iconOffset, indexedFeature,
                     layoutFeatureIndex, feature.index,
                     feature.formattedText ? feature.formattedText->rawText() : std::u16string(),
-                    overscaling, iconRotation, textRotation, radialTextOffset, allowVerticalPlacement, iconType);
+                    overscaling, iconRotation, textRotation, variableTextOffset, allowVerticalPlacement, iconType);
         }
     };