[core] minor fix

Author: zmiao

src/mbgl/text/glyph_pbf.cpp

@@ -8,7 +8,7 @@ std::tuple<std::vector<Glyph>, int32_t, int32_t> parseGlyphPBF(const GlyphRange&
     std::vector<Glyph> glyphs;
     glyphs.reserve(256);
     int32_t ascender{0}, descender{0};
-    bool ascenderSet{false}, descenderSet{0};
+    bool ascenderSet{false}, descenderSet{false};
 
     protozero::pbf_reader glyphs_pbf(data);
 

src/mbgl/text/quads.cpp

@@ -125,11 +125,14 @@ SymbolQuads getGlyphQuads(const Shaping& shapedText,
             // necessary, but we also pull the glyph to the left along the x axis.
             // The y coordinate includes baseline yOffset, therefore, needs to be accounted
             // for when glyph is rotated and translated.
-            float yShift = Shaping::yOffset;
-            if (shapedText.hasBaseline && fontPositions->second.ascender.has_value() &&
-                fontPositions->second.descender.has_value()) {
-                yShift = (-fontPositions->second.ascender.value() + fontPositions->second.descender.value()) / 2;
+            if (shapedText.hasBaseline) {
+                assert(fontPositions->second.ascender && fontPositions->second.descender);
             }
+            const float yShift =
+                (shapedText.hasBaseline
+                     ? ((-(fontPositions->second.ascender.value()) + fontPositions->second.descender.value()) / 2.0 *
+                        positionedGlyph.scale)
+                     : Shaping::yOffset);
             const Point<float> center{-halfAdvance, halfAdvance - yShift};
             const float verticalRotation = -M_PI_2;
 

src/mbgl/text/shaping.cpp

@@ -381,6 +381,9 @@ void shapeLines(Shaping& shaping,
             // with different offset shift. If font's baseline is not applicable, fall back to use a default baseline
             // offset, see shaping.yOffset. Since we're laying out at 24 points, we need also calculate how much it will
             // move when we scale up or down.
+            if (hasBaseline) {
+                assert(glyphs->second.ascender && glyphs->second.descender);
+            }
             const float baselineOffset =
                 (hasBaseline
                      ? ((-(glyphs->second.ascender.value()) + glyphs->second.descender.value()) / 2.0 * section.scale)