[core] improve legibility of labels that follow lines

port https://github.com/mapbox/mapbox-gl-js/pull/4781

This improves legibility of labels that follow lines in pitched views.
The previous approach used the limited information in the shader to
calculate put the glyph in approximatelyright place. The new approach
does this more accurately by doing it on the cpu where we have access to
the entire line geometry.

1 files changed, 7 insertions, 24 deletions

diff --git a/src/mbgl/text/quads.hpp b/src/mbgl/text/quads.hpp
index b29f6b0ad3..33d003c935 100644
--- a/src/mbgl/text/quads.hpp
+++ b/src/mbgl/text/quads.hpp
@@ -19,50 +19,33 @@ public:
                Point<float> bl_,
                Point<float> br_,
                Rect<uint16_t> tex_,
-               float anchorAngle_,
-               float glyphAngle_,
-               Point<float> anchorPoint_,
-               float minScale_,
-               float maxScale_,
-               WritingModeType writingMode_)
+               WritingModeType writingMode_,
+               Point<float> glyphOffset_)
         : tl(std::move(tl_)),
         tr(std::move(tr_)),
         bl(std::move(bl_)),
         br(std::move(br_)),
         tex(std::move(tex_)),
-        anchorAngle(anchorAngle_),
-        glyphAngle(glyphAngle_),
-        anchorPoint(std::move(anchorPoint_)),
-        minScale(minScale_),
-        maxScale(maxScale_),
-        writingMode(writingMode_) {}
+        writingMode(writingMode_),
+        glyphOffset(glyphOffset_) {}
 
     Point<float> tl;
     Point<float> tr;
     Point<float> bl;
     Point<float> br;
     Rect<uint16_t> tex;
-    float anchorAngle, glyphAngle;
-    Point<float> anchorPoint;
-    float minScale;
-    float maxScale;
     WritingModeType writingMode;
+    Point<float> glyphOffset;
 };
 
 using SymbolQuads = std::vector<SymbolQuad>;
 
-SymbolQuad getIconQuad(const Anchor& anchor,
-                       const PositionedIcon& shapedIcon,
-                       const GeometryCoordinates& line,
+SymbolQuad getIconQuad(const PositionedIcon& shapedIcon,
                        const style::SymbolLayoutProperties::Evaluated&,
                        const float layoutTextSize,
-                       style::SymbolPlacementType placement,
                        const Shaping& shapedText);
 
-SymbolQuads getGlyphQuads(Anchor& anchor,
-                          const Shaping& shapedText,
-                          const float boxScale,
-                          const GeometryCoordinates& line,
+SymbolQuads getGlyphQuads(const Shaping& shapedText,
                           const style::SymbolLayoutProperties::Evaluated&,
                           style::SymbolPlacementType placement,
                           const GlyphPositionMap& positions);