Merge pull request #1501 from contour-terminal/fix/merged_codepoints

Fix font rendering for long glyphs

metainfo.xml

@@ -113,6 +113,7 @@
           <li>Add generation of config file from internal state (#1282)</li>
           <li>Add SGRSAVE and SGRRESTORE VT sequences to save and restore SGR state (They intentionally conflict with XTPUSHSGR and XTPOPSGR)</li>
           <li>Update of contour.desktop file (#1423)</li>
+          <li>Fixed overlap of glyphs for long codepoints (#1349)</li>
           <li>Fixed too verbose info during ssh session login (#1447)</li>
           <li>Fixes corruption of sixel image on high resolution (#1049)</li>
           <li>Fixes bad wording of OS/X to macOS (#1462)</li>

src/text_shaper/open_shaper.cpp

@@ -389,6 +389,7 @@ namespace
             gpos.presentation = presentation;
             result.emplace_back(gpos);
         }
+
         return crispy::none_of(result, glyphMissing);
     }
 } // namespace

src/vtrasterizer/TextRenderer.cpp

@@ -582,15 +582,14 @@ void TextRenderer::renderTextGroup(std::u32string_view codepoints,
     text::shape_result const& glyphPositions =
         getOrCreateCachedGlyphPositions(hash, codepoints, clusters, style);
     crispy::point pen = _gridMetrics.mapBottomLeft(initialPenPosition);
-    auto const advanceX = unbox(_gridMetrics.cellSize.width);
 
     for (auto const& glyphPosition: glyphPositions)
     {
         if (auto const* attributes = ensureRasterizedIfDirectMapped(glyphPosition.glyph))
         {
             auto const pen1 = applyGlyphPositionToPen(pen, *attributes, glyphPosition);
             renderRasterizedGlyph(pen1, color, *attributes);
-            pen.x += static_cast<decltype(pen.x)>(advanceX);
+            pen.x += unbox<decltype(pen.x)>(_gridMetrics.cellSize.width);
             continue;
         }
 
@@ -617,10 +616,14 @@ void TextRenderer::renderTextGroup(std::u32string_view codepoints,
 
         if (glyphPosition.advance.x)
         {
+
+            auto numberOfCellsToAdvance =
+                std::rint(glyphPosition.advance.x / unbox<double>(_gridMetrics.cellSize.width));
             // Only advance horizontally, as we're (guess what) a terminal. :-)
             // Only advance in fixed-width steps.
-            // Only advance iff there harfbuzz told us to.
-            pen.x += static_cast<decltype(pen.x)>(advanceX);
+            // Only advance if there harfbuzz told us to.
+            pen.x +=
+                static_cast<decltype(pen.x)>(numberOfCellsToAdvance * (unbox(_gridMetrics.cellSize.width)));
         }
     }
 }