WIP: [terminal_rendewrer] Fixes glyph rendering for some unexpectly oversized glyphs (#423).

Author: christianparpart

Changelog.md

@@ -1,5 +1,6 @@
 ### 0.3.2 (unreleased)
 
+- Fixes glyph rendering for some unexpectly oversized glyphs (#423).
 - Fixes writing to a non-empty line sometimes destroying the contents of that line (#702).
 - Fixes underline decoration for wide character cells.
 - Fixes SGR 8 (Conceal/Hidden) attribute doesn't work as expected (#699).

src/terminal_renderer/TextRenderer.cpp

@@ -748,16 +748,23 @@ auto TextRenderer::createRasterizedGlyph(atlas::TileLocation tileLocation,
     // As I only know of emoji being colored fonts, and those take up 2 cell with units.
 
     // Scale bitmap down iff bitmap is emoji and overflowing in diemensions
-    if (presentation == unicode::PresentationStyle::Emoji && glyph.format == text::bitmap_format::rgba)
+    if (/*presentation == unicode::PresentationStyle::Emoji &&*/ glyph.format == text::bitmap_format::rgba)
     {
         auto const emojiBoundingBox =
             ImageSize { Width(_gridMetrics.cellSize.width.value * numCells),
                         Height::cast_from(unbox<int>(_gridMetrics.cellSize.height) - _gridMetrics.baseline) };
         if (glyph.bitmapSize.height > emojiBoundingBox.height)
         {
+            RasterizerLog()("Scaling oversized glyph of {}+{} down to bounding box {}.",
+                            glyph.bitmapSize,
+                            glyph.position,
+                            emojiBoundingBox);
             auto [scaledGlyph, scaleFactor] = text::scale(glyph, emojiBoundingBox);
             glyph = move(scaledGlyph);
             // glyph.position.y = unbox<int>(glyph.bitmapSize.height) - _gridMetrics.underline.position;
+            // TODO(pr) Adapt glyph.position's x and y accordingly.
+            glyph.position.x = 0; // int(float(glyph.position.x) * scaleFactor);
+            glyph.position.y = unbox<int>(emojiBoundingBox.height); // int(float(glyph.position.y) * scaleFactor);
         }
     }
 

src/text_shaper/shaper.cpp

@@ -39,7 +39,7 @@ tuple<rasterized_glyph, float> scale(rasterized_glyph const& _bitmap, crispy::Im
 
     auto const ratioX = unbox<double>(_bitmap.bitmapSize.width) / unbox<double>(_newSize.width);
     auto const ratioY = unbox<double>(_bitmap.bitmapSize.height) / unbox<double>(_newSize.height);
-    auto const ratio = min(ratioX, ratioY);
+    auto const ratio = max(ratioX, ratioY);
     auto const factor = static_cast<unsigned>(ceil(ratio));
 
     vector<uint8_t> dest;