Merge pull request #1048 from mitchellh/combining

font: position combining character correctly on x-axis

src/font/face/coretext.zig

@@ -397,6 +397,10 @@ pub const Face = struct {
             break :offset_y @intFromFloat(@ceil(baseline_with_offset));
         };
 
+        // Get our advance
+        var advances: [glyphs.len]macos.graphics.Size = undefined;
+        _ = self.font.getAdvancesForGlyphs(.horizontal, &glyphs, &advances);
+
         // std.log.warn("renderGlyph rect={} width={} height={} render_x={} render_y={} offset_y={} ascent={} cell_height={} cell_baseline={}", .{
         //     rect,
         //     width,
@@ -416,10 +420,7 @@ pub const Face = struct {
             .offset_y = offset_y,
             .atlas_x = region.x,
             .atlas_y = region.y,
-
+            .advance_x = @floatCast(advances[0].width),
-            // This is not used, so we don't bother calculating it. If we
-            // ever need it, we can calculate it using getAdvancesForGlyph.
-            .advance_x = 0,
         };
     }
 

src/renderer/Metal.zig

@@ -1787,6 +1787,15 @@ pub fn updateCell(
             .emoji => .fg_color,
         };
 
+        // If this glyph doesn't have an advance, then we assume it is
+        // connected to the previous glyph (perhaps an unsafe assumption...)
+        // and offset by the cell width.
+        // Related: https://github.com/mitchellh/ghostty/issues/1046
+        const extra_offset: i32 = if (glyph.advance_x == 0)
+            @intCast(self.grid_metrics.cell_width)
+        else
+            0;
+
         self.cells.appendAssumeCapacity(.{
             .mode = mode,
             .grid_pos = .{ @as(f32, @floatFromInt(x)), @as(f32, @floatFromInt(y)) },
@@ -1795,7 +1804,7 @@ pub fn updateCell(
             .bg_color = bg,
             .glyph_pos = .{ glyph.atlas_x, glyph.atlas_y },
             .glyph_size = .{ glyph.width, glyph.height },
-            .glyph_offset = .{ glyph.offset_x, glyph.offset_y },
+            .glyph_offset = .{ glyph.offset_x + extra_offset, glyph.offset_y },
         });
     }
 

src/renderer/OpenGL.zig

@@ -1490,6 +1490,15 @@ pub fn updateCell(
             .emoji => .fg_color,
         };
 
+        // If this glyph doesn't have an advance, then we assume it is
+        // connected to the previous glyph (perhaps an unsafe assumption...)
+        // and offset by the cell width.
+        // Related: https://github.com/mitchellh/ghostty/issues/1046
+        const extra_offset: i32 = if (glyph.advance_x == 0)
+            @intCast(self.grid_metrics.cell_width)
+        else
+            0;
+
         self.cells.appendAssumeCapacity(.{
             .mode = mode,
             .grid_col = @intCast(x),
@@ -1499,7 +1508,7 @@ pub fn updateCell(
             .glyph_y = glyph.atlas_y,
             .glyph_width = glyph.width,
             .glyph_height = glyph.height,
-            .glyph_offset_x = glyph.offset_x,
+            .glyph_offset_x = glyph.offset_x + extra_offset,
             .glyph_offset_y = glyph.offset_y,
             .r = colors.fg.r,
             .g = colors.fg.g,