Resize the emoji.

Runtime/ui/painting/txt/mesh_generator.cs

 
             var text = this.textBlob.text;
             var key = new MeshKey(this.textBlob.instanceId, this.scale);
+            var fontInfo = FontManager.instance.getOrCreate(style.fontFamily, style.fontWeight, style.fontStyle);
+            var font = fontInfo.font;
+            
             if (char.IsHighSurrogate(text[this.textBlob.textOffset])) {
                 D.assert(this.textBlob.textSize == 2);
                 
                 var pos = this.textBlob.positions[0];
+                var metrics = FontMetrics.fromFont(font, style.UnityFontSize);
+                
+                var minMaxRect = EmojiUtils.getMinMaxRect(style.fontSize, metrics.ascent, metrics.descent);
+                var minX = minMaxRect.left;
+                var maxX = minMaxRect.right;
+                var minY = minMaxRect.top;
+                var maxY = minMaxRect.bottom;
+                
-                    new Vector3(pos.x, pos.y - style.fontSize, 0),
-                    new Vector3(pos.x + style.fontSize, pos.y - style.fontSize, 0),
-                    new Vector3(pos.x + style.fontSize, pos.y, 0),
-                    new Vector3(pos.x, pos.y, 0),
+                    new Vector3(pos.x + minX, pos.y + minY, 0),
+                    new Vector3(pos.x + maxX, pos.y + minY, 0),
+                    new Vector3(pos.x + maxX, pos.y + maxY, 0),
+                    new Vector3(pos.x + minX, pos.y + maxY, 0),
                 };
                 var tri = new List<int> {
                     0, 1, 2, 0, 2, 3,
                 return this._mesh;
             }
             
-            var fontInfo = FontManager.instance.getOrCreate(style.fontFamily, style.fontWeight, style.fontStyle);
 
             _meshes.TryGetValue(key, out var meshInfo);
             if (meshInfo != null && meshInfo.textureVersion == fontInfo.textureVersion) {
             }
 
-            var font = fontInfo.font;
             var length = this.textBlob.textSize;
             var fontSizeToLoad = Mathf.CeilToInt(style.UnityFontSize * this.scale);
 

Runtime/ui/txt/emoji.cs

                             Resources.Load<Texture2D>("Emoji")
                         );
                     }
-                    catch (Exception e) {
+                    catch (Exception) {
                         _image = null;
                     }
                 }
 
         public const int rowCount = 4;
         public const int colCount = 4;
+
+        public static Rect getMinMaxRect(float fontSize, float ascent, float descent) {
+            return Rect.fromLTWH(fontSize * 0.05f, descent - fontSize, fontSize * 0.9f, fontSize * 0.9f);
+        }
 
         public static Rect getUVRect(int code) {
             bool exist = emojiLookupTable.TryGetValue(code, out int index);

Runtime/ui/txt/layout.cs

             this._advance = 0;
             this._bounds = default;
 
-            Font font;
+            Font font = FontManager.instance.getOrCreate(style.fontFamily, style.fontWeight, style.fontStyle).font;
-                this.layoutEmoji(style);
+                this.layoutEmoji(style, font);
-                font = FontManager.instance.getOrCreate(style.fontFamily, style.fontWeight, style.fontStyle).font;
                 font.RequestCharactersInTextureSafe(buff.text, style.UnityFontSize, style.UnityFontStyle);
 
                 int wordstart = start == buff.size
             this._advance = x;
         }
         
-        void layoutEmoji(TextStyle style) {
+        void layoutEmoji(TextStyle style, Font font) {
             float x = this._advance;
             float letterSpace = style.letterSpacing;
             float letterSpaceHalfLeft = letterSpace * 0.5f;
             this._advances[0] += letterSpaceHalfLeft;
+            
+            var metrics = FontMetrics.fromFont(font, style.UnityFontSize);
-            var maxX = style.fontSize + x;
-            var minY = -style.fontSize;
-            var maxY = 0;
+            var maxX = metrics.descent - metrics.ascent + x;
+            var minY = metrics.ascent;
+            var maxY = metrics.descent;
 
             if (this._bounds.width <= 0 || this._bounds.height <= 0) {
                 this._bounds = UnityEngine.Rect.MinMaxRect(

Tests/Editor/Paragraph.cs

                         new TextSpan(style: new TextStyle(fontSize: 24),
                             text: "Emoji \ud83d\ude0a\ud83d\ude0b\ud83d\ude0d\ud83d\ude0e\ud83d\ude00"),
                         new TextSpan(style: new TextStyle(fontSize: 14),
-                            text: "Emoji \ud83d\ude0a\ud83d\ude0b\ud83d\ude0d\ud83d\ude0e\ud83d\ude00"),
+                            text: "Emoji \ud83d\ude0a\ud83d\ude0b\ud83d\ude0d\ud83d\ude0e\ud83d\ude00 Emoji"),
-                            text: "\ud83d\ude01\ud83d\ude02\ud83d\ude03\ud83d\ude04\ud83d\ude05"),
+                            text: "Emoji \ud83d\ude01\ud83d\ude02\ud83d\ude03\ud83d\ude04\ud83d\ude05"),
+                        new TextSpan(style: new TextStyle(fontSize: 18),
+                            text: "Emoji \ud83d\ude01\ud83d\ude02\ud83d\ude03\ud83d\ude04\ud83d\ude05 Emoji Emoji"),
+                        new TextSpan(style: new TextStyle(fontSize: 18),
+                            text: "Emoji \ud83d\ude01\ud83d\ude02\ud83d\ude03\ud83d\ude04\ud83d\ude05 Emoji Emoji Emoji"),
+                        new TextSpan(style: new TextStyle(fontSize: 18),
+                            text: "Emoji \ud83d\ude01\ud83d\ude02\ud83d\ude03\ud83d\ude04\ud83d\ude05"),
-                            text: "\ud83d\ude06\ud83d\ude1C\ud83d\ude18\ud83d\ude2D\ud83d\ude0C\ud83d\ude1E"),
+                            text: "Emoji \ud83d\ude06\ud83d\ude1C\ud83d\ude18\ud83d\ude2D\ud83d\ude0C\ud83d\ude1EEmoji"),
                         new TextSpan(style: new TextStyle(fontSize: 14),
                             text: "FontSize 14"),
                     })));