Rendering for larger than 100pt emoji on macOS

jsvg/src/main/java/com/github/weisj/jsvg/nodes/text/AbstractGlyphRun.java

@@ -23,11 +23,20 @@
 
 import java.awt.*;
 import java.awt.geom.AffineTransform;
+import java.awt.image.BufferedImage;
 import java.util.List;
+import java.util.logging.Logger;
 
 import org.jetbrains.annotations.NotNull;
 
+import com.github.weisj.jsvg.attributes.font.SVGFont;
+import com.github.weisj.jsvg.renderer.Graphics2DOutput;
+import com.github.weisj.jsvg.renderer.Output;
+import com.github.weisj.jsvg.util.ImageUtil;
+import com.github.weisj.jsvg.util.SystemUtil;
+
 public class AbstractGlyphRun<T extends Shape> {
+    private static final Logger LOGGER = Logger.getLogger(AbstractGlyphRun.class.getName());
     private final @NotNull T shape;
     private final @NotNull List<@NotNull PaintableEmoji> emojis;
 
@@ -53,12 +62,37 @@ public static class PaintableEmoji {
             this.transform = transform;
         }
 
-        public @NotNull EmojiGlyph glyph() {
-            return glyph;
-        }
+        public void render(@NotNull Output output, @NotNull SVGFont font) {
+            output.applyTransform(transform);
+            int fontSize = font.size();
+
+            // The JDK text pipeline on macOS can only render Emoji up to 100pt.
+            // In this case we have to paint to a buffer which is then scaled up.
+            int maxFontSize = SystemUtil.isMacOS ? 100 : Integer.MAX_VALUE;
+
+            if (output.transform().getScaleY() * fontSize > maxFontSize) {
+                // Guess where the baseline ought to be for descenders to be fully visible. Very hackish.
+                float baselinePosition = 0.9f;
+                if (glyph.largeBitmap == null) {
+                    // Size of bitmap is guessed, as there is now reliable way to get the size of the glyph.
+                    BufferedImage bitmap = ImageUtil.createCompatibleTransparentImage(maxFontSize, maxFontSize);
+                    Graphics g = bitmap.getGraphics();
+                    g.setFont(g.getFont().deriveFont((float) maxFontSize));
 
-        public @NotNull AffineTransform transform() {
-            return transform;
+                    g.drawString(glyph.codepoint(), 0, (int) (baselinePosition * maxFontSize));
+                    g.dispose();
+                    glyph.largeBitmap = bitmap;
+                }
+                output.scale((double) fontSize / maxFontSize, (double) fontSize / maxFontSize);
+                output.translate(0, -(int) (baselinePosition * maxFontSize));
+                output.drawImage(glyph.largeBitmap);
+            } else {
+                if (output instanceof Graphics2DOutput) {
+                    Graphics2D g = ((Graphics2DOutput) output).graphics();
+                    g.setFont(g.getFont().deriveFont((float) fontSize));
+                    g.drawString(glyph.codepoint(), 0, 0);
+                }
+            }
         }
     }
 }

jsvg/src/main/java/com/github/weisj/jsvg/nodes/text/EmojiGlyph.java

@@ -22,11 +22,13 @@
 package com.github.weisj.jsvg.nodes.text;
 
 import java.awt.*;
+import java.awt.image.BufferedImage;
 
 import org.jetbrains.annotations.NotNull;
 
 public class EmojiGlyph extends Glyph {
     private final @NotNull String codepoint;
+    BufferedImage largeBitmap;
 
     public EmojiGlyph(@NotNull String codepoint, float advance) {
         super(new Rectangle(), advance, false);

jsvg/src/main/java/com/github/weisj/jsvg/nodes/text/GlyphRenderer.java

@@ -79,19 +79,11 @@ static void renderGlyphRun(@NotNull Output output, @NotNull PaintOrder paintOrde
                 null);
 
         // Experimental Emoji rendering
-        if (output instanceof Graphics2DOutput) {
-            Graphics2DOutput g2dOutput = (Graphics2DOutput) output;
-            Graphics2D g = (Graphics2D) g2dOutput.graphics().create();
-            AffineTransform transform = g.getTransform();
-
-            g.setFont(g.getFont().deriveFont((float) context.font().size()));
-            for (AbstractGlyphRun.PaintableEmoji emoji : glyphRun.emojis()) {
-                g.setTransform(transform);
-                g.transform(emoji.transform());
-                g.drawString(emoji.glyph().codepoint(), 0, 0);
-            }
-
-            g.dispose();
+        SVGFont font = context.font();
+        Output.SafeState safeState = output.safeState();
+        for (AbstractGlyphRun.PaintableEmoji emoji : glyphRun.emojis()) {
+            emoji.render(output, font);
+            safeState.restore();
         }
 
         // Invalidate the glyphRun. Avoids holding onto the RenderContext, which may reference a JComponent.

jsvg/src/main/java/com/github/weisj/jsvg/util/SystemUtil.java

@@ -0,0 +1,30 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2024 Jannis Weis
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+ * NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+package com.github.weisj.jsvg.util;
+
+public final class SystemUtil {
+
+    private SystemUtil() {}
+
+    public static final String OS_NAME = System.getProperty("os.name").toLowerCase();
+    public static final boolean isMacOS = OS_NAME.contains("mac");
+}