6562639: Wrong pixel bounds from TextLayout with white font

Reviewed-by: serb, prr

Author: Daniel Gredler

src/java.desktop/share/classes/java/awt/font/TextLine.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1998, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1998, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -396,10 +396,7 @@ public Rectangle getPixelBounds(FontRenderContext frc, float x, float y) {
                                                  BufferedImage.TYPE_INT_ARGB);
 
             Graphics2D g2d = im.createGraphics();
-            g2d.setColor(Color.WHITE);
-            g2d.fillRect(0, 0, im.getWidth(), im.getHeight());
-
-            g2d.setColor(Color.BLACK);
+            g2d.setColor(Color.WHITE); // white over transparent black bg
             draw(g2d, rx + MARGIN - bounds.x, ry + MARGIN - bounds.y);
 
             result = computePixelBounds(im);
@@ -428,7 +425,7 @@ static Rectangle computePixelBounds(BufferedImage im) {
             loop: while (++t < h) {
                 im.getRGB(0, t, buf.length, 1, buf, 0, w); // w ignored
                 for (int i = 0; i < buf.length; i++) {
-                    if (buf[i] != -1) {
+                    if (buf[i] != 0) {
                         break loop;
                     }
                 }
@@ -441,7 +438,7 @@ static Rectangle computePixelBounds(BufferedImage im) {
             loop: while (--b > t) {
                 im.getRGB(0, b, buf.length, 1, buf, 0, w); // w ignored
                 for (int i = 0; i < buf.length; ++i) {
-                    if (buf[i] != -1) {
+                    if (buf[i] != 0) {
                         break loop;
                     }
                 }
@@ -454,7 +451,7 @@ static Rectangle computePixelBounds(BufferedImage im) {
             loop: while (++l < r) {
                 for (int i = t; i < b; ++i) {
                     int v = im.getRGB(l, i);
-                    if (v != -1) {
+                    if (v != 0) {
                         break loop;
                     }
                 }
@@ -466,7 +463,7 @@ static Rectangle computePixelBounds(BufferedImage im) {
             loop: while (--r > l) {
                 for (int i = t; i < b; ++i) {
                     int v = im.getRGB(r, i);
-                    if (v != -1) {
+                    if (v != 0) {
                         break loop;
                     }
                 }

test/jdk/java/awt/font/TextLayout/TestGetPixelBoundsWithColors.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright (c) 2026, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * @test
+ * @bug 6562639
+ * @summary Verify correct getPixelBounds() behavior regardless of text color.
+ */
+
+import java.awt.Color;
+import java.awt.Font;
+import java.awt.Rectangle;
+import java.awt.font.FontRenderContext;
+import java.awt.font.TextAttribute;
+import java.awt.font.TextLayout;
+import java.awt.geom.Rectangle2D;
+import java.util.HashMap;
+import java.util.Map;
+
+public class TestGetPixelBoundsWithColors {
+
+    private static final Color TRANSPARENT_BLACK = new Color(0, 0, 0, 0);
+    private static final Color TRANSPARENT_WHITE = new Color(255, 255, 255, 0);
+
+    public static void main(String[] args) throws Exception {
+
+        Color[] colors = new Color[] {
+            Color.WHITE, Color.BLACK, Color.YELLOW, Color.RED, Color.GREEN,
+            Color.GRAY, Color.LIGHT_GRAY, Color.DARK_GRAY, Color.PINK,
+            Color.CYAN, Color.MAGENTA, Color.BLUE, null
+        };
+
+        for (Color color : colors) {
+            test(color);
+        }
+
+        testTransparent(TRANSPARENT_BLACK);
+        testTransparent(TRANSPARENT_WHITE);
+    }
+
+    private static void test(Color c) {
+        Map< TextAttribute, Object > underline = new HashMap<>();
+        underline.put(TextAttribute.UNDERLINE, TextAttribute.UNDERLINE_ON);
+        Font font1 = new Font(Font.DIALOG, Font.PLAIN, 60).deriveFont(underline);
+        Map< TextAttribute, Object > foreground = new HashMap<>();
+        foreground.put(TextAttribute.FOREGROUND, c);
+        Font font2 = font1.deriveFont(foreground);
+        FontRenderContext frc = new FontRenderContext(null, true, true);
+        TextLayout layout1 = new TextLayout("TEST", font1, frc);
+        TextLayout layout2 = new TextLayout("TEST", font2, frc);
+        Rectangle r1 = layout1.getPixelBounds(frc, 0, 0);
+        Rectangle r2 = layout2.getPixelBounds(frc, 0, 0);
+        if (!r1.equals(r2)) {
+            throw new RuntimeException("For color " + c + ", " + r1 + " != " + r2);
+        }
+        Rectangle2D bounds = layout1.getBounds();
+        if (Math.abs(bounds.getX() - r1.x) > 3 ||
+            Math.abs(bounds.getY() - r1.y) > 3 ||
+            Math.abs(bounds.getWidth() - r1.width) > 6 ||
+            Math.abs(bounds.getHeight() - r1.height) > 6) {
+            throw new RuntimeException("For color " + c + ", pixel bounds " +
+                r1 + " not similar to " + bounds);
+        }
+    }
+
+    private static void testTransparent(Color c) {
+        Font font1 = new Font(Font.DIALOG, Font.PLAIN, 60);
+        Map< TextAttribute, Object > attributes = new HashMap<>();
+        attributes.put(TextAttribute.FOREGROUND, c);
+        Font font2 = font1.deriveFont(attributes);
+        FontRenderContext frc = new FontRenderContext(null, true, true);
+        TextLayout layout = new TextLayout("TEST", font2, frc);
+        Rectangle r = layout.getPixelBounds(frc, 0, 0);
+        if (!r.isEmpty()) {
+            throw new RuntimeException("Expected empty pixel bounds for " + c + " but got " + r);
+        }
+    }
+}