Fonts: HiDPIUtils: improved vertical position correction of text (on Windows) for various fonts

flatlaf-core/src/main/java/com/formdev/flatlaf/util/HiDPIUtils.java

@@ -16,6 +16,7 @@
 
 package com.formdev.flatlaf.util;
 
+import java.awt.Font;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.font.GlyphVector;
@@ -141,37 +142,101 @@ public class HiDPIUtils
 		if( !useTextYCorrection() || !SystemInfo.isWindows )
 			return 0;
 
-		if( !SystemInfo.isJava_9_orLater )
-			return UIScale.getUserScaleFactor() > 1 ? -UIScale.scale( 0.625f ) : 0;
+		if( !SystemInfo.isJava_9_orLater ) {
+			// Java 8
+			float scaleFactor = getUserScaleFactor();
+			if( scaleFactor > 1 ) {
+				switch( g.getFont().getFamily() ) {
+					case "Segoe UI":
+					case "Segoe UI Light":
+					case "Segoe UI Semibold":
+						return -((scaleFactor == 2.25f || scaleFactor == 4f ? 0.875f : 0.625f) * scaleFactor);
 
-		AffineTransform t = g.getTransform();
-		double scaleY = t.getScaleY();
-		if( scaleY < 1.25 )
-			return 0;
+					case "Noto Sans":
+					case "Open Sans":
+						return -(0.3f * scaleFactor);
 
-		// Text is painted at slightly different Y positions depending on scale factor
-		// and Y position of component.
-		// The exact reason is not yet known (to me), but there are several factors:
-		// - fractional scale factors result in fractional component Y device coordinates
-		// - fractional text Y device coordinates are rounded for horizontal lines of characters
-		// - maybe different rounding methods for drawing primitives (e.g. rectangle) and text
-		// - Java adds 0.5 to X/Y positions before drawing string in BufferedTextPipe.enqueueGlyphList()
+					case "Verdana":
+						return -((scaleFactor < 2 ? 0.4f : 0.3f) * scaleFactor);
+				}
+			}
+		} else {
+			// Java 9 and later
 
-		// this is not the optimal solution, but works very good in most cases
-		// (tested with class FlatPaintingStringTest on Windows 10 with font "Segoe UI")
-		if( scaleY <= 1.25 )
-			return -0.875f;
-		if( scaleY <= 1.5 )
-			return -0.625f;
-		if( scaleY <= 1.75 )
-			return -0.875f;
-		if( scaleY <= 2.0 )
-			return -0.75f;
-		if( scaleY <= 2.25 )
-			return -0.875f;
-		if( scaleY <= 3.5 )
-			return -0.75f;
-		return -0.875f;
+			// Text is painted at slightly different Y positions depending on scale factor
+			// and Y position of component.
+			// The exact reason is not yet known (to me), but there are several factors:
+			// - fractional scale factors result in fractional component Y device coordinates
+			// - fractional text Y device coordinates are rounded for horizontal lines of characters
+			// - maybe different rounding methods for drawing primitives (e.g. rectangle) and text
+			// - Java adds 0.5 to X/Y positions before drawing string in BufferedTextPipe.enqueueGlyphList()
+
+			// this is not the optimal solution, but works very good in most cases
+			// (tested with class FlatPaintingStringTest on Windows 11)
+
+			switch( g.getFont().getFamily() ) {
+				case "Segoe UI":
+				case "Segoe UI Light":
+				case "Segoe UI Semibold":
+				case "Verdana":
+				case Font.DIALOG:
+				case Font.SANS_SERIF:
+					return correctionForScaleY( g, CORRECTION_SEGOE_UI );
+
+				case "Tahoma":
+					return correctionForScaleY( g, CORRECTION_TAHOMA );
+
+				case "Inter":
+				case "Inter Light":
+				case "Inter Semi Bold":
+				case "Roboto":
+					return correctionForScaleY( g, CORRECTION_INTER );
+
+				case "Noto Sans":
+				case "Open Sans":
+					return correctionForScaleY( g, CORRECTION_OPEN_SANS );
+			}
+		}
+
+		return 0;
+	}
+
+	private static final float[]
+		SCALE_FACTORS        = {  1.25f,   1.5f,    1.75f,   2f,      2.25f,   2.5f,    3f,      3.5f,    4f     },
+
+		CORRECTION_SEGOE_UI  = { -0.5f,   -0.5f,   -0.625f, -0.75f,  -0.75f,  -0.75f,  -0.75f,  -0.75f,  -0.875f },
+		CORRECTION_TAHOMA    = { -0.25f,  -0.25f,  -0.25f,  -0f,     -0.125f, -0.125f, -0.125f, -0.125f, -0f     },
+		CORRECTION_INTER     = { -0.25f,  -0.25f,  -0.25f,  -0f,     -0.125f, -0.125f, -0f,     -0.25f,  -0f     },
+		CORRECTION_OPEN_SANS = { -0.5f,   -0.25f,  -0.25f,  -0f,     -0.25f,  -0.25f,  -0f,     -0.25f,  -0.25f  };
+
+	private static float correctionForScaleY( Graphics2D g, float[] correction ) {
+		if( correction.length != 9 )
+			throw new IllegalArgumentException();
+
+		double scaleY = g.getTransform().getScaleY();
+		return (scaleY < 1.25) ? 0 : correction[scaleFactor2index( (float) scaleY )];
+	}
+
+	private static int scaleFactor2index( float scaleFactor ) {
+		for( int i = 0; i < SCALE_FACTORS.length; i++ ) {
+			if( scaleFactor <= SCALE_FACTORS[i] )
+				return i;
+		}
+		return SCALE_FACTORS.length - 1;
+	}
+
+	private static Boolean useDebugScaleFactor;
+
+	private static boolean useDebugScaleFactor() {
+		if( useDebugScaleFactor == null )
+			useDebugScaleFactor = FlatSystemProperties.getBoolean( "FlatLaf.debug.HiDPIUtils.useDebugScaleFactor", false );
+		return useDebugScaleFactor;
+	}
+
+	private static float getUserScaleFactor() {
+		return !useDebugScaleFactor()
+			? UIScale.getUserScaleFactor()
+			: Float.parseFloat( System.getProperty( "FlatLaf.debug.HiDPIUtils.debugScaleFactor", "1" ) );
 	}
 
 	/**

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DemoFrame.java

@@ -352,7 +352,7 @@ class DemoFrame
 		fontMenu.addSeparator();
 		ArrayList<String> families = new ArrayList<>( Arrays.asList(
 			"Arial", "Cantarell", "Comic Sans MS", "DejaVu Sans",
-			"Dialog", "Inter", "Liberation Sans", "Noto Sans", "Roboto",
+			"Dialog", "Inter", "Liberation Sans", "Noto Sans", "Open Sans", "Roboto",
 			"SansSerif", "Segoe UI", "Serif", "Tahoma", "Ubuntu", "Verdana" ) );
 		if( !families.contains( currentFamily ) )
 			families.add( currentFamily );

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatPaintingStringTest.java

@@ -30,6 +30,8 @@ import javax.swing.*;
 import javax.swing.text.StyleContext;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.FlatSystemProperties;
+import com.formdev.flatlaf.fonts.inter.FlatInterFont;
+import com.formdev.flatlaf.fonts.jetbrains_mono.FlatJetBrainsMonoFont;
 import com.formdev.flatlaf.util.Graphics2DProxy;
 import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.JavaCompatibility;
@@ -45,8 +47,12 @@ public class FlatPaintingStringTest
 	public static void main( String[] args ) {
 		System.setProperty( FlatSystemProperties.UI_SCALE, "1x" );
 		System.setProperty( "sun.java2d.uiScale", "1x" );
+		System.setProperty( "FlatLaf.debug.HiDPIUtils.useDebugScaleFactor", "true" );
 
 		SwingUtilities.invokeLater( () -> {
+			FlatInterFont.install();
+			FlatJetBrainsMonoFont.install();
+
 			FlatTestFrame frame = FlatTestFrame.create( args, "FlatPaintingStringTest" );
 
 			ToolTipManager.sharedInstance().setInitialDelay( 0 );
@@ -70,30 +76,32 @@ public class FlatPaintingStringTest
 		String[] families = {
 			// regular
 			"Arial", "Cantarell", "DejaVu Sans",
-			"Dialog", "Helvetica Neue", "Inter", "Liberation Sans", "Noto Sans", "Open Sans", "Roboto",
+			"Dialog", "Helvetica Neue", "Liberation Sans", "Noto Sans", "Open Sans", "Roboto",
 			"SansSerif", "Segoe UI", "Tahoma", "Ubuntu", "Verdana", ".SF NS Text",
+			FlatInterFont.FAMILY,
 
 			// light, semibold
 			"Segoe UI Light", "Segoe UI Semibold",
 			"HelveticaNeue-Thin", "HelveticaNeue-Medium",
 			"Lato Light", "Ubuntu Light", "Cantarell Light",
 			"Lato Semibold", "Ubuntu Medium", "Montserrat SemiBold",
+			FlatInterFont.FAMILY_LIGHT, FlatInterFont.FAMILY_SEMIBOLD,
 
 			// monospaced
 			"Monospaced", "Consolas", "Courier New", "Menlo", "Liberation Mono", "Ubuntu Mono",
+			FlatJetBrainsMonoFont.FAMILY,
 		};
 		Arrays.sort( families, String.CASE_INSENSITIVE_ORDER );
 		DefaultComboBoxModel<String> model = new DefaultComboBoxModel<>();
-		model.addElement( currentFamily );
 		for( String family : families ) {
-			if( !family.equals( currentFamily ) && Arrays.binarySearch( availableFontFamilyNames, family ) >= 0 )
+			if( Arrays.binarySearch( availableFontFamilyNames, family ) >= 0 )
 				model.addElement( family );
 		}
 		fontField.setModel( model );
 		fontField.setSelectedItem( currentFamily );
 		updateFontMetricsLabel();
 
-		add( new JLabel() );
+		add( new JLabel(), "newLine" );
 		add( new JLabel( "none" ) );
 		add( new JLabel( "flatlaf" ) );
 		add( new JLabel() );
@@ -120,9 +128,8 @@ public class FlatPaintingStringTest
 
 		YCorrectionFunction none = (g, scaleFactor) -> 0;
 		YCorrectionFunction flatlaf = (g, scaleFactor) -> {
-			return SystemInfo.isJava_9_orLater
-				? HiDPIUtils.computeTextYCorrection( g )
-				: (scaleFactor > 1 ? -(0.625f * scaleFactor) : 0);
+			System.setProperty( "FlatLaf.debug.HiDPIUtils.debugScaleFactor", Float.toString( scaleFactor ) );
+			return HiDPIUtils.computeTextYCorrection( g );
 		};
 		YCorrectionFunction ty = (g, scaleFactor) -> {
 			// Based on translateY, which is the scaled Y coordinate translation of the graphics context.
@@ -214,8 +221,8 @@ public class FlatPaintingStringTest
 			// columns
 			"[fill]",
 			// rows
-			"[top]unrel" +
-			"[top]"));
+			"[shrink 0,top]unrel" +
+			"[shrink 0,top]"));
 
 		//======== panel1 ========
 		{

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatPaintingStringTest.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.5.0.404" Java: "17.0.2" encoding: "UTF-8"
+JFDML JFormDesigner: "8.0.0.0.194" Java: "17.0.2" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -9,7 +9,7 @@ new FormModel {
 		add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 			"$layoutConstraints": "insets dialog,hidemode 3"
 			"$columnConstraints": "[fill]"
-			"$rowConstraints": "[top]unrel[top]"
+			"$rowConstraints": "[shrink 0,top]unrel[shrink 0,top]"
 		} ) {
 			name: "this"
 			"border": sfield com.jformdesigner.model.FormObject NULL_VALUE