using point sizes for fonts and metrics in logical coordinates

designsystems/fluent2/QskFluent2Skin.cpp

@@ -30,8 +30,6 @@
 
       - Indicator subcontrol might be better than using the border of the selection box
       - cell padding unclear
-
-    - using qskDpToPixels ?
  */
 
 /*
@@ -134,14 +132,17 @@ namespace Fluent2
 
 namespace
 {
-    Q_DECL_UNUSED inline double operator ""_px( long double value )
+    /*
+        mapping between px and logical coordinates
+     */
+    inline constexpr double operator ""_px( long double value )
     {
-        return qskPxToPixels( static_cast< qreal >( value ) );
+        return static_cast< double >( value );
     }
 
-    Q_DECL_UNUSED inline double operator ""_px( unsigned long long value )
+    inline constexpr double operator ""_px( unsigned long long value )
     {
-        return qskPxToPixels( value );
+        return static_cast< double >( value );
     }
 
     inline constexpr QRgb rgbGray( int value, qreal opacity = 1.0 )
@@ -2073,10 +2074,9 @@ void QskFluent2Skin::initHints()
     addTheme( QskAspect::Footer, themeHeader );
 }
 
-static inline QFont createFont( int size, int lineHeight, QFont::Weight weight )
+static inline QFont createFont( qreal size, int lineHeight, QFont::Weight weight )
 {
     Q_UNUSED( lineHeight ); // TODO ...
-    const int pixelSize = qRound( qskPxToPixels( size ) );
 
     QFont font( QStringLiteral( "Segoe UI" ), -1, weight );
 
@@ -2092,7 +2092,8 @@ static inline QFont createFont( int size, int lineHeight, QFont::Weight weight )
         checkFont = false;
     }
 
-    font.setPixelSize( pixelSize );
+    // px: 1/96 inch, pt: 1/72 inch
+    font.setPointSizeF( size * 72.0 / 96.0 );
 
     return font;
 }
@@ -2101,18 +2102,18 @@ void QskFluent2Skin::setupFonts()
 {
     // see: https://fluent2.microsoft.design/typography ( Windows )
 
-    setFont( Fluent2::Caption, createFont( 12, 16, QFont::Normal ) );
+    setFont( Fluent2::Caption, createFont( 12_px, 16_px, QFont::Normal ) );
 
-    setFont( Fluent2::Body, createFont( 14, 20, QFont::Normal ) );
+    setFont( Fluent2::Body, createFont( 14_px, 20_px, QFont::Normal ) );
-    setFont( Fluent2::BodyStrong, createFont( 14, 20, QFont::DemiBold ) );
+    setFont( Fluent2::BodyStrong, createFont( 14_px, 20_px, QFont::DemiBold ) );
-    setFont( Fluent2::BodyStronger, createFont( 18, 24, QFont::Normal ) );
+    setFont( Fluent2::BodyStronger, createFont( 18_px, 24_px, QFont::Normal ) );
 
-    setFont( Fluent2::Subtitle, createFont( 20, 28, QFont::DemiBold ) );
+    setFont( Fluent2::Subtitle, createFont( 20_px, 28_px, QFont::DemiBold ) );
 
-    setFont( Fluent2::Title, createFont( 28, 36, QFont::Normal ) );
+    setFont( Fluent2::Title, createFont( 28_px, 36_px, QFont::Normal ) );
-    setFont( Fluent2::LargeTitle, createFont( 40, 52, QFont::DemiBold ) );
+    setFont( Fluent2::LargeTitle, createFont( 40_px, 52_px, QFont::DemiBold ) );
 
-    setFont( Fluent2::Display, createFont( 68, 92, QFont::DemiBold ) );
+    setFont( Fluent2::Display, createFont( 68_px, 92_px, QFont::DemiBold ) );
 
     // to have something for the unused roles
     QskSkin::completeFontTable();

designsystems/fusion/QskFusionSkin.cpp

@@ -80,14 +80,17 @@ namespace
         }
     };
 
-    Q_DECL_UNUSED inline double operator ""_px( long double value )
+    /*
+        mapping between px and logical coordinates
+     */
+    inline double operator ""_px( long double value )
     {
-        return qskDpToPixels( static_cast< qreal >( value ) );
+        return static_cast< double >( value );
     }
 
-    Q_DECL_UNUSED inline double operator ""_px( unsigned long long value )
+    inline double operator ""_px( unsigned long long value )
     {
-        return qskDpToPixels( value );
+        return static_cast< double >( value );
     }
 
     class Editor : private QskSkinHintTableEditor

designsystems/material3/QskMaterial3Skin.cpp

@@ -101,14 +101,47 @@ namespace
 
 namespace
 {
-    Q_DECL_UNUSED inline double operator ""_dp( long double value )
+    inline constexpr qreal dpToPixels( qreal value )
     {
-        return qskDpToPixels( static_cast< qreal >( value ) );
+        /*
+            see: https://en.wikipedia.org/wiki/Device-independent_pixel
+                 https://developer.android.com/training/multiscreen/screendensities
+
+            One dp is a virtual pixel unit that's roughly equal to one pixel
+            on a medium-density screen ( 160 dpi ).
+
+            One logical pixel is equivalent to 1/96th of an inch.
+         */
+
+        /*
+           For non scalable resources the following density buckets
+           are recommended:
+
+                  ldpi: ( 0 -> 140 )  : 120
+                  mdpi: ( 140 -> 200 ): 160
+                  hdpi: ( 140 -> 280 ): 240
+                 xhdpi: ( 280 -> 400 ): 320
+                xxhdpi: ( 400 -> 560 ): 480
+               xxxhdpi: ( 560 -> ... ): 640
+
+           For some reason the metrics from the Figma model seem to be
+           too small on our deskop system. Until this has bee understood
+           we use the ldpi bucket as the density of the logical coordinate
+           system falls into it.
+
+           Need to find out why TODO ...
+         */
+        return value * 96.0 / 120.0;
     }
 
-    Q_DECL_UNUSED inline double operator ""_dp( unsigned long long value )
+    Q_DECL_UNUSED inline constexpr double operator ""_dp( long double value )
     {
-        return qskDpToPixels( value );
+        return dpToPixels( static_cast< qreal >( value ) );
+    }
+
+    Q_DECL_UNUSED inline constexpr double operator ""_dp( unsigned long long value )
+    {
+        return dpToPixels( value );
     }
 
     class Combination : public QskStateCombination
@@ -1536,16 +1569,11 @@ QskMaterial3Skin::~QskMaterial3Skin()
 {
 }
 
-static inline QFont createFont( int pointSize, int lineHeight,
+static inline QFont createFont( qreal size, int lineHeight,
     qreal spacing, QFont::Weight weight )
 {
     Q_UNUSED( lineHeight );
 
-    // convert to px according to https://www.w3.org/TR/css3-values/#absolute-lengths :
-    const double pxSize = pointSize / 72.0 * 96.0;
-
-    const int pixelSize = qRound( qskDpToPixels( pxSize ) );
-
     QFont font( QStringLiteral( "Roboto" ), -1, weight );
 
     static bool checkFont = true;
@@ -1560,7 +1588,8 @@ static inline QFont createFont( int pointSize, int lineHeight,
         checkFont = false;
     }
 
-    font.setPixelSize( pixelSize );
+    // px: 1/96 inch, pt: 1/72 inch
+    font.setPointSize( size * 72.0 / 96.0 );
 
     if ( spacing > 0.0 )
         font.setLetterSpacing( QFont::AbsoluteSpacing, spacing );
@@ -1570,30 +1599,35 @@ static inline QFont createFont( int pointSize, int lineHeight,
 
 void QskMaterial3Skin::setupFonts()
 {
-    setFont( LabelSmall, createFont( 11, 16, 0.5, QFont::Medium ) );
+    /*
-    setFont( LabelMedium, createFont( 12, 16, 0.5, QFont::Medium ) );
+        Not sure what units are used for the font sizes in the specs.
-    setFont( LabelLarge, createFont( 14, 20, 0.1, QFont::Medium ) );
+        From the results on our desktop system we guess they are in pt
+        - corresponding to the QFont point size.
+     */
+    setFont( LabelSmall, createFont( 11, 16_dp, 0.5, QFont::Medium ) );
+    setFont( LabelMedium, createFont( 12, 16_dp, 0.5, QFont::Medium ) );
+    setFont( LabelLarge, createFont( 14, 20_dp, 0.1, QFont::Medium ) );
 
-    setFont( BodySmall, createFont( 12, 16, 0.4, QFont::Normal ) );
+    setFont( BodySmall, createFont( 12, 16_dp, 0.4, QFont::Normal ) );
-    setFont( BodyMedium, createFont( 14, 20, 0.25, QFont::Normal ) );
+    setFont( BodyMedium, createFont( 14, 20_dp, 0.25, QFont::Normal ) );
-    setFont( BodyLarge, createFont( 16, 24, 0.5, QFont::Normal ) );
+    setFont( BodyLarge, createFont( 16, 24_dp, 0.5, QFont::Normal ) );
 
-    setFont( TitleSmall, createFont( 14, 20, 0.1, QFont::Medium ) );
+    setFont( TitleSmall, createFont( 14, 20_dp, 0.1, QFont::Medium ) );
-    setFont( TitleMedium, createFont( 16, 24, 0.15, QFont::Medium ) );
+    setFont( TitleMedium, createFont( 16, 24_dp, 0.15, QFont::Medium ) );
-    setFont( TitleLarge, createFont( 22, 28, 0.0, QFont::Normal ) );
+    setFont( TitleLarge, createFont( 22, 28_dp, 0.0, QFont::Normal ) );
 
-    setFont( HeadlineSmall, createFont( 24, 32, 0.0, QFont::Normal ) );
+    setFont( HeadlineSmall, createFont( 24, 32_dp, 0.0, QFont::Normal ) );
-    setFont( HeadlineMedium, createFont( 28, 36, 0.0, QFont::Medium ) );
+    setFont( HeadlineMedium, createFont( 28, 36_dp, 0.0, QFont::Medium ) );
-    setFont( HeadlineLarge, createFont( 32, 40, 0.0, QFont::Medium ) );
+    setFont( HeadlineLarge, createFont( 32, 40_dp, 0.0, QFont::Medium ) );
 
-    setFont( DisplaySmall, createFont( 36, 44, 0.0, QFont::Normal ) );
+    setFont( DisplaySmall, createFont( 36, 44_dp, 0.0, QFont::Normal ) );
-    setFont( DisplayMedium, createFont( 45, 52, 0.0, QFont::Normal ) );
+    setFont( DisplayMedium, createFont( 45, 52_dp, 0.0, QFont::Normal ) );
-    setFont( DisplayLarge, createFont( 57, 64, 0.0, QFont::Normal ) );
+    setFont( DisplayLarge, createFont( 57, 64_dp, 0.0, QFont::Normal ) );
 
     // to have something for the unused roles
 
     setFont( { QskFontRole::Subtitle, QskFontRole::Normal },
-        createFont( 16, 24, 0.0, QFont::Normal ) );
+        createFont( 16, 24_dp, 0.0, QFont::Normal ) );
 
     QskSkin::completeFontTable();
 }

src/common/QskPlatform.cpp

@@ -52,44 +52,6 @@ QRect qskPlatformScreenGeometry( const QScreen* screen )
     return screen->handle()->geometry();
 }
 
-static inline qreal qskRoundedDpi( qreal dpi )
-{   
-    // see https://developer.android.com/training/multiscreen/screendensities
-    
-    if( dpi <= 140.0 )
-        return 120.0; // ldpi
-    
-    if( dpi <= 200.0 )
-        return 160.0; // mdpi
-    
-    if( dpi <= 280.0 )
-        return 240.0; // hdpi
-    
-    if( dpi <= 400.0 )
-        return 320.0; // xhdpi
-    
-    if( dpi <= 560.0 )
-        return 480.0; // xxhdpi
-    
-    return 640.0; // xxxhdpi
-}   
-
-qreal qskDpToPixelsFactor()
-{
-    if ( const auto screen = QGuiApplication::primaryScreen() )
-        return qskRoundedDpi( screen->physicalDotsPerInch() ) / 160.0;
-
-    return 1.0;
-}
-
-qreal qskPxToPixelsFactor()
-{
-    if ( const auto screen = QGuiApplication::primaryScreen() )
-        return screen->physicalDotsPerInch() / 96.0;
-
-    return 1.0;
-}
-
 static inline qreal qskWindowDpi( const QWindow* window )
 {
     QScreen* screen = nullptr;

src/common/QskPlatform.h

@@ -22,39 +22,7 @@ QSK_EXPORT QRect qskPlatformScreenGeometry( const QScreen* );
 QSK_EXPORT const QPlatformIntegration* qskPlatformIntegration();
 QSK_EXPORT const QPlatformTheme* qskPlatformTheme();
 
-/*
-    see: https://en.wikipedia.org/wiki/Device-independent_pixel
-
-    One dp is a virtual pixel unit that's roughly equal to one pixel
-    on a medium-density screen ( 160 dpi ). 
-
-    One px is equivalent to 1/96th of an inch.
- */
-
-QSK_EXPORT qreal qskDpToPixelsFactor();
-QSK_EXPORT qreal qskPxToPixelsFactor();
-
 QSK_EXPORT qreal qskInchesToPixels( const QQuickWindow*, qreal mm );
 QSK_EXPORT qreal qskMMToPixels( const QQuickWindow*, qreal mm );
 
-inline qreal qskDpToPixels( qreal value )
-{
-    static qreal factor = -1.0;
-
-    if ( factor < 0.0 )
-        factor = qskDpToPixelsFactor();
-
-    return value * factor;
-}
-
-inline qreal qskPxToPixels( qreal value )
-{
-    static qreal factor = -1.0;
-
-    if ( factor < 0.0 )
-        factor = qskPxToPixelsFactor();
-
-    return value * factor;
-}
-
 #endif

src/controls/QskSkin.cpp

@@ -306,30 +306,24 @@ void QskSkin::declareSkinlet( const QMetaObject* metaObject,
 }
 
 static inline void qskSetFont( QskSkin* skin,
-    QskFontRole::Category category, QskFontRole::Emphasis emphasis,  
+    QskFontRole::Category category, QFont font, qreal pointSize )
-    QFont font, QFont::Weight weight )
 {
-    font.setWeight( weight );
+    font.setPointSize( pointSize );
-    skin->setFont( { category, emphasis }, font );
+    skin->setFont( { category, QskFontRole::Normal }, font );
-}
-
-static inline void qskSetNormalFont( QskSkin* skin,
-    QskFontRole::Category category, QFont font, int pixelSize )
-{
-    font.setPixelSize( qRound( qskDpToPixels( pixelSize ) ) );
-    qskSetFont( skin, category, QskFontRole::Normal, font, QFont::Normal );
 }
 
 void QskSkin::setupFontTable( const QString& family, bool italic )
 {
-    const QFont font( family, -1, -1, italic );
+    QFont font( family );
+    font.setItalic( italic );
+    font.setWeight( QFont::Normal );
 
-    qskSetNormalFont( this, QskFontRole::Caption, font, 10 );
+    qskSetFont( this, QskFontRole::Caption, font, 8 );
-    qskSetNormalFont( this, QskFontRole::Subtitle, font, 15 );
+    qskSetFont( this, QskFontRole::Subtitle, font, 10 );
-    qskSetNormalFont( this, QskFontRole::Body, font, 20 );
+    qskSetFont( this, QskFontRole::Body, font, 12 );
-    qskSetNormalFont( this, QskFontRole::Title, font, 24 );
+    qskSetFont( this, QskFontRole::Title, font, 20 );
-    qskSetNormalFont( this, QskFontRole::Headline, font, 32 );
+    qskSetFont( this, QskFontRole::Headline, font, 30 );
-    qskSetNormalFont( this, QskFontRole::Display, font, 66 );
+    qskSetFont( this, QskFontRole::Display, font, 48 );
 
     completeFontTable();
 }