text/v2: replace Metrics.Height/Width with HLineGap and VLineGap

Updates #2454

examples/keyboard/main.go

@@ -93,7 +93,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 
 	// Use bitmapfont.Face instead of ebitenutil.DebugPrint, since some key names might not be printed with DebugPrint.
 	textOp := &text.DrawOptions{}
-	textOp.LineSpacingInPixels = fontFace.Metrics().Height
+	textOp.LineSpacingInPixels = fontFace.Metrics().HLineGap + fontFace.Metrics().HAscent + fontFace.Metrics().HDescent
 	text.Draw(screen, strings.Join(keyStrs, ", ")+"\n"+strings.Join(keyNames, ", "), fontFace, textOp)
 }
 

examples/text/main.go

@@ -68,7 +68,7 @@ func (g *Game) Update() error {
 	// Initialize the glyphs for special (colorful) rendering.
 	if len(g.glyphs) == 0 {
 		op := &text.LayoutOptions{}
-		op.LineSpacingInPixels = mplusNormalFace.Metrics().Height
+		op.LineSpacingInPixels = mplusNormalFace.Size * 1.5
 		g.glyphs = text.AppendGlyphs(g.glyphs, sampleText, mplusNormalFace, op)
 	}
 	return nil
@@ -79,20 +79,20 @@ func (g *Game) Draw(screen *ebiten.Image) {
 
 	{
 		const x, y = 20, 20
-		w, h := text.Measure(sampleText, mplusNormalFace, mplusNormalFace.Metrics().Height)
+		w, h := text.Measure(sampleText, mplusNormalFace, mplusNormalFace.Size*1.5)
 		vector.DrawFilledRect(screen, x, y, float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(x, y)
-		op.LineSpacingInPixels = mplusNormalFace.Metrics().Height
+		op.LineSpacingInPixels = mplusNormalFace.Size * 1.5
 		text.Draw(screen, sampleText, mplusNormalFace, op)
 	}
 	{
 		const x, y = 20, 120
-		w, h := text.Measure(sampleText, mplusBigFace, mplusBigFace.Metrics().Height)
+		w, h := text.Measure(sampleText, mplusBigFace, mplusBigFace.Size*1.5)
 		vector.DrawFilledRect(screen, x, y, float32(w), float32(h), gray, false)
 		op := &text.DrawOptions{}
 		op.GeoM.Translate(x, y)
-		op.LineSpacingInPixels = mplusBigFace.Metrics().Height
+		op.LineSpacingInPixels = mplusBigFace.Size * 1.5
 		text.Draw(screen, sampleText, mplusBigFace, op)
 	}
 	{
@@ -101,7 +101,7 @@ func (g *Game) Draw(screen *ebiten.Image) {
 		op.GeoM.Rotate(math.Pi / 4)
 		op.GeoM.Translate(x, y)
 		op.Filter = ebiten.FilterLinear
-		op.LineSpacingInPixels = mplusNormalFace.Metrics().Height
+		op.LineSpacingInPixels = mplusNormalFace.Size * 1.5
 		text.Draw(screen, sampleText, mplusNormalFace, op)
 	}
 	{

examples/textinput/main.go

@@ -91,7 +91,7 @@ func (t *TextField) textIndexByCursorPosition(x, y int) (int, bool) {
 		y = 0
 	}
 
-	lineSpacingInPixels := int(fontFace.Metrics().Height)
+	lineSpacingInPixels := int(fontFace.Metrics().HLineGap + fontFace.Metrics().HAscent + fontFace.Metrics().HDescent)
 	var nlCount int
 	var lineStart int
 	var prevAdvance float64
@@ -256,7 +256,7 @@ func (t *TextField) cursorPos() (int, int) {
 		txt += t.state.Text[:t.state.CompositionSelectionStartInBytes]
 	}
 	x := int(text.Advance(txt, fontFace))
-	y := nlCount * int(fontFace.Metrics().Height)
+	y := nlCount * int(fontFace.Metrics().HLineGap+fontFace.Metrics().HAscent+fontFace.Metrics().HDescent)
 	return x, y
 }
 
@@ -274,7 +274,7 @@ func (t *TextField) Draw(screen *ebiten.Image) {
 		cx, cy := t.cursorPos()
 		x += px + cx
 		y += py + cy
-		h := int(fontFace.Metrics().Height)
+		h := int(fontFace.Metrics().HLineGap + fontFace.Metrics().HAscent + fontFace.Metrics().HDescent)
 		vector.StrokeLine(screen, float32(x), float32(y), float32(x), float32(y+h), 1, color.Black, false)
 	}
 
@@ -288,7 +288,7 @@ func (t *TextField) Draw(screen *ebiten.Image) {
 	op := &text.DrawOptions{}
 	op.GeoM.Translate(float64(tx), float64(ty))
 	op.ColorScale.ScaleWithColor(color.Black)
-	op.LineSpacingInPixels = fontFace.Metrics().Height
+	op.LineSpacingInPixels = fontFace.Metrics().HLineGap + fontFace.Metrics().HAscent + fontFace.Metrics().HDescent
 	text.Draw(screen, shownText, fontFace, op)
 }
 
@@ -296,7 +296,7 @@ const textFieldHeight = 24
 
 func textFieldPadding() (int, int) {
 	m := fontFace.Metrics()
-	return 4, (textFieldHeight - int(m.Height)) / 2
+	return 4, (textFieldHeight - int(m.HLineGap+m.HAscent+m.HDescent)) / 2
 }
 
 type Game struct {

text/v2/gotext.go

@@ -189,12 +189,12 @@ func (g *GoTextFace) Metrics() Metrics {
 
 	var m Metrics
 	if h, ok := g.Source.f.FontHExtents(); ok {
-		m.Height = float64(h.Ascender-h.Descender+h.LineGap) * scale
+		m.HLineGap = float64(h.LineGap) * scale
 		m.HAscent = float64(h.Ascender) * scale
 		m.HDescent = float64(-h.Descender) * scale
 	}
 	if v, ok := g.Source.f.FontVExtents(); ok {
-		m.Width = float64(v.Ascender-v.Descender+v.LineGap) * scale
+		m.VLineGap = float64(v.LineGap) * scale
 		m.VAscent = float64(v.Ascender) * scale
 		m.VDescent = float64(-v.Descender) * scale
 	}

text/v2/multi.go

@@ -33,8 +33,8 @@ func (m MultiFace) Metrics() Metrics {
 	var mt Metrics
 	for _, f := range m {
 		mt1 := f.Metrics()
-		if mt1.Height > mt.Height {
+		if mt1.HLineGap > mt.HLineGap {
-			mt.Height = mt1.Height
+			mt.HLineGap = mt1.HLineGap
 		}
 		if mt1.HAscent > mt.HAscent {
 			mt.HAscent = mt1.HAscent
@@ -42,8 +42,8 @@ func (m MultiFace) Metrics() Metrics {
 		if mt1.HDescent > mt.HDescent {
 			mt.HDescent = mt1.HDescent
 		}
-		if mt1.Width > mt.Width {
+		if mt1.VLineGap > mt.VLineGap {
-			mt.Width = mt1.Width
+			mt.VLineGap = mt1.VLineGap
 		}
 		if mt1.VAscent > mt.VAscent {
 			mt.VAscent = mt1.VAscent

text/v2/std.go

@@ -68,7 +68,7 @@ func (s *StdFace) Metrics() Metrics {
 
 	m := s.f.Metrics()
 	return Metrics{
-		Height:   fixed26_6ToFloat64(m.Height),
+		HLineGap: fixed26_6ToFloat64(m.Height - m.Ascent - m.Descent),
 		HAscent:  fixed26_6ToFloat64(m.Ascent),
 		HDescent: fixed26_6ToFloat64(m.Descent),
 	}

text/v2/text.go

@@ -48,8 +48,8 @@ type Face interface {
 // Metrics holds the metrics for a Face.
 // A visual depiction is at https://developer.apple.com/library/mac/documentation/TextFonts/Conceptual/CocoaTextArchitecture/Art/glyph_metrics_2x.png
 type Metrics struct {
-	// Height is the recommended amount of vertical space between two lines of text in pixels.
+	// HLineGap is the recommended amount of vertical space between two lines of text in pixels.
-	Height float64
+	HLineGap float64
 
 	// HAscent is the distance in pixels from the top of a line to its baseline for horizontal lines.
 	HAscent float64
@@ -58,9 +58,9 @@ type Metrics struct {
 	// The value is typically positive, even though a descender goes below the baseline.
 	HDescent float64
 
-	// Width is the recommended amount of horizontal space between two lines of text in pixels.
+	// VLineGap is the recommended amount of horizontal space between two lines of text in pixels.
-	// If the face is StdFace or the font dosen't support a vertical direction, Width is 0.
+	// If the face is StdFace or the font dosen't support a vertical direction, VLineGap is 0.
-	Width float64
+	VLineGap float64
 
 	// VAscent is the distance in pixels from the top of a line to its baseline for vertical lines.
 	// If the face is StdFace or the font dosen't support a vertical direction, VAscent is 0.