tweaks.

draw.go

@@ -245,7 +245,7 @@ func (d draw) TextWithin(r Renderer, text string, box Box, style Style) {
 		lineBox := r.MeasureText(line)
 		switch style.GetTextHorizontalAlign() {
 		case TextHorizontalAlignCenter:
-			tx = box.Left + ((lineBox.Width() - box.Left) >> 1)
+			tx = box.Left + ((box.Width() - lineBox.Width()) >> 1)
 		case TextHorizontalAlignRight:
 			tx = box.Right - lineBox.Width()
 		default:

examples/pie_chart/main.go

@@ -12,8 +12,7 @@ func drawChart(res http.ResponseWriter, req *http.Request) {
 	pie := chart.PieChart{
 		Title: "test\nchart",
 		TitleStyle: chart.Style{
-			Show:     true,
+			Show: true,
-			FontSize: 32,
 		},
 		Width:  512,
 		Height: 512,

pie_chart.go

@@ -242,15 +242,29 @@ func (pc PieChart) styleDefaultsElements() Style {
 
 func (pc PieChart) styleDefaultsTitle() Style {
 	return pc.TitleStyle.InheritFrom(Style{
-		FontColor:           DefaultTextColor,
+		FontColor:           ColorWhite,
 		Font:                pc.GetFont(),
-		FontSize:            24.0,
+		FontSize:            pc.getTitleFontSize(),
 		TextHorizontalAlign: TextHorizontalAlignCenter,
 		TextVerticalAlign:   TextVerticalAlignTop,
-		TextWrap:            TextWrapNone,
+		TextWrap:            TextWrapWord,
 	})
 }
 
+func (pc PieChart) getTitleFontSize() float64 {
+	effectiveDimension := Math.MinInt(pc.GetWidth(), pc.GetHeight())
+	if effectiveDimension >= 2048 {
+		return 48
+	} else if effectiveDimension >= 1024 {
+		return 24
+	} else if effectiveDimension >= 512 {
+		return 18
+	} else if effectiveDimension >= 256 {
+		return 12
+	}
+	return 10
+}
+
 // Box returns the chart bounds as a box.
 func (pc PieChart) Box() Box {
 	dpr := pc.Background.Padding.GetRight(DefaultBackgroundPadding.Right)

style.go

@@ -196,7 +196,7 @@ func (s Style) GetTextHorizontalAlign(defaults ...textHorizontalAlign) textHoriz
 		if len(defaults) > 0 {
 			return defaults[0]
 		}
-		return TextHorizontalAlignLeft
+		return TextHorizontalAlignUnset
 	}
 	return s.TextHorizontalAlign
 }
@@ -207,7 +207,7 @@ func (s Style) GetTextVerticalAlign(defaults ...textVerticalAlign) textVerticalA
 		if len(defaults) > 0 {
 			return defaults[0]
 		}
-		return TextVerticalAlignBaseline
+		return TextVerticalAlignUnset
 	}
 	return s.TextVerticalAlign
 }
@@ -218,7 +218,7 @@ func (s Style) GetTextWrap(defaults ...textWrap) textWrap {
 		if len(defaults) > 0 {
 			return defaults[0]
 		}
-		return TextWrapWord
+		return TextWrapUnset
 	}
 	return s.TextWrap
 }

text.go

@@ -1,6 +1,9 @@
 package chart
 
-import "strings"
+import (
+	"fmt"
+	"strings"
+)
 
 // TextHorizontalAlign is an enum for the horizontal alignment options.
 type textHorizontalAlign int
@@ -71,6 +74,7 @@ func (t text) WrapFit(r Renderer, value string, width int, style Style) []string
 	case TextWrapWord:
 		return t.WrapFitWord(r, value, width, style)
 	}
+	fmt.Printf("text wrap: %#v\n", style.TextWrap)
 	return []string{value}
 }