Add SetUnderlineThickness method

2 files changed, 11 insertions, 2 deletions

diff --git a/def.go b/def.go
index 95da6ba..7fddc82 100644
--- a/def.go
+++ b/def.go
@@ -452,6 +452,7 @@ type Pdf interface {
 	SetTextSpotColor(nameStr string, tint byte)
 	SetTitle(titleStr string, isUTF8 bool)
 	SetTopMargin(margin float64)
+	SetUnderlineThickness(thickness float64)
 	SetXmpMetadata(xmpStream []byte)
 	SetX(x float64)
 	SetXY(x, y float64)
@@ -595,7 +596,8 @@ type Fpdf struct {
 		// Composite values of colors
 		draw, fill, text colorType
 	}
-	spotColorMap map[string]spotColorType // Map of named ink-based colors
+	spotColorMap           map[string]spotColorType // Map of named ink-based colors
+	userUnderlineThickness float64                  // A custom user underline thickness multiplier.
 }
 
 type encType struct {
diff --git a/fpdf.go b/fpdf.go
index d64a324..f77717f 100644
--- a/fpdf.go
+++ b/fpdf.go
@@ -202,6 +202,7 @@ func fpdfNew(orientationStr, unitStr, sizeStr, fontDirStr string, size SizeType)
 	f.layerInit()
 	f.catalogSort = gl.catalogSort
 	f.creationDate = gl.creationDate
+	f.userUnderlineThickness = 1
 	return
 }
 
@@ -3538,10 +3539,16 @@ func blankCount(str string) (count int) {
 	return
 }
 
+// SetUnderlineThickness accepts a multiplier for adjusting the text underline
+// thickness, defaulting to 1. See SetUnderlineThickness example.
+func (f *Fpdf) SetUnderlineThickness(thickness float64) {
+	f.userUnderlineThickness = thickness
+}
+
 // Underline text
 func (f *Fpdf) dounderline(x, y float64, txt string) string {
 	up := float64(f.currentFont.Up)
-	ut := float64(f.currentFont.Ut)
+	ut := float64(f.currentFont.Ut) * f.userUnderlineThickness
 	w := f.GetStringWidth(txt) + f.ws*float64(blankCount(txt))
 	return sprintf("%.2f %.2f %.2f %.2f re f", x*f.k,
 		(f.h-(y-up/1000*f.fontSize))*f.k, w*f.k, -ut/1000*f.fontSizePt)