Merge branch 'underline' of https://github.com/joewestcott/gofpdf int…

…o joewestcott-underline

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 {

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)

fpdf_test.go

@@ -2688,3 +2688,26 @@ func ExampleFpdf_RoundedRect() {
 	// Output:
 	// Successfully generated pdf/Fpdf_RoundedRect.pdf
 }
+
+// ExampleFpdf_SetUnderlineThickness demonstrates how to adjust the text
+// underline thickness.
+func ExampleFpdf_SetUnderlineThickness() {
+	pdf := gofpdf.New("P", "mm", "A4", "") // 210mm x 297mm
+	pdf.AddPage()
+	pdf.SetFont("Arial", "U", 12)
+
+	pdf.SetUnderlineThickness(0.5)
+	pdf.CellFormat(0, 10, "Thin underline", "", 1, "", false, 0, "")
+
+	pdf.SetUnderlineThickness(1)
+	pdf.CellFormat(0, 10, "Normal underline", "", 1, "", false, 0, "")
+
+	pdf.SetUnderlineThickness(2)
+	pdf.CellFormat(0, 10, "Thicker underline", "", 1, "", false, 0, "")
+
+	fileStr := example.Filename("Fpdf_UnderlineThickness")
+	err := pdf.OutputFileAndClose(fileStr)
+	example.Summary(err, fileStr)
+	// Output:
+	// Successfully generated pdf/Fpdf_UnderlineThickness.pdf
+}