From 51229b9921b0afc9b33a3e0ef4f82774733d54f2 Mon Sep 17 00:00:00 2001
From: Christoph Mitterhofer <mitch@pixie.walhalla.org>
Date: Thu, 9 Sep 2021 13:14:39 +0200
Subject: [PATCH] Fixed RTrim(floatstr, "0.") converts "10.0" to "1"

---
 cache_content_text.go   | 15 ++++++++++++---
 fontsizefloat64_test.go | 25 +++++++++++++++++++++++++
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/cache_content_text.go b/cache_content_text.go
index 3f65a27..d81772d 100644
--- a/cache_content_text.go
+++ b/cache_content_text.go
@@ -4,7 +4,8 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"strings"
+	"math"
+	"strconv"
 )
 
 //ContentTypeCell cell
@@ -111,6 +112,14 @@ func (c *cacheContentText) calX() (float64, error) {
 	return 0.0, errors.New("contentType not found")
 }
 
+// FormatFloatTrim converts a float64 into a string, like Sprintf("%.3f")
+// but with trailing zeroes (and possibly ".") removed
+func FormatFloatTrim(floatval float64) (formatted string) {
+	const precisionFactor = 1000.0
+	roundedFontSize := math.Round(precisionFactor*floatval) / precisionFactor
+	return strconv.FormatFloat(roundedFontSize, 'f', -1, 64)
+}
+
 func (c *cacheContentText) write(w io.Writer, protection *PDFProtection) error {
 	r := c.textColor.r
 	g := c.textColor.g
@@ -137,8 +146,8 @@ func (c *cacheContentText) write(w io.Writer, protection *PDFProtection) error {
 
 	fmt.Fprintf(w, "%0.2f %0.2f TD\n", x, y)
 	fmt.Fprintf(w, "/F%d %s Tf\n", c.fontCountIndex,
-		// remove trailing zeroes and comma. "12.000" => "12"
-		strings.TrimRight(fmt.Sprintf("%.3f", c.fontSize), "0."))
+		FormatFloatTrim(c.fontSize))
+
 	if c.txtColorMode == "color" {
 		fmt.Fprintf(w, "%0.3f %0.3f %0.3f rg\n", float64(r)/255, float64(g)/255, float64(b)/255)
 	}
diff --git a/fontsizefloat64_test.go b/fontsizefloat64_test.go
index 018cb72..654a898 100644
--- a/fontsizefloat64_test.go
+++ b/fontsizefloat64_test.go
@@ -1,6 +1,7 @@
 package gopdf
 
 import (
+	"fmt"
 	"testing"
 )
 
@@ -106,5 +107,29 @@ func TestSetFontWithString(t *testing.T) {
 	if err == nil {
 		t.Errorf("SetFont(string) + AddText: Should have gotten an error!\n")
 	}
+}
 
+func ExampleFormatFloatTrim() {
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10.0))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10.01))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10.001))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10.0001))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(10.00001))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(9.99999))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(9.9999))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(9.999))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(9.99))
+	fmt.Printf("/F1 %s Tf\n", FormatFloatTrim(9.9))
+	// Output: /F1 10 Tf
+	// /F1 10 Tf
+	// /F1 10.01 Tf
+	// /F1 10.001 Tf
+	// /F1 10 Tf
+	// /F1 10 Tf
+	// /F1 10 Tf
+	// /F1 10 Tf
+	// /F1 9.999 Tf
+	// /F1 9.99 Tf
+	// /F1 9.9 Tf
 }