[BUG] SetFont(simsun.ttf) doesn't working for chinese font

[researchlab]

I want to display chinese font normally by using SetFont Method to set the font of simsun.ttf or NotoSansSC-Regular.ttf which support display chinese font normally,

but it's doesn't working. so anyone cloud help me how to display chinese font normally ?

Here's the code for my testing,

func RunPdfReport(outputPath string) error {
	//robotoFontRegular, err := model.NewPdfFontFromTTFFile("./NotoSansSC-Regular.ttf")
	robotoFontRegular, err := model.NewPdfFontFromTTFFile("./simsun.ttf")
	if err != nil {
		return err
	}
	robotoFontPro, err := model.NewPdfFontFromTTFFile("./NotoSansSC-Regular.ttf")
	if err != nil {
		return err
	}
	c := creator.New()
	c.SetPageMargins(50, 50, 100, 70)
	
	c.CreateFrontPage(func(args creator.FrontpageFunctionArgs) {
		DoFirstPage(c, robotoFontRegular, robotoFontPro)
	})

	return c.WriteToFile(outputPath)

}
func DoFirstPage(c *creator.Creator, fontRegular *model.PdfFont, fontBold *model.PdfFont) {
	p := c.NewParagraph("中文检测")
	p.SetFont(fontRegular)
	p.SetFontSize(48)
	p.SetMargins(85, 0, 150, 0)
	p.SetColor(creator.ColorRGBFrom8bit(56, 68, 77))
	c.Draw(p)

	p = c.NewParagraph("Example Report")
	p.SetFont(fontRegular)
	p.SetFontSize(30)
	p.SetMargins(85, 0, 0, 0)
	p.SetColor(creator.ColorRGBFrom8bit(45, 148, 215))
	c.Draw(p)
}

[rogchap]

How was this solved?

[gunnsth]

This is an outdated question. Font support has been completely revamped over the least year and font subsetting added as well.

[gunnsth]

Please keep the discussion focused on topic with respect to the library. This is something that we would like the library to support. To discuss other methods please seek other discussion forums and such.

[gunnsth]

The issue with the code in the issue is that it uses NewPdfFontFromTTFFile instead of NewCompositePdfFontFromTTFFile
The function NewPdfFontFromTTFFile only handles simple encodings, whereas NewCompositePdfFontFromTTFFile can use symbolic fonts.
It is also worth pointing out oftentimes symbolic fonts can be very big so it can make sense to enable subsetting in the output. If using creator package that can be achieved with c.EnableFontSubsetting(font). Otherwise can use the font's SubsetRegistered.

By using NewCompositePdfFontFromTTFFile with the code posted above (and fonts that can be found by searching).
output.pdf, which is 5.6MB.
Then by enabling font subsetting, we get:
which is
output_subset.pdf which is 15kB. So it makes a pretty big difference.

[carmel]

Chinese characters will be crowded together, can this be solved?
@gunnsth

[sampila]

Hi @carmel, could you provide a runnable code snippet? by proving runnable code snippet we can further investigate the issue.

However, we tried to reproduce the issue by modifying the code in this issue.

Code

package main

import (
	"fmt"
	"os"

	"github.com/unidoc/unipdf/v3/common"
	"github.com/unidoc/unipdf/v3/common/license"
	"github.com/unidoc/unipdf/v3/creator"
	"github.com/unidoc/unipdf/v3/model"
)

func init() {
	// Make sure to load your metered License API key prior to using the library.
	// If you need a key, you can sign up and create a free one at https://cloud.unidoc.io
	err := license.SetMeteredKey(os.Getenv("UNIDOC_LICENSE_API_KEY"))
	if err != nil {
		fmt.Printf("ERROR: Failed to set metered key: %v\n", err)
		fmt.Printf("Make sure to get a valid key from https://cloud.unidoc.io\n")
		panic(err)
	}
	common.SetLogger(common.NewConsoleLogger(common.LogLevelDebug))
}

func main() {
	if len(os.Args) < 2 {
		fmt.Printf("Usage: go run main.go <output.pdf>\n")
		os.Exit(1)
	}

	outputPath := os.Args[1]
	err := RunPdfReport(outputPath)
	if err != nil {
		fmt.Printf("Error: %v\n", err)
		os.Exit(1)
	}
	fmt.Printf("PDF report written to %s\n", outputPath)
}

func RunPdfReport(outputPath string) error {
	fontRegular, err := model.NewCompositePdfFontFromTTFFile("./fonts/simsun.ttf")
	if err != nil {
		return err
	}
	fontBold, err := model.NewCompositePdfFontFromTTFFile("./fonts/NotoSansSC-Regular.ttf")
	if err != nil {
		return err
	}
	c := creator.New()
	c.SetPageMargins(50, 50, 100, 70)

	c.CreateFrontPage(func(args creator.FrontpageFunctionArgs) {
		DoFirstPage(c, fontRegular, fontBold)
	})

	return c.WriteToFile(outputPath)

}
func DoFirstPage(c *creator.Creator, fontRegular *model.PdfFont, fontBold *model.PdfFont) {
	p := c.NewParagraph("中文检测")
	p.SetFont(fontRegular)
	p.SetFontSize(48)
	p.SetMargins(85, 0, 150, 0)
	p.SetColor(creator.ColorRGBFrom8bit(56, 68, 77))
	c.Draw(p)

	p = c.NewParagraph("Example Report")
	p.SetFont(fontRegular)
	p.SetFontSize(30)
	p.SetMargins(85, 0, 0, 0)
	p.SetColor(creator.ColorRGBFrom8bit(45, 148, 215))
	c.Draw(p)
}

Results

output.pdf

Probably you can try to update the UniPDF to the latest version and checks if the issue still appears.

[carmel]

I've found that it has to do with fonts, and the above problem occurs with Microsoft YaHei, but not with SimFang.

[sampila]

@carmel here the results when I test with Microsoft Yahei font

output.pdf

It's hard to reproduce the issue by guessing, if you could provide runnable code snippet if would be good

[carmel]

Thanks for the example, maybe it's because I'm using a low version of it.

[sampila]

Thanks for the example, maybe it's because I'm using a low version of it.

We are happy able to help, let us know if you still having the issue by sharing runnable code snippet 🙂

Best regards

[gunnsth]

Please open a new issue if the problem reoccurs.