Non-Latin text renders as tofu

[namejiahui]

Summary

I noticed that some characters, such as Chinese characters, are rendered as tofu blocks. I believe this issue is probably not limited to Chinese characters.

Example

package main

import (
	"fmt"

	"github.com/gogpu/gogpu"
	"github.com/gogpu/ui/app"
	"github.com/gogpu/ui/core/button"
	"github.com/gogpu/ui/desktop"
	"github.com/gogpu/ui/primitives"
	"github.com/gogpu/ui/widget"
)

func main() {

	gogpuApp := gogpu.NewApp(gogpu.DefaultConfig().
		WithTitle("Font Demo").
		WithSize(600, 300))

	uiApp := app.New(
		app.WithWindowProvider(gogpuApp),
		app.WithPlatformProvider(gogpuApp),
		app.WithEventSource(gogpuApp.EventSource()),
	)

	uiApp.SetRoot(
		primitives.Box(
			primitives.Text("test: 测试").FontSize(20),
			button.New(button.Text("test2: 测试2"), button.OnClick(func() {
				fmt.Println("Button clicked!")
			})),
			primitives.Text("English text (both work)").FontSize(16).Color(widget.RGBA8(100, 100, 100, 255)),
		).Padding(24).Gap(16).Background(widget.RGBA8(255, 255, 255, 255)),
	)

	if err := desktop.Run(gogpuApp, uiApp); err != nil {
		panic(err)
	}
}

Possible root cause

Using button as an example, it uses DefaultPainter, which internally calls canvas.DrawText.

However, canvas (in internal/render/canvas.go) appears to use Inter as its default font. I believe this is likely the reason why characters that are not supported by Inter cannot be rendered correctly.

To be honest, I haven't found a solution that I'm fully satisfied with for rendering characters that are not covered by Inter, so I decided to open this issue.

Environment

• gogpu/ui v0.1.51
• gogpu v0.50.2
• Go 1.26.5, Linux (Wayland)

Finally, thank you for this project. I really like the ambition behind it