text.BoundString gives a position about a dot to the left

[AlbericC]

When calculating the bounding box for a text (in order to center), we see that the Rectangle from BoundString is almost never at the position the text is, but instead is shifted left. I have not identified the distance : it seems to vary with different fonts.

sample code :

package main

import (
	_ "embed"
	"image/color"
	"log"

	"github.com/hajimehoshi/ebiten/v2"
	"github.com/hajimehoshi/ebiten/v2/ebitenutil"
	"github.com/hajimehoshi/ebiten/v2/text"
	"golang.org/x/image/font"
	"golang.org/x/image/font/opentype"
)

func main() {
	ebiten.RunGame(&Game{Msg: `.HI`})

}

var _ ebiten.Game = &Game{}

// Any font has a similar result though its easy to see here.
// https://github.com/adobe-fonts/source-code-pro/raw/release/TTF/SourceCodePro-Medium.ttf
//go:embed SourceCodePro-Medium.ttf
var myfont []byte

var fontFace font.Face

func init() {
	tt, err := opentype.Parse(myfont)
	if err != nil {
		log.Fatal(err)
	}
	fontFace, err = opentype.NewFace(tt, &opentype.FaceOptions{
		Size:    72,
		DPI:     72,
		Hinting: font.HintingNone,
	})
	if err != nil {
		log.Fatal(err)
	}
}

type Game struct {
	Msg  string
}

func (*Game) Update() error { return nil }
func (g *Game) Draw(screen *ebiten.Image) {
	screen.Fill(color.Gray{128})
	textDims := text.BoundString(fontFace, g.Msg)
	// green rect, white text // supposedly centered
	ebitenutil.DrawRect(screen,
		float64(screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx())/2),
		float64(screen.Bounds().Min.Y+(screen.Bounds().Dy()-textDims.Dy())/2),
		float64(textDims.Dx()), float64(textDims.Dy()), color.RGBA{0, 0xBB, 0, 0x77})
	text.Draw(screen, g.Msg, fontFace,
		screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx())/2,
		screen.Bounds().Min.Y+(screen.Bounds().Dy()+textDims.Dy())/2,
		color.White)
	// reddish rect, yellow text // supposedly top left
	ebitenutil.DrawRect(screen,
		float64(screen.Bounds().Min.X),
		float64(screen.Bounds().Min.Y),
		float64(textDims.Dx()), float64(textDims.Dy()), color.RGBA{0xFF, 0x22, 0, 0x77})
	text.Draw(screen, g.Msg, fontFace,
		screen.Bounds().Min.X,
		screen.Bounds().Min.Y+textDims.Dy(),
		color.RGBA{0xFF, 0xFF, 0, 0x77})
	// blue rect, red text // supposedly bottom right
	ebitenutil.DrawRect(screen,
		float64(screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx())),
		float64(screen.Bounds().Min.Y+(screen.Bounds().Dy()-textDims.Dy())),
		float64(textDims.Dx()), float64(textDims.Dy()), color.RGBA{0, 0x22, 0xFF, 0x77})
	text.Draw(screen, g.Msg, fontFace,
		screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx()),
		screen.Bounds().Min.Y+(screen.Bounds().Dy()),
		color.RGBA{0xFF, 0x22, 0, 0x77})
}
func (*Game) Layout(outsideWidth, outsideHeight int) (screenWidth, screenHeight int) {
	return 256, 128
}

render on screen :

Each time the text is rendered with what (I think) should be its bounding box. It seems to be always rendered too far right. Or the BoundString Rectangle is too far left ?

Thank you for this great module.

[hajimehoshi]

textDims's origin position is the dot position. And, text.Draw's position is also the dot position. Then, I guess

	text.Draw(screen, g.Msg, fontFace,
		screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx())/2,
		screen.Bounds().Min.Y+(screen.Bounds().Dy()+textDims.Dy())/2,
		color.White)

should be

	text.Draw(screen, g.Msg, fontFace,
		screen.Bounds().Min.X+(screen.Bounds().Dx()-textDims.Dx())/2-textDims.Min.X,
		screen.Bounds().Min.Y+(screen.Bounds().Dy()-textDims.Dy())/2-textDims.Min.Y,
		color.White)

[AlbericC]

Thank you ! I sort of assumed that textDims would have its Min at {0,0}, but this actually makes sense.