adam-gui/vendor/github.com/go-text/render/svg.go
2024-04-29 19:13:50 +02:00

55 lines
1.6 KiB
Go

package render
import (
"bytes"
"image"
"image/draw"
"io"
"github.com/go-text/typesetting/opentype/api"
"github.com/go-text/typesetting/shaping"
"github.com/srwiley/oksvg"
"github.com/srwiley/rasterx"
)
func (r *Renderer) drawSVG(g shaping.Glyph, svg api.GlyphSVG, img draw.Image, x, y float32) error {
pixWidth := int(fixed266ToFloat(g.Width) * r.PixScale)
pixHeight := int(fixed266ToFloat(-g.Height) * r.PixScale)
pix, err := renderSVGStream(bytes.NewReader(svg.Source), pixWidth, pixHeight)
if err != nil {
return err
}
rect := image.Rect(int(fixed266ToFloat(g.XBearing)*r.PixScale), int(fixed266ToFloat(-g.YBearing)*r.PixScale),
pixWidth, pixHeight)
draw.Draw(img, rect.Add(image.Point{X: int(x), Y: int(y)}), pix, image.Point{}, draw.Over)
// ignore the svg.Outline shapes, as they are a fallback which we won't use
return nil
}
func renderSVGStream(stream io.Reader, width, height int) (*image.NRGBA, error) {
icon, err := oksvg.ReadIconStream(stream)
if err != nil {
return nil, err
}
iconAspect := float32(icon.ViewBox.W / icon.ViewBox.H)
viewAspect := float32(width) / float32(height)
imgW, imgH := width, height
if viewAspect > iconAspect {
imgW = int(float32(height) * iconAspect)
} else if viewAspect < iconAspect {
imgH = int(float32(width) / iconAspect)
}
icon.SetTarget(icon.ViewBox.X, icon.ViewBox.Y, float64(imgW), float64(imgH))
out := image.NewNRGBA(image.Rect(0, 0, imgW, imgH))
scanner := rasterx.NewScannerGV(int(icon.ViewBox.W), int(icon.ViewBox.H), out, out.Bounds())
raster := rasterx.NewDasher(width, height, scanner)
icon.Draw(raster, 1)
return out, nil
}