Exemplo n.º 1
0
// WriterTo returns an io.WriterTo that will write the plot as
// the specified image format.
//
// Supported formats are:
//
//  eps, jpg|jpeg, pdf, png, svg, and tif|tiff.
func (p *Plot) WriterTo(w, h vg.Length, format string) (io.WriterTo, error) {
	var c interface {
		vg.CanvasSizer
		io.WriterTo
	}
	switch format {
	case "eps":
		c = vgeps.New(w, h)

	case "jpg", "jpeg":
		c = vgimg.JpegCanvas{Canvas: vgimg.New(w, h)}

	case "pdf":
		c = vgpdf.New(w, h)

	case "png":
		c = vgimg.PngCanvas{Canvas: vgimg.New(w, h)}

	case "svg":
		c = vgsvg.New(w, h)

	case "tif", "tiff":
		c = vgimg.TiffCanvas{Canvas: vgimg.New(w, h)}

	default:
		return nil, fmt.Errorf("unsupported format: %q", format)
	}
	p.Draw(draw.New(c))

	return c, nil
}
Exemplo n.º 2
0
func TestIssue179(t *testing.T) {
	scatter, err := plotter.NewScatter(plotter.XYs{{1, 1}, {0, 1}, {0, 0}})
	if err != nil {
		log.Fatal(err)
	}
	p, err := plot.New()
	if err != nil {
		log.Fatal(err)
	}
	p.Add(scatter)
	p.HideAxes()

	c := vgimg.JpegCanvas{Canvas: vgimg.New(5.08*vg.Centimeter, 5.08*vg.Centimeter)}
	p.Draw(draw.New(c))
	b := bytes.NewBuffer([]byte{})
	if _, err = c.WriteTo(b); err != nil {
		t.Error(err)
	}

	f, err := os.Open(filepath.Join("testdata", "issue179.jpg"))
	if err != nil {
		t.Error(err)
	}
	defer f.Close()

	want, err := ioutil.ReadAll(f)
	if err != nil {
		t.Error(err)
	}
	if !bytes.Equal(b.Bytes(), want) {
		t.Error("Image mismatch")
	}
}