Golang GraphicContext.Save方法代码示例

// FillString draws a filled and stroked string.
func FillString(gc draw2d.GraphicContext, x, y, width, height float64) {
	sx, sy := width/100, height/100
	gc.Save()
	gc.SetStrokeColor(image.Black)
	gc.SetLineWidth(1)
	draw2dkit.RoundedRectangle(gc, x+sx*5, y+sy*5, x+sx*95, y+sy*95, sx*10, sy*10)
	gc.FillStroke()
	gc.SetFillColor(image.Black)
	gc.SetFontSize(height / 6)
	gc.Translate(x+sx*6, y+sy*52)
	gc.SetFontData(draw2d.FontData{
		Name:   "luxi",
		Family: draw2d.FontFamilyMono,
		Style:  draw2d.FontStyleBold | draw2d.FontStyleItalic})
	w := gc.FillString("Hug")
	gc.Translate(w+sx, 0)
	left, top, right, bottom := gc.GetStringBounds("cou")
	gc.SetStrokeColor(color.NRGBA{255, 0x33, 0x33, 0x80})
	draw2dkit.Rectangle(gc, left, top, right, bottom)
	gc.SetLineWidth(height / 50)
	gc.Stroke()
	gc.SetFillColor(color.NRGBA{0x33, 0x33, 0xff, 0xff})
	gc.SetStrokeColor(color.NRGBA{0x33, 0x33, 0xff, 0xff})
	gc.SetLineWidth(height / 100)
	gc.StrokeString("Hug")
	gc.Restore()
}

// Draw the image frame with certain parameters.
func Draw(gc draw2d.GraphicContext, png string,
	dw, dh, margin, lineWidth float64) error {
	// Draw frame
	draw2dkit.RoundedRectangle(gc, lineWidth, lineWidth, dw-lineWidth, dh-lineWidth, 100, 100)
	gc.SetLineWidth(lineWidth)
	gc.FillStroke()

	// load the source image
	source, err := draw2dimg.LoadFromPngFile(png)
	if err != nil {
		return err
	}
	// Size of source image
	sw, sh := float64(source.Bounds().Dx()), float64(source.Bounds().Dy())
	// Draw image to fit in the frame
	// TODO Seems to have a transform bug here on draw image
	scale := math.Min((dw-margin*2)/sw, (dh-margin*2)/sh)
	gc.Save()
	gc.Translate((dw-sw*scale)/2, (dh-sh*scale)/2)
	gc.Scale(scale, scale)
	gc.Rotate(0.2)

	gc.DrawImage(source)
	gc.Restore()
	return nil
}

// PathTransform scales a path differently in horizontal and vertical direction.
func PathTransform(gc draw2d.GraphicContext, x, y, width, height float64) {
	gc.Save()
	gc.SetLineWidth(width / 10)
	gc.Translate(x+width/2, y+height/2)
	gc.Scale(1, 4)
	gc.ArcTo(0, 0, width/8, height/8, 0, math.Pi*2)
	gc.Close()
	gc.Stroke()
	gc.Restore()
}

// Main draws a left hand and ear of a gopher. Afterwards it returns
// the filename. This should only be used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
	gc.Save()
	gc.Scale(0.5, 0.5)
	// Draw a (partial) gopher
	Draw(gc)
	gc.Restore()

	// Return the output filename
	return samples.Output("gopher", ext), nil
}

// Main draws a rotated face of the gopher. Afterwards it returns
// the filename. This should only be used during testing.
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
	gc.SetStrokeColor(image.Black)
	gc.SetFillColor(image.White)
	gc.Save()
	// Draw a (partial) gopher
	gc.Translate(-60, 65)
	gc.Rotate(-30 * (math.Pi / 180.0))
	Draw(gc, 48, 48, 240, 72)
	gc.Restore()

	// Return the output filename
	return samples.Output("gopher2", ext), nil
}

// Star draws many lines from a center.
func Star(gc draw2d.GraphicContext, x, y, width, height float64) {
	gc.Save()
	gc.Translate(x+width/2, y+height/2)
	gc.SetLineWidth(width / 40)
	for i := 0.0; i < 360; i = i + 10 { // Go from 0 to 360 degrees in 10 degree steps
		gc.Save()                        // Keep rotations temporary
		gc.Rotate(i * (math.Pi / 180.0)) // Rotate by degrees on stack from 'for'
		gc.MoveTo(0, 0)
		gc.LineTo(width/2, 0)
		gc.Stroke()
		gc.Restore()
	}
	gc.Restore()
}

// Main draws the tiger
func Main(gc draw2d.GraphicContext, ext string) (string, error) {
	gc.Save()

	// flip the image
	gc.Translate(0, 200)
	gc.Scale(0.35, -0.35)
	gc.Translate(70, -200)

	// Tiger postscript drawing
	tiger := samples.Resource("image", "tiger.ps", ext)

	// Draw tiger
	Draw(gc, tiger)
	gc.Restore()

	// Return the output filename
	return samples.Output("postscript", ext), nil
}