Golang Context.BeginPath方法代码示例

func drawDropDown(ctx *nanovgo.Context, text string, x, y, w, h float32) {

	var cornerRadius float32 = 4.0

	bg := nanovgo.LinearGradient(x, y, x, y+h, nanovgo.RGBA(255, 255, 255, 16), nanovgo.RGBA(0, 0, 0, 16))
	ctx.BeginPath()
	ctx.RoundedRect(x+1, y+1, w-2, h-2, cornerRadius-1)
	ctx.SetFillPaint(bg)
	ctx.Fill()

	ctx.BeginPath()
	ctx.RoundedRect(x+0.5, y+0.5, w-1, h-1, cornerRadius-0.5)
	ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 48))
	ctx.Stroke()

	ctx.SetFontSize(20.0)
	ctx.SetFontFace("sans")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 160))
	ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignMiddle)
	ctx.Text(x+h*0.3, y+h*0.5, text)

	ctx.SetFontSize(h * 1.3)
	ctx.SetFontFace("icons")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 64))
	ctx.SetTextAlign(nanovgo.AlignCenter | nanovgo.AlignMiddle)
	ctx.Text(x+w-h*0.5, y+h*0.5, cpToUTF8(IconCHEVRONRIGHT))
}

func drawSearchBox(ctx *nanovgo.Context, text string, x, y, w, h float32) {
	cornerRadius := h/2 - 1

	// Edit
	bg := nanovgo.BoxGradient(x, y+1.5, w, h, h/2, 5, nanovgo.RGBA(0, 0, 0, 16), nanovgo.RGBA(0, 0, 0, 92))
	ctx.BeginPath()
	ctx.RoundedRect(x, y, w, h, cornerRadius)
	ctx.SetFillPaint(bg)
	ctx.Fill()

	/*      ctx.BeginPath();
	        ctx.RoundedRect(x+0.5f,y+0.5f, w-1,h-1, cornerRadius-0.5f);
	        ctx.StrokeColor(ctx.RGBA(0,0,0,48));
	        ctx.Stroke();*/

	ctx.SetFontSize(h * 1.3)
	ctx.SetFontFace("icons")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 64))
	ctx.SetTextAlign(nanovgo.AlignCenter | nanovgo.AlignMiddle)
	ctx.Text(x+h*0.55, y+h*0.55, cpToUTF8(IconSEARCH))

	ctx.SetFontSize(20.0)
	ctx.SetFontFace("sans")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 32))

	ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignMiddle)
	ctx.Text(x+h*1.05, y+h*0.5, text)

	ctx.SetFontSize(h * 1.3)
	ctx.SetFontFace("icons")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 32))
	ctx.SetTextAlign(nanovgo.AlignCenter | nanovgo.AlignMiddle)
	ctx.Text(x+w-h*0.55, y+h*0.55, cpToUTF8(IconCIRCLEDCROSS))
}

func (sf *SpinnerFilter) Draw(self nanogui.Widget, ctx *nanovgo.Context) {
	if sf.isActive() {
		var py int
		fw, fh := sf.Parent().Size()
		if window, ok := sf.Parent().(*nanogui.Window); ok {
			hh := window.Theme().WindowHeaderHeight
			py += hh
			fh -= hh
		}
		sf.SetPosition(0, py)
		sf.SetSize(fw, fh)

		currentTime := nanogui.GetTime() - sf.startTime

		var alpha float32
		var showSpinner bool
		if sf.state == SpinnerFadeIn {
			if currentTime > 1 {
				alpha = 0.7
				showSpinner = true
			} else {
				alpha = currentTime * 0.7
			}
		} else {
			if currentTime > 1 {
				alpha = 0.7
			} else {
				alpha = (1.0 - currentTime) * 0.7
			}
		}
		ctx.Save()
		ctx.BeginPath()
		ctx.SetFillColor(nanovgo.MONOf(0, alpha))
		ctx.Rect(0, float32(py), float32(fw), float32(fh))
		ctx.Fill()
		if showSpinner {
			cx := float32(fw / 2)
			cy := float32(py + fh/2)
			rotation := 2 * math.Pi * float64(currentTime*float32(sf.speed)*float32(sf.num)) / float64(sf.num)
			dr := float64(2 * math.Pi / float64(sf.num))
			ctx.SetStrokeWidth(sf.lineWidth)
			for i := 0; i < sf.num; i++ {
				ctx.BeginPath()
				ctx.MoveTo(cx+float32(math.Cos(rotation))*sf.c1, cy+float32(math.Sin(rotation))*sf.c1)
				ctx.LineTo(cx+float32(math.Cos(rotation))*sf.c2, cy+float32(math.Sin(rotation))*sf.c2)
				ctx.SetStrokeColor(nanovgo.MONOf(1.0, float32(i)/float32(sf.num)))
				ctx.Stroke()
				rotation += dr
			}
		}
		ctx.Restore()
	} else {
		sf.SetSize(0, 0)
		sf.SetVisible(false)
		return
	}
}

func drawEditBoxBase(ctx *nanovgo.Context, x, y, w, h float32) {
	// Edit
	bg := nanovgo.BoxGradient(x+1, y+1+1.5, w-2, h-2, 3, 4, nanovgo.RGBA(255, 255, 255, 32), nanovgo.RGBA(32, 32, 32, 32))
	ctx.BeginPath()
	ctx.RoundedRect(x+1, y+1, w-2, h-2, 4-1)
	ctx.SetFillPaint(bg)
	ctx.Fill()

	ctx.BeginPath()
	ctx.RoundedRect(x+0.5, y+0.5, w-1, h-1, 4-0.5)
	ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 48))
	ctx.Stroke()
}

func drawLines(ctx *nanovgo.Context, x, y, w, h, t float32) {
	var pad float32 = 5.0
	s := w/9.0 - pad*2
	joins := []nanovgo.LineCap{nanovgo.Miter, nanovgo.Round, nanovgo.Bevel}
	caps := []nanovgo.LineCap{nanovgo.Butt, nanovgo.Round, nanovgo.Square}

	ctx.Save()
	defer ctx.Restore()

	pts := []float32{
		-s*0.25 + cosF(t*0.3)*s*0.5,
		sinF(t*0.3) * s * 0.5,
		-s * 0.25,
		0,
		s * 0.25,
		0,
		s*0.25 + cosF(-t*0.3)*s*0.5,
		sinF(-t*0.3) * s * 0.5,
	}
	for i, cap := range caps {
		for j, join := range joins {
			fx := x + s*0.5 + float32(i*3+j)/9.0*w + pad
			fy := y - s*0.5 + pad

			ctx.SetLineCap(cap)
			ctx.SetLineJoin(join)

			ctx.SetStrokeWidth(s * 0.3)
			ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 160))
			ctx.BeginPath()
			ctx.MoveTo(fx+pts[0], fy+pts[1])
			ctx.LineTo(fx+pts[2], fy+pts[3])
			ctx.LineTo(fx+pts[4], fy+pts[5])
			ctx.LineTo(fx+pts[6], fy+pts[7])
			ctx.Stroke()

			ctx.SetLineCap(nanovgo.Butt)
			ctx.SetLineJoin(nanovgo.Bevel)

			ctx.SetStrokeWidth(1.0)
			ctx.SetStrokeColor(nanovgo.RGBA(0, 192, 255, 255))
			ctx.BeginPath()
			ctx.MoveTo(fx+pts[0], fy+pts[1])
			ctx.LineTo(fx+pts[2], fy+pts[3])
			ctx.LineTo(fx+pts[4], fy+pts[5])
			ctx.LineTo(fx+pts[6], fy+pts[7])
			ctx.Stroke()

		}
	}
}

func drawWidths(ctx *nanovgo.Context, x, y, width float32) {
	ctx.Save()
	defer ctx.Restore()

	ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 255))
	for i := 0; i < 20; i++ {
		w := (float32(i) + 0.5) * 0.1
		ctx.SetStrokeWidth(w)
		ctx.BeginPath()
		ctx.MoveTo(x, y)
		ctx.LineTo(x+width, y+width*0.3)
		ctx.Stroke()
		y += 10
	}
}

func drawButton(ctx *nanovgo.Context, preicon int, text string, x, y, w, h float32, col nanovgo.Color) {
	var cornerRadius float32 = 4.0
	var iw float32

	var alpha uint8
	if isBlack(col) {
		alpha = 16
	} else {
		alpha = 32
	}
	bg := nanovgo.LinearGradient(x, y, x, y+h, nanovgo.RGBA(255, 255, 255, alpha), nanovgo.RGBA(0, 0, 0, alpha))
	ctx.BeginPath()
	ctx.RoundedRect(x+1, y+1, w-2, h-2, cornerRadius-1)
	if !isBlack(col) {
		ctx.SetFillColor(col)
		ctx.Fill()
	}
	ctx.SetFillPaint(bg)
	ctx.Fill()

	ctx.BeginPath()
	ctx.RoundedRect(x+0.5, y+0.5, w-1, h-1, cornerRadius-0.5)
	ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 48))
	ctx.Stroke()

	ctx.SetFontSize(20.0)
	ctx.SetFontFace("sans-bold")
	tw, _ := ctx.TextBounds(0, 0, text)
	if preicon != 0 {
		ctx.SetFontSize(h * 1.3)
		ctx.SetFontFace("icons")
		iw, _ = ctx.TextBounds(0, 0, cpToUTF8(preicon))
		iw += h * 0.15

		ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 96))
		ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignMiddle)
		ctx.Text(x+w*0.5-tw*0.5-iw*0.75, y+h*0.5, cpToUTF8(preicon))
	}

	ctx.SetFontSize(20.0)
	ctx.SetFontFace("sans-bold")
	ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignMiddle)
	ctx.SetFillColor(nanovgo.RGBA(0, 0, 0, 160))
	ctx.Text(x+w*0.5-tw*0.5+iw*0.25, y+h*0.5-1, text)
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 160))
	ctx.Text(x+w*0.5-tw*0.5+iw*0.25, y+h*0.5, text)
}

// RenderGraph shows graph
func (pg *PerfGraph) RenderGraph(ctx *nanovgo.Context, x, y float32) {
	avg := pg.GetGraphAverage()
	var w float32 = 200
	var h float32 = 35

	ctx.BeginPath()
	ctx.Rect(x, y, w, h)
	ctx.SetFillColor(backgroundColor)
	ctx.Fill()

	ctx.BeginPath()
	ctx.MoveTo(x, y+h)
	for i := 0; i < nvgGraphHistoryCount; i++ {
		v := float32(1.0) / float32(0.00001+pg.values[(pg.head+i)%nvgGraphHistoryCount])
		if v > 80.0 {
			v = 80.0
		}
		vx := x + float32(i)/float32(nvgGraphHistoryCount-1)*w
		vy := y + h - ((v / 80.0) * h)
		ctx.LineTo(vx, vy)
	}
	ctx.LineTo(x+w, y+h)
	ctx.SetFillColor(graphColor)
	ctx.Fill()

	ctx.SetFontFace(pg.fontFace)

	if len(pg.name) > 0 {
		ctx.SetFontSize(14.0)
		ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignTop)
		ctx.SetFillColor(titleTextColor)
		ctx.Text(x+3, y+1, pg.name)
	}

	ctx.SetFontSize(18.0)
	ctx.SetTextAlign(nanovgo.AlignRight | nanovgo.AlignTop)
	ctx.SetFillColor(fpsTextColor)
	ctx.Text(x+w-3, y+1, fmt.Sprintf("%.2f FPS", 1.0/avg))

	ctx.SetFontSize(15.0)
	ctx.SetTextAlign(nanovgo.AlignRight | nanovgo.AlignBottom)
	ctx.SetFillColor(averageTextColor)
	ctx.Text(x+w-3, y+h+1, fmt.Sprintf("%.2f ms", avg*1000.0))
}

func (i *ImageView) Draw(self Widget, ctx *nanovgo.Context) {
	if i.image == 0 {
		return
	}
	x := float32(i.x)
	y := float32(i.y)
	ow := float32(i.w)
	oh := float32(i.h)

	var w, h float32
	{
		iw, ih, _ := ctx.ImageSize(i.image)
		w = float32(iw)
		h = float32(ih)
	}

	if i.policy == ImageSizePolicyFixed {
		if ow < w {
			h = float32(int(h * ow / w))
			w = ow
		}
		if oh < h {
			w = float32(int(w * oh / h))
			h = oh
		}
	} else { // mPolicy == Expand
		// expand to width
		h = float32(int(h * ow / w))
		w = ow
		// shrink to height, if necessary
		if oh < h {
			w = float32(int(w * oh / h))
			h = oh
		}
	}

	imgPaint := nanovgo.ImagePattern(x, y, w, h, 0, i.image, 1.0)

	ctx.BeginPath()
	ctx.Rect(x, y, w, h)
	ctx.SetFillPaint(imgPaint)
	ctx.Fill()
}

func (p *ProgressBar) Draw(self Widget, ctx *nanovgo.Context) {
	px := float32(p.x)
	py := float32(p.y)
	pw := float32(p.w)
	ph := float32(p.h)
	p.WidgetImplement.Draw(self, ctx)
	paint := nanovgo.BoxGradient(px+1, py+1, pw-2, ph, 3, 4, nanovgo.MONO(0, 32), nanovgo.MONO(0, 92))
	ctx.BeginPath()
	ctx.RoundedRect(px, py, pw, ph, 3)
	ctx.SetFillPaint(paint)
	ctx.Fill()

	value := clampF(p.value, 0.0, 1.0)
	barPos := (pw - 2) * value
	barPaint := nanovgo.BoxGradient(px, py, barPos+1.5, ph-1, 3, 4, nanovgo.MONO(220, 100), nanovgo.MONO(128, 100))
	ctx.BeginPath()
	ctx.RoundedRect(px+1, py+1, barPos, ph-2, 3)
	ctx.SetFillPaint(barPaint)
	ctx.Fill()
}

func (v *VScrollPanel) Draw(self Widget, ctx *nanovgo.Context) {
	if len(v.children) == 0 {
		return
	}
	x := float32(v.x)
	y := float32(v.y)
	w := float32(v.w)
	h := float32(v.h)

	child := v.children[0]
	layout := self.Layout()
	if layout != nil {
		_, v.childPreferredHeight = layout.PreferredSize(self, ctx)
	} else {
		_, v.childPreferredHeight = child.PreferredSize(child, ctx)
	}

	ctx.Save()
	ctx.Translate(x, y)
	ctx.Scissor(0, 0, w, h)
	ctx.Translate(0, -v.scroll*(float32(v.childPreferredHeight)-h))
	if child.Visible() {
		child.Draw(child, ctx)
	}
	ctx.Restore()
	if v.childPreferredHeight > v.h {
		scrollH := h * minF(1.0, h/float32(v.childPreferredHeight))
		scrollH = minF(maxF(20.0, scrollH), h)
		paint := nanovgo.BoxGradient(x+w-12+1, y+4+1, 8, h-8, 3, 4, nanovgo.MONO(0, 32), nanovgo.MONO(0, 92))
		ctx.BeginPath()
		ctx.RoundedRect(x+w-12, y+4, 8, h-8, 3)
		ctx.SetFillPaint(paint)
		ctx.Fill()

		barPaint := nanovgo.BoxGradient(x+y-12-1, y+4+1+(h-8-scrollH)*v.scroll-1, 8, scrollH, 3, 4, nanovgo.MONO(220, 100), nanovgo.MONO(128, 100))
		ctx.BeginPath()
		ctx.RoundedRect(x+w-12+1, y+4+1+(h-8-scrollH)*v.scroll, 8-2, scrollH-2, 2)
		ctx.SetFillPaint(barPaint)
		ctx.Fill()
	}
}

func drawSpinner(ctx *nanovgo.Context, cx, cy, r, t float32) {
	a0 := 0.0 + t*6
	a1 := nanovgo.PI + t*6
	r0 := r
	r1 := r * 0.75

	ctx.Save()
	defer ctx.Restore()

	ctx.BeginPath()
	ctx.Arc(cx, cy, r0, a0, a1, nanovgo.Clockwise)
	ctx.Arc(cx, cy, r1, a1, a0, nanovgo.CounterClockwise)
	ctx.ClosePath()
	ax := cx + cosF(a0)*(r0+r1)*0.5
	ay := cy + sinF(a0)*(r0+r1)*0.5
	bx := cx + cosF(a1)*(r0+r1)*0.5
	by := cy + sinF(a1)*(r0+r1)*0.5
	paint := nanovgo.LinearGradient(ax, ay, bx, by, nanovgo.RGBA(0, 0, 0, 0), nanovgo.RGBA(0, 0, 0, 128))
	ctx.SetFillPaint(paint)
	ctx.Fill()
}

func drawCheckBox(ctx *nanovgo.Context, text string, x, y, w, h float32) {

	ctx.SetFontSize(18.0)
	ctx.SetFontFace("sans")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 160))

	ctx.SetTextAlign(nanovgo.AlignLeft | nanovgo.AlignMiddle)
	ctx.Text(x+28, y+h*0.5, text)

	bg := nanovgo.BoxGradient(x+1, y+float32(int(h*0.5))-9+1, 18, 18, 3, 3, nanovgo.RGBA(0, 0, 0, 32), nanovgo.RGBA(0, 0, 0, 92))
	ctx.BeginPath()
	ctx.RoundedRect(x+1, y+float32(int(h*0.5))-9, 18, 18, 3)
	ctx.SetFillPaint(bg)
	ctx.Fill()

	ctx.SetFontSize(40)
	ctx.SetFontFace("icons")
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 128))
	ctx.SetTextAlign(nanovgo.AlignCenter | nanovgo.AlignMiddle)
	ctx.Text(x+9+2, y+h*0.5, cpToUTF8(IconCHECK))
}

func drawCaps(ctx *nanovgo.Context, x, y, width float32) {
	caps := []nanovgo.LineCap{nanovgo.Butt, nanovgo.Round, nanovgo.Square}
	var lineWidth float32 = 8.0

	ctx.Save()
	defer ctx.Restore()

	ctx.BeginPath()
	ctx.Rect(x-lineWidth/2, y, width+lineWidth, 40)
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 32))
	ctx.Fill()

	ctx.BeginPath()
	ctx.Rect(x, y, width, 40)
	ctx.SetFillColor(nanovgo.RGBA(255, 255, 255, 32))
	ctx.Fill()

	ctx.SetStrokeWidth(lineWidth)

	for i, cap := range caps {
		ctx.SetLineCap(cap)
		ctx.SetStrokeColor(nanovgo.RGBA(0, 0, 0, 255))
		ctx.BeginPath()
		ctx.MoveTo(x, y+float32(i)*10+5)
		ctx.LineTo(x+width, y+float32(i)*10+5)
		ctx.Stroke()
	}
}

// Draw() draws the widget (and all child widgets)
func (w *WidgetImplement) Draw(self Widget, ctx *nanovgo.Context) {
	if debugFlag {
		ctx.SetStrokeWidth(1.0)
		ctx.BeginPath()
		ctx.Rect(float32(w.x)-0.5, float32(w.y)-0.5, float32(w.w)+1.0, float32(w.h)+1.0)
		ctx.SetStrokeColor(nanovgo.RGBA(255, 0, 0, 255))
		ctx.Stroke()
	}

	if len(w.children) == 0 {
		return
	}
	ctx.Translate(float32(w.x), float32(w.y))
	// draw depth 0 items
	var drawLater widgetsAsc = make([]Widget, 0, len(w.children))
	for _, child := range w.children {
		if child.Visible() {
			depth := child.Depth()
			if depth == 0 {
				cx, cy := child.Position()
				cw, ch := child.Size()
				if !self.IsClipped(cx, cy, cw, ch) {
					child.Draw(child, ctx)
				}
			} else {
				drawLater = append(drawLater, child)
			}
		}
	}
	// draw by depth order
	sort.Sort(drawLater)
	for _, child := range drawLater {
		cx, cy := child.Position()
		cw, ch := child.Size()
		if !self.IsClipped(cx, cy, cw, ch) {
			child.Draw(child, ctx)
		}
	}
	ctx.Translate(-float32(w.x), -float32(w.y))
}