Golang Canvas.StrokeLine2方法代码示例

// Plot implements the plot.Plotter interface.
func (g *Grid) Plot(c draw.Canvas, plt *plot.Plot) {
	trX, trY := plt.Transforms(&c)

	if g.Vertical.Color == nil {
		goto horiz
	}
	for _, tk := range plt.X.Tick.Marker.Ticks(plt.X.Min, plt.X.Max) {
		if tk.IsMinor() {
			continue
		}
		x := trX(tk.Value)
		c.StrokeLine2(g.Vertical, x, c.Min.Y, x, c.Min.Y+c.Size().Y)
	}

horiz:
	if g.Horizontal.Color == nil {
		return
	}
	for _, tk := range plt.Y.Tick.Marker.Ticks(plt.Y.Min, plt.Y.Max) {
		if tk.IsMinor() {
			continue
		}
		y := trY(tk.Value)
		c.StrokeLine2(g.Horizontal, c.Min.X, y, c.Min.X+c.Size().X, y)
	}
}

// Plot draws the QuartPlot on Canvas c and Plot plt.
func (b *QuartPlot) Plot(c draw.Canvas, plt *plot.Plot) {
	if b.Horizontal {
		b := &horizQuartPlot{b}
		b.Plot(c, plt)
		return
	}

	trX, trY := plt.Transforms(&c)
	x := trX(b.Location)
	if !c.ContainsX(x) {
		return
	}
	x += b.Offset

	med := draw.Point{X: x, Y: trY(b.Median)}
	q1 := trY(b.Quartile1)
	q3 := trY(b.Quartile3)
	aLow := trY(b.AdjLow)
	aHigh := trY(b.AdjHigh)

	c.StrokeLine2(b.WhiskerStyle, x, aHigh, x, q3)
	if c.ContainsY(med.Y) {
		c.DrawGlyphNoClip(b.MedianStyle, med)
	}
	c.StrokeLine2(b.WhiskerStyle, x, aLow, x, q1)

	ostyle := b.MedianStyle
	ostyle.Radius = b.MedianStyle.Radius / 2
	for _, out := range b.Outside {
		y := trY(b.Value(out))
		if c.ContainsY(y) {
			c.DrawGlyphNoClip(ostyle, draw.Point{X: x, Y: y})
		}
	}
}

// Thumbnail the thumbnail for the Line,
// implementing the plot.Thumbnailer interface.
func (pts *Line) Thumbnail(c *draw.Canvas) {
	if pts.ShadeColor != nil {
		points := []draw.Point{
			{c.Min.X, c.Min.Y},
			{c.Min.X, c.Max.Y},
			{c.Max.X, c.Max.Y},
			{c.Max.X, c.Min.Y},
		}
		poly := c.ClipPolygonY(points)
		c.FillPolygon(*pts.ShadeColor, poly)

		points = append(points, draw.Point{c.Min.X, c.Min.Y})
	} else {
		y := c.Center().Y
		c.StrokeLine2(pts.LineStyle, c.Min.X, y, c.Max.X, y)
	}
}

// draw draws the axis along the left side of a draw.Canvas.
func (a *verticalAxis) draw(c draw.Canvas) {
	x := c.Min.X
	if a.Label.Text != "" {
		x += a.Label.Height(a.Label.Text)
		c.Push()
		c.Rotate(math.Pi / 2)
		c.FillText(a.Label.TextStyle, c.Center().Y, -x, -0.5, 0, a.Label.Text)
		c.Pop()
		x += -a.Label.Font.Extents().Descent
	}
	marks := a.Tick.Marker.Ticks(a.Min, a.Max)
	if w := tickLabelWidth(a.Tick.Label, marks); len(marks) > 0 && w > 0 {
		x += w
	}
	major := false
	for _, t := range marks {
		y := c.Y(a.Norm(t.Value))
		if !c.ContainsY(y) || t.IsMinor() {
			continue
		}
		c.FillText(a.Tick.Label, x, y, -1, -0.5, t.Label)
		major = true
	}
	if major {
		x += a.Tick.Label.Width(" ")
	}
	if a.drawTicks() && len(marks) > 0 {
		len := a.Tick.Length
		for _, t := range marks {
			y := c.Y(a.Norm(t.Value))
			if !c.ContainsY(y) {
				continue
			}
			start := t.lengthOffset(len)
			c.StrokeLine2(a.Tick.LineStyle, x+start, y, x+len, y)
		}
		x += len
	}
	c.StrokeLine2(a.LineStyle, x, c.Min.Y, x, c.Max.Y)
}

// Thumbnail draws a line in the given style down the
// center of a DrawArea as a thumbnail representation
// of the LineStyle of the function.
func (f Function) Thumbnail(c *draw.Canvas) {
	y := c.Center().Y
	c.StrokeLine2(f.LineStyle, c.Min.X, y, c.Max.X, y)
}

// drawCap draws the cap if it is not clipped.
func (e *YErrorBars) drawCap(c *draw.Canvas, x, y vg.Length) {
	if !c.Contains(draw.Point{x, y}) {
		return
	}
	c.StrokeLine2(e.LineStyle, x-e.CapWidth/2, y, x+e.CapWidth/2, y)
}