fixed dependencies

vendor/gonum.org/v1/plot/plotter/polygon.go

@@ -0,0 +1,130 @@
+// Copyright ©2016 The Gonum Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package plotter
+
+import (
+	"image/color"
+	"math"
+
+	"gonum.org/v1/plot"
+	"gonum.org/v1/plot/vg"
+	"gonum.org/v1/plot/vg/draw"
+)
+
+// Polygon implements the Plotter interface, drawing a polygon.
+type Polygon struct {
+	// XYs is a copy of the vertices of this polygon.
+	// Each item in the array holds one ring in the
+	// Polygon.
+	XYs []XYs
+
+	// LineStyle is the style of the line around the edge
+	// of the polygon.
+	draw.LineStyle
+
+	// Color is the fill color of the polygon.
+	Color color.Color
+}
+
+// NewPolygon returns a polygon that uses the default line style and
+// no fill color, where xys are the rings of the polygon.
+// Different backends may render overlapping rings and self-intersections
+// differently, but all built-in backends treat inner rings
+// with the opposite winding order from the outer ring as
+// holes.
+func NewPolygon(xys ...XYer) (*Polygon, error) {
+	data := make([]XYs, len(xys))
+	for i, d := range xys {
+		var err error
+		data[i], err = CopyXYs(d)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return &Polygon{
+		XYs:       data,
+		LineStyle: DefaultLineStyle,
+	}, nil
+}
+
+// Plot draws the polygon, implementing the plot.Plotter
+// interface.
+func (pts *Polygon) Plot(c draw.Canvas, plt *plot.Plot) {
+	trX, trY := plt.Transforms(&c)
+	ps := make([][]vg.Point, len(pts.XYs))
+
+	for i, ring := range pts.XYs {
+		ps[i] = make([]vg.Point, len(ring))
+		for j, p := range ring {
+			ps[i][j].X = trX(p.X)
+			ps[i][j].Y = trY(p.Y)
+		}
+		ps[i] = c.ClipPolygonXY(ps[i])
+	}
+	if pts.Color != nil && len(ps) > 0 {
+		c.SetColor(pts.Color)
+		// allocate enough space for at least 4 path components per ring.
+		// 3 is the minimum but 4 is more common.
+		pa := make(vg.Path, 0, 4*len(ps))
+		for _, ring := range ps {
+			if len(ring) == 0 {
+				continue
+			}
+			pa.Move(ring[0])
+			for _, p := range ring[1:] {
+				pa.Line(p)
+			}
+			pa.Close()
+		}
+		c.Fill(pa)
+	}
+
+	for _, ring := range ps {
+		if len(ring) > 0 && ring[len(ring)-1] != ring[0] {
+			ring = append(ring, ring[0])
+		}
+		c.StrokeLines(pts.LineStyle, c.ClipLinesXY(ring)...)
+	}
+}
+
+// DataRange returns the minimum and maximum
+// x and y values, implementing the plot.DataRanger
+// interface.
+func (pts *Polygon) DataRange() (xmin, xmax, ymin, ymax float64) {
+	xmin = math.Inf(1)
+	xmax = math.Inf(-1)
+	ymin = math.Inf(1)
+	ymax = math.Inf(-1)
+	for _, ring := range pts.XYs {
+		xmini, xmaxi := Range(XValues{ring})
+		ymini, ymaxi := Range(YValues{ring})
+		xmin = math.Min(xmin, xmini)
+		xmax = math.Max(xmax, xmaxi)
+		ymin = math.Min(ymin, ymini)
+		ymax = math.Max(ymax, ymaxi)
+	}
+	return
+}
+
+// Thumbnail creates the thumbnail for the Polygon,
+// implementing the plot.Thumbnailer interface.
+func (pts *Polygon) Thumbnail(c *draw.Canvas) {
+	if pts.Color != nil {
+		points := []vg.Point{
+			{X: c.Min.X, Y: c.Min.Y},
+			{X: c.Min.X, Y: c.Max.Y},
+			{X: c.Max.X, Y: c.Max.Y},
+			{X: c.Max.X, Y: c.Min.Y},
+		}
+		poly := c.ClipPolygonY(points)
+		c.FillPolygon(pts.Color, poly)
+
+		points = append(points, vg.Point{X: c.Min.X, Y: c.Min.Y})
+		c.StrokeLines(pts.LineStyle, points)
+	} else {
+		y := c.Center().Y
+		c.StrokeLine2(pts.LineStyle, c.Min.X, y, c.Max.X, y)
+	}
+}