Add response time badge and chart

vendor/github.com/wcharczuk/go-chart/v2/raster_renderer.go

@@ -0,0 +1,230 @@
+package chart
+
+import (
+	"image"
+	"image/png"
+	"io"
+	"math"
+
+	"github.com/golang/freetype/truetype"
+	"github.com/wcharczuk/go-chart/v2/drawing"
+)
+
+// PNG returns a new png/raster renderer.
+func PNG(width, height int) (Renderer, error) {
+	i := image.NewRGBA(image.Rect(0, 0, width, height))
+	gc, err := drawing.NewRasterGraphicContext(i)
+	if err == nil {
+		return &rasterRenderer{
+			i:  i,
+			gc: gc,
+		}, nil
+	}
+	return nil, err
+}
+
+// rasterRenderer renders chart commands to a bitmap.
+type rasterRenderer struct {
+	i  *image.RGBA
+	gc *drawing.RasterGraphicContext
+
+	rotateRadians *float64
+
+	s Style
+}
+
+func (rr *rasterRenderer) ResetStyle() {
+	rr.s = Style{Font: rr.s.Font}
+	rr.ClearTextRotation()
+}
+
+// GetDPI returns the dpi.
+func (rr *rasterRenderer) GetDPI() float64 {
+	return rr.gc.GetDPI()
+}
+
+// SetDPI implements the interface method.
+func (rr *rasterRenderer) SetDPI(dpi float64) {
+	rr.gc.SetDPI(dpi)
+}
+
+// SetClassName implements the interface method. However, PNGs have no classes.
+func (rr *rasterRenderer) SetClassName(_ string) {}
+
+// SetStrokeColor implements the interface method.
+func (rr *rasterRenderer) SetStrokeColor(c drawing.Color) {
+	rr.s.StrokeColor = c
+}
+
+// SetLineWidth implements the interface method.
+func (rr *rasterRenderer) SetStrokeWidth(width float64) {
+	rr.s.StrokeWidth = width
+}
+
+// StrokeDashArray sets the stroke dash array.
+func (rr *rasterRenderer) SetStrokeDashArray(dashArray []float64) {
+	rr.s.StrokeDashArray = dashArray
+}
+
+// SetFillColor implements the interface method.
+func (rr *rasterRenderer) SetFillColor(c drawing.Color) {
+	rr.s.FillColor = c
+}
+
+// MoveTo implements the interface method.
+func (rr *rasterRenderer) MoveTo(x, y int) {
+	rr.gc.MoveTo(float64(x), float64(y))
+}
+
+// LineTo implements the interface method.
+func (rr *rasterRenderer) LineTo(x, y int) {
+	rr.gc.LineTo(float64(x), float64(y))
+}
+
+// QuadCurveTo implements the interface method.
+func (rr *rasterRenderer) QuadCurveTo(cx, cy, x, y int) {
+	rr.gc.QuadCurveTo(float64(cx), float64(cy), float64(x), float64(y))
+}
+
+// ArcTo implements the interface method.
+func (rr *rasterRenderer) ArcTo(cx, cy int, rx, ry, startAngle, delta float64) {
+	rr.gc.ArcTo(float64(cx), float64(cy), rx, ry, startAngle, delta)
+}
+
+// Close implements the interface method.
+func (rr *rasterRenderer) Close() {
+	rr.gc.Close()
+}
+
+// Stroke implements the interface method.
+func (rr *rasterRenderer) Stroke() {
+	rr.gc.SetStrokeColor(rr.s.StrokeColor)
+	rr.gc.SetLineWidth(rr.s.StrokeWidth)
+	rr.gc.SetLineDash(rr.s.StrokeDashArray, 0)
+	rr.gc.Stroke()
+}
+
+// Fill implements the interface method.
+func (rr *rasterRenderer) Fill() {
+	rr.gc.SetFillColor(rr.s.FillColor)
+	rr.gc.Fill()
+}
+
+// FillStroke implements the interface method.
+func (rr *rasterRenderer) FillStroke() {
+	rr.gc.SetFillColor(rr.s.FillColor)
+	rr.gc.SetStrokeColor(rr.s.StrokeColor)
+	rr.gc.SetLineWidth(rr.s.StrokeWidth)
+	rr.gc.SetLineDash(rr.s.StrokeDashArray, 0)
+	rr.gc.FillStroke()
+}
+
+// Circle fully draws a circle at a given point but does not apply the fill or stroke.
+func (rr *rasterRenderer) Circle(radius float64, x, y int) {
+	xf := float64(x)
+	yf := float64(y)
+
+	rr.gc.MoveTo(xf-radius, yf)                            //9
+	rr.gc.QuadCurveTo(xf-radius, yf-radius, xf, yf-radius) //12
+	rr.gc.QuadCurveTo(xf+radius, yf-radius, xf+radius, yf) //3
+	rr.gc.QuadCurveTo(xf+radius, yf+radius, xf, yf+radius) //6
+	rr.gc.QuadCurveTo(xf-radius, yf+radius, xf-radius, yf) //9
+}
+
+// SetFont implements the interface method.
+func (rr *rasterRenderer) SetFont(f *truetype.Font) {
+	rr.s.Font = f
+}
+
+// SetFontSize implements the interface method.
+func (rr *rasterRenderer) SetFontSize(size float64) {
+	rr.s.FontSize = size
+}
+
+// SetFontColor implements the interface method.
+func (rr *rasterRenderer) SetFontColor(c drawing.Color) {
+	rr.s.FontColor = c
+}
+
+// Text implements the interface method.
+func (rr *rasterRenderer) Text(body string, x, y int) {
+	xf, yf := rr.getCoords(x, y)
+	rr.gc.SetFont(rr.s.Font)
+	rr.gc.SetFontSize(rr.s.FontSize)
+	rr.gc.SetFillColor(rr.s.FontColor)
+	rr.gc.CreateStringPath(body, float64(xf), float64(yf))
+	rr.gc.Fill()
+}
+
+// MeasureText returns the height and width in pixels of a string.
+func (rr *rasterRenderer) MeasureText(body string) Box {
+	rr.gc.SetFont(rr.s.Font)
+	rr.gc.SetFontSize(rr.s.FontSize)
+	rr.gc.SetFillColor(rr.s.FontColor)
+	l, t, r, b, err := rr.gc.GetStringBounds(body)
+	if err != nil {
+		return Box{}
+	}
+	if l < 0 {
+		r = r - l // equivalent to r+(-1*l)
+		l = 0
+	}
+	if t < 0 {
+		b = b - t
+		t = 0
+	}
+
+	if l > 0 {
+		r = r + l
+		l = 0
+	}
+
+	if t > 0 {
+		b = b + t
+		t = 0
+	}
+
+	textBox := Box{
+		Top:    int(math.Ceil(t)),
+		Left:   int(math.Ceil(l)),
+		Right:  int(math.Ceil(r)),
+		Bottom: int(math.Ceil(b)),
+	}
+	if rr.rotateRadians == nil {
+		return textBox
+	}
+
+	return textBox.Corners().Rotate(RadiansToDegrees(*rr.rotateRadians)).Box()
+}
+
+// SetTextRotation sets a text rotation.
+func (rr *rasterRenderer) SetTextRotation(radians float64) {
+	rr.rotateRadians = &radians
+}
+
+func (rr *rasterRenderer) getCoords(x, y int) (xf, yf int) {
+	if rr.rotateRadians == nil {
+		xf = x
+		yf = y
+		return
+	}
+
+	rr.gc.Translate(float64(x), float64(y))
+	rr.gc.Rotate(*rr.rotateRadians)
+	return
+}
+
+// ClearTextRotation clears text rotation.
+func (rr *rasterRenderer) ClearTextRotation() {
+	rr.gc.SetMatrixTransform(drawing.NewIdentityMatrix())
+	rr.rotateRadians = nil
+}
+
+// Save implements the interface method.
+func (rr *rasterRenderer) Save(w io.Writer) error {
+	if typed, isTyped := w.(RGBACollector); isTyped {
+		typed.SetRGBA(rr.i)
+		return nil
+	}
+	return png.Encode(w, rr.i)
+}