go-chart/drawing_helpers.go
2016-07-12 16:47:52 -07:00

158 lines
4.2 KiB
Go

package chart
// DrawLineSeries draws a line series with a renderer.
func DrawLineSeries(r Renderer, canvasBox Box, xrange, yrange Range, s Style, vs ValueProvider) {
if vs.Len() == 0 {
return
}
cb := canvasBox.Bottom
cl := canvasBox.Left
v0x, v0y := vs.GetValue(0)
x0 := cl + xrange.Translate(v0x)
y0 := cb - yrange.Translate(v0y)
var vx, vy float64
var x, y int
fill := s.GetFillColor()
if !fill.IsZero() {
r.SetFillColor(fill)
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
vx, vy = vs.GetValue(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
r.LineTo(x, y)
}
r.LineTo(x, cb)
r.LineTo(x0, cb)
r.Close()
r.Fill()
}
stroke := s.GetStrokeColor()
r.SetStrokeColor(stroke)
r.SetStrokeWidth(s.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
vx, vy = vs.GetValue(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
r.LineTo(x, y)
}
r.Stroke()
}
// MeasureAnnotation measures how big an annotation would be.
func MeasureAnnotation(r Renderer, canvasBox Box, s Style, lx, ly int, label string) Box {
r.SetFont(s.GetFont())
r.SetFontSize(s.GetFontSize(DefaultAnnotationFontSize))
textBox := r.MeasureText(label)
textWidth := textBox.Width()
textHeight := textBox.Height()
halfTextHeight := textHeight >> 1
pt := s.Padding.GetTop(DefaultAnnotationPadding.Top)
pl := s.Padding.GetLeft(DefaultAnnotationPadding.Left)
pr := s.Padding.GetRight(DefaultAnnotationPadding.Right)
pb := s.Padding.GetBottom(DefaultAnnotationPadding.Bottom)
strokeWidth := s.GetStrokeWidth()
top := ly - (pt + halfTextHeight)
right := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth + int(strokeWidth)
bottom := ly + (pb + halfTextHeight)
return Box{
Top: top,
Left: lx,
Right: right,
Bottom: bottom,
}
}
// DrawAnnotation draws an anotation with a renderer.
func DrawAnnotation(r Renderer, canvasBox Box, s Style, lx, ly int, label string) {
r.SetFont(s.GetFont())
r.SetFontSize(s.GetFontSize(DefaultAnnotationFontSize))
textBox := r.MeasureText(label)
textWidth := textBox.Width()
halfTextHeight := textBox.Height() >> 1
pt := s.Padding.GetTop(DefaultAnnotationPadding.Top)
pl := s.Padding.GetLeft(DefaultAnnotationPadding.Left)
pr := s.Padding.GetRight(DefaultAnnotationPadding.Right)
pb := s.Padding.GetBottom(DefaultAnnotationPadding.Bottom)
textX := lx + pl + DefaultAnnotationDeltaWidth
textY := ly + halfTextHeight
ltx := lx + DefaultAnnotationDeltaWidth
lty := ly - (pt + halfTextHeight)
rtx := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth
rty := ly - (pt + halfTextHeight)
rbx := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth
rby := ly + (pb + halfTextHeight)
lbx := lx + DefaultAnnotationDeltaWidth
lby := ly + (pb + halfTextHeight)
//draw the shape...
r.SetFillColor(s.GetFillColor(DefaultAnnotationFillColor))
r.SetStrokeColor(s.GetStrokeColor())
r.SetStrokeWidth(s.GetStrokeWidth())
r.MoveTo(lx, ly)
r.LineTo(ltx, lty)
r.LineTo(rtx, rty)
r.LineTo(rbx, rby)
r.LineTo(lbx, lby)
r.LineTo(lx, ly)
r.Close()
r.FillStroke()
r.SetFontColor(s.GetFontColor(DefaultTextColor))
r.Text(label, textX, textY)
}
// DrawBox draws a box with a given style.
func DrawBox(r Renderer, b Box, s Style) {
r.SetFillColor(s.GetFillColor())
r.SetStrokeColor(s.GetStrokeColor(DefaultStrokeColor))
r.SetStrokeWidth(s.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(b.Left, b.Top)
r.LineTo(b.Right, b.Top)
r.LineTo(b.Right, b.Bottom)
r.LineTo(b.Left, b.Bottom)
r.LineTo(b.Left, b.Top)
r.FillStroke()
}
// DrawText draws text with a given style.
func DrawText(r Renderer, text string, x, y int, s Style) {
r.SetFillColor(s.GetFillColor())
r.SetStrokeColor(s.GetStrokeColor())
r.SetStrokeWidth(s.GetStrokeWidth())
r.SetFont(s.GetFont())
r.SetFontSize(s.GetFontSize())
r.Text(text, x, y)
}
// DrawTextCentered draws text with a given style centered.
func DrawTextCentered(r Renderer, text string, x, y int, s Style) {
r.SetFillColor(s.GetFillColor())
r.SetStrokeColor(s.GetStrokeColor())
r.SetStrokeWidth(s.GetStrokeWidth())
r.SetFont(s.GetFont())
r.SetFontSize(s.GetFontSize())
tb := r.MeasureText(text)
tx := x - (tb.Width() >> 1)
ty := y - (tb.Height() >> 1)
r.Text(text, tx, ty)
}