go-chart/chart.go
2016-07-11 23:51:47 -07:00

440 lines
12 KiB
Go

package chart
import (
"errors"
"io"
"math"
"github.com/golang/freetype/truetype"
)
// Chart is what we're drawing.
type Chart struct {
Title string
TitleStyle Style
Width int
Height int
DPI float64
Background Style
Canvas Style
XAxis XAxis
YAxis YAxis
YAxisSecondary YAxis
Font *truetype.Font
Series []Series
}
// GetDPI returns the dpi for the chart.
func (c Chart) GetDPI(defaults ...float64) float64 {
if c.DPI == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return DefaultDPI
}
return c.DPI
}
// GetFont returns the text font.
func (c Chart) GetFont() (*truetype.Font, error) {
if c.Font == nil {
f, err := GetDefaultFont()
if err != nil {
return nil, err
}
return f, nil
}
return c.Font, nil
}
// Render renders the chart with the given renderer to the given io.Writer.
func (c Chart) Render(rp RendererProvider, w io.Writer) error {
if len(c.Series) == 0 {
return errors.New("Please provide at least one series")
}
c.YAxisSecondary.AxisType = YAxisSecondary
r, err := rp(c.Width, c.Height)
if err != nil {
return err
}
font, err := c.GetFont()
if err != nil {
return err
}
c.Font = font
r.SetFont(font)
r.SetDPI(c.GetDPI(DefaultDPI))
c.drawBackground(r)
var xt, yt, yta []Tick
xr, yr, yra := c.getRanges()
canvasBox := c.getDefaultCanvasBox()
xf, yf, yfa := c.getValueFormatters()
xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
if c.hasAxes() {
xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
canvasBox = c.getAxisAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xt, yt, yta)
xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
}
if c.hasAnnotationSeries() {
canvasBox = c.getAnnotationAdjustedCanvasBox(r, canvasBox, xr, yr, yra, xf, yf, yfa)
xr, yr, yra = c.setRangeDomains(canvasBox, xr, yr, yra)
xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
}
c.drawCanvas(r, canvasBox)
c.drawAxes(r, canvasBox, xr, yr, yra, xt, yt, yta)
for index, series := range c.Series {
c.drawSeries(r, canvasBox, xr, yr, yra, series, index)
}
c.drawTitle(r)
return r.Save(w)
}
func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
var globalMinX, globalMaxX float64 = math.MaxFloat64, 0
var globalMinY, globalMaxY float64 = math.MaxFloat64, 0
var globalMinYA, globalMaxYA float64 = math.MaxFloat64, 0
for _, s := range c.Series {
seriesAxis := s.GetYAxis()
if vp, isValueProvider := s.(ValueProvider); isValueProvider {
seriesLength := vp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy := vp.GetValue(index)
if globalMinX > vx {
globalMinX = vx
}
if globalMaxX < vx {
globalMaxX = vx
}
if seriesAxis == YAxisPrimary {
if globalMinY > vy {
globalMinY = vy
}
if globalMaxY < vy {
globalMaxY = vy
}
} else if seriesAxis == YAxisSecondary {
if globalMinYA > vy {
globalMinYA = vy
}
if globalMaxYA < vy {
globalMaxYA = vy
}
}
}
}
}
if !c.XAxis.Range.IsZero() {
xrange.Min = c.XAxis.Range.Min
xrange.Max = c.XAxis.Range.Max
} else {
xrange.Min = globalMinX
xrange.Max = globalMaxX
//xrange.Min, xrange.Max = xrange.GetRoundedRangeBounds()
}
if !c.YAxis.Range.IsZero() {
yrange.Min = c.YAxis.Range.Min
yrange.Max = c.YAxis.Range.Max
} else {
yrange.Min = globalMinY
yrange.Max = globalMaxY
yrange.Min, yrange.Max = yrange.GetRoundedRangeBounds()
}
if !c.YAxisSecondary.Range.IsZero() {
yrangeAlt.Min = c.YAxisSecondary.Range.Min
yrangeAlt.Max = c.YAxisSecondary.Range.Max
} else {
yrangeAlt.Min = globalMinYA
yrangeAlt.Max = globalMaxYA
yrangeAlt.Min, yrangeAlt.Max = yrangeAlt.GetRoundedRangeBounds()
}
return
}
func (c Chart) getDefaultCanvasBox() Box {
dpl := c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
dpr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
dpb := c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
cb := Box{
Top: c.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
Left: dpl,
Right: c.Width - dpr,
Bottom: c.Height - dpb,
}
cb.Height = cb.Bottom - cb.Top
cb.Width = cb.Right - cb.Left
return cb
}
func (c Chart) getValueFormatters() (x, y, ya ValueFormatter) {
for _, s := range c.Series {
if vfp, isVfp := s.(ValueFormatterProvider); isVfp {
sx, sy := vfp.GetValueFormatters()
if s.GetYAxis() == YAxisPrimary {
x = sx
y = sy
} else if s.GetYAxis() == YAxisSecondary {
x = sx
ya = sy
}
}
}
if c.XAxis.ValueFormatter != nil {
x = c.XAxis.ValueFormatter
}
if c.YAxis.ValueFormatter != nil {
y = c.YAxis.ValueFormatter
}
if c.YAxisSecondary.ValueFormatter != nil {
ya = c.YAxisSecondary.ValueFormatter
}
return
}
func (c Chart) hasAxes() bool {
return c.XAxis.Style.Show || c.YAxis.Style.Show || c.YAxisSecondary.Style.Show
}
func (c Chart) getAxesTicks(r Renderer, xr, yr, yar Range, xf, yf, yfa ValueFormatter) (xticks, yticks, yticksAlt []Tick) {
if c.XAxis.Style.Show {
xticks = c.XAxis.GetTicks(r, xr, xf)
}
if c.YAxis.Style.Show {
yticks = c.YAxis.GetTicks(r, yr, yf)
}
if c.YAxisSecondary.Style.Show {
yticksAlt = c.YAxisSecondary.GetTicks(r, yar, yf)
}
return
}
func (c Chart) getAxisAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xticks, yticks, yticksAlt []Tick) Box {
axesMinX, axesMaxX, axesMinY, axesMaxY := math.MaxInt32, 0, math.MaxInt32, 0
if c.XAxis.Style.Show {
axesBounds := c.XAxis.Measure(r, canvasBox, xr, xticks)
axesMinY = MinInt(axesMinX, axesBounds.Top)
axesMinX = MinInt(axesMinY, axesBounds.Left)
axesMaxX = MaxInt(axesMaxX, axesBounds.Right)
axesMaxY = MaxInt(axesMaxY, axesBounds.Bottom)
}
if c.YAxis.Style.Show {
axesBounds := c.YAxis.Measure(r, canvasBox, yr, yticks)
axesMinY = MinInt(axesMinX, axesBounds.Top)
axesMinX = MinInt(axesMinY, axesBounds.Left)
axesMaxX = MaxInt(axesMaxX, axesBounds.Right)
axesMaxY = MaxInt(axesMaxY, axesBounds.Bottom)
}
if c.YAxisSecondary.Style.Show {
axesBounds := c.YAxisSecondary.Measure(r, canvasBox, yra, yticksAlt)
axesMinY = MinInt(axesMinX, axesBounds.Top)
axesMinX = MinInt(axesMinY, axesBounds.Left)
axesMaxX = MaxInt(axesMaxX, axesBounds.Right)
axesMaxY = MaxInt(axesMaxY, axesBounds.Bottom)
}
newBox := Box{
Top: canvasBox.Top,
Left: canvasBox.Left,
Right: canvasBox.Right,
Bottom: canvasBox.Bottom,
}
if axesMinY < 0 {
// figure out how much top padding to add
delta := -1 * axesMinY
newBox.Top = canvasBox.Top + delta
}
if axesMinX < 0 {
// figure out how much left padding to add
delta := -1 * axesMinX
newBox.Left = canvasBox.Left + delta
}
if axesMaxX > c.Width {
// figure out how much right padding to add
delta := axesMaxX - c.Width
newBox.Right = canvasBox.Right - delta
}
if axesMaxY > c.Height {
//figure out how much bottom padding to add
delta := axesMaxY - c.Height
newBox.Bottom = canvasBox.Bottom - delta
}
newBox.Height = newBox.Bottom - newBox.Top
newBox.Width = newBox.Right - newBox.Left
return newBox
}
func (c Chart) setRangeDomains(canvasBox Box, xr, yr, yra Range) (xr2, yr2, yra2 Range) {
xr2.Min, xr2.Max = xr.Min, xr.Max
xr2.Domain = canvasBox.Width
yr2.Min, yr2.Max = yr.Min, yr.Max
yr2.Domain = canvasBox.Height
yra2.Min, yra2.Max = yra.Min, yra.Max
yra2.Domain = canvasBox.Height
return
}
func (c Chart) hasAnnotationSeries() bool {
for _, s := range c.Series {
if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
if as.Style.Show {
return true
}
}
}
return false
}
func (c Chart) getAnnotationAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xf, yf, yfa ValueFormatter) Box {
annotationMinX, annotationMaxX, annotationMinY, annotationMaxY := math.MaxInt32, 0, math.MaxInt32, 0
for seriesIndex, s := range c.Series {
if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
if as.Style.Show {
style := c.getSeriesStyleDefaults(seriesIndex)
var annotationBounds Box
if as.YAxis == YAxisPrimary {
annotationBounds = as.Measure(r, canvasBox, xr, yr, style)
} else if as.YAxis == YAxisSecondary {
annotationBounds = as.Measure(r, canvasBox, xr, yra, style)
}
annotationMinY = MinInt(annotationMinY, annotationBounds.Top)
annotationMinX = MinInt(annotationMinX, annotationBounds.Left)
annotationMaxX = MaxInt(annotationMaxX, annotationBounds.Right)
annotationMaxY = MaxInt(annotationMaxY, annotationBounds.Bottom)
}
}
}
newBox := Box{
Top: canvasBox.Top,
Left: canvasBox.Left,
Right: canvasBox.Right,
Bottom: canvasBox.Bottom,
}
if annotationMinY < 0 {
// figure out how much top padding to add
delta := -1 * annotationMinY
newBox.Top = canvasBox.Top + delta
}
if annotationMinX < 0 {
// figure out how much left padding to add
delta := -1 * annotationMinX
newBox.Left = canvasBox.Left + delta
}
if annotationMaxX > c.Width {
// figure out how much right padding to add
delta := annotationMaxX - c.Width
newBox.Right = canvasBox.Right - delta
}
if annotationMaxY > c.Height {
//figure out how much bottom padding to add
delta := annotationMaxY - c.Height
newBox.Bottom = canvasBox.Bottom - delta
}
newBox.Height = newBox.Bottom - newBox.Top
newBox.Width = newBox.Right - newBox.Left
return newBox
}
func (c Chart) drawBackground(r Renderer) {
r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
r.SetStrokeColor(c.Background.GetStrokeColor(DefaultBackgroundStrokeColor))
r.SetStrokeWidth(c.Background.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(0, 0)
r.LineTo(c.Width, 0)
r.LineTo(c.Width, c.Height)
r.LineTo(0, c.Height)
r.LineTo(0, 0)
r.Close()
r.FillStroke()
}
func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
r.SetFillColor(c.Canvas.GetFillColor(DefaultCanvasColor))
r.SetStrokeColor(c.Canvas.GetStrokeColor(DefaultCanvasStrokColor))
r.SetStrokeWidth(c.Canvas.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(canvasBox.Left, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.LineTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Left, canvasBox.Top)
r.Close()
r.FillStroke()
}
func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, xticks, yticks, yticksAlt []Tick) {
if c.XAxis.Style.Show {
c.XAxis.Render(r, canvasBox, xrange, xticks)
}
if c.YAxis.Style.Show {
c.YAxis.Render(r, canvasBox, yrange, yticks)
}
if c.YAxisSecondary.Style.Show {
c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, yticksAlt)
}
}
func (c Chart) getSeriesStyleDefaults(seriesIndex int) Style {
strokeColor := GetDefaultSeriesStrokeColor(seriesIndex)
return Style{
StrokeColor: strokeColor,
StrokeWidth: DefaultStrokeWidth,
Font: c.Font,
FontSize: DefaultFontSize,
}
}
func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, s Series, seriesIndex int) {
if s.GetYAxis() == YAxisPrimary {
s.Render(r, canvasBox, xrange, yrange, c.getSeriesStyleDefaults(seriesIndex))
} else if s.GetYAxis() == YAxisSecondary {
s.Render(r, canvasBox, xrange, yrangeAlt, c.getSeriesStyleDefaults(seriesIndex))
}
}
func (c Chart) drawTitle(r Renderer) {
if len(c.Title) > 0 && c.TitleStyle.Show {
r.SetFont(c.TitleStyle.GetFont(c.Font))
r.SetFontColor(c.TitleStyle.GetFontColor(DefaultTextColor))
titleFontSize := c.TitleStyle.GetFontSize(DefaultTitleFontSize)
r.SetFontSize(titleFontSize)
textBox := r.MeasureText(c.Title)
textWidth := textBox.Width
textHeight := textBox.Height
titleX := (c.Width >> 1) - (textWidth >> 1)
titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
r.Text(c.Title, titleX, titleY)
}
}