go-chart/chart.go
2016-07-16 23:45:28 -07:00

482 lines
13 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
defaultFont *truetype.Font
Series []Series
Elements []Renderable
}
// 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 {
if c.Font == nil {
return c.defaultFont
}
return c.Font
}
// GetWidth returns the chart width or the default value.
func (c Chart) GetWidth() int {
if c.Width == 0 {
return DefaultChartWidth
}
return c.Width
}
// GetHeight returns the chart height or the default value.
func (c Chart) GetHeight() int {
if c.Height == 0 {
return DefaultChartHeight
}
return c.Height
}
// 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.GetWidth(), c.GetHeight())
if err != nil {
return err
}
if c.Font == nil {
defaultFont, err := GetDefaultFont()
if err != nil {
return err
}
c.defaultFont = defaultFont
}
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)
err = c.checkRanges(xr, yr, yra)
if err != nil {
return err
}
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)
// do a second pass in case things haven't settled yet.
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)
}
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)
for _, a := range c.Elements {
a(r, canvasBox, c.styleDefaultsElements())
}
return r.Save(w)
}
func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
var minx, maxx float64 = math.MaxFloat64, 0
var miny, maxy float64 = math.MaxFloat64, 0
var minya, maxya float64 = math.MaxFloat64, 0
// note: a possible future optimization is to not scan the series values if
// all axis are represented by either custom ticks or custom ranges.
for _, s := range c.Series {
if s.GetStyle().IsZero() || s.GetStyle().Show {
seriesAxis := s.GetYAxis()
if bvp, isBoundedValueProvider := s.(BoundedValueProvider); isBoundedValueProvider {
seriesLength := bvp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy1, vy2 := bvp.GetBoundedValue(index)
minx = math.Min(minx, vx)
maxx = math.Max(maxx, vx)
if seriesAxis == YAxisPrimary {
miny = math.Min(miny, vy1)
miny = math.Min(miny, vy2)
maxy = math.Max(maxy, vy1)
maxy = math.Max(maxy, vy2)
} else if seriesAxis == YAxisSecondary {
minya = math.Min(minya, vy1)
minya = math.Min(minya, vy2)
maxya = math.Max(maxya, vy1)
maxya = math.Max(maxya, vy2)
}
}
} else if vp, isValueProvider := s.(ValueProvider); isValueProvider {
seriesLength := vp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy := vp.GetValue(index)
minx = math.Min(minx, vx)
maxx = math.Max(maxx, vx)
if seriesAxis == YAxisPrimary {
miny = math.Min(miny, vy)
maxy = math.Max(maxy, vy)
} else if seriesAxis == YAxisSecondary {
minya = math.Min(minya, vy)
maxya = math.Max(maxya, vy)
}
}
}
}
}
if len(c.XAxis.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, 0.0
for _, t := range c.XAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
xrange.Min = tickMin
xrange.Max = tickMax
} else if !c.XAxis.Range.IsZero() {
xrange.Min = c.XAxis.Range.Min
xrange.Max = c.XAxis.Range.Max
} else {
xrange.Min = minx
xrange.Max = maxx
}
if len(c.YAxis.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, 0.0
for _, t := range c.YAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
yrange.Min = tickMin
yrange.Max = tickMax
} else if !c.YAxis.Range.IsZero() {
yrange.Min = c.YAxis.Range.Min
yrange.Max = c.YAxis.Range.Max
} else {
yrange.Min = miny
yrange.Max = maxy
yrange.Min, yrange.Max = yrange.GetRoundedRangeBounds()
}
if len(c.YAxisSecondary.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, 0.0
for _, t := range c.YAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
yrangeAlt.Min = tickMin
yrangeAlt.Max = tickMax
} else if !c.YAxisSecondary.Range.IsZero() {
yrangeAlt.Min = c.YAxisSecondary.Range.Min
yrangeAlt.Max = c.YAxisSecondary.Range.Max
} else {
yrangeAlt.Min = minya
yrangeAlt.Max = maxya
yrangeAlt.Min, yrangeAlt.Max = yrangeAlt.GetRoundedRangeBounds()
}
return
}
func (c Chart) checkRanges(xr, yr, yra Range) error {
if math.IsInf(xr.Delta(), 0) || math.IsNaN(xr.Delta()) {
return errors.New("Invalid (infinite or NaN) x-range delta")
}
if math.IsInf(yr.Delta(), 0) || math.IsNaN(yr.Delta()) {
return errors.New("Invalid (infinite or NaN) y-range delta")
}
if c.hasSecondarySeries() {
if math.IsInf(yra.Delta(), 0) || math.IsNaN(yra.Delta()) {
return errors.New("Invalid (infinite or NaN) y-secondary-range delta")
}
}
return nil
}
func (c Chart) getDefaultCanvasBox() Box {
dpt := c.Background.Padding.GetTop(DefaultBackgroundPadding.Top)
dpl := c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left)
dpr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
dpb := c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
return Box{
Top: dpt,
Left: dpl,
Right: c.GetWidth() - dpr,
Bottom: c.GetHeight() - dpb,
}
}
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, c.styleDefaultsAxis(), xf)
}
if c.YAxis.Style.Show {
yticks = c.YAxis.GetTicks(r, yr, c.styleDefaultsAxis(), yf)
}
if c.YAxisSecondary.Style.Show {
yticksAlt = c.YAxisSecondary.GetTicks(r, yar, c.styleDefaultsAxis(), yfa)
}
return
}
func (c Chart) getAxisAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xticks, yticks, yticksAlt []Tick) Box {
axesOuterBox := canvasBox.Clone()
if c.XAxis.Style.Show {
axesBounds := c.XAxis.Measure(r, canvasBox, xr, c.styleDefaultsAxis(), xticks)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
if c.YAxis.Style.Show {
axesBounds := c.YAxis.Measure(r, canvasBox, yr, c.styleDefaultsAxis(), yticks)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
if c.YAxisSecondary.Style.Show {
axesBounds := c.YAxisSecondary.Measure(r, canvasBox, yra, c.styleDefaultsAxis(), yticksAlt)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
return canvasBox.OuterConstrain(c.Box(), axesOuterBox)
}
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.IsZero() || as.Style.Show {
return true
}
}
}
return false
}
func (c Chart) hasSecondarySeries() bool {
for _, s := range c.Series {
if s.GetYAxis() == YAxisSecondary {
return true
}
}
return false
}
func (c Chart) getAnnotationAdjustedCanvasBox(r Renderer, canvasBox Box, xr, yr, yra Range, xf, yf, yfa ValueFormatter) Box {
annotationSeriesBox := canvasBox.Clone()
for seriesIndex, s := range c.Series {
if as, isAnnotationSeries := s.(AnnotationSeries); isAnnotationSeries {
if as.Style.IsZero() || as.Style.Show {
style := c.styleDefaultsSeries(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)
}
annotationSeriesBox = annotationSeriesBox.Grow(annotationBounds)
}
}
}
return canvasBox.OuterConstrain(c.Box(), annotationSeriesBox)
}
func (c Chart) getBackgroundStyle() Style {
return c.Background.WithDefaultsFrom(c.styleDefaultsBackground())
}
func (c Chart) drawBackground(r Renderer) {
DrawBox(r, c.Box(), c.getBackgroundStyle())
}
func (c Chart) getCanvasStyle() Style {
return c.Canvas.WithDefaultsFrom(c.styleDefaultsCanvas())
}
func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
DrawBox(r, canvasBox, c.getCanvasStyle())
}
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, c.styleDefaultsAxis(), xticks)
}
if c.YAxis.Style.Show {
c.YAxis.Render(r, canvasBox, yrange, c.styleDefaultsAxis(), yticks)
}
if c.YAxisSecondary.Style.Show {
c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, c.styleDefaultsAxis(), yticksAlt)
}
}
func (c Chart) drawSeries(r Renderer, canvasBox Box, xrange, yrange, yrangeAlt Range, s Series, seriesIndex int) {
if s.GetStyle().IsZero() || s.GetStyle().Show {
if s.GetYAxis() == YAxisPrimary {
s.Render(r, canvasBox, xrange, yrange, c.styleDefaultsSeries(seriesIndex))
} else if s.GetYAxis() == YAxisSecondary {
s.Render(r, canvasBox, xrange, yrangeAlt, c.styleDefaultsSeries(seriesIndex))
}
}
}
func (c Chart) drawTitle(r Renderer) {
if len(c.Title) > 0 && c.TitleStyle.Show {
r.SetFont(c.TitleStyle.GetFont(c.GetFont()))
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.GetWidth() >> 1) - (textWidth >> 1)
titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
r.Text(c.Title, titleX, titleY)
}
}
func (c Chart) styleDefaultsBackground() Style {
return Style{
FillColor: DefaultBackgroundColor,
StrokeColor: DefaultBackgroundStrokeColor,
StrokeWidth: DefaultStrokeWidth,
}
}
func (c Chart) styleDefaultsCanvas() Style {
return Style{
FillColor: DefaultCanvasColor,
StrokeColor: DefaultCanvasStrokeColor,
StrokeWidth: DefaultStrokeWidth,
}
}
func (c Chart) styleDefaultsSeries(seriesIndex int) Style {
strokeColor := GetDefaultSeriesStrokeColor(seriesIndex)
return Style{
StrokeColor: strokeColor,
StrokeWidth: DefaultStrokeWidth,
Font: c.GetFont(),
FontSize: DefaultFontSize,
}
}
func (c Chart) styleDefaultsAxis() Style {
return Style{
Font: c.GetFont(),
FontSize: DefaultAxisFontSize,
StrokeColor: DefaultAxisColor,
StrokeWidth: DefaultAxisLineWidth,
}
}
func (c Chart) styleDefaultsElements() Style {
return Style{
Font: c.GetFont(),
}
}
// Box returns the chart bounds as a box.
func (c Chart) Box() Box {
return Box{Right: c.GetWidth(), Bottom: c.GetHeight()}
}