go-chart/chart.go
2018-12-06 16:38:58 +01:00

568 lines
15 KiB
Go

package chart
import (
"errors"
"fmt"
"io"
"math"
"git.gutmet.org/golang-freetype.git/truetype"
util "git.gutmet.org/go-chart.git/util"
)
// Chart is what we're drawing.
type Chart struct {
Title string
TitleStyle Style
ColorPalette ColorPalette
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")
}
if visibleSeriesErr := c.checkHasVisibleSeries(); visibleSeriesErr != nil {
return visibleSeriesErr
}
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 {
r.Save(w)
return err
}
if c.hasAxes() {
xt, yt, yta = c.getAxesTicks(r, xr, yr, yra, xf, yf, yfa)
canvasBox = c.getAxesAdjustedCanvasBox(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.getAxesAdjustedCanvasBox(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) checkHasVisibleSeries() error {
hasVisibleSeries := false
var style Style
for _, s := range c.Series {
style = s.GetStyle()
hasVisibleSeries = hasVisibleSeries || (style.IsZero() || style.Show)
}
if !hasVisibleSeries {
return fmt.Errorf("must have (1) visible series; make sure if you set a style, you set .Show = true")
}
return nil
}
func (c Chart) validateSeries() error {
var err error
for _, s := range c.Series {
err = s.Validate()
if err != nil {
return err
}
}
return nil
}
func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
var minx, maxx float64 = math.MaxFloat64, -math.MaxFloat64
var miny, maxy float64 = math.MaxFloat64, -math.MaxFloat64
var minya, maxya float64 = math.MaxFloat64, -math.MaxFloat64
seriesMappedToSecondaryAxis := false
// 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, isBoundedValuesProvider := s.(BoundedValuesProvider); isBoundedValuesProvider {
seriesLength := bvp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy1, vy2 := bvp.GetBoundedValues(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)
seriesMappedToSecondaryAxis = true
}
}
} else if vp, isValuesProvider := s.(ValuesProvider); isValuesProvider {
seriesLength := vp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy := vp.GetValues(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)
seriesMappedToSecondaryAxis = true
}
}
}
}
}
if c.XAxis.Range == nil {
xrange = &ContinuousRange{}
} else {
xrange = c.XAxis.Range
}
if c.YAxis.Range == nil {
yrange = &ContinuousRange{}
} else {
yrange = c.YAxis.Range
}
if c.YAxisSecondary.Range == nil {
yrangeAlt = &ContinuousRange{}
} else {
yrangeAlt = c.YAxisSecondary.Range
}
if len(c.XAxis.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, -math.MaxFloat64
for _, t := range c.XAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
xrange.SetMin(tickMin)
xrange.SetMax(tickMax)
} else if xrange.IsZero() {
xrange.SetMin(minx)
xrange.SetMax(maxx)
}
if len(c.YAxis.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, -math.MaxFloat64
for _, t := range c.YAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
yrange.SetMin(tickMin)
yrange.SetMax(tickMax)
} else if yrange.IsZero() {
yrange.SetMin(miny)
yrange.SetMax(maxy)
// only round if we're showing the axis
if c.YAxis.Style.Show {
delta := yrange.GetDelta()
roundTo := util.Math.GetRoundToForDelta(delta)
rmin, rmax := util.Math.RoundDown(yrange.GetMin(), roundTo), util.Math.RoundUp(yrange.GetMax(), roundTo)
yrange.SetMin(rmin)
yrange.SetMax(rmax)
}
}
if len(c.YAxisSecondary.Ticks) > 0 {
tickMin, tickMax := math.MaxFloat64, -math.MaxFloat64
for _, t := range c.YAxis.Ticks {
tickMin = math.Min(tickMin, t.Value)
tickMax = math.Max(tickMax, t.Value)
}
yrangeAlt.SetMin(tickMin)
yrangeAlt.SetMax(tickMax)
} else if seriesMappedToSecondaryAxis && yrangeAlt.IsZero() {
yrangeAlt.SetMin(minya)
yrangeAlt.SetMax(maxya)
if c.YAxisSecondary.Style.Show {
delta := yrangeAlt.GetDelta()
roundTo := util.Math.GetRoundToForDelta(delta)
rmin, rmax := util.Math.RoundDown(yrangeAlt.GetMin(), roundTo), util.Math.RoundUp(yrangeAlt.GetMax(), roundTo)
yrangeAlt.SetMin(rmin)
yrangeAlt.SetMax(rmax)
}
}
return
}
func (c Chart) checkRanges(xr, yr, yra Range) error {
xDelta := xr.GetDelta()
if math.IsInf(xDelta, 0) {
return errors.New("infinite x-range delta")
}
if math.IsNaN(xDelta) {
return errors.New("nan x-range delta")
}
if xDelta == 0 {
return errors.New("zero x-range delta; there needs to be at least (2) values")
}
yDelta := yr.GetDelta()
if math.IsInf(yDelta, 0) {
return errors.New("infinite y-range delta")
}
if math.IsNaN(yDelta) {
return errors.New("nan y-range delta")
}
if c.hasSecondarySeries() {
yraDelta := yra.GetDelta()
if math.IsInf(yraDelta, 0) {
return errors.New("infinite secondary y-range delta")
}
if math.IsNaN(yraDelta) {
return errors.New("nan secondary y-range delta")
}
}
return nil
}
func (c Chart) getDefaultCanvasBox() Box {
return c.Box()
}
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.GetValueFormatter()
}
if c.YAxis.ValueFormatter != nil {
y = c.YAxis.GetValueFormatter()
}
if c.YAxisSecondary.ValueFormatter != nil {
ya = c.YAxisSecondary.GetValueFormatter()
}
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.styleDefaultsAxes(), xf)
}
if c.YAxis.Style.Show {
yticks = c.YAxis.GetTicks(r, yr, c.styleDefaultsAxes(), yf)
}
if c.YAxisSecondary.Style.Show {
yticksAlt = c.YAxisSecondary.GetTicks(r, yar, c.styleDefaultsAxes(), yfa)
}
return
}
func (c Chart) getAxesAdjustedCanvasBox(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.styleDefaultsAxes(), xticks)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
if c.YAxis.Style.Show {
axesBounds := c.YAxis.Measure(r, canvasBox, yr, c.styleDefaultsAxes(), yticks)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
if c.YAxisSecondary.Style.Show {
axesBounds := c.YAxisSecondary.Measure(r, canvasBox, yra, c.styleDefaultsAxes(), yticksAlt)
axesOuterBox = axesOuterBox.Grow(axesBounds)
}
return canvasBox.OuterConstrain(c.Box(), axesOuterBox)
}
func (c Chart) setRangeDomains(canvasBox Box, xr, yr, yra Range) (Range, Range, Range) {
xr.SetDomain(canvasBox.Width())
yr.SetDomain(canvasBox.Height())
yra.SetDomain(canvasBox.Height())
return xr, yr, yra
}
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.InheritFrom(c.styleDefaultsBackground())
}
func (c Chart) drawBackground(r Renderer) {
Draw.Box(r, Box{
Right: c.GetWidth(),
Bottom: c.GetHeight(),
}, c.getBackgroundStyle())
}
func (c Chart) getCanvasStyle() Style {
return c.Canvas.InheritFrom(c.styleDefaultsCanvas())
}
func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
Draw.Box(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.styleDefaultsAxes(), xticks)
}
if c.YAxis.Style.Show {
c.YAxis.Render(r, canvasBox, yrange, c.styleDefaultsAxes(), yticks)
}
if c.YAxisSecondary.Style.Show {
c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, c.styleDefaultsAxes(), 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(c.GetColorPalette().TextColor()))
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: c.GetColorPalette().BackgroundColor(),
StrokeColor: c.GetColorPalette().BackgroundStrokeColor(),
StrokeWidth: DefaultBackgroundStrokeWidth,
}
}
func (c Chart) styleDefaultsCanvas() Style {
return Style{
FillColor: c.GetColorPalette().CanvasColor(),
StrokeColor: c.GetColorPalette().CanvasStrokeColor(),
StrokeWidth: DefaultCanvasStrokeWidth,
}
}
func (c Chart) styleDefaultsSeries(seriesIndex int) Style {
return Style{
DotColor: c.GetColorPalette().GetSeriesColor(seriesIndex),
StrokeColor: c.GetColorPalette().GetSeriesColor(seriesIndex),
StrokeWidth: DefaultSeriesLineWidth,
Font: c.GetFont(),
FontSize: DefaultFontSize,
}
}
func (c Chart) styleDefaultsAxes() Style {
return Style{
Font: c.GetFont(),
FontColor: c.GetColorPalette().TextColor(),
FontSize: DefaultAxisFontSize,
StrokeColor: c.GetColorPalette().AxisStrokeColor(),
StrokeWidth: DefaultAxisLineWidth,
}
}
func (c Chart) styleDefaultsElements() Style {
return Style{
Font: c.GetFont(),
}
}
// GetColorPalette returns the color palette for the chart.
func (c Chart) GetColorPalette() ColorPalette {
if c.ColorPalette != nil {
return c.ColorPalette
}
return DefaultColorPalette
}
// Box returns the chart bounds as a box.
func (c Chart) Box() Box {
dpr := c.Background.Padding.GetRight(DefaultBackgroundPadding.Right)
dpb := c.Background.Padding.GetBottom(DefaultBackgroundPadding.Bottom)
return Box{
Top: c.Background.Padding.GetTop(DefaultBackgroundPadding.Top),
Left: c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
Right: c.GetWidth() - dpr,
Bottom: c.GetHeight() - dpb,
}
}