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Merge pull request #1 from wcharczuk/render

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The March Towards v1.0
This commit is contained in:
Will Charczuk 2016-07-10 11:25:53 -07:00 committed by GitHub
commit 04c3cbdcf9
26 changed files with 1023 additions and 514 deletions
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48
annotation_series.go Normal file
View file

@ -0,0 +1,48 @@
package chart
// Annotation is a label on the chart.
type Annotation struct {
X, Y float64
Label string
}
// AnnotationSeries is a series of labels on the chart.
type AnnotationSeries struct {
Name string
Style Style
YAxis YAxisType
Annotations []Annotation
}
// GetName returns the name of the time series.
func (as AnnotationSeries) GetName() string {
return as.Name
}
// GetStyle returns the line style.
func (as AnnotationSeries) GetStyle() Style {
return as.Style
}
// GetYAxis returns which YAxis the series draws on.
func (as AnnotationSeries) GetYAxis() YAxisType {
return as.YAxis
}
// Render draws the series.
func (as AnnotationSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
if as.Style.Show {
style := as.Style.WithDefaultsFrom(Style{
FillColor: DefaultAnnotationFillColor,
FontSize: DefaultAnnotationFontSize,
StrokeColor: defaults.StrokeColor,
StrokeWidth: defaults.StrokeWidth,
Padding: DefaultAnnotationPadding,
})
for _, a := range as.Annotations {
lx := canvasBox.Right - xrange.Translate(a.X)
ly := yrange.Translate(a.Y) + canvasBox.Top
DrawAnnotation(r, canvasBox, xrange, yrange, style, lx, ly, a.Label)
}
}
}

19
axis.go Normal file
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@ -0,0 +1,19 @@
package chart
// YAxisType is a type of y-axis; it can either be primary or secondary.
type YAxisType int
const (
// YAxisPrimary is the primary axis.
YAxisPrimary YAxisType = 0
// YAxisSecondary is the secondary axis.
YAxisSecondary YAxisType = 1
)
// Axis is a chart feature detailing what values happen where.
type Axis interface {
GetName() string
GetStyle() Style
GetTicks(r Renderer, ra Range, vf ValueFormatter) []Tick
Render(c *Chart, r Renderer, canvasBox Box, ra Range, ticks []Tick)
}

2
box.go
View file

@ -20,7 +20,7 @@ func (b Box) IsZero() bool {
// String returns a string representation of the box.
func (b Box) String() string {
return fmt.Sprintf("Box(%d,%d,%d,%d)", b.Top, b.Left, b.Right, b.Bottom)
return fmt.Sprintf("box(%d,%d,%d,%d)", b.Top, b.Left, b.Right, b.Bottom)
}
// GetTop returns a coalesced value with a default.

565
chart.go
View file

@ -3,9 +3,9 @@ package chart
import (
"errors"
"io"
"math"
"github.com/golang/freetype/truetype"
"github.com/wcharczuk/go-chart/drawing"
)
// Chart is what we're drawing.
@ -19,11 +19,10 @@ type Chart struct {
Background Style
Canvas Style
Axes Style
FinalValueLabel Style
XRange Range
YRange Range
XAxis XAxis
YAxis YAxis
YAxisSecondary YAxis
Font *truetype.Font
Series []Series
@ -53,179 +52,257 @@ func (c Chart) GetFont() (*truetype.Font, error) {
}
// Render renders the chart with the given renderer to the given io.Writer.
func (c *Chart) Render(provider RendererProvider, w io.Writer) error {
func (c Chart) Render(rp RendererProvider, w io.Writer) error {
if len(c.Series) == 0 {
return errors.New("Please provide at least one series")
}
r, err := provider(c.Width, c.Height)
r, err := rp(c.Width, c.Height)
if err != nil {
return err
}
if c.hasText() {
font, err := c.GetFont()
if err != nil {
return err
}
c.Font = font
r.SetFont(font)
}
r.SetDPI(c.GetDPI(DefaultDPI))
canvasBox := c.calculateCanvasBox(r)
xrange, yrange := c.initRanges(canvasBox)
xrange, yrange, yrangeAlt := c.getRanges()
canvasBox := c.getDefaultCanvasBox()
xf, yf, yfa := c.getValueFormatters()
xrange, yrange, yrangeAlt = c.setRangeDomains(canvasBox, xrange, yrange, yrangeAlt)
xticks, yticks, yticksAlt := c.getAxesTicks(r, xrange, yrange, yrangeAlt, xf, yf, yfa)
canvasBox = c.getAdjustedCanvasBox(r, canvasBox, xticks, yticks, yticksAlt)
// we do a second pass to take the updated domains into account
xrange, yrange, yrangeAlt = c.setRangeDomains(canvasBox, xrange, yrange, yrangeAlt)
xticks, yticks, yticksAlt = c.getAxesTicks(r, xrange, yrange, yrangeAlt, xf, yf, yfa)
canvasBox = c.getAdjustedCanvasBox(r, canvasBox, xticks, yticks, yticksAlt)
c.drawBackground(r)
c.drawCanvas(r, canvasBox)
c.drawAxes(r, canvasBox, xrange, yrange)
c.drawAxes(r, canvasBox, xrange, yrange, yrangeAlt, xticks, yticks, yticksAlt)
for index, series := range c.Series {
c.drawSeries(r, canvasBox, index, series, xrange, yrange)
c.drawSeries(r, canvasBox, xrange, yrange, yrangeAlt, series, index)
}
c.drawTitle(r)
return r.Save(w)
}
func (c Chart) hasText() bool {
return c.TitleStyle.Show || c.Axes.Show || c.FinalValueLabel.Show
func (c Chart) getRanges() (xrange, yrange, yrangeAlt Range) {
//iterate over each series, pull out the min/max for x,y
var didSetFirstValues bool
var globalMinX, globalMaxX float64
var globalMinY, globalMaxY float64
var globalMinYA, globalMaxYA float64
for _, s := range c.Series {
if vp, isValueProvider := s.(ValueProvider); isValueProvider {
seriesLength := vp.Len()
for index := 0; index < seriesLength; index++ {
vx, vy := vp.GetValue(index)
if didSetFirstValues {
if globalMinX > vx {
globalMinX = vx
}
if globalMaxX < vx {
globalMaxX = vx
}
if s.GetYAxis() == YAxisPrimary {
if globalMinY > vy {
globalMinY = vy
}
if globalMaxY < vy {
globalMaxY = vy
}
} else if s.GetYAxis() == YAxisSecondary {
if globalMinYA > vy {
globalMinYA = vy
}
if globalMaxYA < vy {
globalMaxYA = vy
}
}
} else {
globalMinX, globalMaxX = vx, vx
if s.GetYAxis() == YAxisPrimary {
globalMinY, globalMaxY = vy, vy
} else if s.GetYAxis() == YAxisSecondary {
globalMinYA, globalMaxYA = vy, vy
}
didSetFirstValues = true
}
}
}
}
if !c.XAxis.Range.IsZero() {
xrange.Min = c.XAxis.Range.Min
xrange.Max = c.XAxis.Range.Max
} else {
xrange.Min = globalMinX
xrange.Max = globalMaxX
}
if !c.YAxis.Range.IsZero() {
yrange.Min = c.YAxis.Range.Min
yrange.Max = c.YAxis.Range.Max
} else {
yrange.Min = globalMinY
yrange.Max = globalMaxY
}
if !c.YAxisSecondary.Range.IsZero() {
yrangeAlt.Min = c.YAxisSecondary.Range.Min
yrangeAlt.Max = c.YAxisSecondary.Range.Max
} else {
yrangeAlt.Min = globalMinYA
yrangeAlt.Max = globalMaxYA
}
return
}
func (c Chart) getAxisWidth() int {
asw := 0
if c.Axes.Show {
asw = int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
}
return asw
}
func (c Chart) calculateCanvasBox(r Renderer) Box {
dpr := DefaultBackgroundPadding.Right
finalLabelWidth := c.calculateFinalLabelWidth(r)
if finalLabelWidth > dpr {
dpr = finalLabelWidth
}
axisBottomHeight := c.calculateBottomLabelHeight()
dpb := DefaultBackgroundPadding.Bottom
if dpb < axisBottomHeight {
dpb = axisBottomHeight
}
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: c.Background.Padding.GetLeft(DefaultBackgroundPadding.Left),
Right: c.Width - c.Background.Padding.GetRight(dpr),
Bottom: c.Height - c.Background.Padding.GetBottom(dpb),
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) calculateFinalLabelWidth(r Renderer) int {
if !c.FinalValueLabel.Show {
return 0
}
var finalLabelText string
func (c Chart) getValueFormatters() (x, y, ya ValueFormatter) {
for _, s := range c.Series {
_, lv := s.GetValue(s.Len() - 1)
var ll string
if c.YRange.Formatter != nil {
ll = c.YRange.Formatter(lv)
} else {
ll = s.GetYFormatter()(lv)
}
if len(finalLabelText) < len(ll) {
finalLabelText = ll
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
}
}
r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
textWidth, _ := r.MeasureText(finalLabelText)
asw := c.getAxisWidth()
pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
pr := c.FinalValueLabel.Padding.GetRight(DefaultFinalLabelPadding.Right)
lsw := int(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
return DefaultFinalLabelDeltaWidth +
pl + pr +
textWidth + asw + 2*lsw
}
func (c Chart) calculateBottomLabelHeight() int {
if c.Axes.Show {
return c.getAxisWidth() + int(math.Ceil(c.Axes.GetFontSize(DefaultAxisFontSize))) + DefaultXAxisMargin
}
return 0
}
func (c Chart) initRanges(canvasBox Box) (xrange Range, yrange Range) {
//iterate over each series, pull out the min/max for x,y
var didSetFirstValues bool
var globalMinY, globalMinX float64
var globalMaxY, globalMaxX float64
for _, s := range c.Series {
seriesLength := s.Len()
for index := 0; index < seriesLength; index++ {
vx, vy := s.GetValue(index)
if didSetFirstValues {
if globalMinX > vx {
globalMinX = vx
if c.XAxis.ValueFormatter != nil {
x = c.XAxis.ValueFormatter
}
if globalMinY > vy {
globalMinY = vy
if c.YAxis.ValueFormatter != nil {
y = c.YAxis.ValueFormatter
}
if globalMaxX < vx {
globalMaxX = vx
if c.YAxisSecondary.ValueFormatter != nil {
ya = c.YAxisSecondary.ValueFormatter
}
if globalMaxY < vy {
globalMaxY = vy
}
} else {
globalMinX, globalMaxX = vx, vx
globalMinY, globalMaxY = vy, vy
didSetFirstValues = true
}
}
if xrange.Formatter == nil {
xrange.Formatter = s.GetXFormatter()
}
if yrange.Formatter == nil {
yrange.Formatter = s.GetYFormatter()
}
}
if c.XRange.IsZero() {
xrange.Min = globalMinX
xrange.Max = globalMaxX
} else {
xrange.Min = c.XRange.Min
xrange.Max = c.XRange.Max
}
if c.XRange.Formatter != nil {
xrange.Formatter = c.XRange.Formatter
}
if c.XRange.Ticks != nil {
xrange.Ticks = c.XRange.Ticks
}
xrange.Domain = canvasBox.Width
if c.YRange.IsZero() {
yrange.Min = globalMinY
yrange.Max = globalMaxY
} else {
yrange.Min = c.YRange.Min
yrange.Max = c.YRange.Max
}
if c.YRange.Formatter != nil {
yrange.Formatter = c.YRange.Formatter
}
if c.YRange.Ticks != nil {
yrange.Ticks = c.YRange.Ticks
}
yrange.Domain = canvasBox.Height
return
}
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) getAdjustedCanvasBox(r Renderer, defaults Box, xticks, yticks, yticksAlt []Tick) Box {
canvasBox := Box{}
var dpl, dpr, dpb int
if c.XAxis.Style.Show {
dpb = c.getXAxisHeight(r, xticks)
}
if c.YAxis.Style.Show {
dpr = c.getYAxisWidth(r, yticks)
}
if c.YAxisSecondary.Style.Show {
dpl = c.getYAxisSecondaryWidth(r, yticksAlt)
}
canvasBox.Top = defaults.Top
if dpl != 0 {
canvasBox.Left = c.Canvas.Padding.GetLeft(dpl)
} else {
canvasBox.Left = defaults.Left
}
if dpr != 0 {
canvasBox.Right = c.Width - c.Canvas.Padding.GetRight(dpr)
} else {
canvasBox.Right = defaults.Right
}
if dpb != 0 {
canvasBox.Bottom = c.Height - c.Canvas.Padding.GetBottom(dpb)
} else {
canvasBox.Bottom = defaults.Bottom
}
canvasBox.Width = canvasBox.Right - canvasBox.Left
canvasBox.Height = canvasBox.Bottom - canvasBox.Top
return canvasBox
}
func (c Chart) getXAxisHeight(r Renderer, ticks []Tick) int {
r.SetFontSize(c.XAxis.Style.GetFontSize(DefaultFontSize))
r.SetFont(c.XAxis.Style.GetFont(c.Font))
var tl int
for _, t := range ticks {
_, lh := r.MeasureText(t.Label)
if lh > tl {
tl = lh
}
}
return tl + DefaultXAxisMargin
}
func (c Chart) getYAxisWidth(r Renderer, ticks []Tick) int {
var ll string
for _, t := range ticks {
if len(t.Label) > len(ll) {
ll = t.Label
}
}
r.SetFontSize(c.YAxis.Style.GetFontSize(DefaultFontSize))
r.SetFont(c.YAxis.Style.GetFont(c.Font))
tw, _ := r.MeasureText(ll)
return tw + DefaultYAxisMargin
}
func (c Chart) getYAxisSecondaryWidth(r Renderer, ticks []Tick) int {
var ll string
for _, t := range ticks {
if len(t.Label) > len(ll) {
ll = t.Label
}
}
r.SetFontSize(c.YAxisSecondary.Style.GetFontSize(DefaultFontSize))
r.SetFont(c.YAxisSecondary.Style.GetFont(c.Font))
tw, _ := r.MeasureText(ll)
return tw + DefaultYAxisMargin
}
func (c Chart) setRangeDomains(canvasBox Box, xrange, yrange, yrangeAlt Range) (Range, Range, Range) {
xrange.Domain = canvasBox.Width
yrange.Domain = canvasBox.Height
yrangeAlt.Domain = canvasBox.Height
return xrange, yrange, yrangeAlt
}
func (c Chart) drawBackground(r Renderer) {
r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
r.SetStrokeColor(c.Background.GetStrokeColor(DefaultBackgroundStrokeColor))
@ -252,202 +329,52 @@ func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
r.FillStroke()
}
func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange Range) {
if c.Axes.Show {
r.SetStrokeColor(c.Axes.GetStrokeColor(DefaultAxisColor))
r.SetStrokeWidth(c.Axes.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Top)
r.Stroke()
c.drawXAxisLabels(r, canvasBox, xrange)
c.drawYAxisLabels(r, canvasBox, yrange)
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, YAxisPrimary, yticks)
}
if c.YAxisSecondary.Style.Show {
c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, YAxisSecondary, yticksAlt)
}
}
func (c Chart) generateRangeTicks(r Range, tickCount int, offset float64) []Tick {
var ticks []Tick
rangeTicks := Slices(tickCount, r.Max-r.Min)
for _, rv := range rangeTicks {
ticks = append(ticks, Tick{
RangeValue: rv + offset,
Label: r.Format(rv + offset),
})
}
return ticks
}
func (c Chart) drawYAxisLabels(r Renderer, canvasBox Box, yrange Range) {
tickFontSize := c.Axes.GetFontSize(DefaultAxisFontSize)
asw := c.getAxisWidth()
tx := canvasBox.Right + DefaultFinalLabelDeltaWidth + asw
r.SetFontColor(c.Axes.GetFontColor(DefaultAxisColor))
r.SetFontSize(tickFontSize)
ticks := yrange.Ticks
if ticks == nil {
minimumTickHeight := tickFontSize + DefaultMinimumTickVerticalSpacing
tickCount := int(math.Floor(float64(yrange.Domain) / float64(minimumTickHeight)))
if tickCount > DefaultMaxTickCount {
tickCount = DefaultMaxTickCount
}
ticks = c.generateRangeTicks(yrange, tickCount, yrange.Min)
}
for _, t := range ticks {
v := t.RangeValue
y := yrange.Translate(v)
ty := int(y)
r.Text(t.Label, tx, ty)
func (c Chart) getSeriesStyleDefaults(seriesIndex int) Style {
strokeColor := GetDefaultSeriesStrokeColor(seriesIndex)
return Style{
StrokeColor: strokeColor,
StrokeWidth: DefaultStrokeWidth,
FillColor: strokeColor.WithAlpha(100),
Font: c.Font,
FontSize: DefaultFontSize,
}
}
func (c Chart) drawXAxisLabels(r Renderer, canvasBox Box, xrange Range) {
tickFontSize := c.Axes.GetFontSize(DefaultAxisFontSize)
ty := canvasBox.Bottom + DefaultXAxisMargin + int(tickFontSize)
r.SetFontColor(c.Axes.GetFontColor(DefaultAxisColor))
r.SetFontSize(tickFontSize)
ticks := xrange.Ticks
if ticks == nil {
maxLabelWidth := 60
minimumTickWidth := maxLabelWidth + DefaultMinimumTickHorizontalSpacing
tickCount := int(math.Floor(float64(xrange.Domain) / float64(minimumTickWidth)))
if tickCount > DefaultMaxTickCount {
tickCount = DefaultMaxTickCount
}
ticks = c.generateRangeTicks(xrange, tickCount, xrange.Min)
}
for _, t := range ticks {
v := t.RangeValue
x := xrange.Translate(v)
tx := canvasBox.Left + int(x)
r.Text(t.Label, tx, ty)
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) drawSeries(r Renderer, canvasBox Box, index int, s Series, xrange, yrange Range) {
if s.Len() == 0 {
return
}
cx := canvasBox.Left
cy := canvasBox.Top
cb := canvasBox.Bottom
cw := canvasBox.Width
v0x, v0y := s.GetValue(0)
x0 := cw - xrange.Translate(v0x)
y0 := yrange.Translate(v0y)
var vx, vy float64
var x, y int
fill := s.GetStyle().GetFillColor()
if !fill.IsZero() {
r.SetFillColor(fill)
r.MoveTo(x0+cx, y0+cy)
for i := 1; i < s.Len(); i++ {
vx, vy = s.GetValue(i)
x = cw - xrange.Translate(vx)
y = yrange.Translate(vy)
r.LineTo(x+cx, y+cy)
}
r.LineTo(x+cx, cb)
r.LineTo(x0+cx, cb)
r.Close()
r.Fill()
}
stroke := s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index))
r.SetStrokeColor(stroke)
r.SetStrokeWidth(s.GetStyle().GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(x0+cx, y0+cy)
for i := 1; i < s.Len(); i++ {
vx, vy = s.GetValue(i)
x = cw - xrange.Translate(vx)
y = yrange.Translate(vy)
r.LineTo(x+cx, y+cy)
}
r.Stroke()
c.drawFinalValueLabel(r, canvasBox, index, s, yrange)
}
func (c Chart) drawFinalValueLabel(r Renderer, canvasBox Box, index int, s Series, yrange Range) {
if c.FinalValueLabel.Show {
_, lv := s.GetValue(s.Len() - 1)
ll := yrange.Format(lv)
py := canvasBox.Top
ly := yrange.Translate(lv) + py
r.SetFontSize(c.FinalValueLabel.GetFontSize(DefaultFinalLabelFontSize))
textWidth, _ := r.MeasureText(ll)
textHeight := int(math.Floor(DefaultFinalLabelFontSize))
halfTextHeight := textHeight >> 1
asw := 0
if c.Axes.Show {
asw = int(c.Axes.GetStrokeWidth(DefaultAxisLineWidth))
}
cx := canvasBox.Right + asw
pt := c.FinalValueLabel.Padding.GetTop(DefaultFinalLabelPadding.Top)
pl := c.FinalValueLabel.Padding.GetLeft(DefaultFinalLabelPadding.Left)
pr := c.FinalValueLabel.Padding.GetRight(DefaultFinalLabelPadding.Right)
pb := c.FinalValueLabel.Padding.GetBottom(DefaultFinalLabelPadding.Bottom)
textX := cx + pl + DefaultFinalLabelDeltaWidth
textY := ly + halfTextHeight
ltlx := cx + pl + DefaultFinalLabelDeltaWidth
ltly := ly - (pt + halfTextHeight)
ltrx := cx + pl + pr + textWidth
ltry := ly - (pt + halfTextHeight)
lbrx := cx + pl + pr + textWidth
lbry := ly + (pb + halfTextHeight)
lblx := cx + DefaultFinalLabelDeltaWidth
lbly := ly + (pb + halfTextHeight)
//draw the shape...
r.SetFillColor(c.FinalValueLabel.GetFillColor(DefaultFinalLabelBackgroundColor))
r.SetStrokeColor(c.FinalValueLabel.GetStrokeColor(s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index))))
r.SetStrokeWidth(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
r.MoveTo(cx, ly)
r.LineTo(ltlx, ltly)
r.LineTo(ltrx, ltry)
r.LineTo(lbrx, lbry)
r.LineTo(lblx, lbly)
r.LineTo(cx, ly)
r.Close()
r.FillStroke()
r.SetFontColor(c.FinalValueLabel.GetFontColor(DefaultTextColor))
r.Text(ll, textX, textY)
}
}
func (c Chart) drawTitle(r Renderer) error {
func (c Chart) drawTitle(r Renderer) {
if len(c.Title) > 0 && c.TitleStyle.Show {
r.SetFontColor(c.Canvas.GetFontColor(DefaultTextColor))
titleFontSize := c.Canvas.GetFontSize(DefaultTitleFontSize)
r.SetFont(c.TitleStyle.GetFont(c.Font))
r.SetFontColor(c.TitleStyle.GetFontColor(DefaultTextColor))
titleFontSize := c.TitleStyle.GetFontSize(DefaultTitleFontSize)
r.SetFontSize(titleFontSize)
textWidth, _ := r.MeasureText(c.Title)
textWidthPoints, textHeightPoints := r.MeasureText(c.Title)
textWidth := int(drawing.PointsToPixels(r.GetDPI(), float64(textWidthPoints)))
textHeight := int(drawing.PointsToPixels(r.GetDPI(), float64(textHeightPoints)))
titleX := (c.Width >> 1) - (textWidth >> 1)
titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + int(titleFontSize)
titleY := c.TitleStyle.Padding.GetTop(DefaultTitleTop) + textHeight
r.Text(c.Title, titleX, titleY)
}
return nil
}

50
continuous_series.go Normal file
View file

@ -0,0 +1,50 @@
package chart
// ContinuousSeries represents a line on a chart.
type ContinuousSeries struct {
Name string
Style Style
YAxis YAxisType
XValues []float64
YValues []float64
}
// GetName returns the name of the time series.
func (cs ContinuousSeries) GetName() string {
return cs.Name
}
// GetStyle returns the line style.
func (cs ContinuousSeries) GetStyle() Style {
return cs.Style
}
// Len returns the number of elements in the series.
func (cs ContinuousSeries) Len() int {
return len(cs.XValues)
}
// GetValue gets a value at a given index.
func (cs ContinuousSeries) GetValue(index int) (float64, float64) {
return cs.XValues[index], cs.YValues[index]
}
// GetValueFormatters returns value formatter defaults for the series.
func (cs ContinuousSeries) GetValueFormatters() (x, y ValueFormatter) {
x = FloatValueFormatter
y = FloatValueFormatter
return
}
// GetYAxis returns which YAxis the series draws on.
func (cs ContinuousSeries) GetYAxis() YAxisType {
return cs.YAxis
}
// Render renders the series.
func (cs ContinuousSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
style := cs.Style.WithDefaultsFrom(defaults)
DrawLineSeries(r, canvasBox, xrange, yrange, style, cs)
}

29
defaults.go
View file

@ -24,24 +24,33 @@ const (
DefaultFontSize = 10.0
// DefaultTitleFontSize is the default title font size.
DefaultTitleFontSize = 18.0
// DefaultFinalLabelDeltaWidth is the width of the left triangle out of the final label.
DefaultFinalLabelDeltaWidth = 10
// DefaultFinalLabelFontSize is the font size of the final label.
DefaultFinalLabelFontSize = 10.0
// DefaultAnnotationDeltaWidth is the width of the left triangle out of annotations.
DefaultAnnotationDeltaWidth = 10
// DefaultAnnotationFontSize is the font size of annotations.
DefaultAnnotationFontSize = 10.0
// DefaultAxisFontSize is the font size of the axis labels.
DefaultAxisFontSize = 10.0
// DefaultTitleTop is the default distance from the top of the chart to put the title.
DefaultTitleTop = 10
// DefaultYAxisMargin is the default distance from the right of the canvas to the y axis labels.
DefaultYAxisMargin = 10
// DefaultXAxisMargin is the default distance from bottom of the canvas to the x axis labels.
DefaultXAxisMargin = 10
//DefaultVerticalTickWidth is half the margin.
DefaultVerticalTickWidth = DefaultYAxisMargin >> 1
//DefaultHorizontalTickWidth is half the margin.
DefaultHorizontalTickWidth = DefaultXAxisMargin >> 1
// DefaultMinimumTickHorizontalSpacing is the minimum distance between horizontal ticks.
DefaultMinimumTickHorizontalSpacing = 20
// DefaultMinimumTickVerticalSpacing is the minimum distance between vertical ticks.
DefaultMinimumTickVerticalSpacing = 20
// DefaultDateFormat is the default date format.
DefaultDateFormat = "2006-01-02"
// DefaultMaxTickCount is the maximum number of ticks to draw
DefaultMaxTickCount = 7
)
var (
@ -69,8 +78,8 @@ var (
// DefaultFillColor is the default fill color.
// It is equivalent to #0074d9.
DefaultFillColor = drawing.Color{R: 0, G: 217, B: 116, A: 255}
// DefaultFinalLabelBackgroundColor is the default final label background color.
DefaultFinalLabelBackgroundColor = drawing.Color{R: 255, G: 255, B: 255, A: 255}
// DefaultAnnotationFillColor is the default annotation background color.
DefaultAnnotationFillColor = drawing.Color{R: 255, G: 255, B: 255, A: 255}
)
var (
@ -90,8 +99,8 @@ func GetDefaultSeriesStrokeColor(index int) drawing.Color {
}
var (
// DefaultFinalLabelPadding is the padding around the final label.
DefaultFinalLabelPadding = Box{Top: 5, Left: 0, Right: 7, Bottom: 5}
// DefaultAnnotationPadding is the padding around an annotation.
DefaultAnnotationPadding = Box{Top: 5, Left: 0, Right: 7, Bottom: 5}
// DefaultBackgroundPadding is the default canvas padding config.
DefaultBackgroundPadding = Box{Top: 5, Left: 5, Right: 5, Bottom: 5}
)

95
drawing_helpers.go Normal file
View file

@ -0,0 +1,95 @@
package chart
import "math"
// 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
}
ct := canvasBox.Top
cb := canvasBox.Bottom
cr := canvasBox.Right
v0x, v0y := vs.GetValue(0)
x0 := cr - xrange.Translate(v0x)
y0 := yrange.Translate(v0y) + ct
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 = cr - xrange.Translate(vx)
y = yrange.Translate(vy) + ct
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 = cr - xrange.Translate(vx)
y = yrange.Translate(vy) + ct
r.LineTo(x, y)
}
r.Stroke()
}
// DrawAnnotation draws an anotation with a renderer.
func DrawAnnotation(r Renderer, canvasBox Box, xrange, yrange Range, s Style, lx, ly int, label string) {
r.SetFontSize(s.GetFontSize(DefaultAnnotationFontSize))
textWidth, _ := r.MeasureText(label)
textHeight := int(math.Floor(DefaultAnnotationFontSize))
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)
textX := lx + pl + DefaultAnnotationDeltaWidth
textY := ly + halfTextHeight
ltlx := lx + pl + DefaultAnnotationDeltaWidth
ltly := ly - (pt + halfTextHeight)
ltrx := lx + pl + pr + textWidth
ltry := ly - (pt + halfTextHeight)
lbrx := lx + pl + pr + textWidth
lbry := ly + (pb + halfTextHeight)
lblx := lx + DefaultAnnotationDeltaWidth
lbly := 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(ltlx, ltly)
r.LineTo(ltrx, ltry)
r.LineTo(lbrx, lbry)
r.LineTo(lblx, lbly)
r.LineTo(lx, ly)
r.Close()
r.FillStroke()
r.SetFontColor(s.GetFontColor(DefaultTextColor))
r.Text(label, textX, textY)
}

4
formatter.go
View file

@ -1,4 +0,0 @@
package chart
// Formatter is a function that takes a value and produces a string.
type Formatter func(v interface{}) string

20
range.go
View file

@ -3,23 +3,13 @@ package chart
import (
"fmt"
"math"
"github.com/blendlabs/go-util"
)
// Tick represents a label on an axis.
type Tick struct {
RangeValue float64
Label string
}
// Range represents a continuous range,
// Range represents a boundary for a set of numbers.
type Range struct {
Min float64
Max float64
Domain int
Ticks []Tick
Formatter Formatter
}
// IsZero returns if the range has been set or not.
@ -37,14 +27,6 @@ func (r Range) String() string {
return fmt.Sprintf("Range [%.2f,%.2f] => %d", r.Min, r.Max, r.Domain)
}
// Format formats the value based on the range's formatter.
func (r Range) Format(v interface{}) string {
if r.Formatter != nil {
return r.Formatter(v)
}
return util.StringEmpty
}
// Translate maps a given value into the range space.
// An example would be a 600 px image, with a min of 10 and a max of 100.
// Translate(50) would yield (50.0/90.0)*600 ~= 333.33

5
raster_renderer.go
View file

@ -33,6 +33,11 @@ type rasterRenderer struct {
f *truetype.Font
}
// 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)

6
renderable.go Normal file
View file

@ -0,0 +1,6 @@
package chart
// Renderable is a type that can be rendered onto a chart.
type Renderable interface {
Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style)
}

6
renderer.go
View file

@ -7,11 +7,11 @@ import (
"github.com/wcharczuk/go-chart/drawing"
)
// RendererProvider is a function that returns a renderer.
type RendererProvider func(int, int) (Renderer, error)
// Renderer represents the basic methods required to draw a chart.
type Renderer interface {
// GetDPI gets the DPI for the renderer.
GetDPI() float64
// SetDPI sets the DPI for the renderer.
SetDPI(dpi float64)

4
renderer_provider.go Normal file
View file

@ -0,0 +1,4 @@
package chart
// RendererProvider is a function that returns a renderer.
type RendererProvider func(int, int) (Renderer, error)

120
series.go
View file

@ -1,121 +1,7 @@
package chart
import (
"fmt"
"time"
"github.com/blendlabs/go-util"
)
// Series is a entity data set.
// Series is an alias to Renderable.
type Series interface {
GetName() string
GetStyle() Style
Len() int
GetValue(index int) (float64, float64)
GetXFormatter() Formatter
GetYFormatter() Formatter
}
// TimeSeries is a line on a chart.
type TimeSeries struct {
Name string
Style Style
XValues []time.Time
YValues []float64
}
// GetName returns the name of the time series.
func (ts TimeSeries) GetName() string {
return ts.Name
}
// GetStyle returns the line style.
func (ts TimeSeries) GetStyle() Style {
return ts.Style
}
// Len returns the number of elements in the series.
func (ts TimeSeries) Len() int {
return len(ts.XValues)
}
// GetValue gets a value at a given index.
func (ts TimeSeries) GetValue(index int) (x float64, y float64) {
x = float64(ts.XValues[index].Unix())
y = ts.YValues[index]
return
}
// GetXFormatter returns the x value formatter.
func (ts TimeSeries) GetXFormatter() Formatter {
return func(v interface{}) string {
if typed, isTyped := v.(time.Time); isTyped {
return typed.Format(DefaultDateFormat)
}
if typed, isTyped := v.(int64); isTyped {
return time.Unix(typed, 0).Format(DefaultDateFormat)
}
if typed, isTyped := v.(float64); isTyped {
return time.Unix(int64(typed), 0).Format(DefaultDateFormat)
}
return util.StringEmpty
}
}
// GetYFormatter returns the y value formatter.
func (ts TimeSeries) GetYFormatter() Formatter {
return func(v interface{}) string {
if typed, isTyped := v.(float64); isTyped {
return fmt.Sprintf("%0.2f", typed)
}
return util.StringEmpty
}
}
// ContinuousSeries represents a line on a chart.
type ContinuousSeries struct {
Name string
Style Style
XValues []float64
YValues []float64
}
// GetName returns the name of the time series.
func (cs ContinuousSeries) GetName() string {
return cs.Name
}
// GetStyle returns the line style.
func (cs ContinuousSeries) GetStyle() Style {
return cs.Style
}
// Len returns the number of elements in the series.
func (cs ContinuousSeries) Len() int {
return len(cs.XValues)
}
// GetValue gets a value at a given index.
func (cs ContinuousSeries) GetValue(index int) (float64, float64) {
return cs.XValues[index], cs.YValues[index]
}
// GetXFormatter returns the xs value formatter.
func (cs ContinuousSeries) GetXFormatter() Formatter {
return func(v interface{}) string {
if typed, isTyped := v.(float64); isTyped {
return fmt.Sprintf("%0.2f", typed)
}
return util.StringEmpty
}
}
// GetYFormatter returns the y value formatter.
func (cs ContinuousSeries) GetYFormatter() Formatter {
return cs.GetXFormatter()
GetYAxis() YAxisType
Renderable
}

46
style.go
View file

@ -4,23 +4,28 @@ import (
"fmt"
"strings"
"github.com/golang/freetype/truetype"
"github.com/wcharczuk/go-chart/drawing"
)
// Style is a simple style set.
type Style struct {
Show bool
StrokeColor drawing.Color
FillColor drawing.Color
Padding Box
StrokeWidth float64
StrokeColor drawing.Color
FillColor drawing.Color
FontSize float64
FontColor drawing.Color
Padding Box
Font *truetype.Font
}
// IsZero returns if the object is set or not.
func (s Style) IsZero() bool {
return s.StrokeColor.IsZero() && s.FillColor.IsZero() && s.StrokeWidth == 0 && s.FontSize == 0
return s.StrokeColor.IsZero() && s.FillColor.IsZero() && s.StrokeWidth == 0 && s.FontSize == 0 && s.Font == nil
}
// GetStrokeColor returns the stroke color.
@ -78,6 +83,39 @@ func (s Style) GetFontColor(defaults ...drawing.Color) drawing.Color {
return s.FontColor
}
// GetFont returns the font face.
func (s Style) GetFont(defaults ...*truetype.Font) *truetype.Font {
if s.Font == nil {
if len(defaults) > 0 {
return defaults[0]
}
return nil
}
return s.Font
}
// GetPadding returns the padding.
func (s Style) GetPadding(defaults ...Box) Box {
if s.Padding.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return Box{}
}
return s.Padding
}
// WithDefaultsFrom coalesces two styles into a new style.
func (s Style) WithDefaultsFrom(defaults Style) (final Style) {
final.FillColor = s.GetFillColor(defaults.FillColor)
final.FontColor = s.GetFontColor(defaults.FontColor)
final.Font = s.GetFont(defaults.Font)
final.Padding = s.GetPadding(defaults.Padding)
final.StrokeColor = s.GetStrokeColor(defaults.StrokeColor)
final.StrokeWidth = s.GetStrokeWidth(defaults.StrokeWidth)
return
}
// SVG returns the style as a svg style string.
func (s Style) SVG(dpi float64) string {
sw := s.StrokeWidth

78
testserver/main.go
View file

@ -5,7 +5,6 @@ import (
"net/http"
"github.com/wcharczuk/go-chart"
"github.com/wcharczuk/go-chart/drawing"
"github.com/wcharczuk/go-web"
)
@ -21,38 +20,82 @@ func chartHandler(rc *web.RequestContext) web.ControllerResult {
rc.Response.Header().Set("Content-Type", "image/svg+xml")
}
s1x := []float64{2.0, 3.0, 4.0, 5.0}
s1y := []float64{2.5, 5.0, 2.0, 3.3}
s2x := []float64{0.0, 0.5, 1.0, 1.5}
s2y := []float64{1.1, 1.2, 1.0, 1.3}
c := chart.Chart{
Title: "A Test Chart",
TitleStyle: chart.Style{
Show: true,
FontSize: 26.0,
},
Width: 640,
Height: 480,
Axes: chart.Style{
Width: 1024,
Height: 400,
XAxis: chart.XAxis{
Style: chart.Style{
Show: true,
StrokeWidth: 1.0,
},
YRange: chart.Range{
},
YAxis: chart.YAxis{
Style: chart.Style{
Show: true,
},
Range: chart.Range{
Min: 0.0,
Max: 7.0,
},
FinalValueLabel: chart.Style{
},
YAxisSecondary: chart.YAxis{
Style: chart.Style{
Show: true,
},
Range: chart.Range{
Min: 0.8,
Max: 1.5,
},
},
Series: []chart.Series{
chart.ContinuousSeries{
Name: "a",
XValues: []float64{1.0, 2.0, 3.0, 4.0},
YValues: []float64{2.5, 5.0, 2.0, 3.3},
Style: chart.Style{
FillColor: drawing.Color{R: 0, G: 116, B: 217, A: 128},
},
XValues: s1x,
YValues: s1y,
},
chart.ContinuousSeries{
Name: "b",
XValues: []float64{3.0, 4.0, 5.0, 6.0},
YValues: []float64{6.0, 5.0, 4.0, 1.0},
YAxis: chart.YAxisSecondary,
XValues: s2x,
YValues: s2y,
},
chart.AnnotationSeries{
Name: "a - last value",
Style: chart.Style{
Show: true,
StrokeColor: chart.GetDefaultSeriesStrokeColor(0),
},
Annotations: []chart.Annotation{
chart.Annotation{
X: s1x[len(s1x)-1],
Y: s1y[len(s1y)-1],
Label: chart.FloatValueFormatter(s1y[len(s1y)-1]),
},
},
},
chart.AnnotationSeries{
Name: "b - last value",
YAxis: chart.YAxisSecondary,
Style: chart.Style{
Show: true,
StrokeColor: chart.GetDefaultSeriesStrokeColor(1),
},
Annotations: []chart.Annotation{
chart.Annotation{
X: s2x[len(s2x)-1],
Y: s2y[len(s2y)-1],
Label: chart.FloatValueFormatter(s2y[len(s2y)-1]),
},
},
},
},
}
@ -74,6 +117,9 @@ func main() {
app.SetName("Chart Test Server")
app.SetLogger(web.NewStandardOutputLogger())
app.GET("/", chartHandler)
app.GET("/:format", chartHandler)
app.GET("/format/:format", chartHandler)
app.GET("/favico.ico", func(rc *web.RequestContext) web.ControllerResult {
return rc.Raw([]byte{})
})
log.Fatal(app.Start())
}

25
tick.go Normal file
View file

@ -0,0 +1,25 @@
package chart
// Tick represents a label on an axis.
type Tick struct {
Value float64
Label string
}
// Ticks is an array of ticks.
type Ticks []Tick
// Len returns the length of the ticks set.
func (t Ticks) Len() int {
return len(t)
}
// Swap swaps two elements.
func (t Ticks) Swap(i, j int) {
t[i], t[j] = t[j], t[i]
}
// Less returns if i's value is less than j's value.
func (t Ticks) Less(i, j int) bool {
return t[i].Value < t[j].Value
}

54
time_series.go Normal file
View file

@ -0,0 +1,54 @@
package chart
import "time"
// TimeSeries is a line on a chart.
type TimeSeries struct {
Name string
Style Style
YAxis YAxisType
XValues []time.Time
YValues []float64
}
// GetName returns the name of the time series.
func (ts TimeSeries) GetName() string {
return ts.Name
}
// GetStyle returns the line style.
func (ts TimeSeries) GetStyle() Style {
return ts.Style
}
// Len returns the number of elements in the series.
func (ts TimeSeries) Len() int {
return len(ts.XValues)
}
// GetValue gets a value at a given index.
func (ts TimeSeries) GetValue(index int) (x float64, y float64) {
x = float64(ts.XValues[index].Unix())
y = ts.YValues[index]
return
}
// GetValueFormatters returns value formatter defaults for the series.
func (ts TimeSeries) GetValueFormatters() (x, y ValueFormatter) {
x = TimeValueFormatter
y = FloatValueFormatter
return
}
// GetYAxis returns which YAxis the series draws on.
func (ts TimeSeries) GetYAxis() YAxisType {
return ts.YAxis
}
// Render renders the series.
func (ts TimeSeries) Render(r Renderer, canvasBox Box, xrange, yrange Range, defaults Style) {
style := ts.Style.WithDefaultsFrom(defaults)
DrawLineSeries(r, canvasBox, xrange, yrange, style, ts)
}

30
time_series_test.go Normal file
View file

@ -0,0 +1,30 @@
package chart
import (
"testing"
"time"
"github.com/blendlabs/go-assert"
)
func TestTimeSeriesGetValue(t *testing.T) {
assert := assert.New(t)
ts := TimeSeries{
Name: "Test",
XValues: []time.Time{
time.Now().AddDate(0, 0, -5),
time.Now().AddDate(0, 0, -4),
time.Now().AddDate(0, 0, -3),
time.Now().AddDate(0, 0, -2),
time.Now().AddDate(0, 0, -1),
},
YValues: []float64{
1.0, 2.0, 3.0, 4.0, 5.0,
},
}
x0, y0 := ts.GetValue(0)
assert.NotZero(x0)
assert.Equal(1.0, y0)
}

8
util.go
View file

@ -55,6 +55,10 @@ func Slices(count int, total float64) []float64 {
return values
}
func flf(v float64) string {
return fmt.Sprintf("%.2f", v)
// Float is an alias for float64 that provides a better .String() method.
type Float float64
// String returns the string representation of a float.
func (f Float) String() string {
return fmt.Sprintf("%.2f", f)
}

41
value_formatter.go Normal file
View file

@ -0,0 +1,41 @@
package chart
import (
"fmt"
"time"
)
// ValueFormatter is a function that takes a value and produces a string.
type ValueFormatter func(v interface{}) string
// TimeValueFormatter is a ValueFormatter for timestamps.
func TimeValueFormatter(v interface{}) string {
return TimeValueFormatterWithFormat(v, DefaultDateFormat)
}
// TimeValueFormatterWithFormat is a ValueFormatter for timestamps with a given format.
func TimeValueFormatterWithFormat(v interface{}, dateFormat string) string {
if typed, isTyped := v.(time.Time); isTyped {
return typed.Format(dateFormat)
}
if typed, isTyped := v.(int64); isTyped {
return time.Unix(typed, 0).Format(dateFormat)
}
if typed, isTyped := v.(float64); isTyped {
return time.Unix(int64(typed), 0).Format(dateFormat)
}
return ""
}
// FloatValueFormatter is a ValueFormatter for float64.
func FloatValueFormatter(v interface{}) string {
return FloatValueFormatterWithFormat(v, "%.2f")
}
// FloatValueFormatterWithFormat is a ValueFormatter for float64 with a given format.
func FloatValueFormatterWithFormat(v interface{}, floatFormat string) string {
if typed, isTyped := v.(float64); isTyped {
return fmt.Sprintf(floatFormat, typed)
}
return ""
}

6
value_formatter_provider.go Normal file
View file

@ -0,0 +1,6 @@
package chart
// ValueFormatterProvider is a series that has custom formatters.
type ValueFormatterProvider interface {
GetValueFormatters() (x, y ValueFormatter)
}

7
value_provider.go Normal file
View file

@ -0,0 +1,7 @@
package chart
// ValueProvider is a type that produces values.
type ValueProvider interface {
Len() int
GetValue(index int) (float64, float64)
}

5
vector_renderer.go
View file

@ -36,6 +36,11 @@ type vectorRenderer struct {
fc *font.Drawer
}
// GetDPI returns the dpi.
func (vr *vectorRenderer) GetDPI() float64 {
return vr.dpi
}
// SetDPI implements the interface method.
func (vr *vectorRenderer) SetDPI(dpi float64) {
vr.dpi = dpi

101
xaxis.go Normal file
View file

@ -0,0 +1,101 @@
package chart
import (
"math"
"sort"
"github.com/wcharczuk/go-chart/drawing"
)
// XAxis represents the horizontal axis.
type XAxis struct {
Name string
Style Style
ValueFormatter ValueFormatter
Range Range
Ticks []Tick
}
// GetName returns the name.
func (xa XAxis) GetName() string {
return xa.Name
}
// GetStyle returns the style.
func (xa XAxis) GetStyle() Style {
return xa.Style
}
// GetTicks returns the ticks for a series. It coalesces between user provided ticks and
// generated ticks.
func (xa XAxis) GetTicks(r Renderer, ra Range, vf ValueFormatter) []Tick {
if len(xa.Ticks) > 0 {
return xa.Ticks
}
return xa.generateTicks(r, ra, vf)
}
func (xa XAxis) generateTicks(r Renderer, ra Range, vf ValueFormatter) []Tick {
step := xa.getTickStep(r, ra, vf)
return xa.generateTicksWithStep(ra, step, vf)
}
func (xa XAxis) getTickCount(r Renderer, ra Range, vf ValueFormatter) int {
fontSize := xa.Style.GetFontSize(DefaultFontSize)
r.SetFontSize(fontSize)
// take a cut at determining the 'widest' value.
l0 := vf(ra.Min)
ln := vf(ra.Max)
ll := l0
if len(ln) > len(l0) {
ll = ln
}
llw, _ := r.MeasureText(ll)
textWidth := drawing.PointsToPixels(r.GetDPI(), float64(llw))
width := textWidth + DefaultMinimumTickHorizontalSpacing
count := int(math.Ceil(float64(ra.Domain) / float64(width)))
return count
}
func (xa XAxis) getTickStep(r Renderer, ra Range, vf ValueFormatter) float64 {
tickCount := xa.getTickCount(r, ra, vf)
step := ra.Delta() / float64(tickCount)
return step
}
func (xa XAxis) generateTicksWithStep(ra Range, step float64, vf ValueFormatter) []Tick {
var ticks []Tick
for cursor := ra.Min; cursor < ra.Max; cursor += step {
ticks = append(ticks, Tick{
Value: cursor,
Label: vf(cursor),
})
}
return ticks
}
// Render renders the axis
func (xa XAxis) Render(r Renderer, canvasBox Box, ra Range, ticks []Tick) {
tickFontSize := xa.Style.GetFontSize(DefaultFontSize)
tickHeight := drawing.PointsToPixels(r.GetDPI(), tickFontSize)
ty := canvasBox.Bottom + DefaultXAxisMargin + int(tickHeight)
r.SetStrokeColor(xa.Style.GetStrokeColor(DefaultAxisColor))
r.SetStrokeWidth(xa.Style.GetStrokeWidth(DefaultAxisLineWidth))
r.MoveTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.Stroke()
r.SetFontColor(xa.Style.GetFontColor(DefaultAxisColor))
r.SetFontSize(tickFontSize)
sort.Sort(Ticks(ticks))
for _, t := range ticks {
v := t.Value
x := ra.Translate(v)
tx := canvasBox.Right - x
r.Text(t.Label, tx, ty)
}
}

125
yaxis.go Normal file
View file

@ -0,0 +1,125 @@
package chart
import (
"math"
"sort"
)
// YAxis is a veritcal rule of the range.
// There can be (2) y-axes; a primary and secondary.
type YAxis struct {
Name string
Style Style
ValueFormatter ValueFormatter
Range Range
Ticks []Tick
}
// GetName returns the name.
func (ya YAxis) GetName() string {
return ya.Name
}
// GetStyle returns the style.
func (ya YAxis) GetStyle() Style {
return ya.Style
}
// GetTicks returns the ticks for a series. It coalesces between user provided ticks and
// generated ticks.
func (ya YAxis) GetTicks(r Renderer, ra Range, vf ValueFormatter) []Tick {
if len(ya.Ticks) > 0 {
return ya.Ticks
}
return ya.generateTicks(r, ra, vf)
}
func (ya YAxis) generateTicks(r Renderer, ra Range, vf ValueFormatter) []Tick {
step := ya.getTickStep(r, ra, vf)
return ya.generateTicksWithStep(ra, step, vf)
}
func (ya YAxis) getTickCount(r Renderer, ra Range, vf ValueFormatter) int {
textHeight := int(ya.Style.GetFontSize(DefaultFontSize))
height := textHeight + DefaultMinimumTickVerticalSpacing
count := int(math.Ceil(float64(ra.Domain) / float64(height)))
return count
}
func (ya YAxis) getTickStep(r Renderer, ra Range, vf ValueFormatter) float64 {
tickCount := ya.getTickCount(r, ra, vf)
return ra.Delta() / float64(tickCount)
}
func (ya YAxis) generateTicksWithStep(ra Range, step float64, vf ValueFormatter) []Tick {
var ticks []Tick
for cursor := ra.Min; cursor < ra.Max; cursor += step {
ticks = append(ticks, Tick{
Value: cursor,
Label: vf(cursor),
})
}
return ticks
}
// Render renders the axis.
func (ya YAxis) Render(r Renderer, canvasBox Box, ra Range, axisType YAxisType, ticks []Tick) {
r.SetStrokeColor(ya.Style.GetStrokeColor(DefaultAxisColor))
r.SetStrokeWidth(ya.Style.GetStrokeWidth(DefaultAxisLineWidth))
r.SetFontColor(ya.Style.GetFontColor(DefaultAxisColor))
fontSize := ya.Style.GetFontSize(DefaultFontSize)
r.SetFontSize(fontSize)
sort.Sort(Ticks(ticks))
var lx int
var tx int
if axisType == YAxisPrimary {
lx = canvasBox.Right
tx = canvasBox.Right + DefaultYAxisMargin
r.MoveTo(lx, canvasBox.Bottom)
r.LineTo(lx, canvasBox.Top)
r.Stroke()
for _, t := range ticks {
v := t.Value
ly := ra.Translate(v) + canvasBox.Top
th := int(fontSize) >> 1
ty := ly + th
r.Text(t.Label, tx, ty)
r.MoveTo(lx, ly)
r.LineTo(lx+DefaultVerticalTickWidth, ly)
r.Stroke()
}
} else if axisType == YAxisSecondary {
lx = canvasBox.Left
r.MoveTo(lx, canvasBox.Bottom)
r.LineTo(lx, canvasBox.Top)
r.Stroke()
for _, t := range ticks {
v := t.Value
ly := ra.Translate(v) + canvasBox.Top
ptw, _ := r.MeasureText(t.Label)
tw := ptw
th := int(fontSize)
tx = lx - (int(tw) + (DefaultYAxisMargin >> 1))
ty := ly + th>>1
r.Text(t.Label, tx, ty)
r.MoveTo(lx, ly)
r.LineTo(lx-DefaultVerticalTickWidth, ly)
r.Stroke()
}
}
}