package chart import ( "errors" "io" "math" "github.com/golang/freetype/truetype" "github.com/wcharczuk/go-chart/drawing" ) // 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") } 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, 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 } 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) 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, 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 textHeight int for _, t := range ticks { _, th := r.MeasureText(t.Label) if th > textHeight { textHeight = th } } return textHeight + (2 * DefaultXAxisMargin) // top and bottom. } func (c Chart) getYAxisWidth(r Renderer, ticks []Tick) int { r.SetFontSize(c.YAxis.Style.GetFontSize(DefaultFontSize)) r.SetFont(c.YAxis.Style.GetFont(c.Font)) var textWidth int for _, t := range ticks { tw, _ := r.MeasureText(t.Label) if tw > textWidth { textWidth = tw } } return textWidth + DefaultYAxisMargin } func (c Chart) getYAxisSecondaryWidth(r Renderer, ticks []Tick) int { r.SetFontSize(c.YAxisSecondary.Style.GetFontSize(DefaultFontSize)) r.SetFont(c.YAxisSecondary.Style.GetFont(c.Font)) var textWidth int for _, t := range ticks { tw, _ := r.MeasureText(t.Label) if tw > textWidth { textWidth = tw } } return textWidth + 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) 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) } if annotationMinY > annotationBounds.Top { annotationMinY = annotationBounds.Top } if annotationMinX > annotationBounds.Left { annotationMinX = annotationBounds.Left } if annotationMaxX < annotationBounds.Right { annotationMaxX = annotationBounds.Right } if annotationMaxY < annotationBounds.Bottom { 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 annotationMaxX > c.Width { // figure out how much right padding to add delta := annotationMaxX - c.Width newBox.Right = canvasBox.Right - delta } if annotationMinX < 0 { // figure out how much left padding to add delta := -1 * annotationMinX newBox.Left = canvasBox.Left + delta } if annotationMaxY > c.Height { //figure out how much bottom padding to add delta := annotationMaxY - c.Height println("bottom 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, YAxisPrimary, yticks) } if c.YAxisSecondary.Style.Show { c.YAxisSecondary.Render(r, canvasBox, yrangeAlt, YAxisSecondary, yticksAlt) } } 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) 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) 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) + textHeight r.Text(c.Title, titleX, titleY) } }