updates.

box.go

@@ -0,0 +1,65 @@
+package chart
+
+import "fmt"
+
+// Box represents the main 4 dimensions of a box.
+type Box struct {
+	Top    int
+	Left   int
+	Right  int
+	Bottom int
+}
+
+// IsZero returns if the box is set or not.
+func (b Box) IsZero() bool {
+	return b.Top == 0 && b.Left == 0 && b.Right == 0 && b.Bottom == 0
+}
+
+// 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)
+}
+
+// GetTop returns a coalesced value with a default.
+func (b Box) GetTop(defaults ...int) int {
+	if b.Top == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Top
+}
+
+// GetLeft returns a coalesced value with a default.
+func (b Box) GetLeft(defaults ...int) int {
+	if b.Left == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Left
+}
+
+// GetRight returns a coalesced value with a default.
+func (b Box) GetRight(defaults ...int) int {
+	if b.Right == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Right
+}
+
+// GetBottom returns a coalesced value with a default.
+func (b Box) GetBottom(defaults ...int) int {
+	if b.Bottom == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return 0
+	}
+	return b.Bottom
+}

chart.go

@@ -1,138 +1,83 @@
 package chart
 
 import (
-	"image/color"
 	"io"
 
 	"github.com/golang/freetype/truetype"
 )
 
 // Chart is what we're drawing.
-/*
-	The chart box model is as follows:
-	0,0									width,0
-			cl,ct					cr,ct
-			cl,cb					cr,cb
-	0, height							width,height
-*/
 type Chart struct {
-	Title         string
+	Title      string
-	TitleFontSize float64
+	TitleStyle Style
 
 	Width   int
 	Height  int
-	Padding int
+	Padding Box
 
-	BackgroundColor       color.RGBA
+	Background      Style
-	CanvasBackgroundColor color.RGBA
+	Canvas          Style
+	Axes            Style
+	FinalValueLabel Style
 
-	AxisShow     bool
+	XRange Range
-	AxisStyle    Style
+	YRange Range
-	AxisFontSize float64
-
-	CanvasBorderShow  bool
-	CanvasBorderStyle Style
-
-	FinalValueLabelShow bool
-	FinalValueStyle     Style
-
-	FontColor color.RGBA
-	Font      *truetype.Font
 
+	Font   *truetype.Font
 	Series []Series
 }
 
-// GetTitleFontSize calculates or returns the title font size.
-func (c Chart) GetTitleFontSize() float64 {
-	if c.TitleFontSize != 0 {
-		if c.TitleFontSize > DefaultMinimumFontSize {
-			return c.TitleFontSize
-		}
-	}
-	fontSize := float64(c.Height >> 3)
-	if fontSize > DefaultMinimumFontSize {
-		return fontSize
-	}
-	return DefaultMinimumFontSize
-}
-
 // GetCanvasTop gets the top corner pixel.
 func (c Chart) GetCanvasTop() int {
-	return c.Padding
+	return c.Padding.GetTop(DefaultCanvasPadding.Top)
 }
 
 // GetCanvasLeft gets the left corner pixel.
 func (c Chart) GetCanvasLeft() int {
-	return c.Padding
+	return c.Padding.GetLeft(DefaultCanvasPadding.Left)
 }
 
 // GetCanvasBottom gets the bottom corner pixel.
 func (c Chart) GetCanvasBottom() int {
-	return c.Height - c.Padding
+	return c.Height - c.Padding.GetBottom(DefaultCanvasPadding.Bottom)
 }
 
 // GetCanvasRight gets the right corner pixel.
 func (c Chart) GetCanvasRight() int {
-	return c.Width - c.Padding
+	return c.Width - c.Padding.GetRight(DefaultCanvasPadding.Right)
 }
 
 // GetCanvasWidth returns the width of the canvas.
 func (c Chart) GetCanvasWidth() int {
-	if c.Padding > 0 {
+	return c.Width - (c.Padding.GetLeft(DefaultCanvasPadding.Left) + c.Padding.GetRight(DefaultCanvasPadding.Right))
-		return c.Width - (c.Padding << 1)
-	}
-	return c.Width
 }
 
 // GetCanvasHeight returns the height of the canvas.
 func (c Chart) GetCanvasHeight() int {
-	if c.Padding > 0 {
+	return c.Height - (c.Padding.GetTop(DefaultCanvasPadding.Top) + c.Padding.GetBottom(DefaultCanvasPadding.Bottom))
-		return c.Height - (c.Padding << 1)
-	}
-	return c.Height
 }
 
-// GetBackgroundColor returns the chart background color.
+// GetFont returns the text font.
-func (c Chart) GetBackgroundColor() color.RGBA {
+func (c Chart) GetFont() (*truetype.Font, error) {
-	if ColorIsZero(c.BackgroundColor) {
-		c.BackgroundColor = DefaultBackgroundColor
-	}
-	return c.BackgroundColor
-}
-
-// GetCanvasBackgroundColor returns the canvas background color.
-func (c Chart) GetCanvasBackgroundColor() color.RGBA {
-	if ColorIsZero(c.CanvasBackgroundColor) {
-		c.CanvasBackgroundColor = DefaultCanvasColor
-	}
-	return c.CanvasBackgroundColor
-}
-
-// GetTextFont returns the text font.
-func (c Chart) GetTextFont() (*truetype.Font, error) {
 	if c.Font != nil {
 		return c.Font, nil
 	}
 	return GetDefaultFont()
 }
 
-// GetTextFontColor returns the text font color.
-func (c Chart) GetTextFontColor() color.RGBA {
-	if ColorIsZero(c.FontColor) {
-		c.FontColor = DefaultTextColor
-	}
-	return c.FontColor
-}
-
 // 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(provider RendererProvider, w io.Writer) error {
+	xrange, yrange := c.initRanges()
+	println("xrange", xrange.String())
+	println("yrange", yrange.String())
+
 	r := provider(c.Width, c.Height)
 	c.drawBackground(r)
 	c.drawCanvas(r)
 	c.drawAxes(r)
 
 	for _, series := range c.Series {
-		c.drawSeries(r, series)
+		c.drawSeries(r, series, xrange, yrange)
 	}
 	err := c.drawTitle(r)
 	if err != nil {
@@ -141,46 +86,83 @@ func (c Chart) Render(provider RendererProvider, w io.Writer) error {
 	return r.Save(w)
 }
 
+func (c Chart) initRanges() (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 globalMinY > vy {
+					globalMinY = vy
+				}
+				if globalMaxX < vx {
+					globalMaxX = vx
+				}
+				if globalMaxY < vy {
+					globalMaxY = vy
+				}
+			} else {
+				globalMinX, globalMaxX = vx, vx
+				globalMinY, globalMaxY = vy, vy
+				didSetFirstValues = true
+			}
+		}
+	}
+
+	if c.XRange.IsZero() {
+		xrange.Min = globalMinX
+		xrange.Max = globalMaxX
+	} else {
+		xrange.Min = c.XRange.Min
+		xrange.Max = c.XRange.Max
+	}
+	xrange.Domain = c.GetCanvasWidth()
+
+	if c.YRange.IsZero() {
+		yrange.Min = globalMinY
+		yrange.Max = globalMaxY
+	} else {
+		yrange.Min = c.YRange.Min
+		yrange.Max = c.YRange.Max
+	}
+	yrange.Domain = c.GetCanvasHeight()
+
+	return
+}
+
 func (c Chart) drawBackground(r Renderer) {
-	r.SetStrokeColor(c.GetBackgroundColor())
+	r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
-	r.SetFillColor(c.GetBackgroundColor())
-	r.SetLineWidth(0)
 	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.FillStroke()
 	r.Close()
+	r.Fill()
 }
 
 func (c Chart) drawCanvas(r Renderer) {
-	if !c.CanvasBorderStyle.IsZero() {
+	r.SetFillColor(c.Canvas.GetFillColor(DefaultCanvasColor))
-		r.SetStrokeColor(c.CanvasBorderStyle.GetStrokeColor())
-		r.SetLineWidth(c.CanvasBorderStyle.GetStrokeWidth())
-	} else {
-		r.SetStrokeColor(c.GetCanvasBackgroundColor())
-		r.SetLineWidth(0)
-	}
-	r.SetFillColor(c.GetCanvasBackgroundColor())
 	r.MoveTo(c.GetCanvasLeft(), c.GetCanvasTop())
 	r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
 	r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
 	r.LineTo(c.GetCanvasLeft(), c.GetCanvasBottom())
 	r.LineTo(c.GetCanvasLeft(), c.GetCanvasTop())
-	r.FillStroke()
+	r.Fill()
 	r.Close()
 }
 
 func (c Chart) drawAxes(r Renderer) {
-	if c.AxisShow {
+	if c.Axes.Show {
-		if !c.AxisStyle.IsZero() {
+		r.SetStrokeColor(c.Axes.GetStrokeColor(DefaultAxisColor))
-			r.SetStrokeColor(c.AxisStyle.GetStrokeColor())
+		r.SetLineWidth(c.Axes.GetStrokeWidth(DefaultLineWidth))
-			r.SetLineWidth(c.AxisStyle.GetStrokeWidth())
-		} else {
-			r.SetStrokeColor(DefaultAxisColor)
-			r.SetLineWidth(DefaultAxisLineWidth)
-		}
 		r.MoveTo(c.GetCanvasLeft(), c.GetCanvasBottom())
 		r.LineTo(c.GetCanvasRight(), c.GetCanvasBottom())
 		r.LineTo(c.GetCanvasRight(), c.GetCanvasTop())
@@ -188,46 +170,48 @@ func (c Chart) drawAxes(r Renderer) {
 	}
 }
 
-func (c Chart) drawSeries(r Renderer, s Series) {
+func (c Chart) drawSeries(r Renderer, s Series, xrange, yrange Range) {
-	r.SetLineWidth(s.GetStyle().GetStrokeWidth())
+	r.SetStrokeColor(s.GetStyle().GetStrokeColor(DefaultLineColor))
-	r.SetStrokeColor(s.GetStyle().GetStrokeColor())
+	r.SetLineWidth(s.GetStyle().GetStrokeWidth(DefaultLineWidth))
-
-	xrange := s.GetXRange(c.GetCanvasWidth())
-	yrange := s.GetYRange(c.GetCanvasHeight())
 
 	if s.Len() == 0 {
 		return
 	}
 
-	v0x, v0y := s.GetValue(0)
+	px := c.Padding.GetLeft(DefaultCanvasPadding.Left)
-	x0 := xrange.Translate(v0x)
+	py := c.Padding.GetTop(DefaultCanvasPadding.Top)
-	y0 := yrange.Translate(v0y)
-	r.MoveTo(x0, y0)
 
-	var vx interface{}
+	cw := c.GetCanvasWidth()
-	var vy float64
+
+	v0x, v0y := s.GetValue(0)
+	x0 := cw - xrange.Translate(v0x)
+	y0 := yrange.Translate(v0y)
+	r.MoveTo(x0+px, y0+py)
+
+	var vx, vy float64
 	var x, y int
-	for index := 0; index < s.Len(); index++ {
+	for index := 1; index < s.Len(); index++ {
 		vx, vy = s.GetValue(index)
-		x = xrange.Translate(vx)
+		x = cw - xrange.Translate(vx)
 		y = yrange.Translate(vy)
-		r.LineTo(x, y)
+		r.LineTo(x+px, y+py)
 	}
 	r.Stroke()
 }
 
 func (c Chart) drawTitle(r Renderer) error {
-	if len(c.Title) > 0 {
+	if len(c.Title) > 0 && c.TitleStyle.Show {
-		font, err := c.GetTextFont()
+		font, err := c.GetFont()
 		if err != nil {
 			return err
 		}
-		r.SetFontColor(c.GetTextFontColor())
+		r.SetFontColor(c.Canvas.GetFontColor(DefaultTextColor))
 		r.SetFont(font)
-		r.SetFontSize(c.GetTitleFontSize())
+		titleFontSize := c.Canvas.GetFontSize(DefaultTitleFontSize)
+		r.SetFontSize(titleFontSize)
 		textWidth := r.MeasureText(c.Title)
 		titleX := (c.Width >> 1) - (textWidth >> 1)
-		titleY := c.GetCanvasTop() + int(c.GetTitleFontSize()/2.0)
+		titleY := c.GetCanvasTop() + int(titleFontSize)
 		r.Text(c.Title, titleX, titleY)
 	}
 	return nil

chart_test.go

@@ -15,9 +15,13 @@ func TestChartSingleSeries(t *testing.T) {
 		Title:  "Hello!",
 		Width:  1024,
 		Height: 400,
+		YRange: Range{
+			Min: 0.0,
+			Max: 4.0,
+		},
 		Series: []Series{
 			TimeSeries{
-				Name:    "Goog",
+				Name:    "goog",
 				XValues: []time.Time{now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
 				YValues: []float64{1.0, 2.0, 3.0},
 			},

defaults.go

@@ -12,9 +12,6 @@ const (
 	DefaultChartHeight = 400
 	// DefaultChartWidth is the default chart width.
 	DefaultChartWidth = 200
-	// DefaultPadding is the default gap between the image border and
-	// chart content (referred to as the "canvas").
-	DefaultPadding = 10
 	// DefaultLineWidth is the default chart line width.
 	DefaultLineWidth = 2.0
 	// DefaultAxisLineWidth is the line width of the axis lines.
@@ -23,12 +20,18 @@ const (
 	DefaultDPI = 120.0
 	// DefaultMinimumFontSize is the default minimum font size.
 	DefaultMinimumFontSize = 8.0
+	// DefaultFontSize is the default font size.
+	DefaultFontSize = 10.0
+	// DefaultTitleFontSize is the default title font size.
+	DefaultTitleFontSize = 18.0
+	// DefaultDateFormat is the default date format.
+	DefaultDateFormat = "2006-01-02"
 )
 
 var (
 	// DefaultBackgroundColor is the default chart background color.
 	// It is equivalent to css color:white.
-	DefaultBackgroundColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
+	DefaultBackgroundColor = color.RGBA{R: 239, G: 239, B: 239, A: 255} //color.RGBA{R: 255, G: 255, B: 255, A: 255}
 	// DefaultCanvasColor is the default chart canvas color.
 	// It is equivalent to css color:white.
 	DefaultCanvasColor = color.RGBA{R: 255, G: 255, B: 255, A: 255}
@@ -43,12 +46,17 @@ var (
 	DefaultBorderColor = color.RGBA{R: 239, G: 239, B: 239, A: 255}
 	// DefaultLineColor is the default (1st) series line color.
 	// It is equivalent to #0074d9.
-	DefaultLineColor = color.RGBA{R: 0, G: 217, B: 116, A: 255}
+	DefaultLineColor = color.RGBA{R: 0, G: 116, B: 217, A: 255}
 	// DefaultFillColor is the default fill color.
 	// It is equivalent to #0074d9.
 	DefaultFillColor = color.RGBA{R: 0, G: 217, B: 116, A: 255}
 )
 
+var (
+	// DefaultCanvasPadding is the default canvas padding config.
+	DefaultCanvasPadding = Box{Top: 5, Left: 5, Right: 15, Bottom: 15}
+)
+
 var (
 	_defaultFontLock sync.Mutex
 	_defaultFont     *truetype.Font

range.go

@@ -1,97 +1,36 @@
 package chart
 
 import (
+	"fmt"
 	"math"
-	"time"
 )
 
-// Range is a type that translates values from a range to a domain.
+// Range represents a continuous range,
-type Range interface {
+type Range struct {
-	GetMin() interface{}
+	Min    float64
-	GetMax() interface{}
+	Max    float64
-	Translate(value interface{}) int
+	Domain int
 }
 
-// NewRangeOfFloat64 returns a new Range
+// IsZero returns if the range has been set or not.
-func NewRangeOfFloat64(domain int, values ...float64) Range {
+func (r Range) IsZero() bool {
-	min, max := MinAndMax(values...)
+	return r.Min == 0 && r.Max == 0 && r.Domain == 0
-	return &RangeOfFloat64{
-		MinValue:    min,
-		MaxValue:    max,
-		MinMaxDelta: max - min,
-		Domain:      domain,
-	}
 }
 
-// RangeOfFloat64 represents a continuous range
+// Delta returns the difference between the min and max value.
-// of float64 values mapped to a [0...WindowMaxValue]
+func (r Range) Delta() float64 {
-// interval.
+	return r.Max - r.Min
-type RangeOfFloat64 struct {
-	MinValue    float64
-	MaxValue    float64
-	MinMaxDelta float64
-	Domain      int
 }
 
-// GetMin implements the interface method.
+// String returns a simple string for the range.
-func (r RangeOfFloat64) GetMin() interface{} {
+func (r Range) String() string {
-	return r.MinValue
+	return fmt.Sprintf("Range [%.2f,%.2f] => %d", r.Min, r.Max, r.Domain)
-}
-
-// GetMax implements the interface method.
-func (r RangeOfFloat64) GetMax() interface{} {
-	return r.MaxValue
 }
 
 // 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
-func (r RangeOfFloat64) Translate(value interface{}) int {
+func (r Range) Translate(value float64) int {
-	if typedValue, isTyped := value.(float64); isTyped {
+	finalValue := ((r.Max - value) / r.Delta()) * float64(r.Domain)
-		finalValue := ((r.MaxValue - typedValue) / r.MinMaxDelta) * float64(r.Domain)
+	return int(math.Floor(finalValue))
-		return int(math.Floor(finalValue))
-	}
-	return 0
-}
-
-// NewRangeOfTime makes a new range of time with the given time values.
-func NewRangeOfTime(domain int, values ...time.Time) Range {
-	min, max := MinAndMaxOfTime(values...)
-	r := &RangeOfTime{
-		MinValue:    min,
-		MaxValue:    max,
-		MinMaxDelta: max.Unix() - min.Unix(),
-		Domain:      domain,
-	}
-	return r
-}
-
-// RangeOfTime represents a timeseries.
-type RangeOfTime struct {
-	MinValue    time.Time
-	MaxValue    time.Time
-	MinMaxDelta int64 //unix time difference
-	Domain      int
-}
-
-// GetMin implements the interface method.
-func (r RangeOfTime) GetMin() interface{} {
-	return r.MinValue
-}
-
-// GetMax implements the interface method.
-func (r RangeOfTime) GetMax() interface{} {
-	return r.MaxValue
-}
-
-// Translate maps a given value into the range space (of time).
-// An example would be a 600 px image, with a min of jan-01-2016 and a max of jun-01-2016.
-// Translate(may-01-2016) would yield ... something.
-func (r RangeOfTime) Translate(value interface{}) int {
-	if typed, isTyped := value.(time.Time); isTyped {
-		valueDelta := r.MaxValue.Unix() - typed.Unix()
-		finalValue := (float64(valueDelta) / float64(r.MinMaxDelta)) * float64(r.Domain)
-		return int(math.Floor(finalValue))
-	}
-	return 0
 }

range_test.go

@@ -2,7 +2,6 @@ package chart
 
 import (
 	"testing"
-	"time"
 
 	"github.com/blendlabs/go-assert"
 )
@@ -10,26 +9,7 @@ import (
 func TestRangeTranslate(t *testing.T) {
 	assert := assert.New(t)
 	values := []float64{1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0}
-	r := NewRangeOfFloat64(1000, values...)
+	r := Range{Domain: 1000}
-	assert.Equal(1.0, r.GetMin())
+	r.Min, r.Max = MinAndMax(values...)
-	assert.Equal(8.0, r.GetMax())
 	assert.Equal(428, r.Translate(5.0))
 }
-
-func TestRangeOfTimeTranslate(t *testing.T) {
-	assert := assert.New(t)
-	values := []time.Time{
-		time.Now().AddDate(0, 0, -1),
-		time.Now().AddDate(0, 0, -2),
-		time.Now().AddDate(0, 0, -3),
-		time.Now().AddDate(0, 0, -4),
-		time.Now().AddDate(0, 0, -5),
-		time.Now().AddDate(0, 0, -6),
-		time.Now().AddDate(0, 0, -7),
-		time.Now().AddDate(0, 0, -8),
-	}
-	r := NewRangeOfTime(1000, values...)
-	assert.Equal(values[7], r.GetMin())
-	assert.Equal(values[0], r.GetMax())
-	assert.Equal(571, r.Translate(time.Now().AddDate(0, 0, -5)))
-}

raster_renderer.go

@@ -1,6 +1,7 @@
 package chart
 
 import (
+	"fmt"
 	"image"
 	"image/color"
 	"image/png"
@@ -34,55 +35,60 @@ type rasterRenderer struct {
 
 // SetStrokeColor implements the interface method.
 func (rr *rasterRenderer) SetStrokeColor(c color.RGBA) {
-	println("SetStrokeColor")
+	println("RasterRenderer :: SetStrokeColor", ColorAsString(c))
 	rr.gc.SetStrokeColor(c)
 }
 
 // SetFillColor implements the interface method.
 func (rr *rasterRenderer) SetFillColor(c color.RGBA) {
-	println("SetFillColor")
+	println("RasterRenderer :: SetFillColor", ColorAsString(c))
 	rr.gc.SetFillColor(c)
 }
 
 // SetLineWidth implements the interface method.
-func (rr *rasterRenderer) SetLineWidth(width int) {
+func (rr *rasterRenderer) SetLineWidth(width float64) {
-	println("SetLineWidth", width)
+	println("RasterRenderer :: SetLineWidth", width)
-	rr.gc.SetLineWidth(float64(width))
+	rr.gc.SetLineWidth(width)
 }
 
 // MoveTo implements the interface method.
 func (rr *rasterRenderer) MoveTo(x, y int) {
-	println("MoveTo", x, y)
+	println("RasterRenderer :: MoveTo", x, y)
 	rr.gc.MoveTo(float64(x), float64(y))
 }
 
 // LineTo implements the interface method.
 func (rr *rasterRenderer) LineTo(x, y int) {
-	println("LineTo", x, y)
+	println("RasterRenderer :: LineTo", x, y)
 	rr.gc.LineTo(float64(x), float64(y))
 }
 
 // Close implements the interface method.
 func (rr *rasterRenderer) Close() {
-	println("Close")
+	println("RasterRenderer :: Close")
 	rr.gc.Close()
 }
 
 // Stroke implements the interface method.
 func (rr *rasterRenderer) Stroke() {
-	println("Stroke")
+	println("RasterRenderer :: Stroke")
 	rr.gc.Stroke()
 }
 
+// Fill implements the interface method.
+func (rr *rasterRenderer) Fill() {
+	println("RasterRenderer :: Fill")
+	rr.gc.Fill()
+}
+
 // FillStroke implements the interface method.
 func (rr *rasterRenderer) FillStroke() {
-	println("FillStroke")
+	println("RasterRenderer :: FillStroke")
 	rr.gc.FillStroke()
 }
 
 // Circle implements the interface method.
 func (rr *rasterRenderer) Circle(radius float64, x, y int) {
-	println("Circle", radius, x, y)
 	xf := float64(x)
 	yf := float64(y)
 	rr.gc.MoveTo(xf-radius, yf)              //9
@@ -96,34 +102,32 @@ func (rr *rasterRenderer) Circle(radius float64, x, y int) {
 
 // SetFont implements the interface method.
 func (rr *rasterRenderer) SetFont(f *truetype.Font) {
-	println("SetFont")
 	rr.font = f
 	rr.gc.SetFont(f)
 }
 
 // SetFontSize implements the interface method.
 func (rr *rasterRenderer) SetFontSize(size float64) {
-	println("SetFontSize", size)
+	println("RasterRenderer :: SetFontSize", fmt.Sprintf("%.2f", size))
 	rr.fontSize = size
 	rr.gc.SetFontSize(size)
 }
 
 // SetFontColor implements the interface method.
 func (rr *rasterRenderer) SetFontColor(c color.RGBA) {
-	println("SetFontColor")
+	println("RasterRenderer :: SetFontColor", ColorAsString(c))
 	rr.fontColor = c
 	rr.gc.SetStrokeColor(c)
 }
 
 // Text implements the interface method.
 func (rr *rasterRenderer) Text(body string, x, y int) {
-	println("Text", body, x, y)
+	println("RasterRenderer :: Text", body, x, y)
 	rr.gc.CreateStringPath(body, float64(x), float64(y))
 }
 
 // MeasureText implements the interface method.
 func (rr *rasterRenderer) MeasureText(body string) int {
-	println("MeasureText", body)
 	if rr.fc == nil && rr.font != nil {
 		rr.fc = &font.Drawer{
 			Face: truetype.NewFace(rr.font, &truetype.Options{
@@ -141,6 +145,6 @@ func (rr *rasterRenderer) MeasureText(body string) int {
 
 // Save implements the interface method.
 func (rr *rasterRenderer) Save(w io.Writer) error {
-	println("Save")
+	println("RasterRenderer :: Save")
 	return png.Encode(w, rr.i)
 }

renderer.go

@@ -19,7 +19,7 @@ type Renderer interface {
 	SetFillColor(color.RGBA)
 
 	// SetLineWidth sets the stroke line width.
-	SetLineWidth(width int)
+	SetLineWidth(width float64)
 
 	// MoveTo moves the cursor to a given point.
 	MoveTo(x, y int)
@@ -31,10 +31,13 @@ type Renderer interface {
 	// Close finalizes a shape as drawn by LineTo.
 	Close()
 
-	// Stroke draws the 'stroke' or line component of a shape.
+	// Stroke strokes the path.
 	Stroke()
 
-	// FillStroke draws the 'stroke' and 'fills' a shape.
+	// Fill fills the path, but does not stroke.
+	Fill()
+
+	// FillStroke fills and strokes a path.
 	FillStroke()
 
 	// Circle draws a circle at the given coords with a given radius.

series.go

@@ -1,16 +1,17 @@
 package chart
 
-import "time"
+import (
+	"fmt"
+	"time"
+)
 
 // Series is a entity data set.
 type Series interface {
 	GetName() string
 	GetStyle() Style
 	Len() int
-	GetValue(index int) (interface{}, float64)
+	GetValue(index int) (float64, float64)
-
+	GetLabel(index int) (string, string)
-	GetXRange(domain int) Range
-	GetYRange(domain int) Range
 }
 
 // TimeSeries is a line on a chart.
@@ -37,19 +38,18 @@ func (ts TimeSeries) Len() int {
 	return len(ts.XValues)
 }
 
-// GetXRange returns the x range.
-func (ts TimeSeries) GetXRange(domain int) Range {
-	return NewRangeOfTime(domain, ts.XValues...)
-}
-
-// GetYRange returns the x range.
-func (ts TimeSeries) GetYRange(domain int) Range {
-	return NewRangeOfFloat64(domain, ts.YValues...)
-}
-
 // GetValue gets a value at a given index.
-func (ts TimeSeries) GetValue(index int) (interface{}, float64) {
+func (ts TimeSeries) GetValue(index int) (x float64, y float64) {
-	return ts.XValues[index], ts.YValues[index]
+	x = float64(ts.XValues[index].Unix())
+	y = ts.YValues[index]
+	return
+}
+
+// GetLabel gets a label for the values at a given index.
+func (ts TimeSeries) GetLabel(index int) (xLabel string, yLabel string) {
+	xLabel = ts.XValues[index].Format(DefaultDateFormat)
+	yLabel = fmt.Sprintf("%0.2f", ts.YValues[index])
+	return
 }
 
 // ContinousSeries represents a line on a chart.
@@ -81,12 +81,9 @@ func (cs ContinousSeries) GetValue(index int) (interface{}, float64) {
 	return cs.XValues[index], cs.YValues[index]
 }
 
-// GetXRange returns the x range.
+// GetLabel gets a label for the values at a given index.
-func (cs ContinousSeries) GetXRange(domain int) Range {
+func (cs ContinousSeries) GetLabel(index int) (xLabel string, yLabel string) {
-	return NewRangeOfFloat64(domain, cs.XValues...)
+	xLabel = fmt.Sprintf("%0.2f", cs.XValues[index])
-}
+	yLabel = fmt.Sprintf("%0.2f", cs.YValues[index])
-
+	return
-// GetYRange returns the x range.
-func (cs ContinousSeries) GetYRange(domain int) Range {
-	return NewRangeOfFloat64(domain, cs.YValues...)
 }

series_test.go

@@ -28,29 +28,3 @@ func TestTimeSeriesGetValue(t *testing.T) {
 	assert.NotZero(x0)
 	assert.Equal(1.0, y0)
 }
-
-func TestTimeSeriesRanges(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,
-		},
-	}
-
-	xrange := ts.GetXRange(1000)
-	x0 := xrange.Translate(time.Now().AddDate(0, 0, -3))
-	assert.Equal(500, x0)
-
-	yrange := ts.GetYRange(400)
-	y0 := yrange.Translate(3.0)
-	assert.Equal(200, y0)
-}

style.go

@@ -4,36 +4,70 @@ import "image/color"
 
 // Style is a simple style set.
 type Style struct {
+	Show        bool
 	StrokeColor color.RGBA
 	FillColor   color.RGBA
-	StrokeWidth int
+	StrokeWidth float64
+	FontSize    float64
+	FontColor   color.RGBA
 }
 
 // IsZero returns if the object is set or not.
 func (s Style) IsZero() bool {
-	return ColorIsZero(s.StrokeColor) && ColorIsZero(s.FillColor) && s.StrokeWidth == 0
+	return ColorIsZero(s.StrokeColor) && ColorIsZero(s.FillColor) && s.StrokeWidth == 0 && s.FontSize == 0
 }
 
 // GetStrokeColor returns the stroke color.
-func (s Style) GetStrokeColor() color.RGBA {
+func (s Style) GetStrokeColor(defaults ...color.RGBA) color.RGBA {
 	if ColorIsZero(s.StrokeColor) {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
 		return DefaultLineColor
 	}
 	return s.StrokeColor
 }
 
 // GetFillColor returns the fill color.
-func (s Style) GetFillColor() color.RGBA {
+func (s Style) GetFillColor(defaults ...color.RGBA) color.RGBA {
 	if ColorIsZero(s.FillColor) {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
 		return DefaultFillColor
 	}
 	return s.FillColor
 }
 
 // GetStrokeWidth returns the stroke width.
-func (s Style) GetStrokeWidth() int {
+func (s Style) GetStrokeWidth(defaults ...float64) float64 {
 	if s.StrokeWidth == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
 		return DefaultLineWidth
 	}
 	return s.StrokeWidth
 }
+
+// GetFontSize gets the font size.
+func (s Style) GetFontSize(defaults ...float64) float64 {
+	if s.FontSize == 0 {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return DefaultFontSize
+	}
+	return s.FontSize
+}
+
+// GetFontColor gets the font size.
+func (s Style) GetFontColor(defaults ...color.RGBA) color.RGBA {
+	if ColorIsZero(s.FontColor) {
+		if len(defaults) > 0 {
+			return defaults[0]
+		}
+		return DefaultTextColor
+	}
+	return s.FontColor
+}

testserver/main.go

@@ -0,0 +1,58 @@
+package main
+
+import (
+	"bytes"
+	"log"
+	"time"
+
+	"github.com/wcharczuk/go-chart"
+	"github.com/wcharczuk/go-web"
+)
+
+func main() {
+	app := web.New()
+	app.SetName("Chart Test Server")
+	app.SetLogger(web.NewStandardOutputLogger())
+	app.GET("/", func(rc *web.RequestContext) web.ControllerResult {
+		rc.Response.Header().Set("Content-Type", "image/png")
+		now := time.Now()
+		c := chart.Chart{
+			Title: "Hello!",
+			TitleStyle: chart.Style{
+				Show: true,
+			},
+			Width:  1024,
+			Height: 400,
+			Padding: chart.Box{
+				Right:  40,
+				Bottom: 40,
+			},
+			Axes: chart.Style{
+				Show:        true,
+				StrokeWidth: 1.0,
+			},
+			YRange: chart.Range{
+				Min: 0.0,
+				Max: 7.0,
+			},
+			Series: []chart.Series{
+				chart.TimeSeries{
+					Name: "goog",
+					Style: chart.Style{
+						StrokeWidth: 1.0,
+					},
+					XValues: []time.Time{now.AddDate(0, 0, -4), now.AddDate(0, 0, -3), now.AddDate(0, 0, -2), now.AddDate(0, 0, -1)},
+					YValues: []float64{2.5, 5.0, 2.0, 3.0},
+				},
+			},
+		}
+
+		buffer := bytes.NewBuffer([]byte{})
+		err := c.Render(chart.PNG, buffer)
+		if err != nil {
+			return rc.API().InternalError(err)
+		}
+		return rc.Raw(buffer.Bytes())
+	})
+	log.Fatal(app.Start())
+}

util.go

@@ -1,6 +1,7 @@
 package chart
 
 import (
+	"fmt"
 	"image/color"
 	"time"
 )
@@ -10,6 +11,11 @@ func ColorIsZero(c color.RGBA) bool {
 	return c.R == 0 && c.G == 0 && c.B == 0 && c.A == 0
 }
 
+// ColorAsString returns if a color.RGBA is unset or not.
+func ColorAsString(c color.RGBA) string {
+	return fmt.Sprintf("RGBA(%v,%v,%v,%v)", c.R, c.G, c.G, c.A)
+}
+
 // MinAndMax returns both the min and max in one pass.
 func MinAndMax(values ...float64) (min float64, max float64) {
 	if len(values) == 0 {