works more or less

This commit is contained in:
Will Charczuk 2017-03-04 17:42:10 -08:00
parent 17b28beae8
commit 9c65a94050
10 changed files with 248 additions and 43 deletions

39
_examples/scatter/main.go Normal file
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@ -0,0 +1,39 @@
package main
import (
"log"
"net/http"
"github.com/wcharczuk/go-chart"
"github.com/wcharczuk/go-chart/drawing"
)
func drawChart(res http.ResponseWriter, req *http.Request) {
println("drawing scatter plot")
graph := chart.Chart{
Series: []chart.Series{
chart.ContinuousSeries{
Style: chart.Style{
Show: true,
StrokeWidth: chart.Disabled,
DotWidth: 3,
DotColor: drawing.ColorRed,
},
XValues: chart.Sequence.Random(32, 1024),
YValues: chart.Sequence.Random(32, 1024),
},
},
}
res.Header().Set("Content-Type", "image/png")
err := graph.Render(chart.PNG, res)
if err != nil {
log.Println(err.Error())
}
}
func main() {
http.HandleFunc("/", drawChart)
log.Fatal(http.ListenAndServe(":8080", nil))
}

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@ -141,8 +141,10 @@ func (c Chart) Render(rp RendererProvider, w io.Writer) error {
func (c Chart) checkHasVisibleSeries() error {
hasVisibleSeries := false
var style Style
for _, s := range c.Series {
hasVisibleSeries = hasVisibleSeries || (s.GetStyle().IsZero() || s.GetStyle().Show)
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")

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@ -14,6 +14,8 @@ const (
DefaultChartWidth = 1024
// DefaultStrokeWidth is the default chart stroke width.
DefaultStrokeWidth = 0.0
// DefaultDotWidth is the default chart dot width.
DefaultDotWidth = 0.0
// DefaultSeriesLineWidth is the default line width.
DefaultSeriesLineWidth = 1.0
// DefaultAxisLineWidth is the line width of the axis lines.

25
draw.go
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@ -27,9 +27,8 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
var vx, vy float64
var x, y int
fill := style.GetFillColor()
if !fill.IsZero() {
style.GetFillOptions().WriteToRenderer(r)
if style.ShouldDrawStroke() && style.ShouldDrawFill() {
style.GetFillOptions().WriteDrawingOptionsToRenderer(r)
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
vx, vy = vs.GetValue(i)
@ -43,7 +42,8 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
r.Fill()
}
style.GetStrokeOptions().WriteToRenderer(r)
if style.ShouldDrawStroke() {
style.GetStrokeOptions().WriteDrawingOptionsToRenderer(r)
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
@ -52,7 +52,22 @@ func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style
y = cb - yrange.Translate(vy)
r.LineTo(x, y)
}
r.Stroke()
}
if style.ShouldDrawDot() {
dotWidth := style.GetDotWidth()
style.GetDotOptions().WriteDrawingOptionsToRenderer(r)
for i := 0; i < vs.Len(); i++ {
vx, vy = vs.GetValue(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
r.Circle(dotWidth, x, y)
r.FillStroke()
}
}
}
// BoundedSeries draws a series that implements BoundedValueProvider.

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@ -1,8 +1,6 @@
package drawing
import (
"math"
)
import "math"
const (
// CurveRecursionLimit represents the maximum recursion that is really necessary to subsivide a curve into straight lines
@ -98,31 +96,60 @@ func SubdivideQuad(c, c1, c2 []float64) {
return
}
func traceWindowIndices(i int) (startAt, endAt int) {
startAt = i * 6
endAt = startAt + 6
return
}
func traceCalcDeltas(c []float64) (dx, dy, d float64) {
dx = c[4] - c[0]
dy = c[5] - c[1]
d = math.Abs(((c[2]-c[4])*dy - (c[3]-c[5])*dx))
return
}
func traceIsFlat(dx, dy, d, threshold float64) bool {
return (d * d) < threshold*(dx*dx+dy*dy)
}
func traceGetWindow(curves []float64, i int) []float64 {
startAt, endAt := traceWindowIndices(i)
return curves[startAt:endAt]
}
// TraceQuad generate lines subdividing the curve using a Liner
// flattening_threshold helps determines the flattening expectation of the curve
func TraceQuad(t Liner, quad []float64, flatteningThreshold float64) {
const curveLen = CurveRecursionLimit * 6
const curveEndIndex = curveLen - 1
const lastIteration = CurveRecursionLimit - 1
// Allocates curves stack
var curves [CurveRecursionLimit * 6]float64
curves := make([]float64, curveLen)
// copy 6 elements from the quad path to the stack
copy(curves[0:6], quad[0:6])
i := 0
// current curve
var i int
var c []float64
var dx, dy, d float64
for i >= 0 {
c = curves[i*6:]
dx = c[4] - c[0]
dy = c[5] - c[1]
c = traceGetWindow(curves, i)
dx, dy, d = traceCalcDeltas(c)
d = math.Abs(((c[2]-c[4])*dy - (c[3]-c[5])*dx))
// bail early if the distance is 0
if d == 0 {
return
}
// if it's flat then trace a line
if (d*d) < flatteningThreshold*(dx*dx+dy*dy) || i == len(curves)-1 {
if traceIsFlat(dx, dy, d, flatteningThreshold) || i == lastIteration {
t.LineTo(c[4], c[5])
i--
} else {
// second half of bezier go lower onto the stack
SubdivideQuad(c, curves[(i+1)*6:], curves[i*6:])
SubdivideQuad(c, traceGetWindow(curves, i+1), traceGetWindow(curves, i))
i++
}
}

35
drawing/curve_test.go Normal file
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@ -0,0 +1,35 @@
package drawing
import (
"testing"
assert "github.com/blendlabs/go-assert"
)
type point struct {
X, Y float64
}
type mockLine struct {
inner []point
}
func (ml *mockLine) LineTo(x, y float64) {
ml.inner = append(ml.inner, point{x, y})
}
func (ml mockLine) Len() int {
return len(ml.inner)
}
func TestTraceQuad(t *testing.T) {
assert := assert.New(t)
// Quad
// x1, y1, cpx1, cpy2, x2, y2 float64
// do the 9->12 circle segment
quad := []float64{10, 20, 20, 20, 20, 10}
liner := &mockLine{}
TraceQuad(liner, quad, 0.5)
assert.NotZero(liner.Len())
}

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@ -23,10 +23,10 @@ type Flattener interface {
// Flatten convert curves into straight segments keeping join segments info
func Flatten(path *Path, flattener Flattener, scale float64) {
// First Point
var startX, startY float64 = 0, 0
var startX, startY float64
// Current Point
var x, y float64 = 0, 0
i := 0
var x, y float64
var i int
for _, cmp := range path.Components {
switch cmp {
case MoveToComponent:
@ -43,6 +43,7 @@ func Flatten(path *Path, flattener Flattener, scale float64) {
flattener.LineJoin()
i += 2
case QuadCurveToComponent:
// we include the previous point for the start of the curve
TraceQuad(flattener, path.Points[i-2:], 0.5)
x, y = path.Points[i+2], path.Points[i+3]
flattener.LineTo(x, y)

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@ -1,6 +1,7 @@
package chart
import (
"fmt"
"image"
"image/png"
"io"
@ -116,17 +117,17 @@ func (rr *rasterRenderer) FillStroke() {
rr.gc.FillStroke()
}
// Circle implements the interface method.
// Circle fully draws and strokes a circle at a given point.
func (rr *rasterRenderer) Circle(radius float64, x, y int) {
fmt.Printf("RasterRenderer.Circle(%f, %d, %d)\n", radius, x, y)
xf := float64(x)
yf := float64(y)
rr.gc.MoveTo(xf-radius, yf) //9
rr.gc.QuadCurveTo(xf, yf, xf, yf-radius) //12
rr.gc.QuadCurveTo(xf, yf, xf+radius, yf) //3
rr.gc.QuadCurveTo(xf, yf, xf, yf+radius) //6
rr.gc.QuadCurveTo(xf, yf, xf-radius, yf) //9
rr.gc.Close()
rr.gc.FillStroke()
rr.gc.QuadCurveTo(xf-radius, yf-radius, xf, yf-radius) //12
rr.gc.QuadCurveTo(xf+radius, yf-radius, xf+radius, yf) //3
rr.gc.QuadCurveTo(xf+radius, yf+radius, xf, yf+radius) //6
rr.gc.QuadCurveTo(xf-radius, yf+radius, xf-radius, yf) //9
}
// SetFont implements the interface method.

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@ -8,10 +8,14 @@ import (
var (
// Sequence contains some sequence utilities.
// These utilities can be useful for generating test data.
Sequence = &sequence{}
Sequence = &sequence{
rnd: rand.New(rand.NewSource(time.Now().Unix())),
}
)
type sequence struct{}
type sequence struct {
rnd *rand.Rand
}
// Float64 produces an array of floats from [start,end] by optional steps.
func (s sequence) Float64(start, end float64, steps ...float64) []float64 {
@ -35,11 +39,10 @@ func (s sequence) Float64(start, end float64, steps ...float64) []float64 {
// Random generates a fixed length sequence of random values between (0, scale).
func (s sequence) Random(samples int, scale float64) []float64 {
rnd := rand.New(rand.NewSource(time.Now().Unix()))
values := make([]float64, samples)
for x := 0; x < samples; x++ {
values[x] = rnd.Float64() * scale
values[x] = s.rnd.Float64() * scale
}
return values
@ -47,11 +50,10 @@ func (s sequence) Random(samples int, scale float64) []float64 {
// Random generates a fixed length sequence of random values with a given average, above and below that average by (-scale, scale)
func (s sequence) RandomWithAverage(samples int, average, scale float64) []float64 {
rnd := rand.New(rand.NewSource(time.Now().Unix()))
values := make([]float64, samples)
for x := 0; x < samples; x++ {
jitter := scale - (rnd.Float64() * (2 * scale))
jitter := scale - (s.rnd.Float64() * (2 * scale))
values[x] = average + jitter
}

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@ -8,6 +8,12 @@ import (
"github.com/wcharczuk/go-chart/drawing"
)
const (
// Disabled indicates if the value should be interpreted as set intentionally to zero.
// this is because golang optionals aren't here yet.
Disabled = -1
)
// StyleShow is a prebuilt style with the `Show` property set to true.
func StyleShow() Style {
return Style{
@ -24,7 +30,11 @@ type Style struct {
StrokeColor drawing.Color
StrokeDashArray []float64
DotColor drawing.Color
DotWidth float64
FillColor drawing.Color
FontSize float64
FontColor drawing.Color
Font *truetype.Font
@ -38,7 +48,14 @@ type Style struct {
// 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.FontColor.IsZero() && s.FontSize == 0 && s.Font == nil
return s.StrokeColor.IsZero() &&
s.StrokeWidth == 0 &&
s.DotColor.IsZero() &&
s.DotWidth == 0 &&
s.FillColor.IsZero() &&
s.FontColor.IsZero() &&
s.FontSize == 0 &&
s.Font == nil
}
// String returns a text representation of the style.
@ -83,6 +100,18 @@ func (s Style) String() string {
output = append(output, "\"stroke_dash_array\": null")
}
if s.DotWidth >= 0 {
output = append(output, fmt.Sprintf("\"dot_width\": %0.2f", s.DotWidth))
} else {
output = append(output, "\"dot_width\": null")
}
if !s.DotColor.IsZero() {
output = append(output, fmt.Sprintf("\"dot_color\": %s", s.DotColor.String()))
} else {
output = append(output, "\"dot_color\": null")
}
if !s.FillColor.IsZero() {
output = append(output, fmt.Sprintf("\"fill_color\": %s", s.FillColor.String()))
} else {
@ -132,6 +161,17 @@ func (s Style) GetFillColor(defaults ...drawing.Color) drawing.Color {
return s.FillColor
}
// GetDotColor returns the stroke color.
func (s Style) GetDotColor(defaults ...drawing.Color) drawing.Color {
if s.DotColor.IsZero() {
if len(defaults) > 0 {
return defaults[0]
}
return drawing.ColorTransparent
}
return s.DotColor
}
// GetStrokeWidth returns the stroke width.
func (s Style) GetStrokeWidth(defaults ...float64) float64 {
if s.StrokeWidth == 0 {
@ -143,6 +183,17 @@ func (s Style) GetStrokeWidth(defaults ...float64) float64 {
return s.StrokeWidth
}
// GetDotWidth returns the dot width for scatter plots.
func (s Style) GetDotWidth(defaults ...float64) float64 {
if s.DotWidth == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return DefaultDotWidth
}
return s.DotWidth
}
// GetStrokeDashArray returns the stroke dash array.
func (s Style) GetStrokeDashArray(defaults ...[]float64) []float64 {
if len(s.StrokeDashArray) == 0 {
@ -288,6 +339,10 @@ func (s Style) InheritFrom(defaults Style) (final Style) {
final.StrokeColor = s.GetStrokeColor(defaults.StrokeColor)
final.StrokeWidth = s.GetStrokeWidth(defaults.StrokeWidth)
final.StrokeDashArray = s.GetStrokeDashArray(defaults.StrokeDashArray)
final.DotColor = s.GetDotColor(defaults.DotColor)
final.DotWidth = s.GetDotWidth(defaults.DotWidth)
final.FillColor = s.GetFillColor(defaults.FillColor)
final.FontColor = s.GetFontColor(defaults.FontColor)
final.FontSize = s.GetFontSize(defaults.FontSize)
@ -298,6 +353,7 @@ func (s Style) InheritFrom(defaults Style) (final Style) {
final.TextWrap = s.GetTextWrap(defaults.TextWrap)
final.TextLineSpacing = s.GetTextLineSpacing(defaults.TextLineSpacing)
final.TextRotationDegrees = s.GetTextRotationDegrees(defaults.TextRotationDegrees)
return
}
@ -317,6 +373,16 @@ func (s Style) GetFillOptions() Style {
}
}
// GetDotOptions returns the dot components.
func (s Style) GetDotOptions() Style {
return Style{
StrokeDashArray: nil,
FillColor: s.DotColor,
StrokeColor: s.DotColor,
StrokeWidth: 1.0,
}
}
// GetFillAndStrokeOptions returns the fill and stroke components.
func (s Style) GetFillAndStrokeOptions() Style {
return Style{
@ -340,3 +406,18 @@ func (s Style) GetTextOptions() Style {
TextRotationDegrees: s.TextRotationDegrees,
}
}
// ShouldDrawStroke tells drawing functions if they should draw the stroke.
func (s Style) ShouldDrawStroke() bool {
return !s.StrokeColor.IsZero() && s.StrokeWidth > 0
}
// ShouldDrawDot tells drawing functions if they should draw the dot.
func (s Style) ShouldDrawDot() bool {
return !s.DotColor.IsZero() && s.DotWidth > 0
}
// ShouldDrawFill tells drawing functions if they should draw the stroke.
func (s Style) ShouldDrawFill() bool {
return !s.FillColor.IsZero()
}