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SVG!

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This commit is contained in:
Will Charczuk 2016-07-07 22:18:53 -07:00
parent 3d68b7e51d
commit f843d124d6
7 changed files with 205 additions and 14 deletions
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10
chart.go
View file

@ -191,7 +191,7 @@ func (c Chart) initRanges(canvasBox Box) (xrange Range, yrange Range) {
func (c Chart) drawBackground(r Renderer) {
r.SetFillColor(c.Background.GetFillColor(DefaultBackgroundColor))
r.SetStrokeColor(c.Background.GetStrokeColor(DefaultBackgroundStrokeColor))
r.SetLineWidth(c.Background.GetStrokeWidth(DefaultStrokeWidth))
r.SetStrokeWidth(c.Background.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(0, 0)
r.LineTo(c.Width, 0)
r.LineTo(c.Width, c.Height)
@ -204,7 +204,7 @@ func (c Chart) drawBackground(r Renderer) {
func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
r.SetFillColor(c.Canvas.GetFillColor(DefaultCanvasColor))
r.SetStrokeColor(c.Canvas.GetStrokeColor(DefaultCanvasStrokColor))
r.SetLineWidth(c.Canvas.GetStrokeWidth(DefaultStrokeWidth))
r.SetStrokeWidth(c.Canvas.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(canvasBox.Left, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Top)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
@ -217,7 +217,7 @@ func (c Chart) drawCanvas(r Renderer, canvasBox Box) {
func (c Chart) drawAxes(r Renderer, canvasBox Box, xrange, yrange Range) {
if c.Axes.Show {
r.SetStrokeColor(c.Axes.GetStrokeColor(DefaultAxisColor))
r.SetLineWidth(c.Axes.GetStrokeWidth(DefaultStrokeWidth))
r.SetStrokeWidth(c.Axes.GetStrokeWidth(DefaultStrokeWidth))
r.MoveTo(canvasBox.Left, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Bottom)
r.LineTo(canvasBox.Right, canvasBox.Top)
@ -295,7 +295,7 @@ func (c Chart) drawXAxisLabels(r Renderer, canvasBox Box, xrange Range) {
func (c Chart) drawSeries(r Renderer, canvasBox Box, index int, s Series, xrange, yrange Range) {
r.SetStrokeColor(s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index)))
r.SetLineWidth(s.GetStyle().GetStrokeWidth(DefaultStrokeWidth))
r.SetStrokeWidth(s.GetStyle().GetStrokeWidth(DefaultStrokeWidth))
if s.Len() == 0 {
return
@ -366,7 +366,7 @@ func (c Chart) drawFinalValueLabel(r Renderer, canvasBox Box, index int, s Serie
//draw the shape...
r.SetFillColor(c.FinalValueLabel.GetFillColor(DefaultFinalLabelBackgroundColor))
r.SetStrokeColor(c.FinalValueLabel.GetStrokeColor(s.GetStyle().GetStrokeColor(GetDefaultSeriesStrokeColor(index))))
r.SetLineWidth(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
r.SetStrokeWidth(c.FinalValueLabel.GetStrokeWidth(DefaultAxisLineWidth))
r.MoveTo(cx, ly)
r.LineTo(ltlx, ltly)
r.LineTo(ltrx, ltry)

6
raster_renderer.go
View file

@ -21,7 +21,7 @@ func PNG(width, height int) Renderer {
}
}
// RasterRenderer renders chart commands to a bitmap.
// rasterRenderer renders chart commands to a bitmap.
type rasterRenderer struct {
i *image.RGBA
gc *drawing.GraphicContext
@ -43,7 +43,7 @@ func (rr *rasterRenderer) SetFillColor(c color.RGBA) {
}
// SetLineWidth implements the interface method.
func (rr *rasterRenderer) SetLineWidth(width float64) {
func (rr *rasterRenderer) SetStrokeWidth(width float64) {
rr.gc.SetLineWidth(width)
}
@ -115,7 +115,7 @@ func (rr *rasterRenderer) Text(body string, x, y int) {
rr.gc.Fill()
}
// MeasureText implements the interface method.
// MeasureText uses the truetype font drawer to measure the width of text.
func (rr *rasterRenderer) MeasureText(body string) int {
if rr.fc == nil && rr.font != nil {
rr.fc = &font.Drawer{

4
renderer.go
View file

@ -18,8 +18,8 @@ type Renderer interface {
// SetFillColor sets the current fill color.
SetFillColor(color.RGBA)
// SetLineWidth sets the stroke line width.
SetLineWidth(width float64)
// SetStrokeWidth sets the stroke width.
SetStrokeWidth(width float64)
// MoveTo moves the cursor to a given point.
MoveTo(x, y int)

40
style.go
View file

@ -1,6 +1,10 @@
package chart
import "image/color"
import (
"fmt"
"image/color"
"strings"
)
// Style is a simple style set.
type Style struct {
@ -72,3 +76,37 @@ func (s Style) GetFontColor(defaults ...color.RGBA) color.RGBA {
}
return s.FontColor
}
// SVG returns the style as a svg style string.
func (s Style) SVG() string {
sw := s.StrokeWidth
sc := s.StrokeColor
fc := s.FillColor
fs := s.FontSize
fnc := s.FontColor
strokeWidthText := "stroke-width:0"
if sw != 0 {
strokeWidthText = "stroke-width:" + fmt.Sprintf("%d", int(sw))
}
strokeText := "stroke:none"
if !ColorIsZero(sc) {
strokeText = "stroke:" + ColorAsString(sc)
}
fillText := "fill:none"
if !ColorIsZero(fc) {
fillText = "fill:" + ColorAsString(fc)
}
fontSizeText := ""
if fs != 0 {
fontSizeText = "font-size:" + fmt.Sprintf("%.1f", fs)
}
if !ColorIsZero(fnc) {
fillText = "fill:" + ColorAsString(fnc)
}
return strings.Join([]string{strokeWidthText, strokeText, fillText, fontSizeText}, ";")
}

4
testserver/main.go
View file

@ -14,7 +14,7 @@ func main() {
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")
rc.Response.Header().Set("Content-Type", "image/svg+xml")
now := time.Now()
c := chart.Chart{
Title: "A Test Chart",
@ -49,7 +49,7 @@ func main() {
}
buffer := bytes.NewBuffer([]byte{})
err := c.Render(chart.PNG, buffer)
err := c.Render(chart.SVG, buffer)
if err != nil {
return rc.API().InternalError(err)
}

3
util.go
View file

@ -13,7 +13,8 @@ func ColorIsZero(c color.RGBA) bool {
// 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)
a := float64(c.A) / float64(255)
return fmt.Sprintf("rgba(%v,%v,%v,%.1f)", c.R, c.G, c.B, a)
}
// MinAndMax returns both the min and max in one pass.

152
vector_renderer.go
View file

@ -1 +1,153 @@
package chart
import (
"bytes"
"fmt"
"image/color"
"io"
"strings"
"golang.org/x/image/font"
"github.com/ajstarks/svgo"
"github.com/golang/freetype/truetype"
)
// SVG returns a new png/raster renderer.
func SVG(width, height int) Renderer {
buffer := bytes.NewBuffer([]byte{})
canvas := svg.New(buffer)
canvas.Start(width, height)
return &vectorRenderer{
b: buffer,
c: canvas,
s: &Style{},
p: []string{},
}
}
// vectorRenderer renders chart commands to a bitmap.
type vectorRenderer struct {
b *bytes.Buffer
c *svg.SVG
s *Style
f *truetype.Font
p []string
fc *font.Drawer
}
func (vr *vectorRenderer) SetStrokeColor(c color.RGBA) {
vr.s.StrokeColor = c
}
// SetFillColor implements the interface method.
func (vr *vectorRenderer) SetFillColor(c color.RGBA) {
vr.s.FillColor = c
}
// SetLineWidth implements the interface method.
func (vr *vectorRenderer) SetStrokeWidth(width float64) {
vr.s.StrokeWidth = width
}
// MoveTo implements the interface method.
func (vr *vectorRenderer) MoveTo(x, y int) {
vr.p = append(vr.p, fmt.Sprintf("M %d %d", x, y))
}
// LineTo implements the interface method.
func (vr *vectorRenderer) LineTo(x, y int) {
vr.p = append(vr.p, fmt.Sprintf("L %d %d", x, y))
}
func (vr *vectorRenderer) Close() {
vr.p = append(vr.p, fmt.Sprintf("Z"))
}
// Stroke draws the path with no fill.
func (vr *vectorRenderer) Stroke() {
vr.s.FillColor = color.RGBA{}
vr.s.FontColor = color.RGBA{}
vr.drawPath()
}
// Fill draws the path with no stroke.
func (vr *vectorRenderer) Fill() {
vr.s.StrokeColor = color.RGBA{}
vr.s.StrokeWidth = 0
vr.s.FontColor = color.RGBA{}
vr.drawPath()
}
// FillStroke draws the path with both fill and stroke.
func (vr *vectorRenderer) FillStroke() {
vr.s.FontColor = color.RGBA{}
vr.drawPath()
}
func (vr *vectorRenderer) drawPath() {
vr.c.Path(strings.Join(vr.p, "\n"), vr.s.SVG())
vr.p = []string{}
}
// Circle implements the interface method.
func (vr *vectorRenderer) Circle(radius float64, x, y int) {
vr.c.Circle(x, y, int(radius), vr.s.SVG())
}
// SetFont implements the interface method.
func (vr *vectorRenderer) SetFont(f *truetype.Font) {
vr.f = f
}
// SetFontColor implements the interface method.
func (vr *vectorRenderer) SetFontColor(c color.RGBA) {
vr.s.FontColor = c
}
// SetFontSize implements the interface method.
func (vr *vectorRenderer) SetFontSize(size float64) {
vr.s.FontSize = size
}
func (vr *vectorRenderer) svgFontFace() string {
family := "sans-serif"
if vr.f != nil {
name := vr.f.Name(truetype.NameIDFontFamily)
if len(name) != 0 {
family = fmt.Sprintf(`'%s',%s`, name, family)
}
}
return fmt.Sprintf("font-family:%s", family)
}
// Text draws a text blob.
func (vr *vectorRenderer) Text(body string, x, y int) {
vr.s.FillColor = color.RGBA{}
vr.s.StrokeColor = color.RGBA{}
vr.s.StrokeWidth = 0
vr.c.Text(x, y, body, vr.s.SVG()+";"+vr.svgFontFace())
}
// MeasureText uses the truetype font drawer to measure the width of text.
func (vr *vectorRenderer) MeasureText(body string) int {
if vr.fc == nil && vr.f != nil {
vr.fc = &font.Drawer{
Face: truetype.NewFace(vr.f, &truetype.Options{
DPI: DefaultDPI,
Size: vr.s.FontSize,
}),
}
}
if vr.fc != nil {
dimensions := vr.fc.MeasureString(body)
return dimensions.Floor()
}
return 0
}
func (vr *vectorRenderer) Save(w io.Writer) error {
vr.c.End()
_, err := w.Write(vr.b.Bytes())
return err
}