go-chart/draw.go
2024-10-03 17:09:14 +02:00

339 lines
8.7 KiB
Go

package chart
import (
"math"
)
var (
// Draw contains helpers for drawing common objects.
Draw = &draw{}
)
type draw struct{}
// LineSeries draws a line series with a renderer.
func (d draw) LineSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValuesProvider) {
if vs.Len() == 0 {
return
}
cb := canvasBox.Bottom
cl := canvasBox.Left
v0x, v0y := vs.GetValues(0)
x0 := cl + xrange.Translate(v0x)
y0 := cb - yrange.Translate(v0y)
yv0 := yrange.Translate(0)
var vx, vy float64
var x, y int
if style.ShouldDrawStroke() && style.ShouldDrawFill() {
style.GetFillOptions().WriteDrawingOptionsToRenderer(r)
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
vx, vy = vs.GetValues(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
r.LineTo(x, y)
}
r.LineTo(x, MinInt(cb, cb-yv0))
r.LineTo(x0, MinInt(cb, cb-yv0))
r.LineTo(x0, y0)
r.Fill()
}
if style.ShouldDrawStroke() {
style.GetStrokeOptions().WriteDrawingOptionsToRenderer(r)
vxprev := 0.0
if vs.Len() > 0 {
vxprev, _ = vs.GetValues( 0 ) // make sure vxprev starts at the beginning
}
maxspan := style.GetStrokeMaxSpanGap()
r.MoveTo(x0, y0)
for i := 1; i < vs.Len(); i++ {
vx, vy = vs.GetValues(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
df := vxprev - vx
if df < 0 {
df *= -1 // make it work, regardless of direction ox X-axis
}
if df <= maxspan { // span the gap i.e. connect the two points
r.LineTo(x, y)
} else { // do not span the gap
r.MoveTo(x, y)
}
vxprev = vx
}
r.Stroke()
}
if style.ShouldDrawDot() {
defaultDotWidth := style.GetDotWidth()
style.GetDotOptions().WriteDrawingOptionsToRenderer(r)
for i := 0; i < vs.Len(); i++ {
vx, vy = vs.GetValues(i)
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy)
dotWidth := defaultDotWidth
if style.DotWidthProvider != nil {
dotWidth = style.DotWidthProvider(xrange, yrange, i, vx, vy)
}
if style.DotColorProvider != nil {
dotColor := style.DotColorProvider(xrange, yrange, i, vx, vy)
r.SetFillColor(dotColor)
r.SetStrokeColor(dotColor)
}
r.Circle(dotWidth, x, y)
r.FillStroke()
}
}
}
// BoundedSeries draws a series that implements BoundedValuesProvider.
func (d draw) BoundedSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, bbs BoundedValuesProvider, drawOffsetIndexes ...int) {
drawOffsetIndex := 0
if len(drawOffsetIndexes) > 0 {
drawOffsetIndex = drawOffsetIndexes[0]
}
cb := canvasBox.Bottom
cl := canvasBox.Left
v0x, v0y1, v0y2 := bbs.GetBoundedValues(0)
x0 := cl + xrange.Translate(v0x)
y0 := cb - yrange.Translate(v0y1)
var vx, vy1, vy2 float64
var x, y int
xvalues := make([]float64, bbs.Len())
xvalues[0] = v0x
y2values := make([]float64, bbs.Len())
y2values[0] = v0y2
style.GetFillAndStrokeOptions().WriteToRenderer(r)
r.MoveTo(x0, y0)
for i := 1; i < bbs.Len(); i++ {
vx, vy1, vy2 = bbs.GetBoundedValues(i)
xvalues[i] = vx
y2values[i] = vy2
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy1)
if i > drawOffsetIndex {
r.LineTo(x, y)
} else {
r.MoveTo(x, y)
}
}
y = cb - yrange.Translate(vy2)
r.LineTo(x, y)
for i := bbs.Len() - 1; i >= drawOffsetIndex; i-- {
vx, vy2 = xvalues[i], y2values[i]
x = cl + xrange.Translate(vx)
y = cb - yrange.Translate(vy2)
r.LineTo(x, y)
}
r.Close()
r.FillStroke()
}
// HistogramSeries draws a value provider as boxes from 0.
func (d draw) HistogramSeries(r Renderer, canvasBox Box, xrange, yrange Range, style Style, vs ValuesProvider, barWidths ...int) {
if vs.Len() == 0 {
return
}
//calculate bar width?
seriesLength := vs.Len()
barWidth := int(math.Floor(float64(xrange.GetDomain()) / float64(seriesLength)))
if len(barWidths) > 0 {
barWidth = barWidths[0]
}
cb := canvasBox.Bottom
cl := canvasBox.Left
//foreach datapoint, draw a box.
for index := 0; index < seriesLength; index++ {
vx, vy := vs.GetValues(index)
y0 := yrange.Translate(0)
x := cl + xrange.Translate(vx)
y := yrange.Translate(vy)
d.Box(r, Box{
Top: cb - y0,
Left: x - (barWidth >> 1),
Right: x + (barWidth >> 1),
Bottom: cb - y,
}, style)
}
}
// MeasureAnnotation measures how big an annotation would be.
func (d draw) MeasureAnnotation(r Renderer, canvasBox Box, style Style, lx, ly int, label string) Box {
style.WriteToRenderer(r)
defer r.ResetStyle()
textBox := r.MeasureText(label)
textWidth := textBox.Width()
textHeight := textBox.Height()
halfTextHeight := textHeight >> 1
pt := style.Padding.GetTop(DefaultAnnotationPadding.Top)
pl := style.Padding.GetLeft(DefaultAnnotationPadding.Left)
pr := style.Padding.GetRight(DefaultAnnotationPadding.Right)
pb := style.Padding.GetBottom(DefaultAnnotationPadding.Bottom)
strokeWidth := style.GetStrokeWidth()
top := ly - (pt + halfTextHeight)
right := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth + int(strokeWidth)
bottom := ly + (pb + halfTextHeight)
return Box{
Top: top,
Left: lx,
Right: right,
Bottom: bottom,
}
}
// Annotation draws an anotation with a renderer.
func (d draw) Annotation(r Renderer, canvasBox Box, style Style, lx, ly int, label string) {
style.GetTextOptions().WriteToRenderer(r)
defer r.ResetStyle()
textBox := r.MeasureText(label)
textWidth := textBox.Width()
halfTextHeight := textBox.Height() >> 1
style.GetFillAndStrokeOptions().WriteToRenderer(r)
pt := style.Padding.GetTop(DefaultAnnotationPadding.Top)
pl := style.Padding.GetLeft(DefaultAnnotationPadding.Left)
pr := style.Padding.GetRight(DefaultAnnotationPadding.Right)
pb := style.Padding.GetBottom(DefaultAnnotationPadding.Bottom)
textX := lx + pl + DefaultAnnotationDeltaWidth
textY := ly + halfTextHeight
ltx := lx + DefaultAnnotationDeltaWidth
lty := ly - (pt + halfTextHeight)
rtx := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth
rty := ly - (pt + halfTextHeight)
rbx := lx + pl + pr + textWidth + DefaultAnnotationDeltaWidth
rby := ly + (pb + halfTextHeight)
lbx := lx + DefaultAnnotationDeltaWidth
lby := ly + (pb + halfTextHeight)
r.MoveTo(lx, ly)
r.LineTo(ltx, lty)
r.LineTo(rtx, rty)
r.LineTo(rbx, rby)
r.LineTo(lbx, lby)
r.LineTo(lx, ly)
r.Close()
r.FillStroke()
style.GetTextOptions().WriteToRenderer(r)
r.Text(label, textX, textY)
}
// Box draws a box with a given style.
func (d draw) Box(r Renderer, b Box, s Style) {
s.GetFillAndStrokeOptions().WriteToRenderer(r)
defer r.ResetStyle()
r.MoveTo(b.Left, b.Top)
r.LineTo(b.Right, b.Top)
r.LineTo(b.Right, b.Bottom)
r.LineTo(b.Left, b.Bottom)
r.LineTo(b.Left, b.Top)
r.FillStroke()
}
func (d draw) BoxRotated(r Renderer, b Box, thetaDegrees float64, s Style) {
d.BoxCorners(r, b.Corners().Rotate(thetaDegrees), s)
}
func (d draw) BoxCorners(r Renderer, bc BoxCorners, s Style) {
s.GetFillAndStrokeOptions().WriteToRenderer(r)
defer r.ResetStyle()
r.MoveTo(bc.TopLeft.X, bc.TopLeft.Y)
r.LineTo(bc.TopRight.X, bc.TopRight.Y)
r.LineTo(bc.BottomRight.X, bc.BottomRight.Y)
r.LineTo(bc.BottomLeft.X, bc.BottomLeft.Y)
r.Close()
r.FillStroke()
}
// DrawText draws text with a given style.
func (d draw) Text(r Renderer, text string, x, y int, style Style) {
style.GetTextOptions().WriteToRenderer(r)
defer r.ResetStyle()
r.Text(text, x, y)
}
func (d draw) MeasureText(r Renderer, text string, style Style) Box {
style.GetTextOptions().WriteToRenderer(r)
defer r.ResetStyle()
return r.MeasureText(text)
}
// TextWithin draws the text within a given box.
func (d draw) TextWithin(r Renderer, text string, box Box, style Style) {
style.GetTextOptions().WriteToRenderer(r)
defer r.ResetStyle()
lines := Text.WrapFit(r, text, box.Width(), style)
linesBox := Text.MeasureLines(r, lines, style)
y := box.Top
switch style.GetTextVerticalAlign() {
case TextVerticalAlignBottom, TextVerticalAlignBaseline: // i have to build better baseline handling into measure text
y = y - linesBox.Height()
case TextVerticalAlignMiddle:
y = y + (box.Height() >> 1) - (linesBox.Height() >> 1)
case TextVerticalAlignMiddleBaseline:
y = y + (box.Height() >> 1) - linesBox.Height()
}
var tx, ty int
for _, line := range lines {
lineBox := r.MeasureText(line)
switch style.GetTextHorizontalAlign() {
case TextHorizontalAlignCenter:
tx = box.Left + ((box.Width() - lineBox.Width()) >> 1)
case TextHorizontalAlignRight:
tx = box.Right - lineBox.Width()
default:
tx = box.Left
}
if style.TextRotationDegrees == 0 {
ty = y + lineBox.Height()
} else {
ty = y
}
r.Text(line, tx, ty)
y += lineBox.Height() + style.GetTextLineSpacing()
}
}