package chart import ( "fmt" "math" "strings" util "git.gutmet.org/go-chart.git/util" ) // TicksProvider is a type that provides ticks. type TicksProvider interface { GetTicks(r Renderer, defaults Style, vf ValueFormatter) []Tick } // Tick represents a label on an axis. type Tick struct { Value float64 Label string } // Ticks is an array of ticks. type Ticks []Tick // Len returns the length of the ticks set. func (t Ticks) Len() int { return len(t) } // Swap swaps two elements. func (t Ticks) Swap(i, j int) { t[i], t[j] = t[j], t[i] } // Less returns if i's value is less than j's value. func (t Ticks) Less(i, j int) bool { return t[i].Value < t[j].Value } // String returns a string representation of the set of ticks. func (t Ticks) String() string { var values []string for i, tick := range t { values = append(values, fmt.Sprintf("[%d: %s]", i, tick.Label)) } return strings.Join(values, ", ") } // GenerateContinuousTicks generates a set of ticks. func GenerateContinuousTicks(r Renderer, ra Range, isVertical bool, style Style, vf ValueFormatter) []Tick { if vf == nil { vf = FloatValueFormatter } var ticks []Tick min, max := ra.GetMin(), ra.GetMax() if ra.IsDescending() { ticks = append(ticks, Tick{ Value: max, Label: vf(max), }) } else { ticks = append(ticks, Tick{ Value: min, Label: vf(min), }) } minLabel := vf(min) style.GetTextOptions().WriteToRenderer(r) labelBox := r.MeasureText(minLabel) var tickSize float64 if isVertical { tickSize = float64(labelBox.Height() + DefaultMinimumTickVerticalSpacing) } else { tickSize = float64(labelBox.Width() + DefaultMinimumTickHorizontalSpacing) } domain := float64(ra.GetDomain()) domainRemainder := domain - (tickSize * 2) intermediateTickCount := int(math.Floor(float64(domainRemainder) / float64(tickSize))) rangeDelta := math.Abs(max - min) tickStep := rangeDelta / float64(intermediateTickCount) roundTo := util.Math.GetRoundToForDelta(rangeDelta) / 10 intermediateTickCount = util.Math.MinInt(intermediateTickCount, DefaultTickCountSanityCheck) for x := 1; x < intermediateTickCount; x++ { var tickValue float64 if ra.IsDescending() { tickValue = max - util.Math.RoundUp(tickStep*float64(x), roundTo) } else { tickValue = min + util.Math.RoundUp(tickStep*float64(x), roundTo) } ticks = append(ticks, Tick{ Value: tickValue, Label: vf(tickValue), }) } if ra.IsDescending() { ticks = append(ticks, Tick{ Value: min, Label: vf(min), }) } else { ticks = append(ticks, Tick{ Value: max, Label: vf(max), }) } return ticks }