go-chart/box.go
2018-12-06 16:38:58 +01:00

354 lines
8.4 KiB
Go

package chart
import (
"fmt"
"math"
util "git.gutmet.org/go-chart.git/util"
)
var (
// BoxZero is a preset box that represents an intentional zero value.
BoxZero = Box{IsSet: true}
)
// NewBox returns a new (set) box.
func NewBox(top, left, right, bottom int) Box {
return Box{
IsSet: true,
Top: top,
Left: left,
Right: right,
Bottom: bottom,
}
}
// Box represents the main 4 dimensions of a box.
type Box struct {
Top int
Left int
Right int
Bottom int
IsSet bool
}
// IsZero returns if the box is set or not.
func (b Box) IsZero() bool {
if b.IsSet {
return false
}
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.IsSet && 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.IsSet && 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.IsSet && 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.IsSet && b.Bottom == 0 {
if len(defaults) > 0 {
return defaults[0]
}
return 0
}
return b.Bottom
}
// Width returns the width
func (b Box) Width() int {
return util.Math.AbsInt(b.Right - b.Left)
}
// Height returns the height
func (b Box) Height() int {
return util.Math.AbsInt(b.Bottom - b.Top)
}
// Center returns the center of the box
func (b Box) Center() (x, y int) {
w2, h2 := b.Width()>>1, b.Height()>>1
return b.Left + w2, b.Top + h2
}
// Aspect returns the aspect ratio of the box.
func (b Box) Aspect() float64 {
return float64(b.Width()) / float64(b.Height())
}
// Clone returns a new copy of the box.
func (b Box) Clone() Box {
return Box{
IsSet: b.IsSet,
Top: b.Top,
Left: b.Left,
Right: b.Right,
Bottom: b.Bottom,
}
}
// IsBiggerThan returns if a box is bigger than another box.
func (b Box) IsBiggerThan(other Box) bool {
return b.Top < other.Top ||
b.Bottom > other.Bottom ||
b.Left < other.Left ||
b.Right > other.Right
}
// IsSmallerThan returns if a box is smaller than another box.
func (b Box) IsSmallerThan(other Box) bool {
return b.Top > other.Top &&
b.Bottom < other.Bottom &&
b.Left > other.Left &&
b.Right < other.Right
}
// Equals returns if the box equals another box.
func (b Box) Equals(other Box) bool {
return b.Top == other.Top &&
b.Left == other.Left &&
b.Right == other.Right &&
b.Bottom == other.Bottom
}
// Grow grows a box based on another box.
func (b Box) Grow(other Box) Box {
return Box{
Top: util.Math.MinInt(b.Top, other.Top),
Left: util.Math.MinInt(b.Left, other.Left),
Right: util.Math.MaxInt(b.Right, other.Right),
Bottom: util.Math.MaxInt(b.Bottom, other.Bottom),
}
}
// Shift pushes a box by x,y.
func (b Box) Shift(x, y int) Box {
return Box{
Top: b.Top + y,
Left: b.Left + x,
Right: b.Right + x,
Bottom: b.Bottom + y,
}
}
// Corners returns the box as a set of corners.
func (b Box) Corners() BoxCorners {
return BoxCorners{
TopLeft: Point{b.Left, b.Top},
TopRight: Point{b.Right, b.Top},
BottomRight: Point{b.Right, b.Bottom},
BottomLeft: Point{b.Left, b.Bottom},
}
}
// Fit is functionally the inverse of grow.
// Fit maintains the original aspect ratio of the `other` box,
// but constrains it to the bounds of the target box.
func (b Box) Fit(other Box) Box {
ba := b.Aspect()
oa := other.Aspect()
if oa == ba {
return b.Clone()
}
bw, bh := float64(b.Width()), float64(b.Height())
bw2 := int(bw) >> 1
bh2 := int(bh) >> 1
if oa > ba { // ex. 16:9 vs. 4:3
var noh2 int
if oa > 1.0 {
noh2 = int(bw/oa) >> 1
} else {
noh2 = int(bh*oa) >> 1
}
return Box{
Top: (b.Top + bh2) - noh2,
Left: b.Left,
Right: b.Right,
Bottom: (b.Top + bh2) + noh2,
}
}
var now2 int
if oa > 1.0 {
now2 = int(bh/oa) >> 1
} else {
now2 = int(bw*oa) >> 1
}
return Box{
Top: b.Top,
Left: (b.Left + bw2) - now2,
Right: (b.Left + bw2) + now2,
Bottom: b.Bottom,
}
}
// Constrain is similar to `Fit` except that it will work
// more literally like the opposite of grow.
func (b Box) Constrain(other Box) Box {
newBox := b.Clone()
newBox.Top = util.Math.MaxInt(newBox.Top, other.Top)
newBox.Left = util.Math.MaxInt(newBox.Left, other.Left)
newBox.Right = util.Math.MinInt(newBox.Right, other.Right)
newBox.Bottom = util.Math.MinInt(newBox.Bottom, other.Bottom)
return newBox
}
// OuterConstrain is similar to `Constraint` with the difference
// that it applies corrections
func (b Box) OuterConstrain(bounds, other Box) Box {
newBox := b.Clone()
if other.Top < bounds.Top {
delta := bounds.Top - other.Top
newBox.Top = b.Top + delta
}
if other.Left < bounds.Left {
delta := bounds.Left - other.Left
newBox.Left = b.Left + delta
}
if other.Right > bounds.Right {
delta := other.Right - bounds.Right
newBox.Right = b.Right - delta
}
if other.Bottom > bounds.Bottom {
delta := other.Bottom - bounds.Bottom
newBox.Bottom = b.Bottom - delta
}
return newBox
}
// BoxCorners is a box with independent corners.
type BoxCorners struct {
TopLeft, TopRight, BottomRight, BottomLeft Point
}
// Box return the BoxCorners as a regular box.
func (bc BoxCorners) Box() Box {
return Box{
Top: util.Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y),
Left: util.Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X),
Right: util.Math.MaxInt(bc.TopRight.X, bc.BottomRight.X),
Bottom: util.Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y),
}
}
// Width returns the width
func (bc BoxCorners) Width() int {
minLeft := util.Math.MinInt(bc.TopLeft.X, bc.BottomLeft.X)
maxRight := util.Math.MaxInt(bc.TopRight.X, bc.BottomRight.X)
return maxRight - minLeft
}
// Height returns the height
func (bc BoxCorners) Height() int {
minTop := util.Math.MinInt(bc.TopLeft.Y, bc.TopRight.Y)
maxBottom := util.Math.MaxInt(bc.BottomLeft.Y, bc.BottomRight.Y)
return maxBottom - minTop
}
// Center returns the center of the box
func (bc BoxCorners) Center() (x, y int) {
left := util.Math.MeanInt(bc.TopLeft.X, bc.BottomLeft.X)
right := util.Math.MeanInt(bc.TopRight.X, bc.BottomRight.X)
x = ((right - left) >> 1) + left
top := util.Math.MeanInt(bc.TopLeft.Y, bc.TopRight.Y)
bottom := util.Math.MeanInt(bc.BottomLeft.Y, bc.BottomRight.Y)
y = ((bottom - top) >> 1) + top
return
}
// Rotate rotates the box.
func (bc BoxCorners) Rotate(thetaDegrees float64) BoxCorners {
cx, cy := bc.Center()
thetaRadians := util.Math.DegreesToRadians(thetaDegrees)
tlx, tly := util.Math.RotateCoordinate(cx, cy, bc.TopLeft.X, bc.TopLeft.Y, thetaRadians)
trx, try := util.Math.RotateCoordinate(cx, cy, bc.TopRight.X, bc.TopRight.Y, thetaRadians)
brx, bry := util.Math.RotateCoordinate(cx, cy, bc.BottomRight.X, bc.BottomRight.Y, thetaRadians)
blx, bly := util.Math.RotateCoordinate(cx, cy, bc.BottomLeft.X, bc.BottomLeft.Y, thetaRadians)
return BoxCorners{
TopLeft: Point{tlx, tly},
TopRight: Point{trx, try},
BottomRight: Point{brx, bry},
BottomLeft: Point{blx, bly},
}
}
// Equals returns if the box equals another box.
func (bc BoxCorners) Equals(other BoxCorners) bool {
return bc.TopLeft.Equals(other.TopLeft) &&
bc.TopRight.Equals(other.TopRight) &&
bc.BottomRight.Equals(other.BottomRight) &&
bc.BottomLeft.Equals(other.BottomLeft)
}
func (bc BoxCorners) String() string {
return fmt.Sprintf("BoxC{%s,%s,%s,%s}", bc.TopLeft.String(), bc.TopRight.String(), bc.BottomRight.String(), bc.BottomLeft.String())
}
// Point is an X,Y pair
type Point struct {
X, Y int
}
// DistanceTo calculates the distance to another point.
func (p Point) DistanceTo(other Point) float64 {
dx := math.Pow(float64(p.X-other.X), 2)
dy := math.Pow(float64(p.Y-other.Y), 2)
return math.Pow(dx+dy, 0.5)
}
// Equals returns if a point equals another point.
func (p Point) Equals(other Point) bool {
return p.X == other.X && p.Y == other.Y
}
// String returns a string representation of the point.
func (p Point) String() string {
return fmt.Sprintf("P{%d,%d}", p.X, p.Y)
}