generativeart/arts/circleline.go

58 lines
1.2 KiB
Go

package arts
import (
"github.com/fogleman/gg"
"github.com/jdxyw/generativeart"
"github.com/jdxyw/generativeart/common"
"math"
"math/rand"
)
type point struct {
x, y float64
}
type circleLine struct {
step float64
lineNum int
radius float64
xaixs, yaixs float64
}
// NewCircleLine returns a circleLine object.
func NewCircleLine(step float64, lineNum int, radius, xaixs, yaixs float64) *circleLine {
return &circleLine{
step: step,
lineNum: lineNum,
radius: radius,
xaixs: xaixs,
yaixs: yaixs,
}
}
// Generative draws a cirle line image.
func (cl *circleLine) Generative(c *generativeart.Canva) {
ctex := gg.NewContextForRGBA(c.Img())
ctex.SetLineWidth(c.Opts().LineWidth())
ctex.SetColor(c.Opts().LineColor())
var points []point
for theta := -math.Pi; theta <= math.Pi; theta += cl.step {
x := cl.radius * math.Cos(theta)
y := cl.radius * math.Sin(theta)
xi, yi := common.ConvertCartesianToPixel(x, y, cl.xaixs, cl.yaixs, c.Width(), c.Height())
points = append(points, point{
x: float64(xi),
y: float64(yi),
})
}
for i := 0; i < cl.lineNum; i++ {
p1 := points[rand.Intn(len(points))]
p2 := points[rand.Intn(len(points))]
ctex.MoveTo(p1.x, p1.y)
ctex.LineTo(p2.x, p2.y)
ctex.Stroke()
}
}