add yarn; update readme

README.md

@@ -71,6 +71,7 @@ This package is still working in progress. More types would be added. Welcome an
 - Dots Wave
 - Circle Move
 - Circle Noise
+- Yarn
 
 For these kinds of art, the package provides as many parameters to control the appearance.
 
@@ -107,6 +108,7 @@ NewPixelHole(dotN int)
 NewDotsWave(dotsN int)
 NewCircleMove(circleNum int)
 NewCircleNoise(dotsN, colorMin, colorMax int)
+NewYarn(n int)
 ```
 
 ## Docs
@@ -137,6 +139,8 @@ For those parameters specified for different kinds of art types, they have their
 
 ## Usage and example
 
+Below are some selective examples. For more examples, you could check the example folder.
+
 ### Junas
 
 ```go

arts/yarn.go

@@ -0,0 +1,44 @@
+package arts
+
+import (
+	"github.com/fogleman/gg"
+	"github.com/jdxyw/generativeart"
+	"github.com/jdxyw/generativeart/common"
+)
+
+type yarn struct {
+	n int
+}
+
+// NewYarn returns a yarn object.
+func NewYarn(n int) *yarn {
+	return &yarn{
+		n: n,
+	}
+}
+
+// Generative draws a yarn image.
+func (y *yarn) Generative(c *generativeart.Canva) {
+	ctex := gg.NewContextForRGBA(c.Img())
+	ctex.SetLineWidth(c.Opts().LineWidth())
+	ctex.SetColor(c.Opts().LineColor())
+	noise := common.NewPerlinNoise()
+
+	var offset = 0.0
+	var inc = 0.005
+	for i := 0; i < y.n; i++ {
+		x0 := float64(c.Width()) * noise.Noise1D(offset+15)
+		x1 := float64(c.Width()) * noise.Noise1D(offset+25)
+		x2 := float64(c.Width()) * noise.Noise1D(offset+35)
+		x3 := float64(c.Width()) * noise.Noise1D(offset+45)
+		y0 := float64(c.Height()) * noise.Noise1D(offset+55)
+		y1 := float64(c.Height()) * noise.Noise1D(offset+65)
+		y2 := float64(c.Height()) * noise.Noise1D(offset+75)
+		y3 := float64(c.Height()) * noise.Noise1D(offset+85)
+		ctex.MoveTo(x0, y0)
+		ctex.CubicTo(x1, y1, x2, y2, x3, y3)
+		ctex.Stroke()
+		ctex.ClearPath()
+		offset += inc
+	}
+}

docs/doc.md

@@ -1,3 +1,37 @@
+# Table of Contents
+
+- [Table of Contents](#table-of-contents)
+	- [Color Circle 2](#color-circle-2)
+		- [parameters](#parameters)
+	- [Dot Line](#dot-line)
+		- [parameters](#parameters-1)
+	- [Random Shape](#random-shape)
+		- [parameters](#parameters-2)
+	- [Janus](#janus)
+		- [TODO](#todo)
+		- [parameters](#parameters-3)
+	- [Contour Line](#contour-line)
+		- [parameters](#parameters-4)
+	- [Silk Sky](#silk-sky)
+		- [parameters](#parameters-5)
+	- [Julia](#julia)
+		- [parameters](#parameters-6)
+	- [Noise Line](#noise-line)
+		- [parameters](#parameters-7)
+	- [Ocean Fish](#ocean-fish)
+		- [parameters](#parameters-8)
+	- [Circle Loop2](#circle-loop2)
+		- [parameters](#parameters-9)
+	- [Pixel Hole](#pixel-hole)
+		- [parameters](#parameters-10)
+	- [Dots Wave](#dots-wave)
+		- [parameters](#parameters-11)
+	- [Circle Move](#circle-move)
+		- [parameters](#parameters-12)
+	- [Circle Noise](#circle-noise)
+		- [parameters](#parameters-13)
+	- [Yarn](#yarn)
+		- [parameters](#parameters-14)
 ## Color Circle 2
 
 `Color Circle2` is version 2 of `Color Circle`. It still draws the circle and point cloud.
@@ -7,7 +41,7 @@
 - circleNum: The number of the circle in this drawing.
 
 ```go
-cc := generativeart.NewColorCircle2(30)
+cc := arts.NewColorCircle2(30)
 ```
 
 ![](../images/colorcircle2.png)
@@ -23,7 +57,7 @@ cc := generativeart.NewColorCircle2(30)
 - randColor: Use the specified color or random colors.
 
 ```go
-dl := generativeart.NewDotLine(100, 20, 50, false)
+dl := arts.NewDotLine(100, 20, 50, false)
 ```
 
 ![](../images/dotline.png)
@@ -90,7 +124,7 @@ func julia1(z complex128) complex128 {
 	z = z*z + c
 	return z
 }
-julia := generativeart.NewJulia(julia1, 40, 1.5, 1.5)
+julia := arts.NewJulia(julia1, 40, 1.5, 1.5)
 ```
 
 ![](../images/julia.png)
@@ -104,7 +138,7 @@ julia := generativeart.NewJulia(julia1, 40, 1.5, 1.5)
 - n: The number of random line.
 
 ```go
-nl := generativeart.NewNoiseLine(1000)
+nl := arts.NewNoiseLine(1000)
 ```
 
 ![](../images/noiseline.png)
@@ -119,7 +153,7 @@ nl := generativeart.NewNoiseLine(1000)
 - fishNum: The number of fish.
 
 ```go
-o := generativeart.NewOceanFish(100, 8)
+o := arts.NewOceanFish(100, 8)
 ```
 
 ![](../images/oceanfish.png)
@@ -133,7 +167,7 @@ o := generativeart.NewOceanFish(100, 8)
 - depth: Control the number of circles.
 
 ```go
-cl := generativeart.NewCircleLoop2(7)
+cl := arts.NewCircleLoop2(7)
 ```
 
 ![](../images/colorloop2.png)
@@ -147,7 +181,7 @@ cl := generativeart.NewCircleLoop2(7)
 - dotN: The number of point in each iteration.
 
 ```go
-ph := generativeart.NewPixelHole(60)
+ph := arts.NewPixelHole(60)
 ```
 
 ![](../images/pixelhole.png)
@@ -159,7 +193,7 @@ ph := generativeart.NewPixelHole(60)
 - dotsN: The number of dots wave in the image.
 
 ```go
-d := generativeart.NewDotsWave(300)
+d := arts.NewDotsWave(300)
 ```
 
 ![](../images/dotswave.png)
@@ -172,12 +206,12 @@ d := generativeart.NewDotsWave(300)
 
 
 ```go
-cm := generativeart.NewCircleMove(1000)
+cm := arts.NewCircleMove(1000)
 ```
 
 ![](../images/circlemove.png)
 
-### Circle Noise
+## Circle Noise
 
 ### parameters
 
@@ -186,3 +220,15 @@ cm := generativeart.NewCircleMove(1000)
 - colorMax: The maximum color.
 
 ![](../images/circlenoise.png)
+
+## Yarn
+
+### parameters
+
+- n: The number of curve.
+
+```go
+y := arts.NewYarn(2000)
+```
+
+![](../images/yarn.png)

example/example_yarn.go

@@ -0,0 +1,21 @@
+package main
+
+import (
+	"github.com/jdxyw/generativeart"
+	"github.com/jdxyw/generativeart/arts"
+	"github.com/jdxyw/generativeart/common"
+	"image/color"
+	"math/rand"
+	"time"
+)
+
+func main() {
+	rand.Seed(time.Now().Unix())
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(common.Orange)
+	c.FillBackground()
+	c.SetLineWidth(0.3)
+	c.SetLineColor(color.RGBA{A: 60})
+	c.Draw(arts.NewYarn(2000))
+	c.ToPNG("yarn.png")
+}