add random shapes and update the readme

README.md

@@ -20,6 +20,7 @@
 - Swirl
 - Point Ribbon
 - Janus
+- Random Shapes
 
 For these kinds of art, the package provides as many as parameters to control the appearance. 
 
@@ -45,6 +46,7 @@ NewSwirl(a, b, c, d, xaixs, yaixs float64)
 NewDotLine(n int, ras, canv float64, randColor bool)
 NewPointRibbon(r float64)
 NewJanus(n int, decay float64)
+NewRandomShape(shapeNum int)
 ```
 
 ## General Options
@@ -86,6 +88,28 @@ func main() {
 
 ![](images/silksmoke.png)
 
+### Random Shapes
+
+```go
+func main() {
+	rand.Seed(time.Now().Unix())
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(generativeart.White)
+	c.FillBackground()
+	c.SetColorSchema([]color.RGBA{
+		{0xCF, 0x2B, 0x34, 0xFF},
+		{0xF0, 0x8F, 0x46, 0xFF},
+		{0xF0, 0xC1, 0x29, 0xFF},
+		{0x19, 0x6E, 0x94, 0xFF},
+		{0x35, 0x3A, 0x57, 0xFF},
+	})
+	c.Draw(generativeart.NewRandomShape(150))
+	c.ToPNG("randomshape.png")
+}
+```
+
+![](images/randomshape.png)
+
 ### Spiral Square
 
 ```go
@@ -140,6 +164,8 @@ func main() {
 }
 ```
 
+![](images/dotline.png)
+
 ### Junas
 
 ```go
@@ -157,7 +183,6 @@ func main() {
 
 ![](images/janus.png)
 
-![](images/dotline.png)
 
 ### Julia Set
 
@@ -213,23 +238,6 @@ func main() {
 
 ![](images/pointribbon.png)
 
-### Circle Line
-
-```go
-func main() {
-	rand.Seed(time.Now().Unix())
-	c := generativeart.NewCanva(600, 600)
-	c.SetBackground(generativeart.Tan)
-	c.SetLineWidth(1.0)
-	c.SetLineColor(generativeart.LightPink)
-	c.FillBackground()
-	c.Draw(generativeart.NewCircleLine(0.02, 600, 1.5, 2, 2))
-	c.ToPNG("circleline.png")
-}
-```
-
-![](images/circleline.png)
-
 ### Maze
 
 ```go
@@ -291,3 +299,4 @@ Thanks for the following sites and repos, I got lots of ideas, inspiration, code
 - http://paulbourke.net/fractals/peterdejong/
 - https://editor.p5js.org/kenekk1/sketches/O44Dln5oo
 - https://openprocessing.org/sketch/1071233
+- https://twitter.com/okazz_

example/example_randomshape.go

@@ -0,0 +1,24 @@
+package main
+
+import (
+	"github.com/jdxyw/generativeart"
+	"image/color"
+	"math/rand"
+	"time"
+)
+
+func main() {
+	rand.Seed(time.Now().Unix())
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(generativeart.White)
+	c.FillBackground()
+	c.SetColorSchema([]color.RGBA{
+		{0xCF, 0x2B, 0x34, 0xFF},
+		{0xF0, 0x8F, 0x46, 0xFF},
+		{0xF0, 0xC1, 0x29, 0xFF},
+		{0x19, 0x6E, 0x94, 0xFF},
+		{0x35, 0x3A, 0x57, 0xFF},
+	})
+	c.Draw(generativeart.NewRandomShape(150))
+	c.ToPNG("randomshape.png")
+}

randomshape.go

@@ -0,0 +1,58 @@
+package generativeart
+
+import (
+	"github.com/fogleman/gg"
+	"math"
+	"math/rand"
+)
+
+type randomShape struct {
+	shapeNum int
+}
+
+func NewRandomShape(shapeNum int) *randomShape {
+	return &randomShape{
+		shapeNum: shapeNum,
+	}
+}
+
+// Generative draws a random shape image.
+func (r *randomShape) Generative(c *canva) {
+	ctex := gg.NewContextForRGBA(c.img)
+
+	ctex.Translate(float64(c.width/2), float64(c.height/2))
+	ctex.Rotate(RandomRangeFloat64(-1, 1) * math.Pi * 0.25)
+	ctex.Translate(-float64(c.width/2), -float64(c.height/2))
+
+	for i := 0; i < r.shapeNum; i++ {
+		x := RandomGaussian(0.5, 0.2) * float64(c.width)
+		y := RandomGaussian(0.5, 0.2) * float64(c.height)
+
+		w := RandomRangeFloat64(0, float64(c.width)/3)*RandomRangeFloat64(0, rand.Float64()) + 5.0
+		h := w + RandomRangeFloat64(-1, 1)*3.0
+
+		rnd := rand.Intn(4)
+		theta := math.Pi * 2.0 * float64(rand.Intn(4)) / 4
+
+		ctex.Push()
+		ctex.Translate(x, y)
+		ctex.Rotate(theta)
+		ctex.SetColor(c.opts.colorSchema[rand.Intn(len(c.opts.colorSchema))])
+		switch rnd {
+		case 0:
+			ctex.DrawCircle(0, 0, w/2)
+		case 1:
+			ctex.DrawRectangle(0, 0, w/2, w/2)
+		case 2:
+			if rand.Float64() < 0.5 {
+				ctex.DrawEllipse(0, 0, w/2, h/2)
+			} else {
+				ctex.DrawRectangle(0, 0, w, h)
+			}
+		case 3:
+			ctex.DrawRectangle(0, 0, w*2, RandomRangeFloat64(2, 10))
+		}
+		ctex.Fill()
+		ctex.Pop()
+	}
+}

utils.go

@@ -122,3 +122,7 @@ func RandomRangeInt(min, max int) int {
 func RandomRangeFloat64(min, max float64) float64 {
 	return min + rand.Float64()*(max-min)
 }
+
+func RandomGaussian(mean, std float64) float64 {
+	return rand.NormFloat64()*std + mean
+}