add circle grid

README.md

@@ -25,6 +25,7 @@ This package is still working in progress, more types would be added. Welcome an
 - Random Shapes
 - Color Circle
 - Color Circle2
+- Circle Grid
 
 For these kinds of art, the package provides as many as parameters to control the appearance.
 
@@ -53,6 +54,7 @@ NewJanus(n int, decay float64)
 NewRandomShape(shapeNum int)
 NewColorCircle(circleNum int)
 NewColorCircle2(circleNum int)
+NewCircleGrid(circleNumMin, circleNumMax int)
 ```
 
 ## General Options
@@ -136,6 +138,31 @@ func main() {
 
 ![](images/colorcircle2.png)
 
+### Circle Grid
+
+```go
+func main() {
+	rand.Seed(time.Now().Unix())
+	colors := []color.RGBA{
+		{0xED, 0x34, 0x41, 0xFF},
+		{0xFF, 0xD6, 0x30, 0xFF},
+		{0x32, 0x9F, 0xE3, 0xFF},
+		{0x15, 0x42, 0x96, 0xFF},
+		{0x00, 0x00, 0x00, 0xFF},
+		{0xFF, 0xFF, 0xFF, 0xFF},
+	}
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(color.RGBA{0xDF, 0xEB, 0xF5, 0xFF})
+	c.FillBackground()
+	c.SetColorSchema(colors)
+	c.SetLineWidth(2.0)
+	c.Draw(generativeart.NewCircleGrid(4, 6))
+	c.ToPNG("circlegrid.png")
+}
+```
+
+![](images/circlegrid.png)
+
 ### Silk Smoke
 
 ```go

circlegrid.go

@@ -0,0 +1,106 @@
+package generativeart
+
+import (
+	"github.com/fogleman/gg"
+	"image/color"
+	"math"
+	"math/rand"
+)
+
+type circleGrid struct {
+	circleNumMin, circleNumMax int
+}
+
+// NewCircleGrid returns a circleGrid object.
+func NewCircleGrid(circleNumMin, circleNumMax int) *circleGrid {
+	return &circleGrid{
+		circleNumMin: circleNumMin,
+		circleNumMax: circleNumMax,
+	}
+}
+
+// Generative draws a circle grid image.
+func (cg *circleGrid) Generative(c *canva) {
+	ctex := gg.NewContextForRGBA(c.img)
+	cg.grid(ctex, c)
+	ctex.Translate(float64(c.width)/2, float64(c.height)/2)
+	ctex.Scale(0.9, 0.9)
+	ctex.Translate(-float64(c.width)/2, -float64(c.height)/2)
+
+	seg := RandomRangeInt(cg.circleNumMin, cg.circleNumMax)
+	w := float64(c.width) / float64(seg)
+
+	for i := 0; i < seg; i++ {
+		for j := 0; j < seg; j++ {
+			x := float64(i)*w + w/2
+			y := float64(j)*w + w/2
+			ctex.SetColor(c.opts.colorSchema[rand.Intn(len(c.opts.colorSchema))])
+			ctex.DrawCircle(x, y, w/2*RandomRangeFloat64(0.1, 0.5))
+			ctex.Fill()
+			cg.draw(ctex, c, x, y, w/2*RandomRangeFloat64(0.6, 0.95))
+		}
+	}
+}
+
+func (cg *circleGrid) draw(ctex *gg.Context, c *canva, x, y, r float64) {
+	rnd := rand.Intn(4)
+	col := c.opts.colorSchema[rand.Intn(len(c.opts.colorSchema))]
+	ctex.Push()
+	ctex.Translate(x, y)
+	ctex.Rotate(float64(rand.Intn(10)))
+	ctex.SetColor(col)
+	ctex.SetLineWidth(c.opts.lineWidth)
+
+	switch rnd {
+	case 0:
+		ctex.DrawCircle(0, 0, r)
+		ctex.Stroke()
+	case 1:
+		n := RandomRangeInt(1, 4) * 2
+		ctex.DrawCircle(0, 0, r)
+		ctex.Stroke()
+		for i := 0; i < n; i++ {
+			ctex.Rotate(math.Pi * 2 / float64(n))
+			ctex.DrawCircle(r, 0, r*0.1)
+			ctex.Fill()
+		}
+	case 2:
+		n := RandomRangeInt(8, 20)
+		theta := math.Pi * 0.5 * float64(RandomRangeInt(1, 5))
+		for i := 0; i < n; i++ {
+			d := float64(i) / float64(n)
+			if d > r*0.1 {
+				d = r * 0.1
+			}
+			ctex.Rotate(theta / float64(n))
+			ctex.DrawCircle(r/2, 0, d*2)
+			ctex.Fill()
+		}
+	case 3:
+		n := RandomRangeInt(5, 20)
+		for i := 0; i < n; i++ {
+			ctex.Rotate(math.Pi * 2 / float64(n))
+			ctex.DrawLine(r/2, 0, (r*2/3)-(r*0.05), 0)
+			ctex.Stroke()
+		}
+
+	}
+	ctex.Pop()
+}
+
+func (cg *circleGrid) grid(ctex *gg.Context, c *canva) {
+	var segment int = 100
+	w := float64(c.width) / float64(segment)
+
+	ctex.SetColor(color.RGBA{255, 255, 255, 255})
+	ctex.SetLineWidth(0.6)
+	for i := 0; i < segment; i++ {
+		ctex.DrawLine(0, float64(i)*w, float64(c.width), float64(i)*w)
+		ctex.Stroke()
+	}
+
+	for j := 0; j < segment; j++ {
+		ctex.DrawLine(float64(j)*w, 0, float64(j)*w, float64(c.height))
+		ctex.Stroke()
+	}
+}

example/example_circlegrid.go

@@ -0,0 +1,27 @@
+package main
+
+import (
+	"github.com/jdxyw/generativeart"
+	"image/color"
+	"math/rand"
+	"time"
+)
+
+func main() {
+	rand.Seed(time.Now().Unix())
+	colors := []color.RGBA{
+		{0xED, 0x34, 0x41, 0xFF},
+		{0xFF, 0xD6, 0x30, 0xFF},
+		{0x32, 0x9F, 0xE3, 0xFF},
+		{0x15, 0x42, 0x96, 0xFF},
+		{0x00, 0x00, 0x00, 0xFF},
+		{0xFF, 0xFF, 0xFF, 0xFF},
+	}
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(color.RGBA{0xDF, 0xEB, 0xF5, 0xFF})
+	c.FillBackground()
+	c.SetColorSchema(colors)
+	c.SetLineWidth(2.0)
+	c.Draw(generativeart.NewCircleGrid(4, 6))
+	c.ToPNG("circlegrid.png")
+}