From 590d870f56eaefb43c6cf08f72f3dcba2b4ccd20 Mon Sep 17 00:00:00 2001
From: Yongwei Xing <yongwei.xing@liulishuo.com>
Date: Mon, 5 Jul 2021 15:07:08 +0800
Subject: [PATCH] support multiple images generation with time lapse for
 domainwrap

---
 arts/domainwrap.go             | 33 +++++++++++++++++++++++++++++++++
 example/example_domainwrap2.go | 30 ++++++++++++++++++++++++++++++
 generativeart.go               |  8 ++++++--
 3 files changed, 69 insertions(+), 2 deletions(-)
 create mode 100644 example/example_domainwrap2.go

diff --git a/arts/domainwrap.go b/arts/domainwrap.go
index a1196cd..63c81f6 100644
--- a/arts/domainwrap.go
+++ b/arts/domainwrap.go
@@ -1,9 +1,11 @@
 package arts
 
 import (
+	"fmt"
 	"github.com/jdxyw/generativeart"
 	"github.com/jdxyw/generativeart/common"
 	"image/color"
+	"log"
 )
 
 // ColorMapping maps some parameters to color space.
@@ -15,6 +17,12 @@ type domainWrap struct {
 	scale2           float64
 	xOffset, yOffset float64
 	fn               ColorMapping
+	// How many images would be created in this generation.
+	numImages int
+	// Use these parameters to create images with time lapse.
+	xOffsetStep, yOffsetStep float64
+	// The imagPath for generative images.
+	imgPath string
 }
 
 // NewDomainWrap returns a domainWrap object.
@@ -29,9 +37,34 @@ func NewDomainWrap(scale, scale2, xOffset, yOffset float64, cmap ColorMapping) *
 	}
 }
 
+func (d *domainWrap) SetDynamicParameter(xstep, ystep float64, n int, path string) {
+	d.xOffsetStep = xstep
+	d.yOffsetStep = ystep
+	d.numImages = n
+	d.imgPath = path
+}
+
 // Generative draws a domain warp image.
 // Reference: https://www.iquilezles.org/www/articles/warp/warp.htm
 func (d *domainWrap) Generative(c *generativeart.Canva) {
+	if d.numImages == 0 && len(d.imgPath) == 0 {
+		d.generative(c)
+		return
+	}
+
+	if d.numImages > 0 && len(d.imgPath) == 0 {
+		log.Fatal("Missing the parameters numImages or imgPath")
+	}
+	for i := 0; i < d.numImages; i++ {
+		imgfile := fmt.Sprintf("%v/domainwrap%03d.PNG", d.imgPath, i)
+		d.xOffset += d.xOffsetStep * float64(i)
+		d.yOffset += d.yOffsetStep * float64(i)
+		d.generative(c)
+		c.ToPNG(imgfile)
+	}
+}
+
+func (d *domainWrap) generative(c *generativeart.Canva) {
 	for h := 0.0; h < float64(c.Height()); h += 1.0 {
 		for w := 0.0; w < float64(c.Width()); w += 1.0 {
 			r, m1, m2 := d.pattern(w*d.scale, h*d.scale, d.xOffset, d.yOffset)
diff --git a/example/example_domainwrap2.go b/example/example_domainwrap2.go
new file mode 100644
index 0000000..c727a4d
--- /dev/null
+++ b/example/example_domainwrap2.go
@@ -0,0 +1,30 @@
+package main
+
+import (
+	"github.com/jdxyw/generativeart"
+	"github.com/jdxyw/generativeart/arts"
+	"github.com/jdxyw/generativeart/common"
+	"image/color"
+	"math/rand"
+	"time"
+)
+
+func cmap(r, m1, m2 float64) color.RGBA {
+	rgb := color.RGBA{
+		R: uint8(common.Constrain(m1*200*r, 0, 255)),
+		G: uint8(common.Constrain(r*200, 0, 255)),
+		B: uint8(common.Constrain(m2*255*r, 70, 255)),
+		A: 255,
+	}
+	return rgb
+}
+
+func main() {
+	rand.Seed(time.Now().Unix())
+	c := generativeart.NewCanva(500, 500)
+	c.SetBackground(common.Black)
+	c.FillBackground()
+	d := arts.NewDomainWrap(0.01, 4, 4, 20, cmap)
+	d.SetDynamicParameter(0.005, 0, 100, "./temp")
+	c.Draw(d)
+}
diff --git a/generativeart.go b/generativeart.go
index 9fc30a8..c3145c4 100644
--- a/generativeart.go
+++ b/generativeart.go
@@ -131,6 +131,10 @@ func (c *Canva) Draw(e Engine) {
 	e.Generative(c)
 }
 
+func (c *Canva) DrawTimelapse(e Engine) {
+
+}
+
 // FillBackground fills the background of the Canva.
 func (c *Canva) FillBackground() {
 	draw.Draw(c.Img(), c.Img().Bounds(), &image.Uniform{c.Opts().Background()}, image.ZP, draw.Src)
@@ -142,12 +146,12 @@ func (c *Canva) ToPNG(fpath string) error {
 	if err != nil {
 		return err
 	}
-	if err := png.Encode(f, c.Img()); err != nil {
+	if err = png.Encode(f, c.Img()); err != nil {
 		f.Close()
 		return err
 	}
 
-	if err := f.Close(); err != nil {
+	if err = f.Close(); err != nil {
 		return err
 	}