From e6decd968c66a398b3b571c8179e80c56c97385f Mon Sep 17 00:00:00 2001
From: Yongwei Xing <yongwei.xing@liulishuo.com>
Date: Fri, 26 Feb 2021 17:23:56 +0800
Subject: [PATCH] add some other colors

---
 color.go           | 31 +++++++++++++++++++++----------
 example/example.go | 10 +++++-----
 utils.go           | 26 ++++----------------------
 wave.go            |  4 ++--
 4 files changed, 32 insertions(+), 39 deletions(-)

diff --git a/color.go b/color.go
index 6db9412..bc7c709 100644
--- a/color.go
+++ b/color.go
@@ -2,13 +2,24 @@ package generativeart
 
 import "image/color"
 
-var MistyRose = color.RGBA{0xFF, 0xE4, 0xE1, 0xFF}
-var DarkSalmon = color.RGBA{0xE9, 0x96, 0x7A, 0xFF}
-var Tan = color.RGBA{0xD2, 0xB4, 0x8C, 0xFF}
-var Bisque = color.RGBA{0xFF, 0xE4, 0xC4, 0xFF}
-var Mintcream = color.RGBA{0xF5, 0xFF, 0xFA, 0xFF}
-var Aquamarine = color.RGBA{0x7F, 0xFF, 0xD4, 0xFF}
-var Azure = color.RGBA{0xF0, 0xFF, 0xFF, 0xFF}
-var Lavender = color.RGBA{0xE6, 0xE6, 0xFA, 0xFF}
-var Plum = color.RGBA{0xDD, 0xA0, 0xDD, 0xFF}
-var AntiqueWhite = color.RGBA{0xFA, 0xEB, 0xD7, 0xFF}
+var (
+	MistyRose        = color.RGBA{0xFF, 0xE4, 0xE1, 0xFF}
+	DarkSalmon       = color.RGBA{0xE9, 0x96, 0x7A, 0xFF}
+	Tan              = color.RGBA{0xD2, 0xB4, 0x8C, 0xFF}
+	Bisque           = color.RGBA{0xFF, 0xE4, 0xC4, 0xFF}
+	Mintcream        = color.RGBA{0xF5, 0xFF, 0xFA, 0xFF}
+	Aquamarine       = color.RGBA{0x7F, 0xFF, 0xD4, 0xFF}
+	Azure            = color.RGBA{0xF0, 0xFF, 0xFF, 0xFF}
+	Lavender         = color.RGBA{0xE6, 0xE6, 0xFA, 0xFF}
+	Plum             = color.RGBA{0xDD, 0xA0, 0xDD, 0xFF}
+	AntiqueWhite     = color.RGBA{0xFA, 0xEB, 0xD7, 0xFF}
+	NavajoWhite      = color.RGBA{0xFF, 0xDE, 0xAD, 0xFF}
+	Moccasin         = color.RGBA{0xFF, 0xE4, 0xB5, 0xFF}
+	MediumAquamarine = color.RGBA{0x66, 0xCD, 0xAA, 0xFF}
+	PaleTurquoise    = color.RGBA{0xAF, 0xEE, 0xEE, 0xFF}
+	LightPink        = color.RGBA{0xFF, 0xB6, 0xC1, 0xFF}
+	Tomato           = color.RGBA{0xFF, 0x63, 0x47, 0xFF}
+	Orange           = color.RGBA{0xFF, 0xA5, 0x00, 0xFF}
+	Black            = color.RGBA{0x00, 0x00, 0x00, 0xFF}
+	White            = color.RGBA{0xFF, 0xFF, 0xFF, 0xFF}
+)
diff --git a/example/example.go b/example/example.go
index 2425cda..5adaa95 100644
--- a/example/example.go
+++ b/example/example.go
@@ -6,14 +6,14 @@ import (
 )
 
 func formula1(x, y float64) (float64, float64) {
-	return -0.13*x*x - math.Sin(y*y) + math.Cos(x*y),
-		-0.96*y*y*y - math.Cos(x*x)
+	return 0.18*x*x - math.Sin(y*y),
+		0.059*y*y*y - math.Cos(x*x)
 }
 
 func main() {
-	c := generativeart.NewCanva(800, 800, 4, 4)
-	c.FillBackgroud(generativeart.AntiqueWhite)
+	c := generativeart.NewCanva(1600, 1600, 4, 4)
+	c.FillBackgroud(generativeart.Tomato)
 	g := generativeart.NewWave(formula1)
-	g.GenerativePolar(c, generativeart.DarkSalmon)
+	g.GenerativePolar(c, generativeart.Black)
 	c.ToPng("g1.png")
 }
diff --git a/utils.go b/utils.go
index 24d275d..f26fa7e 100644
--- a/utils.go
+++ b/utils.go
@@ -5,17 +5,8 @@ import "math"
 func ConvertCartesianToPixel(x, y, xaixs, yaixs float64, h, w int) (int, int) {
 	xr, yr := x/xaixs, y/yaixs
 	var i, j int
-	if xr > 0 {
-		i = w/2 + int(float64(w)/2*xr)
-	} else {
-		i = w/2 + int(float64(w)/2*xr)
-	}
-
-	if yr > 0 {
-		j = h/2 + int(float64(h)/2*yr)
-	} else {
-		j = h/2 + int(float64(h)/2*yr)
-	}
+	i = w/2 + int(float64(w)/2*xr)
+	j = h/2 + int(float64(h)/2*yr)
 
 	return i, j
 }
@@ -37,17 +28,8 @@ func ConvertPolarToPixel(r, theta, xaixs, yaixs float64, h, w int) (int, int) {
 
 	xr, yr := x/xaixs, y/yaixs
 	var i, j int
-	if xr > 0 {
-		i = w/2 + int(float64(w)/2*xr)
-	} else {
-		i = w/2 + int(float64(w)/2*xr)
-	}
-
-	if yr > 0 {
-		j = h/2 + int(float64(h)/2*yr)
-	} else {
-		j = h/2 + int(float64(h)/2*yr)
-	}
+	i = w/2 + int(float64(w)/2*xr)
+	j = h/2 + int(float64(h)/2*yr)
 
 	return i, j
 }
diff --git a/wave.go b/wave.go
index 7db3eae..038a75c 100644
--- a/wave.go
+++ b/wave.go
@@ -32,8 +32,8 @@ func (w *wave) GenerativePolar(c *canva, rgba color.RGBA) {
 
 // Generative draws the image in cartesian coordinate system.
 func (w *wave) Generative(c *canva, rgba color.RGBA) {
-	for x := -math.Pi; x <= math.Pi; x += 0.008 {
-		for y := -math.Pi; y <= math.Pi; y += 0.008 {
+	for x := -math.Pi; x <= math.Pi; x += 0.002 {
+		for y := -math.Pi; y <= math.Pi; y += 0.002 {
 			xi, yi := w.fn(x, y)
 			i, j := ConvertCartesianToPixel(xi, yi, c.xaixs, c.yaixs, c.height, c.width)
 			if i < 0 || i > c.width-1 || j < 0 || j > c.height-1 {