From 4983354a6e0a2e690c02864d72f1c03ed3699f68 Mon Sep 17 00:00:00 2001
From: tomsmeding <tom.smeding@gmail.com>
Date: Wed, 5 Apr 2017 21:40:35 +0200
Subject: Colour argument

And some random changes
---
 attract.c | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/attract.c b/attract.c
index 87ca6a1..c4cba5c 100644
--- a/attract.c
+++ b/attract.c
@@ -2,6 +2,7 @@
 #include <stdlib.h>
 #include <stdbool.h>
 #include <string.h>
+#include <math.h>
 #include <complex.h>
 #include <unistd.h>
 #include <pthread.h>
@@ -16,19 +17,16 @@ const int MAXITER=200;
 const double EPS=1e-1;
 
 static double complex att_func(double complex x,double exponent){
-#if 0
-	static const int N=9;
-
-	double complex r=1,y=x;
-	for(int i=1;i<N;i++){
-		r+=y;
-		y*=x;
-	}
-	r+=y;
-	return clog(r);
-#else
 	return clog((1-cpow(x,exponent+1))/(1-x));
-#endif
+
+	// return csqrt(M_SQRT2*x);  // sqrt(2) and 0
+	// return csqrt(1+x);  // phi
+	// return csqrt(2*x-1);  // attracts REALLY SLOWLY to 1+0i
+	// return clog(x);  // two basins and two infinities
+	// return clog(x*x);  // "241" basins
+	// return clog(x*x+x);  // 3 basins but intricate structure
+	// return clog(x*x*x*x+x*x*x+x*x+x+1);  // 2 basin fractal?
+	// return csqrt(x*x*x+x*x+x+1);
 }
 
 struct colour{
@@ -39,8 +37,9 @@ static struct colour make_colour(double complex z){
 	static const double N=3;
 	double norm=cabs(z);
 	if(norm>N)norm=N;
-	int clrv=(int)(norm/N*255);
-	return (struct colour){clrv,clrv,clrv};
+	int normclr=(int)(norm/N*255);
+	int argclr=(int)((carg(z)+M_PI)/(2*M_PI)*255);
+	return (struct colour){normclr,argclr,0};
 }
 
 struct config{
@@ -116,9 +115,9 @@ static void* thread_entry(void *arg_vp){
 }
 
 int main(int argc,char **argv){
-	const double minx=-1.5,miny=-1.5;
-	const double maxx=1.5,maxy=1.5;
-	const double width=500;
+	const double minx=-3,miny=-3;
+	const double maxx=3,maxy=3;
+	const double width=1000;
 
 	struct config cfg={
 		.unitsz=width/(maxx-minx),
-- 
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