From 3a4147a37d4d547985f72236e2f8c7db7c9fcf03 Mon Sep 17 00:00:00 2001
From: dtrg <none@none>
Date: Sat, 28 Apr 2007 22:34:05 +0000
Subject: [PATCH] Added the Mandelbrot generator.

---
 examples/.distr       |  1 +
 examples/README       |  2 ++
 examples/mandelbrot.c | 73 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 76 insertions(+)
 create mode 100644 examples/mandelbrot.c

diff --git a/examples/.distr b/examples/.distr
index 8aaa2deab..3469c16ff 100644
--- a/examples/.distr
+++ b/examples/.distr
@@ -3,6 +3,7 @@ hilo.c
 hilo.mod
 hilo.ocm
 hilo.p
+mandelbrot.c
 paranoia.c
 startrek.c
 startrek.doc
diff --git a/examples/README b/examples/README
index 6e5081886..b77720d95 100644
--- a/examples/README
+++ b/examples/README
@@ -17,8 +17,10 @@ hilo.mod           Modula-2 version of the Hi/Lo game
 hilo.ocm           Occam 1 version of the Hi/Lo game
 hilo.p             Pascal version of the Hi/Lo game
 
+mandelbrot.c       A simple Mandelbrot generator, using floating-point maths
 paranoia.c         An ancient public domain K&R C adventure game
 startrek.c         An even more ancient public domain ANSI C game
+                     (uses the FPU for distance calculation)
 startrek.doc       Manual for above (plus in current directory when running)
 
 Enjoy.
diff --git a/examples/mandelbrot.c b/examples/mandelbrot.c
new file mode 100644
index 000000000..27484ee90
--- /dev/null
+++ b/examples/mandelbrot.c
@@ -0,0 +1,73 @@
+/* $Source$
+ * $State$
+ * $Revision$
+ */
+
+/* Adapted from code by Chris Losinger. (This is the non-obfuscated
+ * version...
+ * 
+ * http://www.codeproject.com/cpp/mandelbrot_obfuscation.asp
+ */
+ 
+#include <stdlib.h>
+#include <unistd.h>
+
+enum
+{
+	ROWS = 40,
+	COLUMNS = 60,
+	
+	MAX_ITERATIONS = 255
+};
+
+void nl(void)
+{
+	write(1, "\n", 1);
+}
+
+void out(int n)
+{
+	const char* chars = "****++++++----  ";
+	write(1, chars + (n/16), 1);
+}
+
+int main(int argc, const char* argv[])
+{
+    /* Size and position of the visible area. */
+    
+    double view_r = -2.3, view_i = -1.0;
+    double zoom = 0.05;
+    int x, y, n;
+
+    for (y=0; y < ROWS; y++)
+    {
+        double c_i = view_i + y * zoom;
+        
+        for (x=0; x < COLUMNS; x++)
+        {
+            double c_r = view_r + x*zoom;
+            double z_r = c_r;
+            double z_i = c_i;
+            
+            for (n=0; n < MAX_ITERATIONS; n++)
+            {
+                double z_r2 = z_r * z_r;
+                double z_i2 = z_i * z_i;
+
+                /* Have we escaped? */
+                
+                if (z_r2 + z_i2 > 4)
+                    break;
+
+                /* z = z^2 + c */
+                z_i = 2 * z_r * z_i + c_i;
+                z_r = z_r2 - z_i2 + c_r;
+            }
+
+           	out(n);
+        }
+        nl();
+    }
+    
+    return 0;
+}