Initial revision

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@370 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 59 insertions, 0 deletions

diff --git a/ext/mandel/mandel.c b/ext/mandel/mandel.c
new file mode 100644
index 0000000000..359c0756da
--- /dev/null
+++ b/ext/mandel/mandel.c
@@ -0,0 +1,59 @@
+/************************************************
+
+  mandel.c -
+
+  $Author$
+
+************************************************/
+
+#include "ruby.h"
+#include "math.h"
+
+static VALUE
+mandel(self, re, im, max)
+    VALUE self;
+    VALUE re;
+    VALUE im;
+    VALUE max;
+{
+    double real, image;
+    double z_real, z_image;
+    double tmp_real;
+    int maximum;
+    int i;
+	
+    Check_Type(re, T_FLOAT);
+    Check_Type(im, T_FLOAT);
+    Check_Type(max, T_FIXNUM);
+
+    real = RFLOAT(re)->value;
+    image = RFLOAT(im)->value;
+    maximum = FIX2INT(max);
+
+    /***
+    z = c = Complex(re, im)
+    for i in 0 .. $max_deapth
+      z = (z * z) + c
+      break if z.abs > 2
+    end
+    return i
+    ***/
+
+    z_real = real;
+    z_image = image;
+    for (i = 0; i < maximum; i++) {
+	tmp_real = ((z_real * z_real) - (z_image * z_image)) + real;
+	z_image = ((z_real * z_image) + (z_image * z_real)) + image;
+	z_real = tmp_real;
+	if ( ((z_real * z_real) + (z_image * z_image)) > 4.0 ) {
+	    break;
+	}
+    }
+    return INT2FIX(i);
+}
+
+Init_mandel()
+{
+    VALUE mMandel = rb_define_module("Mandel");
+    rb_define_module_function(mMandel, "mandel", mandel, 3);
+}