From 6954aaeccfaf962c31ef5f1c9a5d62b14df1537f Mon Sep 17 00:00:00 2001
From: lynxeyed-atsu <lynxeyed@xj9.so-net.ne.jp>
Date: Wed, 27 Jun 2012 21:48:25 +0900
Subject: added Random function

---
 src/core/arithmetical.cpp | 37 +++++++++++++++++++++++++++++++++++++
 src/core/arithmetical.h   | 11 +++++++++++
 2 files changed, 48 insertions(+)
 create mode 100755 src/core/arithmetical.cpp

(limited to 'src')

diff --git a/src/core/arithmetical.cpp b/src/core/arithmetical.cpp
new file mode 100755
index 0000000..ad90612
--- /dev/null
+++ b/src/core/arithmetical.cpp
@@ -0,0 +1,37 @@
+#include <libmary.h>
+#include <arithmetical.h>
+
+unsigned int random_seed;
+
+void randomSeed(unsigned int seed)
+{
+	random_seed = seed;
+	return;
+}
+
+
+// random algorithm using Fibonacci-LFSR
+unsigned int random(void)
+{
+    unsigned int shift_bit;
+	shift_bit = (random_seed & 0x0001) ^
+			((random_seed & 0x0004) >> 2) ^
+			((random_seed & 0x0008) >> 3) ^
+			((random_seed & 0x0020) >> 5);
+	random_seed = (random_seed >> 1) | (shift_bit << 15);
+	return random_seed;
+}
+
+long random(long max_num)
+{
+	if(max_num ==0) return 0;
+	return random() % max_num;
+}
+
+long random(long min_num, long max_num)
+{
+	if(min_num >= max_num)return 0;
+	if(max_num == 0) return 0;
+
+	return random( max_num - min_num ) + min_num;
+}
diff --git a/src/core/arithmetical.h b/src/core/arithmetical.h
index bae4440..a087807 100755
--- a/src/core/arithmetical.h
+++ b/src/core/arithmetical.h
@@ -45,5 +45,16 @@
 #define map(x,in_min,in_max,out_min,out_max) \
 (((x) - (in_min)) * ((out_max) - (out_min)) / ((in_max) - (in_min)) + (out_min))
 
+#ifdef __cplusplus
+	extern "C++" {
+#endif
+
+void randomSeed(unsigned int seed);
+unsigned int random(void);
+long random(long max_num);
+long random(long min_num, long max_num);
 
+#ifdef __cplusplus
+	}
+#endif
 #endif /* ARITHMETICAL_H_ */
-- 
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