Moved Stars45 to StarsEx

1 files changed, 146 insertions, 0 deletions

diff --git a/StarsEx/Random.cpp b/StarsEx/Random.cpp
new file mode 100644
index 0000000..18f6031
--- /dev/null
+++ b/StarsEx/Random.cpp
@@ -0,0 +1,146 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2022, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+
+    AUTHOR:       John DiCamillo
+
+
+    OVERVIEW
+    ========
+    Utility functions for generating random numbers and locations.
+*/
+
+#include "Random.h"
+
+// +----------------------------------------------------------------------+
+
+void RandomInit()
+{
+    srand(timeGetTime());
+}
+
+// +----------------------------------------------------------------------+
+
+Point RandomDirection()
+{
+    Point p = Point(rand() - 16384, rand() - 16384, 0);
+    p.Normalize();
+    return p;
+}
+
+// +----------------------------------------------------------------------+
+
+Point RandomPoint()
+{
+    Point p = Point(rand() - 16384, rand() - 16384, 0);
+    p.Normalize();
+    p *= 15e3 + rand()/3;
+    return p;
+}
+
+// +----------------------------------------------------------------------+
+
+Vec3 RandomVector(double radius)
+{
+    Vec3 v = Vec3(rand() - 16384, rand() - 16384, rand() - 16384);
+    v.Normalize();
+
+    if (radius > 0)
+    v *= (float) radius;
+    else
+    v *= (float) Random(radius/3, radius);
+
+    return v;
+}
+
+// +----------------------------------------------------------------------+
+
+double Random(double min, double max)
+{
+    double delta = max - min;
+    double r     = delta * rand() / 32768.0;
+
+    return min + r;
+}
+
+// +----------------------------------------------------------------------+
+
+int RandomIndex()
+{
+    static int index     = 0;
+    static int table[16] = { 0, 9, 4, 7, 14, 11, 2, 12, 1, 5, 13, 8, 6, 10, 3, 15 };
+
+    int r = 1 + ((rand() & 0x0700) >> 8);
+    index += r;
+    if (index > 1e7) index = 0;
+    return table[index % 16];
+}
+
+// +----------------------------------------------------------------------+
+
+bool RandomChance(int wins, int tries)
+{
+    double fraction = 256.0 * wins / tries;
+    double r        = (rand() >> 4) & 0xFF;
+
+    return r < fraction;
+}
+
+// +----------------------------------------------------------------------+
+
+int RandomSequence(int current, int range)
+{
+    if (range > 1) {
+        int step = (int) Random(1, range-1);
+        return (current + step) % range;
+    }
+
+    return current;
+}
+
+// +----------------------------------------------------------------------+
+
+int RandomShuffle(int count)
+{
+    static int  set_size = -1;
+    static BYTE set[256];
+    static int  index    = -1;
+
+    if (count < 0 || count > 250)
+    return 0;
+
+    if (set_size != count) {
+        set_size = count;
+        index    = -1;
+    }
+
+    // need to reshuffle
+    if (index < 0 || index > set_size-1) {
+        // set up the deck
+        int tmp[256];
+        for (int i = 0; i < 256; i++)
+        tmp[i] = i;
+
+        // shuffle the cards
+        for (int i = 0; i < set_size; i++) {
+            int n     = (int) Random(0, set_size);
+            int tries = set_size;
+            while (tmp[n] < 0 && tries--) {
+                n = (n+1) % set_size;
+            }
+
+            if (tmp[n] >= 0) {
+                set[i] = tmp[n];
+                tmp[n] = -1;
+            }
+            else {
+                set[i] = 0;
+            }
+        }
+
+        index = 0;
+    }
+
+    return set[index++];
+}