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+/* Starshatter OpenSource Distribution
+ Copyright (c) 1997-2004, Destroyer Studios LLC.
+ All Rights Reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+ this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright notice,
+ this list of conditions and the following disclaimer in the documentation
+ and/or other materials provided with the distribution.
+ * Neither the name "Destroyer Studios" nor the names of its contributors
+ may be used to endorse or promote products derived from this software
+ without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ POSSIBILITY OF SUCH DAMAGE.
+
+ SUBSYSTEM: nGenEx.lib
+ FILE: Random.cpp
+ AUTHOR: John DiCamillo
+
+
+ OVERVIEW
+ ========
+ Utility functions for generating random numbers and locations.
+*/
+
+#include "MemDebug.h"
+#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++];
+}