random generator now based on pcg-random

pcg/pcg_basic.h

@@ -0,0 +1,78 @@
+/*
+ * PCG Random Number Generation for C.
+ *
+ * Copyright 2014 Melissa O'Neill <oneill@pcg-random.org>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * For additional information about the PCG random number generation scheme,
+ * including its license and other licensing options, visit
+ *
+ *     http://www.pcg-random.org
+ */
+
+/*
+ * This code is derived from the full C implementation, which is in turn
+ * derived from the canonical C++ PCG implementation. The C++ version
+ * has many additional features and is preferable if you can use C++ in
+ * your project.
+ */
+
+#ifndef PCG_BASIC_H_INCLUDED
+#define PCG_BASIC_H_INCLUDED 1
+
+#include <inttypes.h>
+
+#if __cplusplus
+extern "C" {
+#endif
+
+struct pcg_state_setseq_64 {    // Internals are *Private*.
+    uint64_t state;             // RNG state.  All values are possible.
+    uint64_t inc;               // Controls which RNG sequence (stream) is
+                                // selected. Must *always* be odd.
+};
+typedef struct pcg_state_setseq_64 pcg32_random_t;
+
+// If you *must* statically initialize it, here's one.
+
+#define PCG32_INITIALIZER   { 0x853c49e6748fea9bULL, 0xda3e39cb94b95bdbULL }
+
+// pcg32_srandom(initstate, initseq)
+// pcg32_srandom_r(rng, initstate, initseq):
+//     Seed the rng.  Specified in two parts, state initializer and a
+//     sequence selection constant (a.k.a. stream id)
+
+void pcg32_srandom(uint64_t initstate, uint64_t initseq);
+void pcg32_srandom_r(pcg32_random_t* rng, uint64_t initstate,
+                     uint64_t initseq);
+
+// pcg32_random()
+// pcg32_random_r(rng)
+//     Generate a uniformly distributed 32-bit random number
+
+uint32_t pcg32_random(void);
+uint32_t pcg32_random_r(pcg32_random_t* rng);
+
+// pcg32_boundedrand(bound):
+// pcg32_boundedrand_r(rng, bound):
+//     Generate a uniformly distributed number, r, where 0 <= r < bound
+
+uint32_t pcg32_boundedrand(uint32_t bound);
+uint32_t pcg32_boundedrand_r(pcg32_random_t* rng, uint32_t bound);
+
+#if __cplusplus
+}
+#endif
+
+#endif // PCG_BASIC_H_INCLUDED