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authorkwolekr <kwolekr@minetest.net>2015-03-22 00:01:46 -0400
committerkwolekr <kwolekr@minetest.net>2015-03-22 00:48:08 -0400
commit3993093f51544d4eb44efb57c973e29107ea2f7a (patch)
tree0533167edce0dbd2cb8f03c37b880e57cfd7916d /src/util
parent7679396ebbb38115eedbfb8e9636dff50cdf2075 (diff)
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Add support for the PCG32 PRNG algo (and associated script APIs)
Diffstat (limited to 'src/util')
-rw-r--r--src/util/numeric.cpp59
-rw-r--r--src/util/numeric.h8
2 files changed, 32 insertions, 35 deletions
diff --git a/src/util/numeric.cpp b/src/util/numeric.cpp
index 19f927134..a1f1fd0ab 100644
--- a/src/util/numeric.cpp
+++ b/src/util/numeric.cpp
@@ -22,6 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
#include "log.h"
#include "../constants.h" // BS, MAP_BLOCKSIZE
+#include "../noise.h" // PseudoRandom, PcgRandom
#include <string.h>
#include <iostream>
@@ -115,36 +116,32 @@ void FacePositionCache::generateFacePosition(u16 d)
myrand
*/
-static unsigned long next = 1;
+PcgRandom g_pcgrand;
-/* RAND_MAX assumed to be 32767 */
-int myrand(void)
+u32 myrand()
{
- next = next * 1103515245 + 12345;
- return((unsigned)(next/65536) % 32768);
+ return g_pcgrand.next();
}
-void mysrand(unsigned seed)
+void mysrand(unsigned int seed)
{
- next = seed;
+ g_pcgrand.seed(seed);
+}
+
+void myrand_bytes(void *out, size_t len)
+{
+ g_pcgrand.bytes(out, len);
}
int myrand_range(int min, int max)
{
- if(max-min > MYRAND_MAX)
- {
- errorstream<<"WARNING: myrand_range: max-min > MYRAND_MAX"<<std::endl;
- max = min + MYRAND_MAX;
- }
- if(min > max)
- {
- errorstream<<"WARNING: myrand_range: min > max"<<std::endl;
- return max;
- }
- return (myrand()%(max-min+1))+min;
+ return g_pcgrand.range(min, max);
}
-// 64-bit unaligned version of MurmurHash
+
+/*
+ 64-bit unaligned version of MurmurHash
+*/
u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
{
const u64 m = 0xc6a4a7935bd1e995ULL;
@@ -159,12 +156,12 @@ u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
memcpy(&k, data, sizeof(u64));
data++;
- k *= m;
- k ^= k >> r;
- k *= m;
-
+ k *= m;
+ k ^= k >> r;
+ k *= m;
+
h ^= k;
- h *= m;
+ h *= m;
}
const unsigned char *data2 = (const unsigned char *)data;
@@ -178,13 +175,13 @@ u64 murmur_hash_64_ua(const void *key, int len, unsigned int seed)
case 1: h ^= (u64)data2[0];
h *= m;
}
-
+
h ^= h >> r;
h *= m;
h ^= h >> r;
-
+
return h;
-}
+}
/*
@@ -197,7 +194,7 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
f32 camera_fov, f32 range, f32 *distance_ptr)
{
v3s16 blockpos_nodes = blockpos_b * MAP_BLOCKSIZE;
-
+
// Block center position
v3f blockpos(
((float)blockpos_nodes.X + MAP_BLOCKSIZE/2) * BS,
@@ -213,7 +210,7 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
if(distance_ptr)
*distance_ptr = d;
-
+
// If block is far away, it's not in sight
if(d > range)
return false;
@@ -221,7 +218,7 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
// Maximum radius of a block. The magic number is
// sqrt(3.0) / 2.0 in literal form.
f32 block_max_radius = 0.866025403784 * MAP_BLOCKSIZE * BS;
-
+
// If block is (nearly) touching the camera, don't
// bother validating further (that is, render it anyway)
if(d < block_max_radius)
@@ -242,7 +239,7 @@ bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir,
// Cosine of the angle between the camera direction
// and the block direction (camera_dir is an unit vector)
f32 cosangle = dforward / blockpos_adj.getLength();
-
+
// If block is not in the field of view, skip it
if(cosangle < cos(camera_fov / 2))
return false;
diff --git a/src/util/numeric.h b/src/util/numeric.h
index 42d9a87a9..ccc9fbee4 100644
--- a/src/util/numeric.h
+++ b/src/util/numeric.h
@@ -239,10 +239,10 @@ inline float wrapDegrees_180(float f)
/*
Pseudo-random (VC++ rand() sucks)
*/
-int myrand(void);
-void mysrand(unsigned seed);
-#define MYRAND_MAX 32767
-
+#define MYRAND_RANGE 0xffffffff
+u32 myrand();
+void mysrand(unsigned int seed);
+void myrand_bytes(void *out, size_t len);
int myrand_range(int min, int max);
/*