summaryrefslogtreecommitdiffstatshomepage
path: root/3rdparty/bx/tests/rng_test.cpp
diff options
context:
space:
mode:
Diffstat (limited to '3rdparty/bx/tests/rng_test.cpp')
-rw-r--r--3rdparty/bx/tests/rng_test.cpp88
1 files changed, 88 insertions, 0 deletions
diff --git a/3rdparty/bx/tests/rng_test.cpp b/3rdparty/bx/tests/rng_test.cpp
new file mode 100644
index 00000000000..89fef3f05d7
--- /dev/null
+++ b/3rdparty/bx/tests/rng_test.cpp
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2010-2017 Branimir Karadzic. All rights reserved.
+ * License: https://github.com/bkaradzic/bx#license-bsd-2-clause
+ */
+
+#include "test.h"
+
+#include <bx/rng.h>
+#include <bx/file.h>
+
+const uint32_t kMax = 10<<20;
+
+template<typename Ty>
+void testRng(const char* _name, Ty* _rng)
+{
+ uint32_t histBits[32];
+ uint32_t histUint8[256];
+
+ bx::memSet(histBits, 0, sizeof(histBits) );
+ bx::memSet(histUint8, 0, sizeof(histUint8) );
+
+ for (uint32_t ii = 0; ii < kMax; ++ii)
+ {
+ uint32_t val = _rng->gen();
+
+ for (uint32_t shift = 0; shift < 32; ++shift)
+ {
+ const uint32_t mask = 1<<shift;
+ histBits[shift] += !!(0 != (val & mask) );
+ }
+
+ const uint32_t mf000 = (val & 0xff000000)>>24;
+ const uint32_t m0f00 = (val & 0x00ff0000)>>16;
+ const uint32_t m00f0 = (val & 0x0000ff00)>> 8;
+ const uint32_t m000f = (val & 0x000000ff)>> 0;
+
+ histUint8[mf000]++;
+ histUint8[m0f00]++;
+ histUint8[m00f0]++;
+ histUint8[m000f]++;
+ }
+
+ bx::WriterI* writer = bx::getNullOut();
+ bx::writePrintf(writer, "%s\n", _name);
+
+ {
+ bx::writePrintf(writer, "\tbits histogram:\n");
+ uint32_t min = UINT32_MAX;
+ uint32_t max = 0;
+
+ for (uint32_t ii = 0; ii < BX_COUNTOF(histBits); ++ii)
+ {
+ bx::writePrintf(writer, "\t\t%3d: %d\n", ii, histBits[ii]);
+ min = bx::min(min, histBits[ii]);
+ max = bx::max(max, histBits[ii]);
+ }
+
+ bx::writePrintf(writer, "\tmin: %d, max: %d (diff: %d)\n", min, max, max-min);
+
+ REQUIRE(max-min < 8000);
+ }
+
+ {
+ bx::writePrintf(writer, "\tuint8_t histogram:\n");
+ uint32_t min = UINT32_MAX;
+ uint32_t max = 0;
+
+ for (uint32_t ii = 0; ii < BX_COUNTOF(histUint8); ++ii)
+ {
+ bx::writePrintf(writer, "\t\t%3d: %d\n", ii, histUint8[ii]);
+ min = bx::min(min, histUint8[ii]);
+ max = bx::max(max, histUint8[ii]);
+ }
+
+ bx::writePrintf(writer, "\tmin: %d, max: %d (diff: %d)\n", min, max, max-min);
+
+ REQUIRE(max-min < 8000);
+ }
+}
+
+TEST_CASE("Rng", "")
+{
+ bx::RngMwc mwc;
+ testRng("RngMwc", &mwc);
+
+ bx::RngShr3 shr3;
+ testRng("RngShr3", &shr3);
+}