Add random module to test lib

libsdl-org · Nov 27, 2012 · b48dc15 · b48dc15
1 parent 9e9b99b
commit b48dc15
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diff --git a/include/SDL_test.h b/include/SDL_test.h
@@ -32,6 +32,7 @@
 
 #include "SDL.h"
 #include "SDL_test_font.h"
+#include "SDL_test_random.h"
 
 #include "begin_code.h"
 /* Set up for C function definitions, even when using C++ */

diff --git a/include/SDL_test_random.h b/include/SDL_test_random.h
@@ -0,0 +1,123 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+/**
+ *  \file SDL_test_random.h
+ *  
+ *  Include file for SDL test framework.
+ *
+ *  This code is a part of the SDL2_test library, not the main SDL library.
+ */
+
+/* 
+
+ A "32-bit Multiply with carry random number generator. Very fast. 
+ Includes a list of recommended multipliers.                         
+
+ multiply-with-carry generator: x(n) = a*x(n-1) + carry mod 2^32.
+ period: (a*2^31)-1
+ 
+*/
+
+#ifndef _SDL_test_random_h
+#define _SDL_test_random_h
+
+#include "begin_code.h"
+/* Set up for C function definitions, even when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+extern "C" {
+/* *INDENT-ON* */
+#endif
+
+/* Function prototypes */
+
+
+/* ------- Definitions ------- */
+
+/*
+ * Macros that return random number in a specific format.
+ * Float values are in the range [0.0-1.0].
+ */
+#define SDL_TestRandomInt(c)		((int)SDL_TestRandom(c))
+#define SDL_TestRandomFloat(c)		((double)SDL_TestRandom(c)/(unsigned long)0xffffffff)
+
+/*
+ * Context structure for the random number generator state.
+ */
+  typedef struct {
+    unsigned int a;
+    unsigned int x;
+    unsigned int c;
+    unsigned int ah;
+    unsigned int al;
+  } SDLTest_RandomContext;
+
+/* ---- Function Prototypes -------- */
+
+/**
+ *  \brief Initialize random number generator with two integers. 
+ *
+ * Note: The random sequence of numbers returned by ...Random() is the
+ *       same for the same two integers and has a period of 2^31.
+ *
+ *  \param rndContext     pointer to context structure
+ *  \param xi         integer that defines the random sequence
+ *  \param ci         integer that defines the random sequence
+ *
+ */
+ void SDLTest_RandomInit(SDLTest_RandomContext * rndContext, unsigned int xi,
+				  unsigned int ci);
+
+/**
+ *  \brief Initialize random number generator based on current system time. 
+ *
+ *  \param rndContext     pointer to context structure
+ *
+ */
+ void SDLTest_RandomInitTime(SDLTest_RandomContext *rndContext);
+
+
+/**
+ *  \brief Initialize random number generator based on current system time. 
+ *
+ * Note: ...RandomInit() or ...RandomInitTime() must have been called
+ *       before using this function.
+ *
+ *  \param rndContext     pointer to context structure
+ *
+ *  \returns A random number (32bit unsigned integer)
+ *
+ */
+ unsigned int SDLTest_Random(SDLTest_RandomContext *rndContext);
+
+
+/* Ends C function definitions when using C++ */
+#ifdef __cplusplus
+/* *INDENT-OFF* */
+}
+/* *INDENT-ON* */
+#endif
+#include "close_code.h"
+
+#endif /* _SDL_test_random_h */
+
+/* vi: set ts=4 sw=4 expandtab: */
diff --git a/src/test/SDL_test_random.c b/src/test/SDL_test_random.c
@@ -0,0 +1,92 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2012 Sam Lantinga <slouken@libsdl.org>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+/*
+
+ A portable "32-bit Multiply with carry" random number generator.
+
+ Used by the fuzzer component. 
+ Original source code contributed by A. Schiffler for GSOC project.
+
+*/
+
+#include "SDL_config.h"
+
+#include <time.h>
+
+#include "SDL_test.h"
+
+/* Initialize random number generator with two integer variables */
+
+void SDLTest_RandomInit(SDLTest_RandomContext * rndContext, unsigned int xi, unsigned int ci)
+{
+  if (rndContext==NULL) return;
+
+  /*
+   * Choose a value for 'a' from this list
+   * 1791398085 1929682203 1683268614 1965537969 1675393560
+   * 1967773755 1517746329 1447497129 1655692410 1606218150
+   * 2051013963 1075433238 1557985959 1781943330 1893513180
+   * 1631296680 2131995753 2083801278 1873196400 1554115554 
+   */
+  rndContext->a = 1655692410;
+  rndContext->x = 30903;
+  rndContext->c = 0;
+  if (xi != 0) {
+      rndContext->x = xi;
+  }
+  rndContext->c = ci;
+  rndContext->ah = rndContext->a >> 16;
+  rndContext->al = rndContext->a & 65535;
+}
+
+/* Initialize random number generator from system time */
+
+void SDLTest_RandomInitTime(SDLTest_RandomContext * rndContext)
+{
+  int a, b;
+
+  if (rndContext==NULL) return;
+
+  srand((unsigned int)time(NULL));
+  a=rand();
+  srand(clock());
+  b=rand();
+  SDLTest_RandomInit(rndContext, a, b);
+}
+
+/* Returns random numbers */
+
+unsigned int SDLTest_Random(SDLTest_RandomContext * rndContext)
+{
+  unsigned int xh, xl;
+
+  if (rndContext==NULL) return -1;
+
+  xh = rndContext->x >> 16, xl = rndContext->x & 65535;
+  rndContext->x = rndContext->x * rndContext->a + rndContext->c;
+  rndContext->c =
+    xh * rndContext->ah + ((xh * rndContext->al) >> 16) +
+    ((xl * rndContext->ah) >> 16);
+  if (xl * rndContext->al >= (~rndContext->c + 1))
+    rndContext->c++;
+  return (rndContext->x);
+}