imports.c

mesa-6.5-minigui源码

/**
 * \file imports.c
 * Standard C library function wrappers.
 * 
 * Imports are services which the device driver or window system or
 * operating system provides to the core renderer.  The core renderer (Mesa)
 * will call these functions in order to do memory allocation, simple I/O,
 * etc.
 *
 * Some drivers will want to override/replace this file with something
 * specialized, but that'll be rare.
 *
 * Eventually, I want to move roll the glheader.h file into this.
 *
 * The OpenGL SI's __GLimports structure allows per-context specification of
 * replacements for the standard C lib functions.  In practice that's probably
 * never needed; compile-time replacements are far more likely.
 *
 * The _mesa_*() functions defined here don't in general take a context
 * parameter.  I guess we can change that someday, if need be.
 * So for now, the __GLimports stuff really isn't used.
 *
 * \todo Functions still needed:
 * - scanf
 * - qsort
 * - rand and RAND_MAX
 *
 * \note When compiled into a XFree86 module these functions wrap around
 * XFree86 own wrappers.
 */

/*
 * Mesa 3-D graphics library
 * Version:  6.5
 *
 * Copyright (C) 1999-2006  Brian Paul   All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
 * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */



#include "imports.h"
#include "context.h"
#include "version.h"


#define MAXSTRING 4000  /* for vsnprintf() */

#ifdef WIN32
#define vsnprintf _vsnprintf
#elif defined(__IBMC__) || defined(__IBMCPP__) || ( defined(__VMS) && __CRTL_VER < 70312000 )
extern int vsnprintf(char *str, size_t count, const char *fmt, va_list arg);
#ifdef __VMS
#include "vsnprintf.c"
#endif
#endif

/* If we don't actually want to use the libcwrapper junk (even though we're
 * building an Xorg server module), then just undef IN_MODULE to signal that to
 * the following code.  It's left around for now to allow compiling of newish
 * Mesa with older servers, but this whole mess should go away at some point.
 */
#ifdef NO_LIBCWRAPPER
#undef IN_MODULE
#endif

/**********************************************************************/
/** \name Memory */
/*@{*/

/** Wrapper around either malloc() or xf86malloc() */
void *
_mesa_malloc(size_t bytes)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86malloc(bytes);
#else
   return malloc(bytes);
#endif
}

/** Wrapper around either calloc() or xf86calloc() */
void *
_mesa_calloc(size_t bytes)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86calloc(1, bytes);
#else
   return calloc(1, bytes);
#endif
}

/** Wrapper around either free() or xf86free() */
void
_mesa_free(void *ptr)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   xf86free(ptr);
#else
   free(ptr);
#endif
}

/**
 * Allocate aligned memory.
 *
 * \param bytes number of bytes to allocate.
 * \param alignment alignment (must be greater than zero).
 * 
 * Allocates extra memory to accommodate rounding up the address for
 * alignment and to record the real malloc address.
 *
 * \sa _mesa_align_free().
 */
void *
_mesa_align_malloc(size_t bytes, unsigned long alignment)
{
   uintptr_t ptr, buf;

   ASSERT( alignment > 0 );

   ptr = (uintptr_t) _mesa_malloc(bytes + alignment + sizeof(void *));
   if (!ptr)
      return NULL;

   buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
   *(uintptr_t *)(buf - sizeof(void *)) = ptr;

#ifdef DEBUG
   /* mark the non-aligned area */
   while ( ptr < buf - sizeof(void *) ) {
      *(unsigned long *)ptr = 0xcdcdcdcd;
      ptr += sizeof(unsigned long);
   }
#endif

   return (void *) buf;
}

/**
 * Same as _mesa_align_malloc(), but using _mesa_calloc() instead of
 * _mesa_malloc()
 */
void *
_mesa_align_calloc(size_t bytes, unsigned long alignment)
{
   uintptr_t ptr, buf;

   ASSERT( alignment > 0 );

   ptr = (uintptr_t) _mesa_calloc(bytes + alignment + sizeof(void *));
   if (!ptr)
      return NULL;

   buf = (ptr + alignment + sizeof(void *)) & ~(uintptr_t)(alignment - 1);
   *(uintptr_t *)(buf - sizeof(void *)) = ptr;

#ifdef DEBUG
   /* mark the non-aligned area */
   while ( ptr < buf - sizeof(void *) ) {
      *(unsigned long *)ptr = 0xcdcdcdcd;
      ptr += sizeof(unsigned long);
   }
#endif

   return (void *)buf;
}

/**
 * Free memory which was allocated with either _mesa_align_malloc()
 * or _mesa_align_calloc().
 * \param ptr pointer to the memory to be freed.
 * The actual address to free is stored in the word immediately before the
 * address the client sees.
 */
void
_mesa_align_free(void *ptr)
{
#if 0
   _mesa_free( (void *)(*(unsigned long *)((unsigned long)ptr - sizeof(void *))) );
#else
   void **cubbyHole = (void **) ((char *) ptr - sizeof(void *));
   void *realAddr = *cubbyHole;
   _mesa_free(realAddr);
#endif
}

/** Reallocate memory */
void *
_mesa_realloc(void *oldBuffer, size_t oldSize, size_t newSize)
{
   const size_t copySize = (oldSize < newSize) ? oldSize : newSize;
   void *newBuffer = _mesa_malloc(newSize);
   if (newBuffer && oldBuffer && copySize > 0)
      _mesa_memcpy(newBuffer, oldBuffer, copySize);
   if (oldBuffer)
      _mesa_free(oldBuffer);
   return newBuffer;
}

/** memcpy wrapper */
void *
_mesa_memcpy(void *dest, const void *src, size_t n)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86memcpy(dest, src, n);
#elif defined(SUNOS4)
   return memcpy((char *) dest, (char *) src, (int) n);
#else
   return memcpy(dest, src, n);
#endif
}

/** Wrapper around either memset() or xf86memset() */
void
_mesa_memset( void *dst, int val, size_t n )
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   xf86memset( dst, val, n );
#elif defined(SUNOS4)
   memset( (char *) dst, (int) val, (int) n );
#else
   memset(dst, val, n);
#endif
}

/**
 * Fill memory with a constant 16bit word.
 * \param dst destination pointer.
 * \param val value.
 * \param n number of words.
 */
void
_mesa_memset16( unsigned short *dst, unsigned short val, size_t n )
{
   while (n-- > 0)
      *dst++ = val;
}

/** Wrapper around either memcpy() or xf86memcpy() or bzero() */
void
_mesa_bzero( void *dst, size_t n )
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   xf86memset( dst, 0, n );
#elif defined(__FreeBSD__)
   bzero( dst, n );
#else
   memset( dst, 0, n );
#endif
}

/** Wrapper around either memcmp() or xf86memcmp() */
int
_mesa_memcmp( const void *s1, const void *s2, size_t n )
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86memcmp( s1, s2, n );
#elif defined(SUNOS4)
   return memcmp( (char *) s1, (char *) s2, (int) n );
#else
   return memcmp(s1, s2, n);
#endif
}

/*@}*/


/**********************************************************************/
/** \name Math */
/*@{*/

/** Wrapper around either sin() or xf86sin() */
double
_mesa_sin(double a)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86sin(a);
#else
   return sin(a);
#endif
}

/** Single precision wrapper around either sin() or xf86sin() */
float
_mesa_sinf(float a)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return (float) xf86sin((double) a);
#else
   return (float) sin((double) a);
#endif
}

/** Wrapper around either cos() or xf86cos() */
double
_mesa_cos(double a)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86cos(a);
#else
   return cos(a);
#endif
}

/** Single precision wrapper around either asin() or xf86asin() */
float
_mesa_asinf(float x)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return (float) xf86asin((double) x);
#else
   return (float) asin((double) x);
#endif
}

/** Single precision wrapper around either atan() or xf86atan() */
float
_mesa_atanf(float x)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return (float) xf86atan((double) x);
#else
   return (float) atan((double) x);
#endif
}

/** Wrapper around either sqrt() or xf86sqrt() */
double
_mesa_sqrtd(double x)
{
#if defined(XFree86LOADER) && defined(IN_MODULE)
   return xf86sqrt(x);
#else
   return sqrt(x);
#endif
}


/*
 * A High Speed, Low Precision Square Root
 * by Paul Lalonde and Robert Dawson
 * from "Graphics Gems", Academic Press, 1990
 *
 * SPARC implementation of a fast square root by table
 * lookup.
 * SPARC floating point format is as follows:
 *
 * BIT 31 	30 	23 	22 	0
 *     sign	exponent	mantissa
 */
static short sqrttab[0x100];    /* declare table of square roots */

static void init_sqrt_table(void)
{
#if defined(USE_IEEE) && !defined(DEBUG)
   unsigned short i;
   fi_type fi;     /* to access the bits of a float in  C quickly  */
                   /* we use a union defined in glheader.h         */

   for(i=0; i<= 0x7f; i++) {
      fi.i = 0;

      /*
       * Build a float with the bit pattern i as mantissa
       * and an exponent of 0, stored as 127
       */

      fi.i = (i << 16) | (127 << 23);
      fi.f = _mesa_sqrtd(fi.f);

      /*
       * Take the square root then strip the first 7 bits of
       * the mantissa into the table
       */

      sqrttab[i] = (fi.i & 0x7fffff) >> 16;

      /*
       * Repeat the process, this time with an exponent of
       * 1, stored as 128
       */

      fi.i = 0;
      fi.i = (i << 16) | (128 << 23);
      fi.f = sqrt(fi.f);
      sqrttab[i+0x80] = (fi.i & 0x7fffff) >> 16;
   }
#else
   (void) sqrttab;  /* silence compiler warnings */
#endif /*HAVE_FAST_MATH*/
}


/**
 * Single precision square root.
 */
float
_mesa_sqrtf( float x )
{
#if defined(USE_IEEE) && !defined(DEBUG)
   fi_type num;
                                /* to access the bits of a float in C
                                 * we use a union from glheader.h     */

   short e;                     /* the exponent */
   if (x == 0.0F) return 0.0F;  /* check for square root of 0 */
   num.f = x;
   e = (num.i >> 23) - 127;     /* get the exponent - on a SPARC the */
                                /* exponent is stored with 127 added */
   num.i &= 0x7fffff;           /* leave only the mantissa */
   if (e & 0x01) num.i |= 0x800000;
                                /* the exponent is odd so we have to */
                                /* look it up in the second half of  */
                                /* the lookup table, so we set the   */
                                /* high bit                                */
   e >>= 1;                     /* divide the exponent by two */
                                /* note that in C the shift */
                                /* operators are sign preserving */
                                /* for signed operands */
   /* Do the table lookup, based on the quaternary mantissa,
    * then reconstruct the result back into a float
    */
   num.i = ((sqrttab[num.i >> 16]) << 16) | ((e + 127) << 23);

   return num.f;
#else
   return (float) _mesa_sqrtd((double) x);