#include "precompiled.h"
#include "0ad_warning_disable.h"
# include <stdlib.h>
# include <string.h>

# include "sr_buffer.h"

//=== SrBuffer =======================================================================

# define BUF(i) ((char*)buffer)+(sizeofx*(i))

void* sr_buffer_size ( void* buffer, int sizeofx, int& size, int newsize )
 { 
   if ( size==newsize ) return buffer;
   size = newsize;
   if ( size==0 )
    { if (buffer) { free(buffer); buffer=0; } }
   else
    { buffer = realloc ( buffer, (size_t)(sizeofx*size) ); }
   return buffer;
 }

void* sr_buffer_insert ( void* buffer, int sizeofx, int& size, int i, int dp )
 { 
   size += dp;
   buffer = realloc ( buffer, (size_t)(sizeofx*size) );
   if ( i<size-dp )
     memmove ( BUF(i+dp), BUF(i), sizeofx*(size-dp-i) ); // ok with overlap
   return buffer; 
 }

void* sr_buffer_remove ( void* buffer, int sizeofx, int& size, int i, int dp )
 { 
   if ( i<size-dp ) memmove ( BUF(i), BUF(i+dp), sizeofx*(size-(i+dp)) );
   return sr_buffer_size ( buffer, sizeofx, size, size-dp );
 }

void* sr_buffer_copy ( void* buffer, int sizeofx, int& size, const void* buffertocp, int sizetocp )
 { 
   if ( buffer==buffertocp ) return buffer;
   buffer = sr_buffer_size ( buffer, sizeofx, size, sizetocp );
   if ( buffer ) memcpy ( buffer, buffertocp, sizeofx*size ); // no overlap
   return buffer;
 }

# undef BUF

//=== End of File =====================================================================

/* Note:
void *memmove( void *dest, const void *src, size_t count );
If some regions of the source area and the destination overlap,
memmove ensures that the original source bytes in the overlapping
region are copied before being overwritten

void *memcpy( void *dest, const void *src, size_t count );
If the source and destination overlap, memcpy function does not
ensure that the original source bytes in the overlapping region
are copied before being overwritten. Use memmove to handle
overlapping regions. */