NAME
SDL_GetRowStretchCode, SDL_NewRowStretchCode - (SDL_stretchcode.h)
SYNOPSIS
#include <SDL_stretch.h>
extern unsigned char* SDL_GetRowStretchCode(void);
extern unsigned char* SDL_NewRowStretchCode(unsigned size);
DESCRIPTION
TheRowStretchCode is a shared buffer between Stretch-routines that use
no extra buffer-argument. You should call SDL_SetRowStretchCode to fill
this internal buffer and set a "call"-operation for your target cpu to
execute this static buffer. That is done for effiency as the RowStretch
is often called in a tight loop for each Row in a rectengular stretch
and it is best to not use a variable argument with an indirect call or
a function call that would build up a callframe and release that
callframe later.
If you do not need that effiency, use PutRowStretchCode and
RunRowStretchCode which are also good in a multithreading environment.
To allocate a new buffer for usage with Put/Run you can use the
NewRowStretchCode routine which is also used on NX machines (e.g.
AMD64) where the data segment is set to be not-executable (in that case
it will allocate from heap and use mprotect). if the argument is 0 then
a buffer of the default size is allocated. If the buffer allocation (or
mprotect) fails it will return NULL and SDL_SetError.