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/*
SDL_stretch - Stretch Functions For The Simple DirectMedia Layer
Copyright (C) 2003 Guido Draheim
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Guido Draheim, guidod@gmx.de
*/
#ifndef _SDL_STRETCHCODE_IMPLEMENTATION_
#define _SDL_STRETCHCODE_IMPLEMENTATION_
/* development header - do not use */
#define SDL_STRETCHCODE_BUFFERSIZE 8192
/**
* TheRowStretchCode is a shared buffer between Stretch-routines that
* use no extra buffer-argument. You should call SDL_SetRowStretchCode
* to fill this 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.
*/
extern unsigned char SDL_TheRowStretchCode[SDL_STRETCHCODE_BUFFERSIZE];
/**
* The SetRowStretchCode is a wrapper around PutRowStretchCode that
* uses the Adress and Size of the shared SDL_TheRowStretchCode buffer.
* The PutRowStretchCode will fill the given buffer with an assembler
* stream that should be called with SDL_RunRowStretchCode. The
* assembler stream is usually faster as all the scale decisions are
* done in advance of the execution. This helps when a RunCode is
* done multiple times with the same src_w/dst_w/bpp pair. All the
* pixel-get and pixel-set calls are unrolled in that buffer. Therefore,
* the buffer should be big enough - as a rule of thumb use a buffer
* of size (src_w+dst_w)*5
*
* If PutCode or SetCode fails, a null is returned. Otherwise, the
* start adress of the Assembler is returned, which is the input
* argument of PutCode.
*/
unsigned char* SDL_SetRowStretchCode(int src_w, int dst_w, int bpp);
/** => SDL_SetRowStretchCode */
unsigned char* SDL_PutRowStretchCode(unsigned char* buffer, int buflen,
int src_w, int dst_w, int bpp);
/** => SDL_SetRowStretchCode */
void SDL_RunRowStretchCode(unsigned char* buffer,
unsigned char* src,
unsigned char* dst);
/** => SDL_SetRowStretchCode
* If SDL_SetRowStretchCode fails, this function must be used instead.
* This function and its cousins are singular routines that work in
* a tight loop to scale a single row. The number specified the
* byte-width of each pixel.
*/
void SDL_StretchRow1(Uint8 *src, int src_w, Uint8 *dst, int dst_w);
/** => SDL_SetRowStretchCode */
void SDL_StretchRow2(Uint16 *src, int src_w, Uint16 *dst, int dst_w);
/** => SDL_SetRowStretchCode */
void SDL_StretchRow3(Uint8 *src, int src_w, Uint8 *dst, int dst_w);
/** => SDL_SetRowStretchCode */
void SDL_StretchRow4(Uint32 *src, int src_w, Uint32 *dst, int dst_w);
#endif
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