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SDL_blit.c
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/*
SDL - Simple DirectMedia Layer
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Copyright (C) 1997-2006 Sam Lantinga
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This library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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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
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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Sam Lantinga
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slouken@libsdl.org
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*/
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#include "SDL_config.h"
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#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_blit.h"
#include "SDL_RLEaccel_c.h"
#include "SDL_pixels_c.h"
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#if defined(__GNUC__) && (defined(__i386__) || defined(__x86_64__)) && SDL_ASSEMBLY_ROUTINES
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#define MMX_ASMBLIT
#endif
#if defined(MMX_ASMBLIT)
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#include "SDL_cpuinfo.h"
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#include "mmx.h"
#endif
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/* The general purpose software blit routine */
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static int
SDL_SoftBlit(SDL_Surface * src, SDL_Rect * srcrect,
SDL_Surface * dst, SDL_Rect * dstrect)
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int okay;
int src_locked;
int dst_locked;
/* Everything is okay at the beginning... */
okay = 1;
/* Lock the destination if it's in hardware */
dst_locked = 0;
if (SDL_MUSTLOCK(dst)) {
if (SDL_LockSurface(dst) < 0) {
okay = 0;
} else {
dst_locked = 1;
}
}
/* Lock the source if it's in hardware */
src_locked = 0;
if (SDL_MUSTLOCK(src)) {
if (SDL_LockSurface(src) < 0) {
okay = 0;
} else {
src_locked = 1;
}
}
/* Set up source and destination buffer pointers, and BLIT! */
if (okay && srcrect->w && srcrect->h) {
SDL_BlitInfo info;
SDL_loblit RunBlit;
/* Set up the blit information */
info.s_pixels = (Uint8 *) src->pixels +
(Uint16) srcrect->y * src->pitch +
(Uint16) srcrect->x * src->format->BytesPerPixel;
info.s_width = srcrect->w;
info.s_height = srcrect->h;
info.s_skip = src->pitch - info.s_width * src->format->BytesPerPixel;
info.d_pixels = (Uint8 *) dst->pixels +
(Uint16) dstrect->y * dst->pitch +
(Uint16) dstrect->x * dst->format->BytesPerPixel;
info.d_width = dstrect->w;
info.d_height = dstrect->h;
info.d_skip = dst->pitch - info.d_width * dst->format->BytesPerPixel;
info.aux_data = src->map->sw_data->aux_data;
info.src = src->format;
info.table = src->map->table;
info.dst = dst->format;
RunBlit = src->map->sw_data->blit;
/* Run the actual software blit */
RunBlit(&info);
}
/* We need to unlock the surfaces if they're locked */
if (dst_locked) {
SDL_UnlockSurface(dst);
}
if (src_locked) {
SDL_UnlockSurface(src);
}
/* Blit is done! */
return (okay ? 0 : -1);
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}
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#ifdef MMX_ASMBLIT
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static __inline__ void
SDL_memcpyMMX(Uint8 * to, const Uint8 * from, int len)
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int i;
for (i = 0; i < len / 8; i++) {
__asm__ __volatile__(" movq (%0), %%mm0\n"
" movq %%mm0, (%1)\n"::"r"(from),
"r"(to):"memory");
from += 8;
to += 8;
}
if (len & 7)
SDL_memcpy(to, from, len & 7);
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static __inline__ void
SDL_memcpySSE(Uint8 * to, const Uint8 * from, int len)
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int i;
__asm__ __volatile__(" prefetchnta (%0)\n"
" prefetchnta 64(%0)\n"
" prefetchnta 128(%0)\n"
" prefetchnta 192(%0)\n"::"r"(from));
for (i = 0; i < len / 8; i++) {
__asm__ __volatile__(" prefetchnta 256(%0)\n"
" movq (%0), %%mm0\n"
" movntq %%mm0, (%1)\n"::"r"(from),
"r"(to):"memory");
from += 8;
to += 8;
}
if (len & 7)
SDL_memcpy(to, from, len & 7);
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}
#endif
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static void
SDL_BlitCopy(SDL_BlitInfo * info)
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{
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Uint8 *src, *dst;
int w, h;
int srcskip, dstskip;
w = info->d_width * info->dst->BytesPerPixel;
h = info->d_height;
src = info->s_pixels;
dst = info->d_pixels;
srcskip = w + info->s_skip;
dstskip = w + info->d_skip;
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#ifdef MMX_ASMBLIT
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if (SDL_HasSSE()) {
while (h--) {
SDL_memcpySSE(dst, src, w);
src += srcskip;
dst += dstskip;
}
__asm__ __volatile__(" emms\n"::);
} else if (SDL_HasMMX()) {
while (h--) {
SDL_memcpyMMX(dst, src, w);
src += srcskip;
dst += dstskip;
}
__asm__ __volatile__(" emms\n"::);
} else
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while (h--) {
SDL_memcpy(dst, src, w);
src += srcskip;
dst += dstskip;
}
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}
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static void
SDL_BlitCopyOverlap(SDL_BlitInfo * info)
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{
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Uint8 *src, *dst;
int w, h;
int srcskip, dstskip;
w = info->d_width * info->dst->BytesPerPixel;
h = info->d_height;
src = info->s_pixels;
dst = info->d_pixels;
srcskip = w + info->s_skip;
dstskip = w + info->d_skip;
if (dst < src) {
while (h--) {
SDL_memcpy(dst, src, w);
src += srcskip;
dst += dstskip;
}
} else {
src += ((h - 1) * srcskip);
dst += ((h - 1) * dstskip);
while (h--) {
SDL_revcpy(dst, src, w);
src -= srcskip;
dst -= dstskip;
}
}
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}
/* Figure out which of many blit routines to set up on a surface */
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int
SDL_CalculateBlit(SDL_Surface * surface)
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{
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int blit_index;
/* Clean everything out to start */
if ((surface->flags & SDL_RLEACCEL) == SDL_RLEACCEL) {
SDL_UnRLESurface(surface, 1);
}
surface->map->sw_blit = NULL;
/* Get the blit function index, based on surface mode */
/* { 0 = nothing, 1 = colorkey, 2 = alpha, 3 = colorkey+alpha } */
blit_index = 0;
blit_index |= (!!(surface->flags & SDL_SRCCOLORKEY)) << 0;
if (surface->flags & SDL_SRCALPHA
&& (surface->format->alpha != SDL_ALPHA_OPAQUE
|| surface->format->Amask)) {
blit_index |= 2;
}
/* Check for special "identity" case -- copy blit */
if (surface->map->identity && blit_index == 0) {
surface->map->sw_data->blit = SDL_BlitCopy;
/* Handle overlapping blits on the same surface */
if (surface == surface->map->dst) {
surface->map->sw_data->blit = SDL_BlitCopyOverlap;
}
} else {
if (surface->format->BitsPerPixel < 8) {
surface->map->sw_data->blit =
SDL_CalculateBlit0(surface, blit_index);
} else {
switch (surface->format->BytesPerPixel) {
case 1:
surface->map->sw_data->blit =
SDL_CalculateBlit1(surface, blit_index);
break;
case 2:
case 3:
case 4:
surface->map->sw_data->blit =
SDL_CalculateBlitN(surface, blit_index);
break;
default:
surface->map->sw_data->blit = NULL;
break;
}
}
}
/* Make sure we have a blit function */
if (surface->map->sw_data->blit == NULL) {
SDL_InvalidateMap(surface->map);
SDL_SetError("Blit combination not supported");
return (-1);
}
/* Choose software blitting function */
if (surface->flags & SDL_RLEACCELOK) {
if (surface->map->identity
&& (blit_index == 1
|| (blit_index == 3 && !surface->format->Amask))) {
if (SDL_RLESurface(surface) == 0)
surface->map->sw_blit = SDL_RLEBlit;
} else if (blit_index == 2 && surface->format->Amask) {
if (SDL_RLESurface(surface) == 0)
surface->map->sw_blit = SDL_RLEAlphaBlit;
}
}
if (surface->map->sw_blit == NULL) {
surface->map->sw_blit = SDL_SoftBlit;
}
return (0);
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}
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/* vi: set ts=4 sw=4 expandtab: */