SDL_yuv.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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/* This is the implementation of the YUV video surface support */
#include "SDL_video.h"
#include "SDL_sysvideo.h"
#include "SDL_yuvfuncs.h"
#include "SDL_yuv_sw_c.h"
SDL_Overlay *SDL_CreateYUVOverlay(int w, int h, Uint32 format,
SDL_Surface *display)
{
SDL_VideoDevice *video = current_video;
SDL_VideoDevice *this = current_video;
const char *yuv_hwaccel;
SDL_Overlay *overlay;
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if ( (display->flags & SDL_OPENGL) == SDL_OPENGL ) {
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SDL_SetError("YUV overlays are not supported in OpenGL mode");
return NULL;
}
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/* Display directly on video surface, if possible */
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if ( SDL_getenv("SDL_VIDEO_YUV_DIRECT") ) {
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if ( (display == SDL_PublicSurface) &&
((SDL_VideoSurface->format->BytesPerPixel == 2) ||
(SDL_VideoSurface->format->BytesPerPixel == 4)) ) {
display = SDL_VideoSurface;
}
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}
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overlay = NULL;
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yuv_hwaccel = SDL_getenv("SDL_VIDEO_YUV_HWACCEL");
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if ( ((display == SDL_VideoSurface) && video->CreateYUVOverlay) &&
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(!yuv_hwaccel || (SDL_atoi(yuv_hwaccel) > 0)) ) {
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overlay = video->CreateYUVOverlay(this, w, h, format, display);
}
/* If hardware YUV overlay failed ... */
if ( overlay == NULL ) {
overlay = SDL_CreateYUV_SW(this, w, h, format, display);
}
return overlay;
}
int SDL_LockYUVOverlay(SDL_Overlay *overlay)
{
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return overlay->hwfuncs->Lock(current_video, overlay);
}
void SDL_UnlockYUVOverlay(SDL_Overlay *overlay)
{
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overlay->hwfuncs->Unlock(current_video, overlay);
}
int SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect)
{
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SDL_Rect src, dst;
int srcx, srcy, srcw, srch;
int dstx, dsty, dstw, dsth;
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if ( overlay == NULL || dstrect == NULL ) {
SDL_SetError("Passed NULL overlay or dstrect");
return -1;
}
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/* Clip the rectangle to the screen area */
srcx = 0;
srcy = 0;
srcw = overlay->w;
srch = overlay->h;
dstx = dstrect->x;
dsty = dstrect->y;
dstw = dstrect->w;
dsth = dstrect->h;
if ( dstx < 0 ) {
srcw += (dstx * overlay->w) / dstrect->w;
dstw += dstx;
srcx -= (dstx * overlay->w) / dstrect->w;
dstx = 0;
}
if ( (dstx+dstw) > current_video->screen->w ) {
int extra = (dstx+dstw - current_video->screen->w);
srcw -= (extra * overlay->w) / dstrect->w;
dstw -= extra;
}
if ( dsty < 0 ) {
srch += (dsty * overlay->h) / dstrect->h;
dsth += dsty;
srcy -= (dsty * overlay->h) / dstrect->h;
dsty = 0;
}
if ( (dsty+dsth) > current_video->screen->h ) {
int extra = (dsty+dsth - current_video->screen->h);
srch -= (extra * overlay->h) / dstrect->h;
dsth -= extra;
}
if ( srcw <= 0 || srch <= 0 ||
srch <= 0 || dsth <= 0 ) {
return 0;
}
/* Ugh, I can't wait for SDL_Rect to be int values */
src.x = srcx;
src.y = srcy;
src.w = srcw;
src.h = srch;
dst.x = dstx;
dst.y = dsty;
dst.w = dstw;
dst.h = dsth;
return overlay->hwfuncs->Display(current_video, overlay, &src, &dst);
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}
void SDL_FreeYUVOverlay(SDL_Overlay *overlay)
{
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if ( overlay == NULL ) {
return;
}
if ( overlay->hwfuncs ) {
overlay->hwfuncs->FreeHW(current_video, overlay);
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}
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}