/*

SDL - Simple DirectMedia Layer

Copyright (C) 1997-2006 Sam Lantinga

This library is free software; you can redistribute it and/or

modify it under the terms of the GNU Lesser General Public

License as published by the Free Software Foundation; either

version 2.1 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

Lesser General Public License for more details.

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

Sam Lantinga

slouken@libsdl.org

*/

#include "SDL_config.h"

/* 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;

if ( (display->flags & SDL_OPENGL) == SDL_OPENGL ) {

SDL_SetError("YUV overlays are not supported in OpenGL mode");

return NULL;

}

/* Display directly on video surface, if possible */

if ( SDL_getenv("SDL_VIDEO_YUV_DIRECT") ) {

if ( (display == SDL_PublicSurface) &&

((SDL_VideoSurface->format->BytesPerPixel == 2) ||

(SDL_VideoSurface->format->BytesPerPixel == 4)) ) {

display = SDL_VideoSurface;

}

}

overlay = NULL;

yuv_hwaccel = SDL_getenv("SDL_VIDEO_YUV_HWACCEL");

if ( ((display == SDL_VideoSurface) && video->CreateYUVOverlay) &&

(!yuv_hwaccel || (SDL_atoi(yuv_hwaccel) > 0)) ) {

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)

{

if ( overlay == NULL ) {

SDL_SetError("Passed NULL overlay");

return -1;

}

return overlay->hwfuncs->Lock(current_video, overlay);

}

void SDL_UnlockYUVOverlay(SDL_Overlay *overlay)

{

if ( overlay == NULL ) {

return;

}

overlay->hwfuncs->Unlock(current_video, overlay);

}

int SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect)

{

SDL_Rect src, dst;

int srcx, srcy, srcw, srch;

int dstx, dsty, dstw, dsth;

if ( overlay == NULL || dstrect == NULL ) {

SDL_SetError("Passed NULL overlay or dstrect");

return -1;

}

/* 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);

}

void SDL_FreeYUVOverlay(SDL_Overlay *overlay)

{

if ( overlay == NULL ) {

return;

}

if ( overlay->hwfuncs ) {

overlay->hwfuncs->FreeHW(current_video, overlay);

}

SDL_free(overlay);

}