/*

    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);

}