sdlgfxblitfunc.h File Reference

(986a3bf)

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Functions
int	SDLgfxBlitRGBA (const SDL_Surface *const src, const SDL_Rect *const srcrect, SDL_Surface *const dst, const SDL_Rect *const dstrect)

Function Documentation

SDLgfxBlitRGBA()

int SDLgfxBlitRGBA	(	const SDL_Surface *const	src,
		const SDL_Rect *const	srcrect,
		SDL_Surface *const	dst,
		const SDL_Rect *const	dstrect
	)

Definition at line 437 of file sdlgfxblitfunc.cpp.

{
 SDL_Rect sr;
 SDL_Rect dr;
 int srcx;
 int srcy;
 int w;
 int h;
 
 /*
 * Make sure the surfaces aren't locked
 */
 if (src == nullptr ||
 dst == nullptr)
 {
 reportAlways("SDLgfxBlitRGBA: passed a NULL surface")
 return -1;
 }
 
 /*
 * If the destination rectangle is NULL, use the entire dest surface
 */
 if (dstrect == nullptr)
 {
 dr.x = 0;
 dr.y = 0;
 dr.w = CAST_U16(dst->w);
 dr.h = CAST_U16(dst->h);
 }
 else
 {
 dr = *dstrect;
 }
 
 /*
 * Clip the source rectangle to the source surface
 */
 if (srcrect != nullptr)
 {
 int maxw;
 int maxh;
 
 srcx = srcrect->x;
 w = srcrect->w;
 maxw = src->w - srcx;
 if (maxw < w)
 w = maxw;
 
 srcy = srcrect->y;
 h = srcrect->h;
 maxh = src->h - srcy;
 if (maxh < h)
 h = maxh;
 }
 else
 {
 srcx = 0;
 srcy = 0;
 w = src->w;
 h = src->h;
 }
 
 /*
 * Clip the destination rectangle against the clip rectangle
 */
 const SDL_Rect *const clip = &dst->clip_rect;
 int dx;
 int dy;
 
 dx = clip->x - dr.x;
 if (dx > 0)
 {
 w -= dx;
 dr.x += dx;
 srcx += CAST_S16(dx);
 }
 dx = dr.x + w - clip->x - clip->w;
 if (dx > 0)
 w -= dx;
 
 dy = clip->y - dr.y;
 if (dy > 0)
 {
 h -= dy;
 dr.y += dy;
 srcy += CAST_S16(dy);
 }
 dy = dr.y + h - clip->y - clip->h;
 if (dy > 0)
 h -= dy;
 
 if (w > 0 && h > 0)
 {
 sr.x = CAST_S16(srcx);
 sr.y = CAST_S16(srcy);
 sr.w = dr.w = CAST_U16(w);
 sr.h = dr.h = CAST_U16(h);
 return _SDL_gfxBlitRGBACall(src, &sr, dst, &dr);
 }
 
 return 0;
}

References _SDL_gfxBlitRGBACall(), CAST_S16, CAST_U16, and reportAlways.

Referenced by SDLImageHelper::combineSurface(), and TestLauncher::testBlitSpeed().