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Software scaling support. Not very fast, but it seems to work.

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KenRogoway committed Feb 14, 2011
1 parent 69af9a3 commit ea308dc521305636f3c5cc31f4ec244f993d2a69

File 3 of 3 in ea308dc

@@ -639,6 +639,51 @@ SDL_UpperBlit(SDL_Surface * src, const SDL_Rect * srcrect,
return 0;
}

/*
* Scale and blit a surface
*/
int
SDL_BlitScaled(SDL_Surface * src, const SDL_Rect * srcrect,
SDL_Surface * dst, const SDL_Rect * dstrect)
{
/* Save off the original dst width, height */
int dstW = dstrect->w;
int dstH = dstrect->h;
SDL_Rect final_dst = *dstrect;
SDL_Rect final_src = *srcrect;

/* Clip the dst surface to the dstrect */
SDL_SetClipRect( dst, &final_dst );

/* If the dest was clipped to a zero sized rect then exit */
if ( dst->clip_rect.w <= 0 || dst->clip_rect.h <= 0 ) {
return -1;
}

/* Did the dst width change? */
if ( dstW != dst->clip_rect.w ) {
/* scale the src width appropriately */
final_src.w = final_src.w * dst->clip_rect.w / dstW;
}

/* Did the dst height change? */
if ( dstH != dst->clip_rect.h ) {
/* scale the src width appropriately */
final_src.h = final_src.h * dst->clip_rect.h / dstH;
}

/* Clip the src surface to the srcrect */
SDL_SetClipRect( src, &final_src );

src->map->info.flags |= SDL_COPY_NEAREST;

if ( src->format->format == dst->format->format && !SDL_ISPIXELFORMAT_INDEXED(src->format->format) ) {
return SDL_SoftStretch( src, &final_src, dst, &final_dst );
} else {
return SDL_LowerBlit( src, &final_src, dst, &final_dst );
}
}

/*
* Lock a surface to directly access the pixels
*/

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