pandory500/SDL-mirror
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Software scaling support. Not very fast, but it seems to work.

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This commit is contained in:
Ken Rogoway 2011-02-14 11:50:18 -06:00
parent 20b4d9f762
commit 32d70d6f2b
3 changed files with 62 additions and 1 deletions
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11
include/SDL_surface.h
View file

@ -464,6 +464,17 @@ extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface * src,
SDL_Surface * dst,
const SDL_Rect * dstrect);
/**
* \brief Perform a fast, low quality, stretch blit between two surfaces of the
* different pixel formats.
*
* \note This function calls SDL_SoftStretch or SDL_LowerBlit.
*/
extern DECLSPEC int SDLCALL SDL_BlitScaled
(SDL_Surface * src, const SDL_Rect * srcrect,
SDL_Surface * dst, const SDL_Rect * dstrect);
/* Ends C function definitions when using C++ */
#ifdef __cplusplus
/* *INDENT-OFF* */

7
src/render/software/SDL_render_sw.c
View file

@ -364,7 +364,12 @@ SW_RenderCopy(SDL_Renderer * renderer, SDL_Texture * texture,
if (!surface) {
return -1;
}
return SDL_BlitSurface(src, srcrect, surface, &final_rect);
if ( srcrect->w == final_rect.w && srcrect->h == final_rect.h ) {
return SDL_BlitSurface(src, srcrect, surface, &final_rect);
} else {
return SDL_BlitScaled(src, srcrect, surface, &final_rect);
}
}
static int

45
src/video/SDL_surface.c
View file

@ -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
*/