0ct0pu5/wesnoth
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Fix Alpha Blending issues in SDL2

Browse source 
This commit introduces a new function, sdl_copy_portion that should be
used when copying portions of the screen area for later copying back
onto the screen area. The function does a copy without alpha blending,
thus emulating the functionality that SDL1.2 provides.
This commit is contained in:
Andreas Löf 2015-09-24 16:02:39 +12:00
parent 9ae3b29f4a
commit 171963739b
5 changed files with 19 additions and 8 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
src/cursor.cpp
View file

@ -272,7 +272,7 @@ void draw(surface screen)
, cursor_y - shift_y[current_cursor]
, surf->w
, surf->h);
sdl_blit(screen,&area,cursor_buf,NULL);
sdl_copy_portion(screen,&area,cursor_buf,NULL);
// Blit the surface
sdl_blit(surf,NULL,screen,&area);

10
src/floating_label.cpp
View file

@ -260,6 +260,10 @@ void floating_label::draw(surface screen)
return;
}
if(screen == NULL) {
return;
}
create_surface();
if(surf_ == NULL) {
return;
@ -272,13 +276,9 @@ void floating_label::draw(surface screen)
}
}
if(screen == NULL) {
return;
}
SDL_Rect rect = sdl::create_rect(xpos(surf_->w), ypos_, surf_->w, surf_->h);
const clip_rect_setter clip_setter(screen, &clip_rect_);
sdl_blit(screen,&rect,buf_,NULL);
sdl_copy_portion(screen,&rect,buf_,NULL);
sdl_blit(surf_,NULL,screen,&rect);
update_rect(rect);

2
src/halo.cpp
View file

@ -240,7 +240,7 @@ bool halo_impl::effect::render()
buffer_.assign(get_surface_portion(screen,rect));
} else {
SDL_Rect rect = rect_;
sdl_blit(screen,&rect,buffer_,NULL);
sdl_copy_portion(screen,&rect,buffer_,NULL);
}
sdl_blit(surf_,NULL,screen,&rect);

2
src/sdl/utils.cpp
View file

@ -2548,7 +2548,7 @@ surface get_surface_portion(const surface &src, SDL_Rect &area, bool optimize_fo
return NULL;
}
sdl_blit(src, &area, dst, NULL);
sdl_copy_portion(src, &area, dst, NULL);
return optimize_format ? display_format_alpha(dst) : dst;
}

11
src/sdl/utils.hpp
View file

@ -113,6 +113,17 @@ inline void sdl_blit(const surface& src, SDL_Rect* src_rect, surface& dst, SDL_R
SDL_BlitSurface(src, src_rect, dst, dst_rect);
}
inline void sdl_copy_portion(const surface& screen, SDL_Rect* screen_rect, surface& dst, SDL_Rect* dst_rect){
#if SDL_VERSION_ATLEAST(2, 0, 0)
SDL_SetSurfaceBlendMode(screen, SDL_BLENDMODE_NONE);
SDL_SetSurfaceBlendMode(dst, SDL_BLENDMODE_NONE);
#endif
SDL_BlitSurface(screen, screen_rect, dst, dst_rect);
#if SDL_VERSION_ATLEAST(2, 0, 0)
SDL_SetSurfaceBlendMode(screen, SDL_BLENDMODE_BLEND);
#endif
}
/**
* This method blends a RGBA color. The method takes as input a surface,
* the RGB color to blend and a value specifying how much blending to apply.