Mercurial > sdl-ios-xcode
view src/video/SDL_yuv.c @ 1542:a8bf1aa21020
Fixed bug #15
SDL_blit_A.mmx-speed.patch.txt --
Speed improvements and a bugfix for the current GCC inline mmx
asm code:
- Changed some ops and removed some resulting useless ones.
- Added some instruction parallelism (some gain)
The resulting speed on my Xeon improved upto 35% depending on
the function (measured in fps).
- Fixed a bug where BlitRGBtoRGBSurfaceAlphaMMX() was
setting the alpha component on the destination surfaces (to
opaque-alpha) even when the surface had none.
SDL_blit_A.mmx-msvc.patch.txt --
MSVC mmx intrinsics version of the same GCC asm code.
MSVC compiler tries to parallelize the code and to avoid
register stalls, but does not always do a very good job.
Per-surface blending MSVC functions run quite a bit faster
than their pure-asm counterparts (upto 55% faster for 16bit
ones), but the per-pixel blending runs somewhat slower than asm.
- BlitRGBtoRGBSurfaceAlphaMMX and BlitRGBtoRGBPixelAlphaMMX (and all
variants) can now also handle formats other than (A)RGB8888. Formats
like RGBA8888 and some quite exotic ones are allowed -- like
RAGB8888, or actually anything having channels aligned on 8bit
boundary and full 8bit alpha (for per-pixel alpha blending).
The performance cost of this change is virtually 0 for per-surface
alpha blending (no extra ops inside the loop) and a single non-MMX
op inside the loop for per-pixel blending. In testing, the per-pixel
alpha blending takes a ~2% performance hit, but it still runs much
faster than the current code in CVS. If necessary, a separate function
with this functionality can be made.
This code requires Processor Pack for VC6.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Wed, 15 Mar 2006 15:39:29 +0000 |
parents | d910939febfa |
children | 51038e80ae59 |
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/* 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) { return overlay->hwfuncs->Lock(current_video, overlay); } void SDL_UnlockYUVOverlay(SDL_Overlay *overlay) { overlay->hwfuncs->Unlock(current_video, overlay); } int SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect) { return overlay->hwfuncs->Display(current_video, overlay, dstrect); } void SDL_FreeYUVOverlay(SDL_Overlay *overlay) { if ( overlay ) { if ( overlay->hwfuncs ) { overlay->hwfuncs->FreeHW(current_video, overlay); } SDL_free(overlay); } }