Mercurial > sdl-ios-xcode
view docs/man3/SDL_ListModes.3 @ 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 | e5bc29de3f0a |
children | 546f7c1eb755 |
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.TH "SDL_ListModes" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_ListModes\- Returns a pointer to an array of available screen dimensions for the given format and video flags .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_Rect **\fBSDL_ListModes\fP\fR(\fBSDL_PixelFormat *format, Uint32 flags\fR); .SH "DESCRIPTION" .PP Return a pointer to an array of available screen dimensions for the given format and video flags, sorted largest to smallest\&. Returns \fBNULL\fP if there are no dimensions available for a particular format, or \fB-1\fR if any dimension is okay for the given format\&. .PP If \fBformat\fR is \fBNULL\fP, the mode list will be for the format returned by \fISDL_GetVideoInfo()\fR->\fBvfmt\fR\&. The \fBflag\fR parameter is an OR\&'d combination of \fIsurface\fR flags\&. The flags are the same as those used \fI\fBSDL_SetVideoMode\fP\fR and they play a strong role in deciding what modes are valid\&. For instance, if you pass \fBSDL_HWSURFACE\fP as a flag only modes that support hardware video surfaces will be returned\&. .SH "EXAMPLE" .PP .nf \f(CWSDL_Rect **modes; int i; \&. \&. \&. /* Get available fullscreen/hardware modes */ modes=SDL_ListModes(NULL, SDL_FULLSCREEN|SDL_HWSURFACE); /* Check is there are any modes available */ if(modes == (SDL_Rect **)0){ printf("No modes available! "); exit(-1); } /* Check if or resolution is restricted */ if(modes == (SDL_Rect **)-1){ printf("All resolutions available\&. "); } else{ /* Print valid modes */ printf("Available Modes "); for(i=0;modes[i];++i) printf(" %d x %d ", modes[i]->w, modes[i]->h); } \&. \&.\fR .fi .PP .SH "SEE ALSO" .PP \fI\fBSDL_SetVideoMode\fP\fR, \fI\fBSDL_GetVideoInfo\fP\fR, \fI\fBSDL_Rect\fR\fR, \fI\fBSDL_PixelFormat\fR\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01