Mercurial > sdl-ios-xcode
view docs/man3/SDL_JoyHatEvent.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 |
line wrap: on
line source
.TH "SDL_JoyHatEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" .SH "NAME" SDL_JoyHatEvent\- Joystick hat position change event structure .SH "STRUCTURE DEFINITION" .PP .nf \f(CWtypedef struct{ Uint8 type; Uint8 which; Uint8 hat; Uint8 value; } SDL_JoyHatEvent;\fR .fi .PP .SH "STRUCTURE DATA" .TP 20 \fBtype\fR \fBSDL_JOY\fP .TP 20 \fBwhich\fR Joystick device index .TP 20 \fBhat\fR Joystick hat index .TP 20 \fBvalue\fR Hat position .SH "DESCRIPTION" .PP \fBSDL_JoyHatEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_JOYHATMOTION\fP is reported\&. .PP A \fBSDL_JOYHATMOTION\fP event occurs when ever a user moves a hat on the joystick\&. The field \fBwhich\fR is the index of the joystick that reported the event and \fBhat\fR is the index of the hat (for a more detailed exlaination see the \fIJoystick section\fR)\&. \fBvalue\fR is the current position of the hat\&. It is a logically OR\&'d combination of the following values (whose meanings should be pretty obvious:) : .IP "" 10 \fBSDL_HAT_CENTERED\fP .IP "" 10 \fBSDL_HAT_UP\fP .IP "" 10 \fBSDL_HAT_RIGHT\fP .IP "" 10 \fBSDL_HAT_DOWN\fP .IP "" 10 \fBSDL_HAT_LEFT\fP .PP The following defines are also provided: .IP "" 10 \fBSDL_HAT_RIGHTUP\fP .IP "" 10 \fBSDL_HAT_RIGHTDOWN\fP .IP "" 10 \fBSDL_HAT_LEFTUP\fP .IP "" 10 \fBSDL_HAT_LEFTDOWN\fP .SH "SEE ALSO" .PP \fI\fBSDL_Event\fR\fR, \fIJoystick Functions\fR, \fI\fBSDL_JoystickEventState\fP\fR, \fI\fBSDL_JoystickGetHat\fP\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59