Mercurial > sdl-ios-xcode

view docs/html/sdljoyaxisevent.html @ 1542:a8bf1aa21020

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
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 355632dca928
children
line wrap: on
line source

<HTML
><HEAD
><TITLE
>SDL_JoyAxisEvent</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="SDL Event Structures."
HREF="eventstructures.html"><LINK
REL="PREVIOUS"
TITLE="SDL_MouseButtonEvent"
HREF="sdlmousebuttonevent.html"><LINK
REL="NEXT"
TITLE="SDL_JoyButtonEvent"
HREF="sdljoybuttonevent.html"></HEAD
><BODY
CLASS="REFENTRY"
BGCOLOR="#FFF8DC"
TEXT="#000000"
LINK="#0000ee"
VLINK="#551a8b"
ALINK="#ff0000"
><DIV
CLASS="NAVHEADER"
><TABLE
SUMMARY="Header navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TH
COLSPAN="3"
ALIGN="center"
>SDL Library Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
ALIGN="left"
VALIGN="bottom"
><A
HREF="sdlmousebuttonevent.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="80%"
ALIGN="center"
VALIGN="bottom"
></TD
><TD
WIDTH="10%"
ALIGN="right"
VALIGN="bottom"
><A
HREF="sdljoybuttonevent.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
></TABLE
><HR
ALIGN="LEFT"
WIDTH="100%"></DIV
><H1
><A
NAME="SDLJOYAXISEVENT"
></A
>SDL_JoyAxisEvent</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN4203"
></A
><H2
>Name</H2
>SDL_JoyAxisEvent&nbsp;--&nbsp;Joystick axis motion event structure</DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4206"
></A
><H2
>Structure Definition</H2
><PRE
CLASS="PROGRAMLISTING"
>typedef struct{
  Uint8 type;
  Uint8 which;
  Uint8 axis;
  Sint16 value;
} SDL_JoyAxisEvent;</PRE
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4209"
></A
><H2
>Structure Data</H2
><DIV
CLASS="INFORMALTABLE"
><A
NAME="AEN4211"
></A
><P
></P
><TABLE
BORDER="0"
CLASS="CALSTABLE"
><TBODY
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>type</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="LITERAL"
>SDL_JOYAXISMOTION</TT
></TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>which</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Joystick device index</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>axis</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Joystick axis index</TD
></TR
><TR
><TD
ALIGN="LEFT"
VALIGN="TOP"
><TT
CLASS="STRUCTFIELD"
><I
>value</I
></TT
></TD
><TD
ALIGN="LEFT"
VALIGN="TOP"
>Axis value (range: -32768 to 32767)</TD
></TR
></TBODY
></TABLE
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4231"
></A
><H2
>Description</H2
><P
><SPAN
CLASS="STRUCTNAME"
>SDL_JoyAxisEvent</SPAN
> is a member of the <A
HREF="sdlevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
></A
> union and is used when an event of type <TT
CLASS="LITERAL"
>SDL_JOYAXISMOTION</TT
> is reported.</P
><P
>A <TT
CLASS="LITERAL"
>SDL_JOYAXISMOTION</TT
> event occurs when ever a user moves an axis on the joystick. The field <TT
CLASS="STRUCTFIELD"
><I
>which</I
></TT
> is the index of the joystick that reported the event and <TT
CLASS="STRUCTFIELD"
><I
>axis</I
></TT
> is the index of the axis (for a more detailed explaination see the <A
HREF="joystick.html"
>Joystick section</A
>). <TT
CLASS="STRUCTFIELD"
><I
>value</I
></TT
> is the current position of the axis.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN4244"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlevent.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_Event</SPAN
></A
>,
<A
HREF="joystick.html"
>Joystick Functions</A
>,
<A
HREF="sdljoystickeventstate.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickEventState</TT
></A
>,
<A
HREF="sdljoystickgetaxis.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickGetAxis</TT
></A
></P
></DIV
><DIV
CLASS="NAVFOOTER"
><HR
ALIGN="LEFT"
WIDTH="100%"><TABLE
SUMMARY="Footer navigation table"
WIDTH="100%"
BORDER="0"
CELLPADDING="0"
CELLSPACING="0"
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
><A
HREF="sdlmousebuttonevent.html"
ACCESSKEY="P"
>Prev</A
></TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="index.html"
ACCESSKEY="H"
>Home</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
><A
HREF="sdljoybuttonevent.html"
ACCESSKEY="N"
>Next</A
></TD
></TR
><TR
><TD
WIDTH="33%"
ALIGN="left"
VALIGN="top"
>SDL_MouseButtonEvent</TD
><TD
WIDTH="34%"
ALIGN="center"
VALIGN="top"
><A
HREF="eventstructures.html"
ACCESSKEY="U"
>Up</A
></TD
><TD
WIDTH="33%"
ALIGN="right"
VALIGN="top"
>SDL_JoyButtonEvent</TD
></TR
></TABLE
></DIV
></BODY
></HTML
>