view docs/man3/SDL_MouseMotionEvent.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_MouseMotionEvent" "3" "Tue 11 Sep 2001, 22:59" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_MouseMotionEvent\- Mouse motion event structure
.SH "STRUCTURE DEFINITION"
.PP
.nf
\f(CWtypedef struct{
  Uint8 type;
  Uint8 state;
  Uint16 x, y;
  Sint16 xrel, yrel;
} SDL_MouseMotionEvent;\fR
.fi
.PP
.SH "STRUCTURE DATA"
.TP 20
\fBtype\fR
\fBSDL_MOUSEMOTION\fP
.TP 20
\fBstate\fR
The current button state
.TP 20
\fBx\fR, \fBy\fR
The X/Y coordinates of the mouse
.TP 20
\fBxrel\fR, \fByrel\fR
Relative motion in the X/Y direction
.SH "DESCRIPTION"
.PP
\fBSDL_MouseMotionEvent\fR is a member of the \fI\fBSDL_Event\fR\fR union and is used when an event of type \fBSDL_MOUSEMOTION\fP is reported\&.
.PP
Simply put, a \fBSDL_MOUSEMOTION\fP type event occurs when a user moves the mouse within the application window or when \fI\fBSDL_WarpMouse\fP\fR is called\&. Both the absolute (\fBx\fR and \fBy\fR) and relative (\fBxrel\fR and \fByrel\fR) coordinates are reported along with the current button states (\fBstate\fR)\&. The button state can be interpreted using the \fBSDL_BUTTON\fP macro (see \fI\fBSDL_GetMouseState\fP\fR)\&.
.PP
If the cursor is hidden (\fI\fBSDL_ShowCursor\fP(0)\fR) and the input is grabbed (\fI\fBSDL_WM_GrabInput\fP(SDL_GRAB_ON)\fR), then the mouse will give relative motion events even when the cursor reaches the edge fo the screen\&. This is currently only implemented on Windows and Linux/Unix-a-likes\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_Event\fR\fR, \fI\fBSDL_MouseButtonEvent\fR\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 22:59