view docs/man3/SDL_GLattr.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_GLattr" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_GLattr\- SDL GL Attributes
.SH "ATTRIBUTES"
.TP 20
\fBSDL_GL_RED_SIZE\fP
Size of the framebuffer red component, in bits
.TP 20
\fBSDL_GL_GREEN_SIZE\fP
Size of the framebuffer green component, in bits
.TP 20
\fBSDL_GL_BLUE_SIZE\fP
Size of the framebuffer blue component, in bits
.TP 20
\fBSDL_GL_ALPHA_SIZE\fP
Size of the framebuffer alpha component, in bits
.TP 20
\fBSDL_GL_DOUBLEBUFFER\fP
0 or 1, enable or disable double buffering
.TP 20
\fBSDL_GL_BUFFER_SIZE\fP
Size of the framebuffer, in bits
.TP 20
\fBSDL_GL_DEPTH_SIZE\fP
Size of the depth buffer, in bits
.TP 20
\fBSDL_GL_STENCIL_SIZE\fP
Size of the stencil buffer, in bits
.TP 20
\fBSDL_GL_ACCUM_RED_SIZE\fP
Size of the accumulation buffer red component, in bits
.TP 20
\fBSDL_GL_ACCUM_GREEN_SIZE\fP
Size of the accumulation buffer green component, in bits
.TP 20
\fBSDL_GL_ACCUM_BLUE_SIZE\fP
Size of the accumulation buffer blue component, in bits
.TP 20
\fBSDL_GL_ACCUM_ALPHA_SIZE\fP
Size of the accumulation buffer alpha component, in bits
.SH "DESCRIPTION"
.PP
While you can set most OpenGL attributes normally, the attributes list above must be known \fIbefore\fP SDL sets the video mode\&. These attributes a set and read with \fI\fBSDL_GL_SetAttribute\fP\fR and \fI\fBSDL_GL_GetAttribute\fP\fR\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_GL_SetAttribute\fP\fR, \fI\fBSDL_GL_GetAttribute\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01