Von: Thomas Zimmermann Betreff: [SDL] [PATCH] Make static variables const Datum: Tue, 19 May 2009 19:45:37 +0200 Hi, this is a set of simple changes which make some of SDL's internal static arrays constant. The purpose is to shrink the number of write-able static bytes and thus increase the number of memory pages shared between SDL applications. The patch set is against trunk@4513. Each of the attached patch files is specific to a sub-system. The set is completed by a second mail, because of the list's 40 KiB limit. The files readelf-r4513.txt and readelf-const-patch.txt where made by calling 'readelf -S libSDL.so'. They show the difference in ELF sections without and with the patch. Some numbers measured on my x86-64: Before [13] .rodata PROGBITS 00000000000eaaa0 000eaaa0 0000000000008170 0000000000000000 A 0 0 32 [19] .data.rel.ro PROGBITS 00000000003045e0 001045e0 00000000000023d0 0000000000000000 WA 0 0 32 [23] .data PROGBITS 00000000003076e0 001076e0 0000000000004988 0000000000000000 WA 0 0 32 After [13] .rodata PROGBITS 00000000000eaaa0 000eaaa0 0000000000009a50 0000000000000000 A 0 0 32 [19] .data.rel.ro PROGBITS 0000000000306040 00106040 0000000000002608 0000000000000000 WA 0 0 32 [23] .data PROGBITS 0000000000309360 00109360 0000000000002e88 0000000000000000 WA 0 0 32 The size of the write-able data section decreased considerably. Some entries became const-after-relocation, while most of its content went straight into the read-only data section. Best regards, Thomas

.TH "SDL_SetColorKey" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" 
.SH "NAME"
SDL_SetColorKey \- Sets the color key (transparent pixel) in a blittable surface and RLE acceleration\&.
.SH "SYNOPSIS"
.PP
\fB#include "SDL\&.h"
.sp
\fBint \fBSDL_SetColorKey\fP\fR(\fBSDL_Surface *surface, Uint32 flag, Uint32 key\fR);
.SH "DESCRIPTION"
.PP
 Sets the color key (transparent pixel) in a blittable surface and enables or disables RLE blit acceleration\&.
.PP
RLE acceleration can substantially speed up blitting of images with large horizontal runs of transparent pixels (i\&.e\&., pixels that match the \fBkey\fR value)\&. The \fBkey\fR must be of the same pixel format as the \fBsurface\fR, \fI\fBSDL_MapRGB\fP\fR is often useful for obtaining an acceptable value\&.
.PP
If \fBflag\fR is \fBSDL_SRCCOLORKEY\fP then \fBkey\fR is the transparent pixel value in the source image of a blit\&.
.PP
If \fBflag\fR is OR\&'d with \fBSDL_RLEACCEL\fP then the surface will be draw using RLE acceleration when drawn with \fISDL_BlitSurface\fR\&. The surface will actually be encoded for RLE acceleration the first time \fISDL_BlitSurface\fR or \fISDL_DisplayFormat\fR is called on the surface\&.
.PP
If \fBflag\fR is 0, this function clears any current color key\&.
.SH "RETURN VALUE"
.PP
This function returns \fB0\fR, or \fB-1\fR if there was an error\&.
.SH "SEE ALSO"
.PP
\fI\fBSDL_BlitSurface\fP\fR, \fI\fBSDL_DisplayFormat\fP\fR, \fI\fBSDL_MapRGB\fP\fR, \fI\fBSDL_SetAlpha\fP\fR
...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01