Mercurial > sdl-ios-xcode
view docs/man3/SDL_DisplayFormatAlpha.3 @ 4431:d660ca4f7b1f SDL-1.2
Fixed bug 944
Tatu Kilappa 2010-02-11 12:13:20 PST
When compiling with -Wconversion, gcc complains about a cast in SDL_endian.h
that might change the result as we are casting from an int into an Uint16. This
is of course not visible unless we are on a non-x86 platform where the
assembler is not available.
While it's not really an error, the warning is really annoying. To fix, change
SDL_endian.h line 87 to:
return(Uint16)((x<<8)|(x>>8));
Thank you.
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Tue, 13 Apr 2010 21:46:10 -0700 |
| parents | 1238da4a7112 |
| children |
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.TH "SDL_DisplayFormatAlpha" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_DisplayFormatAlpha \- Convert a surface to the display format .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBSDL_Surface *\fBSDL_DisplayFormatAlpha\fP\fR(\fBSDL_Surface *surface\fR); .SH "DESCRIPTION" .PP This function takes a surface and copies it to a new surface of the pixel format and colors of the video framebuffer plus an alpha channel, suitable for fast blitting onto the display surface\&. It calls \fISDL_ConvertSurface\fR .PP If you want to take advantage of hardware colorkey or alpha blit acceleration, you should set the colorkey and alpha value before calling this function\&. .PP This function can be used to convert a colourkey to an alpha channel, if the \fBSDL_SRCCOLORKEY\fP flag is set on the surface\&. The generated surface will then be transparent (alpha=0) where the pixels match the colourkey, and opaque (alpha=255) elsewhere\&. .SH "RETURN VALUE" .PP If the conversion fails or runs out of memory, it returns \fBNULL\fR .SH "SEE ALSO" .PP \fISDL_ConvertSurface\fR, \fISDL_SetAlpha\fR, \fISDL_SetColorKey\fR, \fISDL_DisplayFormat\fR, \fISDL_Surface\fR .\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01