Mercurial > sdl-ios-xcode
view docs/man3/SDL_MapRGB.3 @ 911:04a403e4ccf5
Date: Mon, 3 May 2004 03:15:01 +0100
From: David Symmonds
Subject: SDL Typedef Structs
Hi, Thanks for the SDL libraries, I have been using them for about a year
now and they are really brilliant. One thing that I have just found whilst
using them through C++ (and needing forward declarations) is that when you
typedef structs you sometimes use
typedef struct Name
{
...
}Name;
e.g. SDL_Surface
and other times use
typedef struct
{
...
}Name;
e.g. SDL_Rect
The first type works fine, when I define a header file I can just put
'struct Name;' at the top and use the Name throughout. However, the second
type is harder to use in a header, and I haven't found a way yet, other than
to include 'SDL.h' in the header file (undesirable). Would there be any harm
in changing the definition of SDL_Rect and such like to the second form?
| author | Sam Lantinga <slouken@libsdl.org> |
|---|---|
| date | Sun, 18 Jul 2004 22:57:40 +0000 |
| parents | e5bc29de3f0a |
| children | 546f7c1eb755 |
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.TH "SDL_MapRGB" "3" "Tue 11 Sep 2001, 23:01" "SDL" "SDL API Reference" .SH "NAME" SDL_MapRGB\- Map a RGB color value to a pixel format\&. .SH "SYNOPSIS" .PP \fB#include "SDL\&.h" .sp \fBUint32 \fBSDL_MapRGB\fP\fR(\fBSDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b\fR); .SH "DESCRIPTION" .PP Maps the RGB color value to the specified pixel format and returns the pixel value as a 32-bit int\&. .PP If the format has a palette (8-bit) the index of the closest matching color in the palette will be returned\&. .PP If the specified pixel format has an alpha component it will be returned as all 1 bits (fully opaque)\&. .SH "RETURN VALUE" .PP A pixel value best approximating the given RGB color value for a given pixel format\&. If the pixel format bpp (color depth) is less than 32-bpp then the unused upper bits of the return value can safely be ignored (e\&.g\&., with a 16-bpp format the return value can be assigned to a \fBUint16\fP, and similarly a \fBUint8\fP for an 8-bpp format)\&. .SH "SEE ALSO" .PP \fI\fBSDL_GetRGB\fP\fR, \fI\fBSDL_GetRGBA\fP\fR, \fI\fBSDL_MapRGBA\fP\fR, \fI\fBSDL_PixelFormat\fR\fR ...\" created by instant / docbook-to-man, Tue 11 Sep 2001, 23:01