view docs/html/sdlmaprgba.html @ 1525:23a347cfbed8

Fixed bug #38 I'm using SDL 1.2.9 with Visual C++ 7.0 on Windows 2000. Here's the setup: my game starts in a window, with SDL_WM_GrabInput(SDL_GRAB_ON) to constrain the cursor to the game window. The mouse cursor is outside of the window when the game launches, and when the window appears the cursor is grabbed and placed at the top left corner of the inside of the game window. At this point, if I click the mouse without moving it, the SDL_MOUSEBUTTONDOWN event's mouse coordinates are (65535,65535).
author Sam Lantinga <slouken@libsdl.org>
date Tue, 14 Mar 2006 06:00:30 +0000
parents 355632dca928
children
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>SDL_MapRGBA</H1
><DIV
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><A
NAME="AEN1687"
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><H2
>Name</H2
>SDL_MapRGBA&nbsp;--&nbsp;Map a RGBA color value to a pixel format.</DIV
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CLASS="REFSYNOPSISDIV"
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>Synopsis</H2
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><P
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><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>Uint32 <B
CLASS="FSFUNC"
>SDL_MapRGBA</B
></CODE
>(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b, Uint8 a);</CODE
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><A
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><H2
>Description</H2
><P
>Maps the RGBA color value to the specified pixel format and returns the
pixel value as a 32-bit int.</P
><P
>If the format has a palette (8-bit) the index of the closest matching
color in the palette will be returned.</P
><P
>If the specified pixel format has no alpha component the alpha value
will be ignored (as it will be in formats with a palette).</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1702"
></A
><H2
>Return Value</H2
><P
>A pixel value best approximating the given RGBA 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
<SPAN
CLASS="TYPE"
>Uint16</SPAN
>, and similarly a <SPAN
CLASS="TYPE"
>Uint8</SPAN
> for an 8-bpp
format).</P
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><H2
>See Also</H2
><P
><A
HREF="sdlgetrgb.html"
>SDL_GetRGB</A
>,
<A
HREF="sdlgetrgba.html"
>SDL_GetRGBA</A
>,
<A
HREF="sdlmaprgb.html"
>SDL_MapRGB</A
>,
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HREF="sdlpixelformat.html"
>SDL_PixelFormat</A
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