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Patch from Antonio SJ Musumeci: " This code with SDL-1.2.8 and CVS: #include <stdio.h> #include <stdlib.h> #include <SDL.h> int main(int argc, char** argv) { char alphabet[26] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"; char buffer_file[27] = {0}; char buffer_mem[27] = {0}; int rv_file; int rv_mem; FILE* file_ptr; SDL_RWops* rwop_file; SDL_RWops* rwop_mem; file_ptr = fopen("./blah", "w"); fwrite(alphabet, 1, sizeof(alphabet), file_ptr); fclose(file_ptr); rwop_mem = SDL_RWFromMem(alphabet, sizeof(alphabet)); rwop_file = SDL_RWFromFile("./blah", "r"); rv_mem = SDL_RWread(rwop_mem , buffer_mem, 5, 6); rv_file = SDL_RWread(rwop_file, buffer_file, 5, 6); printf("From File: %d %s\n" "From Mem: %d %s\n", rv_file, buffer_file, rv_mem, buffer_mem); printf("Seek end of File: %d\n" "Seek end of Mem: %d\n", SDL_RWseek(rwop_file, 0, SEEK_END), SDL_RWseek(rwop_mem , 0, SEEK_END)); SDL_RWclose(rwop_file); SDL_RWclose(rwop_mem); return 0; } Produces this output: From File: 5 ABCDEFGHIJKLMNOPQRSTUVWXYZ From Mem: 5 ABCDEFGHIJKLMNOPQRSTUVWXY Seek end of File: 26 Seek end of Mem: 26 " --ryan.
author Ryan C. Gordon <icculus@icculus.org>
date Fri, 24 Jun 2005 12:48:38 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>SDL_MapRGB</TITLE
><META
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"><LINK
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>SDL Library Documentation</TH
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><HR
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><H1
><A
NAME="SDLMAPRGB"
></A
>SDL_MapRGB</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN1652"
></A
><H2
>Name</H2
>SDL_MapRGB&nbsp;--&nbsp;Map a RGB color value to a pixel format.</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN1655"
></A
><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN1656"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>Uint32 <B
CLASS="FSFUNC"
>SDL_MapRGB</B
></CODE
>(SDL_PixelFormat *fmt, Uint8 r, Uint8 g, Uint8 b);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1662"
></A
><H2
>Description</H2
><P
>Maps the RGB 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 an alpha component it will be returned
as all 1 bits (fully opaque).</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1667"
></A
><H2
>Return Value</H2
><P
>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
<SPAN
CLASS="TYPE"
>Uint16</SPAN
>, and similarly a <SPAN
CLASS="TYPE"
>Uint8</SPAN
> for an 8-bpp
format).</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN1672"
></A
><H2
>See Also</H2
><P
><A
HREF="sdlgetrgb.html"
><TT
CLASS="FUNCTION"
>SDL_GetRGB</TT
></A
>,
<A
HREF="sdlgetrgba.html"
><TT
CLASS="FUNCTION"
>SDL_GetRGBA</TT
></A
>,
<A
HREF="sdlmaprgba.html"
><TT
CLASS="FUNCTION"
>SDL_MapRGBA</TT
></A
>,
<A
HREF="sdlpixelformat.html"
><SPAN
CLASS="STRUCTNAME"
>SDL_PixelFormat</SPAN
></A
></P
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