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Adjusted default choice of audio driver. If a driver can definitely see available devices, it is chosen. Otherwise, we'll take the first driver that initializes but saw no devices...this might be because it can't enumerate them, or there really aren't any available. This prevents the dsp driver from hogging control when there are no /dev/dsp* nodes (for example, on a Linux box with ALSA and no OSS emulation).
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 01 Jan 2009 07:54:58 +0000
parents 355632dca928
children
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<HTML
><HEAD
><TITLE
>Event Examples</TITLE
><META
NAME="GENERATOR"
CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+
"><LINK
REL="HOME"
TITLE="SDL Library Documentation"
HREF="index.html"><LINK
REL="UP"
TITLE="Examples"
HREF="guideexamples.html"><LINK
REL="PREVIOUS"
TITLE="Examples"
HREF="guideexamples.html"><LINK
REL="NEXT"
TITLE="Audio Examples"
HREF="guideaudioexamples.html"></HEAD
><BODY
CLASS="SECT1"
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LINK="#0000ee"
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><TABLE
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BORDER="0"
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><TR
><TH
COLSPAN="3"
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>SDL Library Documentation</TH
></TR
><TR
><TD
WIDTH="10%"
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><A
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>Prev</A
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><TD
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>Chapter 4. Examples</TD
><TD
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><A
HREF="guideaudioexamples.html"
ACCESSKEY="N"
>Next</A
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><HR
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WIDTH="100%"></DIV
><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="GUIDEEVENTEXAMPLES"
></A
>Event Examples</H1
><P
></P
><DIV
CLASS="SECT2"
><H2
CLASS="SECT2"
><A
NAME="AEN375"
></A
>Filtering and Handling Events</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>#include &#60;stdio.h&#62;
#include &#60;stdlib.h&#62;

#include "SDL.h"

/* This function may run in a separate event thread */
int FilterEvents(const SDL_Event *event) {
    static int boycott = 1;

    /* This quit event signals the closing of the window */
    if ( (event-&#62;type == SDL_QUIT) &#38;&#38; boycott ) {
        printf("Quit event filtered out -- try again.\n");
        boycott = 0;
        return(0);
    }
    if ( event-&#62;type == SDL_MOUSEMOTION ) {
        printf("Mouse moved to (%d,%d)\n",
                event-&#62;motion.x, event-&#62;motion.y);
        return(0);    /* Drop it, we've handled it */
    }
    return(1);
}

int main(int argc, char *argv[])
{
    SDL_Event event;

    /* Initialize the SDL library (starts the event loop) */
    if ( SDL_Init(SDL_INIT_VIDEO) &#60; 0 ) {
        fprintf(stderr,
                "Couldn't initialize SDL: %s\n", SDL_GetError());
        exit(1);
    }

    /* Clean up on exit, exit on window close and interrupt */
    atexit(SDL_Quit);

    /* Ignore key events */
    SDL_EventState(SDL_KEYDOWN, SDL_IGNORE);
    SDL_EventState(SDL_KEYUP, SDL_IGNORE);

    /* Filter quit and mouse motion events */
    SDL_SetEventFilter(FilterEvents);

    /* The mouse isn't much use unless we have a display for reference */
    if ( SDL_SetVideoMode(640, 480, 8, 0) == NULL ) {
        fprintf(stderr, "Couldn't set 640x480x8 video mode: %s\n",
                        SDL_GetError());
        exit(1);
    }

    /* Loop waiting for ESC+Mouse_Button */
    while ( SDL_WaitEvent(&#38;event) &#62;= 0 ) {
        switch (event.type) {
            case SDL_ACTIVEEVENT: {
                if ( event.active.state &#38; SDL_APPACTIVE ) {
                    if ( event.active.gain ) {
                        printf("App activated\n");
                    } else {
                        printf("App iconified\n");
                    }
                }
            }
            break;
                    
            case SDL_MOUSEBUTTONDOWN: {
                Uint8 *keys;

                keys = SDL_GetKeyState(NULL);
                if ( keys[SDLK_ESCAPE] == SDL_PRESSED ) {
                    printf("Bye bye...\n");
                    exit(0);
                }
                printf("Mouse button pressed\n");
            }
            break;

            case SDL_QUIT: {
                printf("Quit requested, quitting.\n");
                exit(0);
            }
            break;
        }
    }
    /* This should never happen */
    printf("SDL_WaitEvent error: %s\n", SDL_GetError());
    exit(1);
}</PRE
></P
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WIDTH="100%"
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>Prev</A
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>