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| 4 | >Time Examples</TITLE |
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| 37 | ><TH |
| 38 | COLSPAN="3" |
| 39 | ALIGN="center" |
| 40 | >SDL Library Documentation</TH |
| 41 | ></TR |
| 42 | ><TR |
| 43 | ><TD |
| 44 | WIDTH="10%" |
| 45 | ALIGN="left" |
| 46 | VALIGN="bottom" |
| 47 | ><A |
| 48 | HREF="guidecdromexamples.html" |
| 49 | ACCESSKEY="P" |
| 50 | >Prev</A |
| 51 | ></TD |
| 52 | ><TD |
| 53 | WIDTH="80%" |
| 54 | ALIGN="center" |
| 55 | VALIGN="bottom" |
| 56 | >Chapter 4. Examples</TD |
| 57 | ><TD |
| 58 | WIDTH="10%" |
| 59 | ALIGN="right" |
| 60 | VALIGN="bottom" |
| 61 | ><A |
| 62 | HREF="reference.html" |
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| 64 | >Next</A |
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| 69 | ALIGN="LEFT" |
| 70 | WIDTH="100%"></DIV |
| 71 | ><DIV |
| 72 | CLASS="SECT1" |
| 73 | ><H1 |
| 74 | CLASS="SECT1" |
| 75 | ><A |
| 76 | NAME="GUIDETIMEEXAMPLES" |
| 77 | ></A |
| 78 | >Time Examples</H1 |
| 79 | ><P |
| 80 | ></P |
| 81 | ><DIV |
| 82 | CLASS="SECT2" |
| 83 | ><H2 |
| 84 | CLASS="SECT2" |
| 85 | ><A |
| 86 | NAME="AEN412" |
| 87 | ></A |
| 88 | >Time based game loop</H2 |
| 89 | ><P |
| 90 | ><PRE |
| 91 | CLASS="PROGRAMLISTING" |
| 92 | >#define TICK_INTERVAL 30 |
| 93 | |
| 94 | static Uint32 next_time; |
| 95 | |
| 96 | Uint32 time_left(void) |
| 97 | { |
| 98 | Uint32 now; |
| 99 | |
| 100 | now = SDL_GetTicks(); |
| 101 | if(next_time <= now) |
| 102 | return 0; |
| 103 | else |
| 104 | return next_time - now; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | /* main game loop */ |
| 109 | |
| 110 | next_time = SDL_GetTicks() + TICK_INTERVAL; |
| 111 | while ( game_running ) { |
| 112 | update_game_state(); |
| 113 | SDL_Delay(time_left()); |
| 114 | next_time += TICK_INTERVAL; |
| 115 | } </PRE |
| 116 | ></P |
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| 133 | VALIGN="top" |
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| 135 | HREF="guidecdromexamples.html" |
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| 163 | >CDROM Examples</TD |
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| 177 | >SDL Reference</TD |
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