sdl-ios-xcode: docs/html/guideinputkeyboard.html comparison

comparison docs/html/guideinputkeyboard.html @ 55:55f1f1b3e27d

Added new docs for SDL 1.2.1

author	Sam Lantinga <slouken@lokigames.com>
date	Sun, 10 Jun 2001 19:31:57 +0000
parents	74212992fb08
children	355632dca928

comparison

equal deleted inserted replaced

-:028447a8a758
+:55f1f1b3e27d
 ><HEAD
 ><TITLE
 >Handling the Keyboard</TITLE
 ><META
 NAME="GENERATOR"
-CONTENT="Modular DocBook HTML Stylesheet Version 1.61
+CONTENT="Modular DocBook HTML Stylesheet Version 1.64
 "><LINK
 REL="HOME"
 TITLE="SDL Library Documentation"
 HREF="index.html"><LINK
 REL="UP"
 ><DIV
 CLASS="SECT2"
 ><H2
 CLASS="SECT2"
 ><A
-NAME="AEN205"
+NAME="AEN271"
 >Keyboard Related Structures</A
 ></H2
 ><P
 >It should make it a lot easier to understand this tutorial is you are familiar with the data types involved in keyboard access, so I'll explain them first.</P
 ><DIV
 CLASS="SECT3"
 ><H3
 CLASS="SECT3"
 ><A
-NAME="AEN208"
+NAME="AEN274"
 >SDLKey</A
 ></H3
 ><P
 ><SPAN
 CLASS="STRUCTNAME"
 ><DIV
 CLASS="SECT3"
 ><H3
 CLASS="SECT3"
 ><A
-NAME="AEN216"
+NAME="AEN282"
 >SDLMod</A
 ></H3
 ><P
 >SDLMod is an enumerated type, similar to <SPAN
 CLASS="STRUCTNAME"
 ><DIV
 CLASS="SECT3"
 ><H3
 CLASS="SECT3"
 ><A
-NAME="AEN222"
+NAME="AEN288"
 >SDL_keysym</A
 ></H3
 ><PRE
 CLASS="PROGRAMLISTING"
 >typedef struct{
 ><DIV
 CLASS="SECT3"
 ><H3
 CLASS="SECT3"
 ><A
-NAME="AEN241"
+NAME="AEN307"
 >SDL_KeyboardEvent</A
 ></H3
 ><PRE
 CLASS="PROGRAMLISTING"
 >typedef struct{
 ><DIV
 CLASS="SECT2"
 ><H2
 CLASS="SECT2"
 ><A
-NAME="AEN258"
+NAME="AEN324"
 >Reading Keyboard Events</A
 ></H2
 ><P
 >Reading keybaord events from the event queue is quite simple (the event queue and using it is described <A
 HREF="sdlevent.html"
 CLASS="LITERAL"
 >SDL_KEYDOWN</TT
 > events using a <TT
 CLASS="LITERAL"
 >switch</TT
-> statement, like so:
+> statement, like so:</P
-<PRE
+><DIV
+CLASS="EXAMPLE"
+><A
+NAME="AEN334"
+></A
+><P
+><B
+>Example 3-10. Reading Keyboard Events</B
+></P
+><PRE
 CLASS="PROGRAMLISTING"
 >  SDL_Event event;
 .
 .
 /* Poll for events. SDL_PollEvent() returns 0 when there are no  */
 break;
 }
 }
 .
 .</PRE
->
+></DIV
-This is a very basic example. No information about the key press or release is interpreted. We will explore the other extreme out our first full example below - reporting all available information about a keyboard event.</P
+><P
+>This is a very basic example. No information about the key press or release is interpreted. We will explore the other extreme out our first full example below - reporting all available information about a keyboard event.</P
 ></DIV
 ><DIV
 CLASS="SECT2"
 ><H2
 CLASS="SECT2"
 ><A
-NAME="AEN269"
+NAME="AEN338"
 >A More Detailed Look</A
 ></H2
 ><P
 >Before we can read events SDL must be initialised with <A
 HREF="sdlinit.html"
 ></BLOCKQUOTE
 ></DIV
 ><DIV
 CLASS="EXAMPLE"
 ><A
-NAME="AEN282"
+NAME="AEN351"
 ></A
 ><P
 ><B
->Example 3-1. keys.c - Key event information</B
+>Example 3-11. Interpreting Key Event Information</B
 ></P
 ><PRE
 CLASS="PROGRAMLISTING"
 >&#13;    #include "SDL.h"
 SDL_Event event;
 int quit = 0;
 /* Initialise SDL */
-if( SDL_Init( SDL_INIT_VIDEO ) ){
+if( SDL_Init( SDL_INIT_VIDEO ) &#60; 0){
 fprintf( stderr, "Could not initialise SDL: %s\n", SDL_GetError() );
 exit( -1 );
 }
 /* Set a video mode */
 ><DIV
 CLASS="SECT2"
 ><H2
 CLASS="SECT2"
 ><A
-NAME="AEN285"
+NAME="AEN354"
 >Game-type Input</A
 ></H2
 ><P
 >I have found that people using keyboard events for games and other interactive applications don't always understand one fundemental point.</P
 ><A
-NAME="AEN288"
+NAME="AEN357"
 ></A
 ><BLOCKQUOTE
 CLASS="BLOCKQUOTE"
 ><P
 >Keyboard events <I
 .
 .</PRE
 >
 At first glance you may think this is a perfectly reasonable piece of code for the task, but it isn't. Like I said keyboard events only occur when a key changes state, so the user would have to press and release the left cursor key 100 times to move the alien 100 pixels to the left.</P
 ><P
->To get around this problem we must not use the events to change the position of the alien, we use the events to set flags which are then used in a seperate section of code to move the alien. Something like this:
+>To get around this problem we must not use the events to change the position of the alien, we use the events to set flags which are then used in a seperate section of code to move the alien. Something like this:</P
-<PRE
+><DIV
+CLASS="EXAMPLE"
+><A
+NAME="AEN363"
+></A
+><P
+><B
+>Example 3-12. Proper Game Movement</B
+></P
+><PRE
 CLASS="PROGRAMLISTING"
 >    /* Alien screen coordinates */
 int alien_x=0, alien_y=0;
 int alien_xvel=0, alien_yvel=0;
 .
 .
 .
 /* Update the alien position */
 alien_x += alien_xvel;
 alien_y += alien_yvel;</PRE
->
+></DIV
-As can be seen, we use two extra variables, alien_xvel and alien_yvel, which represent the motion of the ship, it is these variables that we update when we detect keypresses and releases.</P
+><P
+>As can be seen, we use two extra variables, alien_xvel and alien_yvel, which represent the motion of the ship, it is these variables that we update when we detect keypresses and releases.</P
 ></DIV
 ></DIV
 ><DIV
 CLASS="NAVFOOTER"
 ><HR

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comparison docs/html/guideinputkeyboard.html @ 55:55f1f1b3e27d