[sdl_omap.git] / docs / html / sdljoystickgetball.html

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>SDL_JoystickGetBall</H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN6433"
></A
><H2
>Name</H2
>SDL_JoystickGetBall&nbsp;--&nbsp;Get relative trackball motion</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN6436"
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><H2
>Synopsis</H2
><DIV
CLASS="FUNCSYNOPSIS"
><A
NAME="AEN6437"
></A
><P
></P
><PRE
CLASS="FUNCSYNOPSISINFO"
>#include "SDL.h"</PRE
><P
><CODE
><CODE
CLASS="FUNCDEF"
>int <B
CLASS="FSFUNC"
>SDL_JoystickGetBall</B
></CODE
>(SDL_Joystick *joystick, int ball, int *dx, int *dy);</CODE
></P
><P
></P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6443"
></A
><H2
>Description</H2
><P
>Get the <TT
CLASS="PARAMETER"
><I
>ball</I
></TT
> axis change.</P
><P
>Trackballs can only return relative motion since the last call to <TT
CLASS="FUNCTION"
>SDL_JoystickGetBall</TT
>, these motion deltas a placed into <TT
CLASS="PARAMETER"
><I
>dx</I
></TT
> and <TT
CLASS="PARAMETER"
><I
>dy</I
></TT
>.</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6451"
></A
><H2
>Return Value</H2
><P
>Returns <SPAN
CLASS="RETURNVALUE"
>0</SPAN
> on success or <SPAN
CLASS="RETURNVALUE"
>-1</SPAN
> on failure</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN6456"
></A
><H2
>Examples</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>int delta_x, delta_y;
SDL_Joystick *joy;
.
.
.
SDL_JoystickUpdate();
if(SDL_JoystickGetBall(joy, 0, &#38;delta_x, &#38;delta_y)==-1)
  printf("TrackBall Read Error!\n");
printf("Trackball Delta- X:%d, Y:%d\n", delta_x, delta_y);</PRE
></P
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><A
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></A
><H2
>See Also</H2
><P
><A
HREF="sdljoysticknumballs.html"
><TT
CLASS="FUNCTION"
>SDL_JoystickNumBalls</TT
></A
></P
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>
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	4	>SDL_JoystickGetBall</TITLE
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	10	TITLE="SDL Library Documentation"
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	13	TITLE="Joystick"
	14	HREF="joystick.html"><LINK
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	16	TITLE="SDL_JoystickGetButton"
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	25	LINK="#0000ee"
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	40	>SDL Library Documentation</TH
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	44	WIDTH="10%"
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	62	HREF="sdljoystickclose.html"
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	64	>Next</A
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66	></TR
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68	><HR
69	ALIGN="LEFT"
70	WIDTH="100%"></DIV
71	><H1
72	><A
73	NAME="SDLJOYSTICKGETBALL"
74	></A
75	>SDL_JoystickGetBall</H1
76	><DIV
77	CLASS="REFNAMEDIV"
78	><A
79	NAME="AEN6433"
80	></A
81	><H2
82	>Name</H2
83	>SDL_JoystickGetBall -- Get relative trackball motion</DIV
84	><DIV
85	CLASS="REFSYNOPSISDIV"
86	><A
87	NAME="AEN6436"
88	></A
89	><H2
90	>Synopsis</H2
91	><DIV
92	CLASS="FUNCSYNOPSIS"
93	><A
94	NAME="AEN6437"
95	></A
96	><P
97	></P
98	><PRE
99	CLASS="FUNCSYNOPSISINFO"
100	>#include "SDL.h"</PRE
101	><P
102	><CODE
103	><CODE
104	CLASS="FUNCDEF"
105	>int <B
106	CLASS="FSFUNC"
107	>SDL_JoystickGetBall</B
108	></CODE
109	>(SDL_Joystick joystick, int ball, int dx, int *dy);</CODE
110	></P
111	><P
112	></P
113	></DIV
114	></DIV
115	><DIV
116	CLASS="REFSECT1"
117	><A
118	NAME="AEN6443"
119	></A
120	><H2
121	>Description</H2
122	><P
123	>Get the <TT
124	CLASS="PARAMETER"
125	><I
126	>ball</I
127	></TT
128	> axis change.</P
129	><P
130	>Trackballs can only return relative motion since the last call to <TT
131	CLASS="FUNCTION"
132	>SDL_JoystickGetBall</TT
133	>, these motion deltas a placed into <TT
134	CLASS="PARAMETER"
135	><I
136	>dx</I
137	></TT
138	> and <TT
139	CLASS="PARAMETER"
140	><I
141	>dy</I
142	></TT
143	>.</P
144	></DIV
145	><DIV
146	CLASS="REFSECT1"
147	><A
148	NAME="AEN6451"
149	></A
150	><H2
151	>Return Value</H2
152	><P
153	>Returns <SPAN
154	CLASS="RETURNVALUE"
155	>0</SPAN
156	> on success or <SPAN
157	CLASS="RETURNVALUE"
158	>-1</SPAN
159	> on failure</P
160	></DIV
161	><DIV
162	CLASS="REFSECT1"
163	><A
164	NAME="AEN6456"
165	></A
166	><H2
167	>Examples</H2
168	><P
169	><PRE
170	CLASS="PROGRAMLISTING"
171	>int delta_x, delta_y;
172	SDL_Joystick *joy;
173	.
174	.
175	.
176	SDL_JoystickUpdate();
177	if(SDL_JoystickGetBall(joy, 0, &delta_x, &delta_y)==-1)
178	printf("TrackBall Read Error!\n");
179	printf("Trackball Delta- X:%d, Y:%d\n", delta_x, delta_y);</PRE
180	></P
181	></DIV
182	><DIV
183	CLASS="REFSECT1"
184	><A
185	NAME="AEN6460"
186	></A
187	><H2
188	>See Also</H2
189	><P
190	><A
191	HREF="sdljoysticknumballs.html"
192	><TT
193	CLASS="FUNCTION"
194	>SDL_JoystickNumBalls</TT
195	></A
196	></P
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199	CLASS="NAVFOOTER"
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211	ALIGN="left"
212	VALIGN="top"
213	><A
214	HREF="sdljoystickgetbutton.html"
215	ACCESSKEY="P"
216	>Prev</A
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242	>SDL_JoystickGetButton</TD
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250	>Up</A
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262	>