1 <HTML 2 ><HEAD 3 ><TITLE 4 >SDL_JoyBallEvent</TITLE 5 ><META 6 NAME="GENERATOR" 7 CONTENT="Modular DocBook HTML Stylesheet Version 1.76b+ 8 "><LINK 9 REL="HOME" 10 TITLE="SDL Library Documentation" 11 HREF="index.html"><LINK 12 REL="UP" 13 TITLE="SDL Event Structures." 14 HREF="eventstructures.html"><LINK 15 REL="PREVIOUS" 16 TITLE="SDL_JoyHatEvent" 17 HREF="sdljoyhatevent.html"><LINK 18 REL="NEXT" 19 TITLE="SDL_ResizeEvent" 20 HREF="sdlresizeevent.html"></HEAD 21 ><BODY 22 CLASS="REFENTRY" 23 BGCOLOR="#FFF8DC" 24 TEXT="#000000" 25 LINK="#0000ee" 26 VLINK="#551a8b" 27 ALINK="#ff0000" 28 ><DIV 29 CLASS="NAVHEADER" 30 ><TABLE 31 SUMMARY="Header navigation table" 32 WIDTH="100%" 33 BORDER="0" 34 CELLPADDING="0" 35 CELLSPACING="0" 36 ><TR 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="sdljoyhatevent.html" 49 ACCESSKEY="P" 50 >Prev</A 51 ></TD 52 ><TD 53 WIDTH="80%" 54 ALIGN="center" 55 VALIGN="bottom" 56 ></TD 57 ><TD 58 WIDTH="10%" 59 ALIGN="right" 60 VALIGN="bottom" 61 ><A 62 HREF="sdlresizeevent.html" 63 ACCESSKEY="N" 64 >Next</A 65 ></TD 66 ></TR 67 ></TABLE 68 ><HR 69 ALIGN="LEFT" 70 WIDTH="100%"></DIV 71 ><H1 72 ><A 73 NAME="SDLJOYBALLEVENT" 74 ></A 75 >SDL_JoyBallEvent</H1 76 ><DIV 77 CLASS="REFNAMEDIV" 78 ><A 79 NAME="AEN4396" 80 ></A 81 ><H2 82 >Name</H2 83 >SDL_JoyBallEvent -- Joystick trackball motion event structure</DIV 84 ><DIV 85 CLASS="REFSECT1" 86 ><A 87 NAME="AEN4399" 88 ></A 89 ><H2 90 >Structure Definition</H2 91 ><PRE 92 CLASS="PROGRAMLISTING" 93 >typedef struct{ 94 Uint8 type; 95 Uint8 which; 96 Uint8 ball; 97 Sint16 xrel, yrel; 98 } SDL_JoyBallEvent;</PRE 99 ></DIV 100 ><DIV 101 CLASS="REFSECT1" 102 ><A 103 NAME="AEN4402" 104 ></A 105 ><H2 106 >Structure Data</H2 107 ><DIV 108 CLASS="INFORMALTABLE" 109 ><A 110 NAME="AEN4404" 111 ></A 112 ><P 113 ></P 114 ><TABLE 115 BORDER="0" 116 CLASS="CALSTABLE" 117 ><TBODY 118 ><TR 119 ><TD 120 ALIGN="LEFT" 121 VALIGN="TOP" 122 ><TT 123 CLASS="STRUCTFIELD" 124 ><I 125 >type</I 126 ></TT 127 ></TD 128 ><TD 129 ALIGN="LEFT" 130 VALIGN="TOP" 131 ><TT 132 CLASS="LITERAL" 133 >SDL_JOYBALLMOTION</TT 134 ></TD 135 ></TR 136 ><TR 137 ><TD 138 ALIGN="LEFT" 139 VALIGN="TOP" 140 ><TT 141 CLASS="STRUCTFIELD" 142 ><I 143 >which</I 144 ></TT 145 ></TD 146 ><TD 147 ALIGN="LEFT" 148 VALIGN="TOP" 149 >Joystick device index</TD 150 ></TR 151 ><TR 152 ><TD 153 ALIGN="LEFT" 154 VALIGN="TOP" 155 ><TT 156 CLASS="STRUCTFIELD" 157 ><I 158 >ball</I 159 ></TT 160 ></TD 161 ><TD 162 ALIGN="LEFT" 163 VALIGN="TOP" 164 >Joystick trackball index</TD 165 ></TR 166 ><TR 167 ><TD 168 ALIGN="LEFT" 169 VALIGN="TOP" 170 ><TT 171 CLASS="STRUCTFIELD" 172 ><I 173 >xrel</I 174 ></TT 175 >, <TT 176 CLASS="STRUCTFIELD" 177 ><I 178 >yrel</I 179 ></TT 180 ></TD 181 ><TD 182 ALIGN="LEFT" 183 VALIGN="TOP" 184 >The relative motion in the X/Y direction</TD 185 ></TR 186 ></TBODY 187 ></TABLE 188 ><P 189 ></P 190 ></DIV 191 ></DIV 192 ><DIV 193 CLASS="REFSECT1" 194 ><A 195 NAME="AEN4425" 196 ></A 197 ><H2 198 >Description</H2 199 ><P 200 ><SPAN 201 CLASS="STRUCTNAME" 202 >SDL_JoyBallEvent</SPAN 203 > is a member of the <A 204 HREF="sdlevent.html" 205 ><SPAN 206 CLASS="STRUCTNAME" 207 >SDL_Event</SPAN 208 ></A 209 > union and is used when an event of type <TT 210 CLASS="LITERAL" 211 >SDL_JOYBALLMOTION</TT 212 > is reported.</P 213 ><P 214 >A <TT 215 CLASS="LITERAL" 216 >SDL_JOYBALLMOTION</TT 217 > event occurs when a user moves a trackball on the joystick. The field <TT 218 CLASS="STRUCTFIELD" 219 ><I 220 >which</I 221 ></TT 222 > is the index of the joystick that reported the event and <TT 223 CLASS="STRUCTFIELD" 224 ><I 225 >ball</I 226 ></TT 227 > is the index of the trackball (for a more detailed explaination see the <A 228 HREF="joystick.html" 229 >Joystick section</A 230 >). Trackballs only return relative motion, this is the change in position on the ball since it was last polled (last cycle of the event loop) and it is stored in <TT 231 CLASS="STRUCTFIELD" 232 ><I 233 >xrel</I 234 ></TT 235 > and <TT 236 CLASS="STRUCTFIELD" 237 ><I 238 >yrel</I 239 ></TT 240 >.</P 241 ></DIV 242 ><DIV 243 CLASS="REFSECT1" 244 ><A 245 NAME="AEN4439" 246 ></A 247 ><H2 248 >See Also</H2 249 ><P 250 ><A 251 HREF="sdlevent.html" 252 ><SPAN 253 CLASS="STRUCTNAME" 254 >SDL_Event</SPAN 255 ></A 256 >, 257 <A 258 HREF="joystick.html" 259 >Joystick Functions</A 260 >, 261 <A 262 HREF="sdljoystickeventstate.html" 263 ><TT 264 CLASS="FUNCTION" 265 >SDL_JoystickEventState</TT 266 ></A 267 >, 268 <A 269 HREF="sdljoystickgetball.html" 270 ><TT 271 CLASS="FUNCTION" 272 >SDL_JoystickGetBall</TT 273 ></A 274 ></P 275 ></DIV 276 ><DIV 277 CLASS="NAVFOOTER" 278 ><HR 279 ALIGN="LEFT" 280 WIDTH="100%"><TABLE 281 SUMMARY="Footer navigation table" 282 WIDTH="100%" 283 BORDER="0" 284 CELLPADDING="0" 285 CELLSPACING="0" 286 ><TR 287 ><TD 288 WIDTH="33%" 289 ALIGN="left" 290 VALIGN="top" 291 ><A 292 HREF="sdljoyhatevent.html" 293 ACCESSKEY="P" 294 >Prev</A 295 ></TD 296 ><TD 297 WIDTH="34%" 298 ALIGN="center" 299 VALIGN="top" 300 ><A 301 HREF="index.html" 302 ACCESSKEY="H" 303 >Home</A 304 ></TD 305 ><TD 306 WIDTH="33%" 307 ALIGN="right" 308 VALIGN="top" 309 ><A 310 HREF="sdlresizeevent.html" 311 ACCESSKEY="N" 312 >Next</A 313 ></TD 314 ></TR 315 ><TR 316 ><TD 317 WIDTH="33%" 318 ALIGN="left" 319 VALIGN="top" 320 >SDL_JoyHatEvent</TD 321 ><TD 322 WIDTH="34%" 323 ALIGN="center" 324 VALIGN="top" 325 ><A 326 HREF="eventstructures.html" 327 ACCESSKEY="U" 328 >Up</A 329 ></TD 330 ><TD 331 WIDTH="33%" 332 ALIGN="right" 333 VALIGN="top" 334 >SDL_ResizeEvent</TD 335 ></TR 336 ></TABLE 337 ></DIV 338 ></BODY 339 ></HTML 340 >
