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76 CLASS="CHAPTER" |
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77 ><H1 |
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81 >Chapter 8. Events</H1 |
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82 ><DIV |
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83 CLASS="TOC" |
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84 ><DL |
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85 ><DT |
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86 ><B |
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87 >Table of Contents</B |
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88 ></DT |
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89 ><DT |
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90 ><A |
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91 HREF="event.html#AEN3691" |
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92 >Introduction</A |
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96 HREF="eventstructures.html" |
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97 >SDL Event Structures.</A |
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98 ></DT |
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99 ><DT |
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101 HREF="eventfunctions.html" |
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102 >Event Functions.</A |
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103 ></DT |
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108 ><H1 |
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113 >Introduction</H1 |
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114 ><P |
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115 >Event handling allows your application to receive input from the user. Event handling is initalised (along with video) with a call to: |
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116 <PRE |
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117 CLASS="PROGRAMLISTING" |
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118 >SDL_Init(SDL_INIT_VIDEO);</PRE |
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119 > |
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120 Internally, SDL stores all the events waiting to be handled in an event queue. Using functions like <A |
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121 HREF="sdlpollevent.html" |
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122 ><TT |
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123 CLASS="FUNCTION" |
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124 >SDL_PollEvent</TT |
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125 ></A |
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126 > and <A |
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127 HREF="sdlpeepevents.html" |
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128 ><TT |
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129 CLASS="FUNCTION" |
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130 >SDL_PeepEvents</TT |
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131 ></A |
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132 > you can observe and handle waiting input events.</P |
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133 ><P |
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134 >The key to event handling in SDL is the <A |
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135 HREF="sdlevent.html" |
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136 ><SPAN |
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137 CLASS="STRUCTNAME" |
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138 >SDL_Event</SPAN |
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139 ></A |
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140 > union. The event queue itself is composed of a series of <SPAN |
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141 CLASS="STRUCTNAME" |
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142 >SDL_Event</SPAN |
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143 > unions, one for each waiting event. <SPAN |
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144 CLASS="STRUCTNAME" |
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145 >SDL_Event</SPAN |
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146 > unions are read from the queue with the <TT |
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147 CLASS="FUNCTION" |
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148 >SDL_PollEvent</TT |
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149 > function and it is then up to the application to process the information stored with them.</P |
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