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1、linux多点触控协议briefintroductionInordertouseapowerfulmultitouchdevice,onesolutionistoreportdetailedfingertouchdatatotheuserlayer・Themultitouchprotocoldescribedinthisdocumentallowsthekerneldrivertoreportanymultifingerdatatotheuserlayer・InstructionsAnyonefingertouchdatais
2、packagedintoaABSeventpackageinordertosendonlyABSMTeventpacketscanbeidentifiedasthemultitouchdata,callinputmtsync()functioncangenerateaSYNMTREPORTevent,thefunctionofreceivingandprocessingtheinformationandfingertouchinformationreadytoreceivetheotherfingers・Finally,cal
3、ltheinput_sync()functiontoreporttoEVSYN/SYNREPORTEventcompletesthestartofapackageandpreparestoprocessthenextpackage・TheABS_MTprotocoldefinestheattributesofevents,theseeventsaredividedintoseveralcategories,allowingonlyapartoftheapplication,multitoucheventsshouldbemin
4、imumincludingABSMTPOSITIONXandABSMTPOSITIONX,thesetwoeventsareusedtodescribethemultitouchfingertouchtrajectory.Ifthedevicesupportsthetwoevents,thenABS_MT_TOUCH_MAJORandABS_MT_WIDTH_MAJORareusedtoprovidefingersizeandtouchareasize,respective!y.TheTOUCHandWIDTHparamete
5、rsaregiven,ifonefingerontheglassthroughtheglass,youwillseetworegions,oneisthecontactfingerandtheglassarea,describedbyABS_MT_TOUCH_MAJOR,isanareathesizeofthefingeritself,ABS_MT_WIDTH_IAJORdescription,contactfingersandtheglassareaissmallerthanthefingeritselfthesize,t
6、hroughthesetwoparameters,canbeconvertedtopressureshot・ThefingerpressurecanalsobesupplieddirectlythroughtheABS_MT_PRESSUREparameter・InadditiontotheMAJORparameters,canalsoprovideaMINORparameter,thefingercanbethoughtofasanellipse,MAJORandMINORcanbeconsideredandtheshort
7、axisofthelongaxisoftheellipse,theellipsecentercanbedescribedORIENTATIONthisparameter・TheABS_MT_TOOL_TYPEparameterisusedtodescribethetypeoftouchtool(finger,touchpen,etc・)・Differentdevicesmayhavesomeotherinformationthatneedstobepassedtotheuserlayer・Forexample,ABS_MT_B
8、LOB_IDisusedtodescribethecollectionofedgesofrectangles.Atpresent,onlyafewdevicescanbesupported,andtheABS_MT_TRACKING_IDeventisusedtoreport
