README.touch
changeset 7127 5011ddf43295
parent 6987 7084af936d82
equal deleted inserted replaced
7126:6fce42265686 7127:5011ddf43295
    26 event.tfinger.pressure - the pressure of the touch (0..1)
    26 event.tfinger.pressure - the pressure of the touch (0..1)
    27 
    27 
    28 SDL_FINGERMOTION:
    28 SDL_FINGERMOTION:
    29 Sent when a finger (or stylus) is moved on the touch device.
    29 Sent when a finger (or stylus) is moved on the touch device.
    30 Fields:
    30 Fields:
    31 Same as FINGERDOWN but with additional:
    31 Same as SDL_FINGERDOWN but with additional:
    32 event.tfinger.dx       - change in x coordinate during this motion event.
    32 event.tfinger.dx       - change in x coordinate during this motion event.
    33 event.tfinger.dy       - change in y coordinate during this motion event.
    33 event.tfinger.dy       - change in y coordinate during this motion event.
    34 
    34 
    35 SDL_FINGERUP:
    35 SDL_FINGERUP:
    36 Sent when a finger (or stylus) is lifted from the touch device.
    36 Sent when a finger (or stylus) is lifted from the touch device.
    37 Fields:
    37 Fields:
    38 Same as FINGERDOWN.
    38 Same as SDL_FINGERDOWN.
    39 
    39 
    40 
    40 
    41 ===========================================================================
    41 ===========================================================================
    42 Functions
    42 Functions
    43 ===========================================================================
    43 ===========================================================================
    50 This returns a SDL_TouchID.
    50 This returns a SDL_TouchID.
    51 IMPORTANT: If the touch has been removed, or there is no touch with the given ID, SDL_GetTouchID will return 0. Be sure to check for this!
    51 IMPORTANT: If the touch has been removed, or there is no touch with the given ID, SDL_GetTouchID will return 0. Be sure to check for this!
    52 
    52 
    53 The number of touch devices can be queried with SDL_GetNumTouchDevices().
    53 The number of touch devices can be queried with SDL_GetNumTouchDevices().
    54 
    54 
    55 A SDL_Touch may be used to get pointers to SDL_Finger.
    55 A SDL_TouchID may be used to get pointers to SDL_Finger.
    56 
    56 
    57 SDL_GetNumTouchFingers(touchID) may be used to get the number of fingers currently down on the device.
    57 SDL_GetNumTouchFingers(touchID) may be used to get the number of fingers currently down on the device.
    58 
    58 
    59 The most common reason to access SDL_Finger is to query the fingers outside the event. In most cases accessing the fingers is using the event. This would be accomplished by code like the following:
    59 The most common reason to access SDL_Finger is to query the fingers outside the event. In most cases accessing the fingers is using the event. This would be accomplished by code like the following:
    60 
    60 
    63 
    63 
    64 
    64 
    65 
    65 
    66 To get a SDL_Finger, call SDL_GetTouchFinger(touchID,index), where touchID is a SDL_TouchID, and index is the requested finger.
    66 To get a SDL_Finger, call SDL_GetTouchFinger(touchID,index), where touchID is a SDL_TouchID, and index is the requested finger.
    67 This returns a SDL_Finger*, or NULL if the finger does not exist, or has been removed.
    67 This returns a SDL_Finger*, or NULL if the finger does not exist, or has been removed.
    68 A SDL_Finger is guaranteed to be persistent for the duration of a touch, but it will be de-allocated as soon as the finger is removed. This occurs when the SDL_FINGERUP event is _added_ to the event queue, and thus _before_ the FINGERUP event is polled.
    68 A SDL_Finger is guaranteed to be persistent for the duration of a touch, but it will be de-allocated as soon as the finger is removed. This occurs when the SDL_FINGERUP event is _added_ to the event queue, and thus _before_ the SDL_FINGERUP event is polled.
    69 As a result, be very careful to check for NULL return values.
    69 As a result, be very careful to check for NULL return values.
    70 
    70 
    71 A SDL_Finger has the following fields:
    71 A SDL_Finger has the following fields:
    72 >x,y,pressure:
    72 >x,y,pressure:
    73 	The current coordinates of the touch.
    73 	The current coordinates of the touch.