cscg22-gearboy

CSCG 2022 Challenge 'Gearboy'
git clone https://git.sinitax.com/sinitax/cscg22-gearboy
Log | Files | Refs | sfeed.txt

README-touch.md (4025B)

      1Touch
      2===========================================================================
      3System Specific Notes
      4===========================================================================
      5Linux:
      6The linux touch system is currently based off event streams, and proc/bus/devices. The active user must be given permissions to read /dev/input/TOUCHDEVICE, where TOUCHDEVICE is the event stream for your device. Currently only Wacom tablets are supported. If you have an unsupported tablet contact me at jim.tla+sdl_touch@gmail.com and I will help you get support for it.
      7
      8Mac:
      9The Mac and iPhone APIs are pretty. If your touch device supports them then you'll be fine. If it doesn't, then there isn't much we can do.
     10
     11iPhone: 
     12Works out of box.
     13
     14Windows:
     15Unfortunately there is no windows support as of yet. Support for Windows 7 is planned, but we currently have no way to test. If you have a Windows 7 WM_TOUCH supported device, and are willing to help test please contact me at jim.tla+sdl_touch@gmail.com
     16
     17===========================================================================
     18Events
     19===========================================================================
     20SDL_FINGERDOWN:
     21Sent when a finger (or stylus) is placed on a touch device.
     22Fields:
     23* event.tfinger.touchId  - the Id of the touch device.
     24* event.tfinger.fingerId - the Id of the finger which just went down.
     25* event.tfinger.x        - the x coordinate of the touch (0..1)
     26* event.tfinger.y        - the y coordinate of the touch (0..1)
     27* event.tfinger.pressure - the pressure of the touch (0..1)
     28
     29SDL_FINGERMOTION:
     30Sent when a finger (or stylus) is moved on the touch device.
     31Fields:
     32Same as SDL_FINGERDOWN but with additional:
     33* event.tfinger.dx       - change in x coordinate during this motion event.
     34* event.tfinger.dy       - change in y coordinate during this motion event.
     35
     36SDL_FINGERUP:
     37Sent when a finger (or stylus) is lifted from the touch device.
     38Fields:
     39Same as SDL_FINGERDOWN.
     40
     41
     42===========================================================================
     43Functions
     44===========================================================================
     45SDL provides the ability to access the underlying SDL_Finger structures.
     46These structures should _never_ be modified.
     47
     48The following functions are included from SDL_touch.h
     49
     50To get a SDL_TouchID call SDL_GetTouchDevice(int index).
     51This returns a SDL_TouchID.
     52IMPORTANT: If the touch has been removed, or there is no touch with the given index, SDL_GetTouchDevice() will return 0. Be sure to check for this!
     53
     54The number of touch devices can be queried with SDL_GetNumTouchDevices().
     55
     56A SDL_TouchID may be used to get pointers to SDL_Finger.
     57
     58SDL_GetNumTouchFingers(touchID) may be used to get the number of fingers currently down on the device.
     59
     60The 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:
     61
     62      float x = event.tfinger.x;
     63      float y = event.tfinger.y;
     64
     65
     66
     67To get a SDL_Finger, call SDL_GetTouchFinger(SDL_TouchID touchID, int index), where touchID is a SDL_TouchID, and index is the requested finger.
     68This returns a SDL_Finger *, or NULL if the finger does not exist, or has been removed.
     69A 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.
     70As a result, be very careful to check for NULL return values.
     71
     72A SDL_Finger has the following fields:
     73* x, y:
     74	The current coordinates of the touch.
     75* pressure:
     76	The pressure of the touch.
     77
     78
     79===========================================================================
     80Notes
     81===========================================================================
     82For a complete example see test/testgesture.c
     83
     84Please direct questions/comments to:
     85   jim.tla+sdl_touch@gmail.com
     86   (original author, API was changed since)