README.touch
changeset 4690 baf8195aeb92
parent 4689 f9ab8df6d45a
child 4693 2ede56a19f2f
     1.1 --- a/README.touch	Sun Aug 15 00:36:28 2010 -0400
     1.2 +++ b/README.touch	Thu Aug 19 13:47:12 2010 -0400
     1.3 @@ -1,3 +1,18 @@
     1.4 +===========================================================================
     1.5 +System Specific Notes
     1.6 +===========================================================================
     1.7 +Linux:
     1.8 +The 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.
     1.9 +
    1.10 +Mac: 
    1.11 +The Mac and Iphone API's 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.
    1.12 +
    1.13 +iPhone: 
    1.14 +Works out of box.
    1.15 +
    1.16 +Winows:
    1.17 +Unfortunately 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
    1.18 +
    1.19  ===========================================================================
    1.20  Events
    1.21  ===========================================================================
    1.22 @@ -14,8 +29,8 @@
    1.23  Sent when a finger (or stylus) is moved on the touch device.
    1.24  Fields:
    1.25  Same as FINGERDOWN but with additional:
    1.26 -event.tfginer.dx       - chagne in x coordinate during this motion event.
    1.27 -event.tfginer.dy       - chagne in y coordinate during this motion event.
    1.28 +event.tfginer.dx       - change in x coordinate during this motion event.
    1.29 +event.tfginer.dy       - change in y coordinate during this motion event.
    1.30  
    1.31  SDL_FINGERMOTION:
    1.32  Sent when a finger (or stylus) is lifted from the touch device.
    1.33 @@ -36,13 +51,13 @@
    1.34  IMPORTANT: If the touch has been removed, or there is no touch with the given ID, SDL_GetTouch will return null. Be sure to check for this!
    1.35  
    1.36  An SDL_Touch has the following fields:
    1.37 +>xres,yres,pressures:
    1.38 +	The resolution at which x,y, and pressure values are reported. Currently these will always be equal to 2^15, but this may not always be the case. 
    1.39 +
    1.40  >pressure_max, pressure_min, x_max, x_min, y_max, y_min
    1.41  	Which give, respectively, the maximum and minumum values that the touch digitizer can return for pressure, x coordiniate, and y coordinate AS REPORTED BY THE OPERATING SYSTEM.
    1.42  On Mac/iPhone systems _max will always be 0, and _min will always be 1. 
    1.43  
    1.44 ->xres,yres,pressures:
    1.45 -	The resolution at which x,y, and pressure values are reported. Currently these will always be equal to 2^15, but this may not always be the case. 
    1.46 -
    1.47  >native_xres,native_yres,native_pressureres:
    1.48  	The native resolution of the touch device AS REPORTED BY THE OPERATING SYSTEM.
    1.49  On Mac/iPhone systems these will always be 1.
    1.50 @@ -54,18 +69,19 @@
    1.51  	An array of pointers to the fingers which are on the device.
    1.52  
    1.53  
    1.54 -The most common reason to get a touch device is to normalize inputs. This would look something like:
    1.55 +The most common reason to access a touch device is to normalize inputs. This would be accomplished by code like the following:
    1.56  
    1.57        SDL_Touch* inTouch = SDL_GetTouch(event.tfinger.touchId);
    1.58 -      if(inTouch == NULL) continue;
    1.59 +      if(inTouch == NULL) continue; //The touch has been removed
    1.60  
    1.61        float x = ((float)event.tfinger.x)/inTouch->xres;
    1.62 -      float y = ((float)event.tfinger.y)/inTouch->yres;      
    1.63 +      float y = ((float)event.tfinger.y)/inTouch->yres;
    1.64 +
    1.65  
    1.66  
    1.67  To get an SDL_Finger, call SDL_GetFinger(touch,fingerId), where touch is a pointer to an SDL_Touch device, and fingerId is the id of the requested finger.
    1.68  This returns an SDL_Finger*, or null if the finger does not exist, or has been removed.
    1.69 -An 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 seen. 
    1.70 +An 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. 
    1.71  As a result, be very careful to check for null return values.
    1.72  
    1.73  An SDL_Finger has the following fields:
    1.74 @@ -74,4 +90,12 @@
    1.75  >xdelta,ydelta: 
    1.76  	The change in position resulting from the last finger motion.
    1.77  >last_x, last_y, last_pressure:
    1.78 -	 The previous coordinates of the touch.
    1.79 \ No newline at end of file
    1.80 +	 The previous coordinates of the touch.
    1.81 +
    1.82 +===========================================================================
    1.83 +Notes
    1.84 +===========================================================================
    1.85 +For a complete example see test/testgesture.c
    1.86 +
    1.87 +Please direct questions/comments to:
    1.88 +   jim.tla+sdl_touch@gmail.com
    1.89 \ No newline at end of file