README.touch
changeset 4690 baf8195aeb92
parent 4689 f9ab8df6d45a
child 4693 2ede56a19f2f
--- a/README.touch	Sun Aug 15 00:36:28 2010 -0400
+++ b/README.touch	Thu Aug 19 13:47:12 2010 -0400
@@ -1,3 +1,18 @@
+===========================================================================
+System Specific Notes
+===========================================================================
+Linux:
+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.
+
+Mac: 
+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.
+
+iPhone: 
+Works out of box.
+
+Winows:
+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
+
 ===========================================================================
 Events
 ===========================================================================
@@ -14,8 +29,8 @@
 Sent when a finger (or stylus) is moved on the touch device.
 Fields:
 Same as FINGERDOWN but with additional:
-event.tfginer.dx       - chagne in x coordinate during this motion event.
-event.tfginer.dy       - chagne in y coordinate during this motion event.
+event.tfginer.dx       - change in x coordinate during this motion event.
+event.tfginer.dy       - change in y coordinate during this motion event.
 
 SDL_FINGERMOTION:
 Sent when a finger (or stylus) is lifted from the touch device.
@@ -36,13 +51,13 @@
 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!
 
 An SDL_Touch has the following fields:
+>xres,yres,pressures:
+	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. 
+
 >pressure_max, pressure_min, x_max, x_min, y_max, y_min
 	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.
 On Mac/iPhone systems _max will always be 0, and _min will always be 1. 
 
->xres,yres,pressures:
-	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. 
-
 >native_xres,native_yres,native_pressureres:
 	The native resolution of the touch device AS REPORTED BY THE OPERATING SYSTEM.
 On Mac/iPhone systems these will always be 1.
@@ -54,18 +69,19 @@
 	An array of pointers to the fingers which are on the device.
 
 
-The most common reason to get a touch device is to normalize inputs. This would look something like:
+The most common reason to access a touch device is to normalize inputs. This would be accomplished by code like the following:
 
       SDL_Touch* inTouch = SDL_GetTouch(event.tfinger.touchId);
-      if(inTouch == NULL) continue;
+      if(inTouch == NULL) continue; //The touch has been removed
 
       float x = ((float)event.tfinger.x)/inTouch->xres;
-      float y = ((float)event.tfinger.y)/inTouch->yres;      
+      float y = ((float)event.tfinger.y)/inTouch->yres;
+
 
 
 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.
 This returns an SDL_Finger*, or null if the finger does not exist, or has been removed.
-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. 
+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. 
 As a result, be very careful to check for null return values.
 
 An SDL_Finger has the following fields:
@@ -74,4 +90,12 @@
 >xdelta,ydelta: 
 	The change in position resulting from the last finger motion.
 >last_x, last_y, last_pressure:
-	 The previous coordinates of the touch.
\ No newline at end of file
+	 The previous coordinates of the touch.
+
+===========================================================================
+Notes
+===========================================================================
+For a complete example see test/testgesture.c
+
+Please direct questions/comments to:
+   jim.tla+sdl_touch@gmail.com
\ No newline at end of file