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authorJim Grandpre <jim.tla@gmail.com>2010-08-19 13:47:12 -0400
committerJim Grandpre <jim.tla@gmail.com>2010-08-19 13:47:12 -0400
commitf1b2b9f8016d764c060a98dffc73e6fca31d0aef (patch)
treeb34b8c1c307f803175fb2b17a5f25a0f337d7aec /README.touch
parent794c5cb3ee58b4d790ebd1e87da60b40e646609c (diff)
Updated README's
Diffstat (limited to 'README.touch')
-rw-r--r--README.touch44
1 files changed, 34 insertions, 10 deletions
diff --git a/README.touch b/README.touch
index becb89fb..4ce12718 100644
--- a/README.touch
+++ b/README.touch
@@ -1,4 +1,19 @@
===========================================================================
+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
===========================================================================
SDL_FINGERDOWN:
@@ -14,8 +29,8 @@ SDL_FINGERMOTION:
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 @@ This returns an SDL_Touch*.
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 @@ On Mac/iPhone systems these will always be 1.
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 @@ An SDL_Finger has the following fields:
>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