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| author | 3gg <3gg@shellblade.net> | 2024-05-04 16:51:29 -0700 |
|---|---|---|
| committer | 3gg <3gg@shellblade.net> | 2024-05-04 16:51:29 -0700 |
| commit | 8222bfe56d4dabe8d92fc4b25ea1b0163b16f3e1 (patch) | |
| tree | 763389e42276035ac134d94eb1dc32293b88d807 /src/contrib/SDL-2.30.2/docs/README-touch.md | |
Initial commit.
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diff --git a/src/contrib/SDL-2.30.2/docs/README-touch.md b/src/contrib/SDL-2.30.2/docs/README-touch.md new file mode 100644 index 0000000..66c1b2b --- /dev/null +++ b/src/contrib/SDL-2.30.2/docs/README-touch.md | |||
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| 1 | Touch | ||
| 2 | =========================================================================== | ||
| 3 | System Specific Notes | ||
| 4 | =========================================================================== | ||
| 5 | Linux: | ||
| 6 | 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. | ||
| 7 | |||
| 8 | Mac: | ||
| 9 | The 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 | |||
| 11 | iPhone: | ||
| 12 | Works out of box. | ||
| 13 | |||
| 14 | Windows: | ||
| 15 | 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 | ||
| 16 | |||
| 17 | =========================================================================== | ||
| 18 | Events | ||
| 19 | =========================================================================== | ||
| 20 | SDL_FINGERDOWN: | ||
| 21 | Sent when a finger (or stylus) is placed on a touch device. | ||
| 22 | Fields: | ||
| 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 | |||
| 29 | SDL_FINGERMOTION: | ||
| 30 | Sent when a finger (or stylus) is moved on the touch device. | ||
| 31 | Fields: | ||
| 32 | Same 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 | |||
| 36 | SDL_FINGERUP: | ||
| 37 | Sent when a finger (or stylus) is lifted from the touch device. | ||
| 38 | Fields: | ||
| 39 | Same as SDL_FINGERDOWN. | ||
| 40 | |||
| 41 | |||
| 42 | =========================================================================== | ||
| 43 | Functions | ||
| 44 | =========================================================================== | ||
| 45 | SDL provides the ability to access the underlying SDL_Finger structures. | ||
| 46 | These structures should _never_ be modified. | ||
| 47 | |||
| 48 | The following functions are included from SDL_touch.h | ||
| 49 | |||
| 50 | To get a SDL_TouchID call SDL_GetTouchDevice(int index). | ||
| 51 | This returns a SDL_TouchID. | ||
| 52 | IMPORTANT: 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 | |||
| 54 | The number of touch devices can be queried with SDL_GetNumTouchDevices(). | ||
| 55 | |||
| 56 | A SDL_TouchID may be used to get pointers to SDL_Finger. | ||
| 57 | |||
| 58 | SDL_GetNumTouchFingers(touchID) may be used to get the number of fingers currently down on the device. | ||
| 59 | |||
| 60 | 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: | ||
| 61 | |||
| 62 | float x = event.tfinger.x; | ||
| 63 | float y = event.tfinger.y; | ||
| 64 | |||
| 65 | |||
| 66 | |||
| 67 | To get a SDL_Finger, call SDL_GetTouchFinger(SDL_TouchID touchID, int index), where touchID is a SDL_TouchID, and index is the requested finger. | ||
| 68 | This returns a SDL_Finger *, or NULL if the finger does not exist, or has been removed. | ||
| 69 | 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. | ||
| 70 | As a result, be very careful to check for NULL return values. | ||
| 71 | |||
| 72 | A 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 | =========================================================================== | ||
| 80 | Notes | ||
| 81 | =========================================================================== | ||
| 82 | For a complete example see test/testgesture.c | ||
| 83 | |||
| 84 | Please direct questions/comments to: | ||
| 85 | jim.tla+sdl_touch@gmail.com | ||
| 86 | (original author, API was changed since) | ||