Add touch API

src/touch.rs

@@ -1,19 +1,48 @@
+use std::ptr;
+
+pub type TouchDevice = ll::SDL_TouchID;
+
+#[deriving(Eq)]
+pub struct Finger {
+    id: TouchDevice,
+    x: f32,
+    y: f32,
+    pressure: f32,
+}
 
 pub mod ll {
-	use std::libc::{c_float, c_int, int64_t};
+    use std::libc::{c_int, int64_t};
+    use touch::Finger;
 
-	pub type SDL_TouchID = int64_t;
-	pub type SDL_FingerID = int64_t;
+    pub type SDL_TouchID = int64_t;
+    pub type SDL_FingerID = int64_t;
+    pub type SDL_Finger = Finger;
 
-	pub struct SDL_Finger {
-	    id: SDL_FingerID,
-	    x: c_float,
-	    y: c_float,
-	    pressure: c_float,
-	}
-
-	externfn!(fn SDL_GetNumTouchDevices() -> c_int)
-	externfn!(fn SDL_GetTouchDevice(index: c_int) -> SDL_TouchID)
-	externfn!(fn SDL_GetNumTouchFingers(touchID: SDL_TouchID) -> c_int)
-	externfn!(fn SDL_GetTouchFinger(touchID: SDL_TouchID, index: c_int))
+    externfn!(fn SDL_GetNumTouchDevices() -> c_int)
+    externfn!(fn SDL_GetTouchDevice(index: c_int) -> SDL_TouchID)
+    externfn!(fn SDL_GetNumTouchFingers(touchID: SDL_TouchID) -> c_int)
+    externfn!(fn SDL_GetTouchFinger(touchID: SDL_TouchID, index: c_int) ->
+              *SDL_Finger)
+}
+
+pub fn get_num_touch_devices() -> int {
+    unsafe { ll::SDL_GetNumTouchDevices() as int }
+}
+
+pub fn get_touch_device(index: int) -> TouchDevice {
+    unsafe { ll::SDL_GetTouchDevice(index as i32) }
+}
+
+pub fn get_num_touch_fingers(touch: TouchDevice) -> int {
+    unsafe { ll::SDL_GetNumTouchFingers(touch) as int }
+}
+
+pub fn get_touch_finger(touch: TouchDevice, index: int) -> Option<Finger> {
+    let raw = unsafe { ll::SDL_GetTouchFinger(touch, index as i32) };
+
+    if raw == ptr::null() {
+        None
+    } else {
+        unsafe { Some(*raw) }
+    }
 }