1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89

use wrap::*;
use user_data::{UserDataTypes, RawUserData};
use dynamics::world::{World, JointHandle};
use dynamics::joints::{Joint, JointType, JointDef};

pub struct GearJointDef {
    pub collide_connected: bool,
    pub joint_1: JointHandle,
    pub joint_2: JointHandle,
    pub ratio: f32,
}

impl GearJointDef {
    pub fn new(joint_1: JointHandle, joint_2: JointHandle) -> GearJointDef {
        GearJointDef {
            collide_connected: false,
            joint_1: joint_1,
            joint_2: joint_2,
            ratio: 1.,
        }
    }
}

impl JointDef for GearJointDef {
    fn joint_type() -> JointType
        where Self: Sized
    {
        JointType::Gear
    }

    unsafe fn create<U: UserDataTypes>(&self, world: &mut World<U>) -> *mut ffi::Joint {
        self.try_create(world).expect("joint create failed: invalid joint handle")
    }

    unsafe fn try_create<U: UserDataTypes>(&self, world: &mut World<U>) -> Option<*mut ffi::Joint> {
        Some(ffi::World_create_gear_joint(world.mut_ptr(),
                                          self.collide_connected,
                                          world.try_joint_mut(self.joint_1)?.mut_base_ptr(),
                                          world.try_joint_mut(self.joint_2)?.mut_base_ptr(),
                                          self.ratio))
    }
}

wrap_joint! {
    ffi::GearJoint => GearJoint (JointType::Gear)
    < ffi::GearJoint_as_joint
    > ffi::Joint_as_gear_joint
}

impl GearJoint {
    pub fn ratio(&self) -> f32 {
        unsafe { ffi::GearJoint_get_ratio(self.ptr()) }
    }

    pub fn joint_1(&self) -> JointHandle {
        unsafe { ffi::GearJoint_get_joint_1(self.ptr() as *mut ffi::GearJoint).handle() }
    }

    pub fn joint_2(&self) -> JointHandle {
        unsafe { ffi::GearJoint_get_joint_2(self.ptr() as *mut ffi::GearJoint).handle() }
    }

    pub fn set_ratio(&mut self, ratio: f32) {
        unsafe { ffi::GearJoint_set_ratio(self.mut_ptr(), ratio) }
    }
}

#[doc(hidden)]
pub mod ffi {
    pub use dynamics::world::ffi::World;
    pub use dynamics::joints::ffi::Joint;

    pub enum GearJoint {}

    extern "C" {
        pub fn World_create_gear_joint(world: *mut World,
                                       collide_connected: bool,
                                       joint_a: *mut Joint,
                                       joint_b: *mut Joint,
                                       ratio: f32)
                                       -> *mut Joint;
        pub fn GearJoint_as_joint(slf: *mut GearJoint) -> *mut Joint;
        pub fn Joint_as_gear_joint(slf: *mut Joint) -> *mut GearJoint;
        pub fn GearJoint_get_joint_1(slf: *mut GearJoint) -> *mut Joint;
        pub fn GearJoint_get_joint_2(slf: *mut GearJoint) -> *mut Joint;
        pub fn GearJoint_set_ratio(slf: *mut GearJoint, ratio: f32);
        pub fn GearJoint_get_ratio(slf: *const GearJoint) -> f32;
    }
}