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
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173

//! General graphics-related utility functions.

use ::{cgmath, collision, rand};
use ::{rs_utils};

///////////////////////////////////////////////////////////////////////////////
//  structs                                                                  //
///////////////////////////////////////////////////////////////////////////////

#[derive(Clone,Debug,PartialEq)]
pub struct Pose3d <S : cgmath::BaseFloat> {
  pub position : cgmath::Point3 <S>,
  pub yaw      : cgmath::Rad    <S>,
  pub pitch    : cgmath::Rad    <S>
  // TODO: roll ?
}

///////////////////////////////////////////////////////////////////////////////
//  functions                                                                //
///////////////////////////////////////////////////////////////////////////////

/// Computes an orientation basis based on given yaw and pitch.
pub fn orientation_from_yaw_pitch (
  yaw : cgmath::Rad <f32>, pitch : cgmath::Rad <f32>
) -> cgmath::Basis3 <f32> {
  use cgmath::Rotation3;
  let heading = cgmath::Basis3::from_angle_z (yaw);
  cgmath::Basis3::from_axis_angle (heading.as_ref().x, pitch) * heading
}

/// Clamp a 2D point to the given AABB rectangle, returns true if point was
/// modified, or false otherwise if the point is already within the volume.
///
/// # Examples
///
/// ```
/// # extern crate gl_utils;
/// # extern crate cgmath;
/// # extern crate collision;
/// # fn main () {
/// # use gl_utils::graphics::point2d_clamp;
/// let mut point = cgmath::Point2::<i32>::new (-1, -1);
/// assert!{
///   point2d_clamp (
///     &collision::Aabb2::<i32>::new ((0,0).into(), (10,10).into()),
///     &mut point)
/// }
/// assert_eq!(point, (0,0).into());
/// assert!{
///   !point2d_clamp (
///     &collision::Aabb2::<i32>::new ((-5,-5).into(), (5,5).into()),
///     &mut point)
/// }
/// assert_eq!(point, (0,0).into());
/// let mut point = cgmath::Point2::<f64>::new (-1.0, -1.0);
/// assert!{
///   point2d_clamp (
///     &collision::Aabb2::<f64>::new ((0.0,0.0).into(), (10.0,10.0).into()),
///     &mut point)
/// }
/// assert_eq!(point, (0.0,0.0).into());
/// assert!{
///   !point2d_clamp (
///     &collision::Aabb2::<f64>::new ((-5.0,-5.0).into(), (5.0,5.0).into()),
///     &mut point)
/// }
/// assert_eq!(point, (0.0,0.0).into());
/// # }
/// ```

pub fn point2d_clamp <S : cgmath::BaseNum> (
  aabb : &collision::Aabb2 <S>, point : &mut cgmath::Point2 <S>
) -> bool {
  use collision::Contains;
  if !aabb.contains (point) {
    point.x = rs_utils::numeric::min_partial (point.x, aabb.max.x);
    point.x = rs_utils::numeric::max_partial (point.x, aabb.min.x);
    point.y = rs_utils::numeric::min_partial (point.y, aabb.max.y);
    point.y = rs_utils::numeric::max_partial (point.y, aabb.min.y);
    true
  } else {
    false
  }
}

/// Convenience method that calls `cgmath::ortho` on the given `Ortho` struct
#[inline]
pub fn projection_mat_orthographic <S : cgmath::BaseFloat> (
  ortho : &cgmath::Ortho <S>
) -> cgmath::Matrix4 <S> {
  cgmath::ortho (
    ortho.left,
    ortho.right,
    ortho.bottom,
    ortho.top,
    ortho.near,
    ortho.far)
}

/// Convenience method calling `cgmath::perspective` on the given
/// `PerspectiveFov` struct.
///
/// This will transform points in right-handed camera (view, eye) space
/// (negative Z axis into the scene, positive Y axis 'up') into left-handed 4D
/// homogenous clip space where the Z axis is reversed with positive Z into the
/// screen while X and Y orientations remain unchanged.
#[inline]
pub fn projection_mat_perspective <S : cgmath::BaseFloat> (
  perspective_fov : &cgmath::PerspectiveFov <S>
) -> cgmath::Matrix4 <S> {
  cgmath::perspective (
    perspective_fov.fovy,
    perspective_fov.aspect,
    perspective_fov.near,
    perspective_fov.far)
}

/// Generate a random point contained in the give AABB
///
/// ```
/// # extern crate gl_utils;
/// # extern crate cgmath;
/// # extern crate collision;
/// # extern crate rand;
/// # fn main () {
/// # use gl_utils::graphics::*;
/// use collision::Contains;
/// use rand::SeedableRng;
/// // random sequence will be the same each time this is run
/// let mut rng = rand::XorShiftRng::new_unseeded();
/// let aabb = collision::Aabb3::<f32>::new (
///   [-10.0, -10.0, -10.0].into(),
///   [ 10.0,  10.0,  10.0].into());
/// let point = rand_point3d (&mut rng, &aabb);
/// assert!(aabb.contains (&point));
/// let point = rand_point3d (&mut rng, &aabb);
/// assert!(aabb.contains (&point));
/// let point = rand_point3d (&mut rng, &aabb);
/// assert!(aabb.contains (&point));
/// let point = rand_point3d (&mut rng, &aabb);
/// assert!(aabb.contains (&point));
/// let point = rand_point3d (&mut rng, &aabb);
/// assert!(aabb.contains (&point));
/// # }
/// ```

#[inline]
pub fn rand_point3d <S, R>
  (rng : &mut R, aabb : &collision::Aabb3 <S>) -> cgmath::Point3 <S>
where
  S : cgmath::BaseFloat + rand::distributions::range::SampleRange,
  R : rand::Rng
{
  [ rng.gen_range (aabb.min.x, aabb.max.x),
    rng.gen_range (aabb.min.y, aabb.max.y),
    rng.gen_range (aabb.min.z, aabb.max.z)
  ].into()
}

///////////////////////////////////////////////////////////////////////////////
//  impls                                                                    //
///////////////////////////////////////////////////////////////////////////////

impl <S : cgmath::BaseFloat> Default for Pose3d <S> {
  fn default() -> Self {
    use cgmath::{EuclideanSpace, Zero};
    Pose3d {
      position: cgmath::Point3::origin(),
      yaw:      cgmath::Rad::zero(),
      pitch:    cgmath::Rad::zero()
    }
  }
}