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
use Context;
use math::{
    multiply,
    shear,
    scale,
    orient,
    rotate_radians,
    translate,
    Matrix2d,
    Vec2d,
    Scalar,
};
use radians::Radians;

/// Implemented by contexts that can transform.
pub trait Transformed: Sized {
    /// Appends transform to the current one.
    fn append_transform(self, transform: Matrix2d) -> Self;

    /// Prepends transform to the current one.
    fn prepend_transform(self, transform: Matrix2d) -> Self;

    /// Translate x an y in local coordinates.
    fn trans(self, x: Scalar, y: Scalar) -> Self;

    /// Rotates degrees in local coordinates.
    #[inline(always)]
    fn rot_deg(self, angle: Scalar) -> Self {
        let pi: Scalar = Radians::_180();
        self.rot_rad(angle * pi / 180.0)
    }

    /// Rotate radians in local coordinates.
    fn rot_rad(self, angle: Scalar) -> Self;

    /// Orients x axis to look at point locally.
    ///
    /// Leaves x axis unchanged if the point to
    /// look at is the origin.
    fn orient(self, x: Scalar, y: Scalar) -> Self;

    /// Scales in local coordinates.
    fn scale(self, sx: Scalar, sy: Scalar) -> Self;

    /// Scales in both directions in local coordinates.
    #[inline(always)]
    fn zoom(self, s: Scalar) -> Self {
        self.scale(s, s)
    }

    /// Flips vertically in local coordinates.
    #[inline(always)]
    fn flip_v(self) -> Self {
        self.scale(1.0, -1.0)
    }

    /// Flips horizontally in local coordinates.
    #[inline(always)]
    fn flip_h(self) -> Self {
        self.scale(-1.0, 1.0)
    }

    /// Flips horizontally and vertically in local coordinates.
    #[inline(always)]
    fn flip_hv(self) -> Self {
        self.scale(-1.0, -1.0)
    }

    /// Shears in local coordinates.
    fn shear(self, v: Vec2d) -> Self;
}

impl Transformed for Matrix2d {
    #[inline(always)]
    fn append_transform(self, transform: Matrix2d) -> Self {
        multiply(self, transform)
    }

    #[inline(always)]
    fn prepend_transform(self, transform: Matrix2d) -> Self {
        multiply(transform, self)
    }

    #[inline(always)]
    fn trans(self, x: Scalar, y: Scalar) -> Self {
        let trans = translate([x, y]);
        multiply(self, trans)
    }

    #[inline(always)]
    fn rot_rad(self, angle: Scalar) -> Self {
        let rot = rotate_radians(angle);
        multiply(self, rot)
    }

    #[inline(always)]
    fn orient(self, x: Scalar, y: Scalar) -> Self {
        let orient = orient(x, y);
        multiply(self, orient)
    }

    #[inline(always)]
    fn scale(self, sx: Scalar, sy: Scalar) -> Self {
        let scale = scale(sx, sy);
        multiply(self, scale)
    }

    #[inline(always)]
    fn shear(self, v: Vec2d) -> Self {
        let shear = shear(v);
        multiply(self, shear)
    }
}

impl Transformed for Context {
    #[inline(always)]
    fn append_transform(mut self, transform: Matrix2d) -> Self {
        self.transform = self.transform.append_transform(transform);
        self
    }

    #[inline(always)]
    fn prepend_transform(mut self, transform: Matrix2d) -> Self {
        self.transform = self.transform.prepend_transform(transform);
        self
    }

    #[inline(always)]
    fn trans(mut self, x: Scalar, y: Scalar) -> Self {
        self.transform = self.transform.trans(x, y);
        self
    }

    #[inline(always)]
    fn rot_rad(mut self, angle: Scalar) -> Self {
        self.transform = self.transform.rot_rad(angle);
        self
    }

    #[inline(always)]
    fn orient(mut self, x: Scalar, y: Scalar) -> Self {
        self.transform = self.transform.orient(x, y);
        self
    }

    #[inline(always)]
    fn scale(mut self, sx: Scalar, sy: Scalar) -> Self {
        self.transform = self.transform.scale(sx, sy);
        self
    }

    #[inline(always)]
    fn shear(mut self, v: Vec2d) -> Self {
        self.transform = self.transform.shear(v);
        self
    }
}