willow 0.0.3

Willow is a library for using the WebGL API in WebAssembly projects.
Documentation 
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

use cfg_if::cfg_if;
use web_sys::{WebGlRenderingContext, WebGlUniformLocation};

/// Types that can be used as a uniform argument type.
pub trait UniformType: Sized + Copy + 'static {
    /// Applies the uniform value to the specified location.
    fn apply_uniform(self, context: &WebGlRenderingContext, location: &WebGlUniformLocation);
}

macro_rules! impl_uniform {
    ($ty:ty; $method:ident, |$x:ident| ($($value:expr),*)) => {
        impl UniformType for $ty {
            fn apply_uniform(self, context: &WebGlRenderingContext, location: &WebGlUniformLocation) {
                let $x = self;
                context.$method(Some(location), $($value),*);
            }
        }
    }
}

/// Types that can be used as an attribute argument type.
pub trait AttributeType: Sized + Copy + 'static {
    /// Number of components in the type.
    fn num_comps() -> usize;

    /// Corresponding GLenum specifying the data type of each component in the array,
    /// e.g. `WebGlRenderingContext::UNSIGNED_SHORT`.
    fn gl_type() -> u32;
}

macro_rules! impl_attribute {
    ($ty:ty; $glty:ident) => {
        impl AttributeType for $ty {
            fn num_comps() -> usize {
                1
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        impl AttributeType for ($ty, $ty) {
            fn num_comps() -> usize {
                2
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        impl AttributeType for ($ty, $ty, $ty) {
            fn num_comps() -> usize {
                3
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        impl AttributeType for ($ty, $ty, $ty, $ty) {
            fn num_comps() -> usize {
                4
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        #[cfg(feature = "nalgebra")]
        impl AttributeType for nalgebra::Vector2<$ty> {
            fn num_comps() -> usize {
                2
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        #[cfg(feature = "nalgebra")]
        impl AttributeType for nalgebra::Vector3<$ty> {
            fn num_comps() -> usize {
                3
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }

        #[cfg(feature = "nalgebra")]
        impl AttributeType for nalgebra::Vector4<$ty> {
            fn num_comps() -> usize {
                4
            }

            fn gl_type() -> u32 {
                WebGlRenderingContext::$glty
            }
        }
    };
}

impl_attribute!(i8; BYTE);
impl_attribute!(i16; SHORT);
impl_attribute!(u8; UNSIGNED_BYTE);
impl_attribute!(u16; UNSIGNED_SHORT);
impl_attribute!(f32; FLOAT);

impl_uniform!(i32; uniform1i, |x| (x));
impl_uniform!(f32; uniform1f, |x| (x));

impl_uniform!((i32, i32); uniform2i, |x| (x.0, x.1));
impl_uniform!((f32, f32); uniform2f, |x| (x.0, x.1));

impl_uniform!((i32, i32, i32); uniform3i, |x| (x.0, x.1, x.2));
impl_uniform!((f32, f32, f32); uniform3f, |x| (x.0, x.1, x.2));

impl_uniform!((i32, i32, i32, i32); uniform4i, |x| (x.0, x.1, x.2, x.3));
impl_uniform!((f32, f32, f32, f32); uniform4f, |x| (x.0, x.1, x.2, x.3));

cfg_if! {
    if #[cfg(feature = "nalgebra")] {
        impl_uniform!(nalgebra::Vector2<i32>; uniform2i, |x| (x[0], x[1]));
        impl_uniform!(nalgebra::Vector2<f32>; uniform2f, |x| (x[0], x[1]));

        impl_uniform!(nalgebra::Vector3<i32>; uniform3i, |x| (x[0], x[1], x[2]));
        impl_uniform!(nalgebra::Vector3<f32>; uniform3f, |x| (x[0], x[1], x[2]));

        impl_uniform!(nalgebra::Vector4<i32>; uniform4i, |x| (x[0], x[1], x[2], x[3]));
        impl_uniform!(nalgebra::Vector4<f32>; uniform4f, |x| (x[0], x[1], x[2], x[3]));

        impl_uniform!(nalgebra::Matrix2<f32>; uniform_matrix2fv_with_f32_array, |x| (false, x.as_slice()));
        impl_uniform!(nalgebra::Matrix3<f32>; uniform_matrix3fv_with_f32_array, |x| (false, x.as_slice()));
        impl_uniform!(nalgebra::Matrix4<f32>; uniform_matrix4fv_with_f32_array, |x| (false, x.as_slice()));
    }
}