glium 0.3.3

High-level and safe OpenGL wrapper.
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

extern crate glutin;

#[macro_use]
extern crate glium;

use glium::Surface;

mod support;

fn main() {
    use glium::DisplayBuild;

    // building the display, ie. the main object
    let display = glutin::WindowBuilder::new()
        .with_depth_buffer(24)
        .build_glium()
        .unwrap();

    // building the vertex and index buffers
    let vertex_buffer = support::load_wavefront(&display, include_bytes!("support/teapot.obj"));

    // the program
    let program = program!(&display,
        140 => {
            vertex: "
                #version 140

                uniform mat4 persp_matrix;
                uniform mat4 view_matrix;

                in vec3 position;
                in vec3 normal;
                out vec3 v_position;
                out vec3 v_normal;

                void main() {
                    v_position = position;
                    v_normal = normal;
                    gl_Position = persp_matrix * view_matrix * vec4(v_position * 0.005, 1.0);
                }
            ",

            fragment: "
                #version 140

                in vec3 v_normal;
                out vec4 f_color;

                const vec3 LIGHT = vec3(-0.2, 0.8, 0.1);

                void main() {
                    float lum = max(dot(normalize(v_normal), normalize(LIGHT)), 0.0);
                    vec3 color = (0.3 + 0.7 * lum) * vec3(1.0, 1.0, 1.0);
                    f_color = vec4(color, 1.0);
                }
            ",
        },

        110 => {
            vertex: "
                #version 110

                uniform mat4 persp_matrix;
                uniform mat4 view_matrix;

                attribute vec3 position;
                attribute vec3 normal;
                varying vec3 v_position;
                varying vec3 v_normal;

                void main() {
                    v_position = position;
                    v_normal = normal;
                    gl_Position = persp_matrix * view_matrix * vec4(v_position * 0.005, 1.0);
                }
            ",

            fragment: "
                #version 110

                varying vec3 v_normal;

                const vec3 LIGHT = vec3(-0.2, 0.8, 0.1);

                void main() {
                    float lum = max(dot(normalize(v_normal), normalize(LIGHT)), 0.0);
                    vec3 color = (0.3 + 0.7 * lum) * vec3(1.0, 1.0, 1.0);
                    gl_FragColor = vec4(color, 1.0);
                }
            ",
        }
    ).unwrap();

    //
    let mut camera = support::camera::CameraState::new();
    
    // the main loop
    support::start_loop(|| {
        camera.update();

        // building the uniforms
        let uniforms = uniform! {
            persp_matrix: camera.get_perspective(),
            view_matrix: camera.get_view(),
        };

        // draw parameters
        let params = glium::DrawParameters {
            depth_test: glium::DepthTest::IfLess,
            depth_write: true,
            .. std::default::Default::default()
        };

        // drawing a frame
        let mut target = display.draw();
        target.clear_color_and_depth((0.0, 0.0, 0.0, 0.0), 1.0);
        target.draw(&vertex_buffer,
                    &glium::index::NoIndices(glium::index::PrimitiveType::TrianglesList),
                    &program, &uniforms, &params).unwrap();
        target.finish();

        // polling and handling the events received by the window
        for event in display.poll_events() {
            match event {
                glutin::Event::Closed => return support::Action::Stop,
                ev => camera.process_input(&ev),
            }
        }

        support::Action::Continue
    });
}