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
|
use glow::*;
use iced_glow::Color;
pub struct Scene {
program: glow::Program,
vertex_array: glow::VertexArray,
}
impl Scene {
pub fn new(gl: &glow::Context, shader_version: &str) -> Self {
unsafe {
let vertex_array = gl
.create_vertex_array()
.expect("Cannot create vertex array");
gl.bind_vertex_array(Some(vertex_array));
let program = gl.create_program().expect("Cannot create program");
let (vertex_shader_source, fragment_shader_source) = (
r#"const vec2 verts[3] = vec2[3](
vec2(0.5f, 1.0f),
vec2(0.0f, 0.0f),
vec2(1.0f, 0.0f)
);
out vec2 vert;
void main() {
vert = verts[gl_VertexID];
gl_Position = vec4(vert - 0.5, 0.0, 1.0);
}"#,
r#"precision highp float;
in vec2 vert;
out vec4 color;
void main() {
color = vec4(vert, 0.5, 1.0);
}"#,
);
let shader_sources = [
(glow::VERTEX_SHADER, vertex_shader_source),
(glow::FRAGMENT_SHADER, fragment_shader_source),
];
let mut shaders = Vec::with_capacity(shader_sources.len());
for (shader_type, shader_source) in shader_sources.iter() {
let shader = gl
.create_shader(*shader_type)
.expect("Cannot create shader");
gl.shader_source(
shader,
&format!("{}\n{}", shader_version, shader_source),
);
gl.compile_shader(shader);
if !gl.get_shader_compile_status(shader) {
panic!("{}", gl.get_shader_info_log(shader));
}
gl.attach_shader(program, shader);
shaders.push(shader);
}
gl.link_program(program);
if !gl.get_program_link_status(program) {
panic!("{}", gl.get_program_info_log(program));
}
for shader in shaders {
gl.detach_shader(program, shader);
gl.delete_shader(shader);
}
gl.use_program(Some(program));
Self {
program,
vertex_array,
}
}
}
pub fn clear(&self, gl: &glow::Context, background_color: Color) {
let [r, g, b, a] = background_color.into_linear();
unsafe {
gl.clear_color(r, g, b, a);
gl.clear(glow::COLOR_BUFFER_BIT);
}
}
pub fn draw(&self, gl: &glow::Context) {
unsafe {
gl.bind_vertex_array(Some(self.vertex_array));
gl.use_program(Some(self.program));
gl.draw_arrays(glow::TRIANGLES, 0, 3);
}
}
pub fn cleanup(&self, gl: &glow::Context) {
unsafe {
gl.delete_program(self.program);
gl.delete_vertex_array(self.vertex_array);
}
}
}
|
