summaryrefslogtreecommitdiff
path: root/engine/src/opengl/shader.rs
blob: 36dc1a476d7d911e3f5d47bf638cd020651e5c62 (plain)
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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
use std::ffi::CStr;
use std::ptr::null_mut;

use crate::matrix::Matrix;
use crate::vector::Vec3;

#[derive(Debug)]
pub struct Shader
{
    shader: gl::types::GLuint,
}

impl Shader
{
    pub fn new(kind: Kind) -> Self
    {
        let shader = unsafe { gl::CreateShader(kind.into_gl()) };

        Self { shader }
    }

    pub fn set_source(&mut self, source: &str) -> Result<(), Error>
    {
        if !source.is_ascii() {
            return Err(Error::SourceNotAscii);
        }

        unsafe {
            #[allow(clippy::cast_possible_wrap, clippy::cast_possible_truncation)]
            gl::ShaderSource(
                self.shader,
                1,
                &source.as_ptr().cast(),
                &(source.len() as gl::types::GLint),
            );
        }

        Ok(())
    }

    pub fn compile(&mut self) -> Result<(), Error>
    {
        unsafe {
            gl::CompileShader(self.shader);
        }

        let mut compile_success = gl::types::GLint::default();

        unsafe {
            gl::GetShaderiv(self.shader, gl::COMPILE_STATUS, &mut compile_success);
        }

        if compile_success == 0 {
            let info_log = self.get_info_log();

            return Err(Error::CompileFailed(info_log));
        }

        Ok(())
    }

    fn get_info_log(&self) -> String
    {
        let mut buf = vec![gl::types::GLchar::default(); 512];

        unsafe {
            #[allow(clippy::cast_possible_wrap, clippy::cast_possible_truncation)]
            gl::GetShaderInfoLog(
                self.shader,
                buf.len() as gl::types::GLsizei,
                null_mut(),
                buf.as_mut_ptr(),
            );
        }

        let info_log = unsafe { CStr::from_ptr(buf.as_ptr()) };

        unsafe { String::from_utf8_unchecked(info_log.to_bytes().to_vec()) }
    }
}

impl Drop for Shader
{
    fn drop(&mut self)
    {
        unsafe {
            gl::DeleteShader(self.shader);
        }
    }
}

/// Shader kind.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
pub enum Kind
{
    Vertex,
    Fragment,
}

impl Kind
{
    fn into_gl(self) -> gl::types::GLenum
    {
        match self {
            Self::Vertex => gl::VERTEX_SHADER,
            Self::Fragment => gl::FRAGMENT_SHADER,
        }
    }
}

/// Shader program
#[derive(Debug, PartialEq, Eq, Hash)]
pub struct Program
{
    program: gl::types::GLuint,
}

impl Program
{
    pub fn new() -> Self
    {
        let program = unsafe { gl::CreateProgram() };

        Self { program }
    }

    pub fn attach(&mut self, shader: &Shader)
    {
        unsafe {
            gl::AttachShader(self.program, shader.shader);
        }
    }

    pub fn link(&mut self) -> Result<(), Error>
    {
        unsafe {
            gl::LinkProgram(self.program);
        }

        let mut link_success = gl::types::GLint::default();

        unsafe {
            gl::GetProgramiv(self.program, gl::LINK_STATUS, &mut link_success);
        }

        if link_success == 0 {
            let info_log = self.get_info_log();

            return Err(Error::CompileFailed(info_log));
        }

        Ok(())
    }

    pub fn activate(&self)
    {
        unsafe {
            gl::UseProgram(self.program);
        }
    }

    pub fn set_uniform_matrix_4fv(&mut self, name: &CStr, matrix: &Matrix<f32, 4, 4>)
    {
        let uniform_location =
            unsafe { gl::GetUniformLocation(self.program, name.as_ptr().cast()) };

        unsafe {
            gl::ProgramUniformMatrix4fv(
                self.program,
                uniform_location,
                1,
                gl::FALSE,
                matrix.as_ptr(),
            );
        }
    }

    pub fn set_uniform_vec_3fv(&mut self, name: &CStr, vec: &Vec3<f32>)
    {
        let uniform_location =
            unsafe { gl::GetUniformLocation(self.program, name.as_ptr().cast()) };

        unsafe {
            gl::ProgramUniform3fv(self.program, uniform_location, 1, vec.as_ptr());
        }
    }

    pub fn set_uniform_1fv(&mut self, name: &CStr, num: f32)
    {
        let uniform_location =
            unsafe { gl::GetUniformLocation(self.program, name.as_ptr().cast()) };

        unsafe {
            gl::ProgramUniform1fv(self.program, uniform_location, 1, &num);
        }
    }

    pub fn set_uniform_1i(&mut self, name: &CStr, num: i32)
    {
        let uniform_location =
            unsafe { gl::GetUniformLocation(self.program, name.as_ptr().cast()) };

        unsafe {
            gl::ProgramUniform1i(self.program, uniform_location, num);
        }
    }

    fn get_info_log(&self) -> String
    {
        let mut buf = vec![gl::types::GLchar::default(); 512];

        unsafe {
            #[allow(clippy::cast_possible_wrap, clippy::cast_possible_truncation)]
            gl::GetProgramInfoLog(
                self.program,
                buf.len() as gl::types::GLsizei,
                null_mut(),
                buf.as_mut_ptr(),
            );
        }

        let info_log = unsafe { CStr::from_ptr(buf.as_ptr()) };

        unsafe { String::from_utf8_unchecked(info_log.to_bytes().to_vec()) }
    }
}

impl Drop for Program
{
    fn drop(&mut self)
    {
        unsafe {
            gl::DeleteProgram(self.program);
        }
    }
}

/// Shader error.
#[derive(Debug, thiserror::Error)]
pub enum Error
{
    #[error("All characters in source are not within the ASCII range")]
    SourceNotAscii,

    #[error("Failed to compile: {0}")]
    CompileFailed(String),
}