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

use super::errors::*;

use std::path::Path;
use std::fs::File;
use std::io::Read;

use raw::{attach_shader, compile_shader, create_program, create_shader, delete_program, delete_shader, detach_shader,
          get_integer_i_v, get_program_info_log, get_shader_info_log, link_program, shader_source, use_program,
          GetParameterName, ProgramId, ShaderType};

#[derive(Debug)]
pub struct ComputeProgram {
    id: ProgramId,
}

impl ComputeProgram {
    #[allow(unused_must_use)]
    pub fn new(sources: &[&str]) -> Result<ComputeProgram> {
        let program_id: ProgramId;
        unsafe {
            let shader_id = create_shader(ShaderType::Compute);

            shader_source(shader_id, sources);
            compile_shader(shader_id);

            let shader_info_log = get_shader_info_log(shader_id);

            match shader_info_log {
                Ok(log) => if log.len() > 1 {
                    delete_shader(shader_id);
                    bail!(log);
                },
                Err(_) => {
                    delete_shader(shader_id);
                    shader_info_log.chain_err(|| "Could not get shader compilation log")?;
                }
            }

            program_id = create_program();
            let attach_status = attach_shader(program_id, shader_id);
            if attach_status.is_err() {
                delete_program(program_id);
                delete_shader(shader_id);
                attach_status.chain_err(|| "Could not attach shader")?;
            }

            let link_status = link_program(program_id);
            if link_status.is_err() {
                let program_info_log = get_program_info_log(program_id);
                match program_info_log {
                    Ok(log) => if log.len() > 1 {
                        delete_program(program_id);
                        delete_shader(shader_id);
                        bail!(log);
                    },
                    Err(_) => {
                        delete_program(program_id);
                        delete_shader(shader_id);
                        program_info_log.chain_err(|| "Could not get program link log")?;
                    }
                }
            }

            // ignoring error, because according to spec it cannot fail
            // because program_id is program object, shader_id is shader object
            //         shader_id is attached to program_id
            detach_shader(program_id, shader_id);

            delete_shader(shader_id);
        }
        Ok(ComputeProgram { id: program_id })
    }

    pub fn from_file(filepath: &Path) -> Result<ComputeProgram> {
        let mut file = match File::open(&filepath) {
            Ok(file) => file,
            Err(e) => return Err(format!("Could not open shader file : {}", e).into()),
        };

        let mut source = String::new();
        match file.read_to_string(&mut source) {
            Ok(_) => {}
            Err(e) => return Err(format!("Could not read shader file! : {}", e).into()),
        };

        ComputeProgram::new(&[source.as_str()])
    }

    pub fn bind(&self) -> Result<()> {
        unsafe { use_program(self.id).chain_err(|| "Could not bind compute program") }
    }

    pub fn get_id(&self) -> ProgramId {
        self.id
    }

    pub fn max_group_count() -> (u32, u32, u32) {
        unsafe {
            let x = get_integer_i_v(GetParameterName::MaxComputeWorkGroupCount, 0).unwrap() as u32;
            let y = get_integer_i_v(GetParameterName::MaxComputeWorkGroupCount, 1).unwrap() as u32;
            let z = get_integer_i_v(GetParameterName::MaxComputeWorkGroupCount, 2).unwrap() as u32;

            (x, y, z)
        }
    }

    pub fn max_group_size() -> (u32, u32, u32) {
        unsafe {
            let x = get_integer_i_v(GetParameterName::MaxComputeWorkGroupSize, 0).unwrap() as u32;
            let y = get_integer_i_v(GetParameterName::MaxComputeWorkGroupSize, 1).unwrap() as u32;
            let z = get_integer_i_v(GetParameterName::MaxComputeWorkGroupSize, 2).unwrap() as u32;

            (x, y, z)
        }
    }

    pub fn max_group_invocations() -> u32 {
        unsafe { get_integer_i_v(GetParameterName::MaxComputeWorkGroupInvocations, 0).unwrap() as u32 }
    }
}

impl Drop for ComputeProgram {
    fn drop(&mut self) {
        unsafe {
            delete_program(self.id);
        }
    }
}