gfx 0.1.7

A high-performance, bindless graphics API
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

use device;
use device::shade::{Stage, CreateShaderError, ShaderModel};
use super::mesh::{Mesh, VertexFormat};

/// Program linking error
#[derive(Copy, Clone, PartialEq, Debug)]
pub enum ProgramError {
    /// Unable to compile the vertex shader
    Vertex(CreateShaderError),
    /// Unable to compile the fragment shader
    Fragment(CreateShaderError),
    /// Unable to link
    Link(()),
}

/// A type storing shader source for different graphics APIs and versions.
#[allow(missing_docs)]
#[derive(Copy, Clone, PartialEq, Debug)]
pub struct ShaderSource<'a> {
    pub glsl_120: Option<&'a [u8]>,
    pub glsl_130: Option<&'a [u8]>,
    pub glsl_140: Option<&'a [u8]>,
    pub glsl_150: Option<&'a [u8]>,
    pub glsl_430: Option<&'a [u8]>,
    // TODO: hlsl_sm_N...
    pub targets: &'a [&'a str],
}

impl<'a> ShaderSource<'a> {
    /// Create an empty shader source. Useful for specifying the remaining
    /// structure members upon construction.
    pub fn empty() -> ShaderSource<'a> {
        ShaderSource {
            glsl_120: None,
            glsl_130: None,
            glsl_140: None,
            glsl_150: None,
            glsl_430: None,
            targets: &[],
        }
    }

    /// Pick one of the stored versions that is the highest supported by the device.
    pub fn choose(&self, model: ShaderModel) -> Result<&'a [u8], ()> {
        // following https://www.opengl.org/wiki/Detecting_the_Shader_Model
        let version = model.to_number();
        Ok(match *self {
            ShaderSource { glsl_430: Some(s), .. } if version >= 50 => s,
            ShaderSource { glsl_150: Some(s), .. } if version >= 40 => s,
            ShaderSource { glsl_140: Some(s), .. } if version >= 40 => s,
            ShaderSource { glsl_130: Some(s), .. } if version >= 30 => s,
            ShaderSource { glsl_120: Some(s), .. } if version >= 20 => s,
            _ => return Err(()),
        })
    }
}


/// Backend extension trait for convenience methods
pub trait DeviceExt: device::Device {
    /// Create a new renderer
    fn create_renderer(&mut self) -> ::Renderer<<Self as device::Device>::CommandBuffer>;
    /// Create a new mesh from the given vertex data.
    /// Convenience function around `create_buffer` and `Mesh::from_format`.
    fn create_mesh<T: VertexFormat + Copy>(&mut self, data: &[T]) -> Mesh;
    /// Create a simple program given a vertex shader with a fragment one.
    fn link_program(&mut self, vs_code: &[u8], fs_code: &[u8])
                    -> Result<device::ProgramHandle, ProgramError>;
    /// Create a simple program given `ShaderSource` versions of vertex and
    /// fragment shaders, chooss the matching versions for the device.
    fn link_program_source(&mut self, vs_src: ShaderSource, fs_src: ShaderSource)
                           -> Result<device::ProgramHandle, ProgramError>;
}

impl<D: device::Device> DeviceExt for D {
    fn create_renderer(&mut self) -> ::Renderer<D::CommandBuffer> {
        ::Renderer {
            command_buffer: device::draw::CommandBuffer::new(),
            data_buffer: device::draw::DataBuffer::new(),
            common_array_buffer: self.create_array_buffer(),
            draw_frame_buffer: self.create_frame_buffer(),
            read_frame_buffer: self.create_frame_buffer(),
            default_frame_buffer: device::get_main_frame_buffer(),
            render_state: super::RenderState::new(),
            parameters: super::ParamStorage::new(),
        }
    }

    fn create_mesh<T: VertexFormat + Copy>(&mut self, data: &[T]) -> Mesh {
        let nv = data.len();
        debug_assert!(nv < {
            use std::num::Int;
            let val: device::VertexCount = Int::max_value();
            val as usize
        });
        let buf = self.create_buffer_static(data);
        Mesh::from_format(buf, nv as device::VertexCount)
    }

    fn link_program(&mut self, vs_code: &[u8], fs_code: &[u8])
                    -> Result<device::ProgramHandle, ProgramError> {
        let vs = match self.create_shader(Stage::Vertex, vs_code) {
            Ok(s) => s,
            Err(e) => return Err(ProgramError::Vertex(e)),
        };
        let fs = match self.create_shader(Stage::Fragment, fs_code) {
            Ok(s) => s,
            Err(e) => return Err(ProgramError::Fragment(e)),
        };

        self.create_program(&[vs, fs], None)
            .map_err(|e| ProgramError::Link(e))
    }

    fn link_program_source(&mut self, vs_src: ShaderSource, fs_src: ShaderSource)
                           -> Result<device::ProgramHandle, ProgramError> {
        let model = self.get_capabilities().shader_model;
        let err_model = CreateShaderError::ModelNotSupported;

        let vs = match vs_src.choose(model) {
            Ok(code) => match self.create_shader(Stage::Vertex, code) {
                Ok(s) => s,
                Err(e) => return Err(ProgramError::Vertex(e)),
            },
            Err(_) => return Err(ProgramError::Vertex(err_model))
        };

        let fs = match fs_src.choose(model) {
            Ok(code) => match self.create_shader(Stage::Fragment, code) {
                Ok(s) => s,
                Err(e) => return Err(ProgramError::Fragment(e)),
            },
            Err(_) => return Err(ProgramError::Fragment(err_model))
        };

        self.create_program(&[vs, fs], Some(fs_src.targets))
            .map_err(|e| ProgramError::Link(e))
    }
}