gate 0.6.3

A specialized 2D game library
Documentation 
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

// Copyright 2017-2019 Matthew D. Michelotti
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use std::{ptr, str, mem};
use std::os::raw::{c_void, c_char};

use gl::types::*;
use gl;

use super::shader_util;
use crate::renderer::shaders;

pub struct SpriteProgram {
    pub handle: GLuint,
    pub vao: GLuint,
    vs: GLuint,
    fs: GLuint,
    pub uniform_tex: GLint,
    pub uniform_inv_tex_dims: GLint,
}

impl SpriteProgram {
    pub fn new() -> SpriteProgram {
        let vs = shader_util::compile_shader(shaders::VS_SPRITE_SRC, gl::VERTEX_SHADER);
        let fs = shader_util::compile_shader(shaders::FS_SPRITE_SRC, gl::FRAGMENT_SHADER);
        let handle = shader_util::link_program(vs, fs);
        let vao = SpriteProgram::make_vao(handle);
        unsafe {
            SpriteProgram {
                handle, vao, vs, fs,
                uniform_tex: gl::GetUniformLocation(handle, c_str!("tex")),
                uniform_inv_tex_dims: gl::GetUniformLocation(handle, c_str!("inv_tex_dims")),
            }
        }
    }

    fn make_vao(program_handle: GLuint) -> GLuint {
        let mut vao = 0;
        unsafe {
            let attrib_vert = gl::GetAttribLocation(program_handle, c_str!("vert"));
            let attrib_vs_inv_tex_sample_dims = gl::GetAttribLocation(program_handle, c_str!("vs_inv_tex_sample_dims"));
            let attrib_vs_tex_vert_rb = gl::GetAttribLocation(program_handle, c_str!("vs_tex_vert_rb"));
            let attrib_vs_flash_ratio = gl::GetAttribLocation(program_handle, c_str!("vs_flash_ratio"));

            gl::GenVertexArrays(1, &mut vao);
            gl::BindVertexArray(vao);

            // TODO be consistent with the gl::TRUE/FALSE values in gl::VertexAttribPointer...

            gl::EnableVertexAttribArray(attrib_vert as GLuint);
            gl::VertexAttribPointer(attrib_vert as GLuint, 2, gl::FLOAT, gl::FALSE, 7*mem::size_of::<GLfloat>() as i32, ptr::null());

            gl::EnableVertexAttribArray(attrib_vs_inv_tex_sample_dims as GLuint);
            gl::VertexAttribPointer(attrib_vs_inv_tex_sample_dims as GLuint, 2, gl::FLOAT, gl::TRUE, 7*mem::size_of::<GLfloat>() as i32,
                                    (2 * mem::size_of::<GLfloat>()) as *const c_void);

            gl::EnableVertexAttribArray(attrib_vs_tex_vert_rb as GLuint);
            gl::VertexAttribPointer(attrib_vs_tex_vert_rb as GLuint, 2, gl::FLOAT, gl::TRUE, 7*mem::size_of::<GLfloat>() as i32,
                                    (4 * mem::size_of::<GLfloat>()) as *const c_void);

            gl::EnableVertexAttribArray(attrib_vs_flash_ratio as GLuint);
            gl::VertexAttribPointer(attrib_vs_flash_ratio as GLuint, 1, gl::FLOAT, gl::TRUE, 7*mem::size_of::<GLfloat>() as i32,
                                    (6 * mem::size_of::<GLfloat>()) as *const c_void);

            gl::BindVertexArray(0);
        }
        vao
    }
}

impl Drop for SpriteProgram {
    fn drop(&mut self) {
        unsafe {
            gl::DeleteProgram(self.handle);
            gl::DeleteShader(self.fs);
            gl::DeleteShader(self.vs);
            gl::DeleteVertexArrays(1, &self.vao);
        }
    }
}