gl_helpers 0.1.1

extern crate gl;
extern crate glutin;
extern crate time;
extern crate vec3;
extern crate mat4;
extern crate gl_helpers;


use std::f32;
use glutin::GlContext;
use gl::types::*;

use gl_helpers::*;


static FB_DATA: [GLfloat; 16] = [
    // position     uv
     1f32,  1f32,   1f32, 1f32,
    -1f32,  1f32,   0f32, 1f32,
     1f32, -1f32,   1f32, 0f32,
    -1f32, -1f32,   0f32, 0f32
];
static CUBE_DATA: [GLfloat; 288] = [
    1.0, 1.0, -1.0, 0.577349, 0.577349, -0.577349, 0.0, 0.0, 1.0, -1.0, -1.0, 0.577349, -0.577349, -0.577349, 1.0, 0.0, -1.0, -1.0, -1.0, -0.577349, -0.577349, -0.577349, 1.0, 1.0, 1.0, 1.0, 1.0, 0.577349, 0.577349, 0.577349, 0.0, 0.0, -1.0, 1.0, 1.0, -0.577349, 0.577349, 0.577349, 1.0, 0.0, -1.0, -1.0, 1.0, -0.577349, -0.577349, 0.577349, 1.0, 1.0, 1.0, 1.0, -1.0, 0.577349, 0.577349, -0.577349, 0.0, 0.0, 1.0, 1.0, 1.0, 0.577349, 0.577349, 0.577349, 1.0, 0.0, 1.0, -1.0, 1.0, 0.577349, -0.577349, 0.577349, 1.0, 1.0, 1.0, -1.0, -1.0, 0.577349, -0.577349, -0.577349, 0.0, 0.0, 1.0, -1.0, 1.0, 0.577349, -0.577349, 0.577349, 1.0, 0.0, -1.0, -1.0, 1.0, -0.577349, -0.577349, 0.577349, 1.0, 1.0, -1.0, -1.0, -1.0, -0.577349, -0.577349, -0.577349, 0.0, 0.0, -1.0, -1.0, 1.0, -0.577349, -0.577349, 0.577349, 1.0, 0.0, -1.0, 1.0, 1.0, -0.577349, 0.577349, 0.577349, 1.0, 1.0, 1.0, 1.0, 1.0, 0.577349, 0.577349, 0.577349, 0.0, 0.0, 1.0, 1.0, -1.0, 0.577349, 0.577349, -0.577349, 1.0, 0.0, -1.0, 1.0, -1.0, -0.577349, 0.577349, -0.577349, 1.0, 1.0, -1.0, 1.0, -1.0, -0.577349, 0.577349, -0.577349, 0.0, 1.0, 1.0, 1.0, -1.0, 0.577349, 0.577349, -0.577349, 0.0, 0.0, -1.0, -1.0, -1.0, -0.577349, -0.577349, -0.577349, 1.0, 1.0, 1.0, -1.0, 1.0, 0.577349, -0.577349, 0.577349, 0.0, 1.0, 1.0, 1.0, 1.0, 0.577349, 0.577349, 0.577349, 0.0, 0.0, -1.0, -1.0, 1.0, -0.577349, -0.577349, 0.577349, 1.0, 1.0, 1.0, -1.0, -1.0, 0.577349, -0.577349, -0.577349, 0.0, 1.0, 1.0, 1.0, -1.0, 0.577349, 0.577349, -0.577349, 0.0, 0.0, 1.0, -1.0, 1.0, 0.577349, -0.577349, 0.577349, 1.0, 1.0, -1.0, -1.0, -1.0, -0.577349, -0.577349, -0.577349, 0.0, 1.0, 1.0, -1.0, -1.0, 0.577349, -0.577349, -0.577349, 0.0, 0.0, -1.0, -1.0, 1.0, -0.577349, -0.577349, 0.577349, 1.0, 1.0, -1.0, 1.0, -1.0, -0.577349, 0.577349, -0.577349, 0.0, 1.0, -1.0, -1.0, -1.0, -0.577349, -0.577349, -0.577349, 0.0, 0.0, -1.0, 1.0, 1.0, -0.577349, 0.577349, 0.577349, 1.0, 1.0, -1.0, 1.0, 1.0, -0.577349, 0.577349, 0.577349, 0.0, 1.0, 1.0, 1.0, 1.0, 0.577349, 0.577349, 0.577349, 0.0, 0.0, -1.0, 1.0, -1.0, -0.577349, 0.577349, -0.577349, 1.0, 1.0
];
static CUBE_INDEX_DATA: [u16; 36] = [
    0, 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
];

static FB_VERTEX:  &'static str = "
    #version 120

    attribute vec2 position;
    attribute vec2 uv;

    varying vec2 v_uv;

    void main() {
        gl_Position = vec4(position, 0.0, 1.0);
        v_uv = uv;
    }
";

static FB_FRAGMENT:  &'static str = "
    #version 120

    uniform sampler2D diffuse;

    varying vec2 v_uv;

    void main() {
        gl_FragColor = texture2D(diffuse, v_uv);
    }
";

static CUBE_VERTEX: &'static str = "
    #version 120

    uniform mat4 projection;
    uniform mat4 model_view;
    uniform vec3 light;

    attribute vec3 position;
    attribute vec3 normal;
    attribute vec2 uv;

    varying vec3 v_light;
    varying vec3 v_normal;
    varying vec2 v_uv;

    void main() {
        gl_Position = projection * model_view * vec4(position, 1.0);
        v_light = normalize(light - position);
        v_normal = normal;
        v_uv = uv;
    }
";

static CUBE_FRAGMENT: &'static str = "
    #version 120

    varying vec3 v_light;
    varying vec3 v_normal;
    varying vec2 v_uv;

    void main() {
        vec3 light_dir = v_light;
        vec3 color = vec3(v_uv, 0.5);
        vec3 intensity = vec3(0.75, 0.75, 0.75);
        float dprod = dot(light_dir, v_normal);

        if (dprod > 0.75) {
            intensity = vec3(1.0, 1.0, 1.0);
        } else if (dprod > 0.25) {
            intensity = vec3(0.8, 0.8, 0.8);
        }

        gl_FragColor = vec4(color * intensity, 1.0);
    }
";

fn main() {
    let mut screen_width = 1024_usize;
    let mut screen_height = 768_usize;

    let mut events_loop = glutin::EventsLoop::new();
    let window = glutin::WindowBuilder::new()
        .with_title("Framebuffer")
        .with_dimensions(screen_width as u32, screen_height as u32);
    let gl_window = glutin::GlWindow::new(
        window,
        glutin::ContextBuilder::new()
            .with_vsync(true),
        &events_loop
    ).unwrap();

    unsafe {
        gl_window.make_current().unwrap();
    }

    gl::load_with(|symbol| gl_window.get_proc_address(symbol) as *const _);

    let gl_info = GLInfo::new();
    println!("{}", gl_info.version());
    println!(
        "OpenGL version: {:?}.{:?}, GLSL version {:?}.{:?}0",
        gl_info.major(), gl_info.minor(), gl_info.glsl_major(), gl_info.glsl_minor()
    );

    gl_set_defaults();

    static SIZE: usize = 8_usize;
    let fb_program = GLProgram::new(FB_VERTEX, FB_FRAGMENT);

    let mut fb_texture = GLTexture::new_null_2d(
        screen_width / SIZE,
        screen_height / SIZE,
        DataFormat::RGBA,
        DataKind::UnsignedByte,
        FilterMode::None,
        Wrap::Clamp,
        false
    );

    let fb_framebuffer = GLFramebuffer::new(&fb_texture, &[Attachment::Color], 0);
    let fb_renderbuffer = GLRenderbuffer::new(DataFormat::DepthComponent, Attachment::Depth, screen_width / SIZE, screen_height / SIZE);

    let mut fb_vertex_array = GLVertexArray::new();

    fb_vertex_array.bind();

    let fb_buffer = GLBuffer::new(BufferTarget::Array, 4, Usage::StaticDraw, &FB_DATA);

    fb_buffer.bind();
    fb_vertex_array.add_attribute(&fb_buffer, fb_program.get_attribute("position"), 0);
    fb_vertex_array.add_attribute(&fb_buffer, fb_program.get_attribute("uv"), 2);


    let cube_program = GLProgram::new(CUBE_VERTEX, CUBE_FRAGMENT);

    let mut cube_vertex_array = GLVertexArray::new();

    cube_vertex_array.bind();

    let cube_buffer = GLBuffer::new(BufferTarget::Array, 8, Usage::StaticDraw, &CUBE_DATA);
    let cube_index_buffer = GLBuffer::new(BufferTarget::ElementArray, 0, Usage::StaticDraw, &CUBE_INDEX_DATA);

    cube_buffer.bind();
    cube_vertex_array.add_attribute(&cube_buffer, cube_program.get_attribute("position"), 0);
    cube_vertex_array.add_attribute(&cube_buffer, cube_program.get_attribute("normal"), 3);
    cube_vertex_array.add_attribute(&cube_buffer, cube_program.get_attribute("uv"), 5);
    cube_index_buffer.bind();


    let mut playing = true;

    let start_time = time::now();
    let mut last_time = start_time;
    let mut current_time;
    let mut ms = 0f32;
    let mut dt;

    let fov = 45_f32 * (f32::consts::PI / 180_f32);
    //let ortho_size: f32 = 2_f32;

    let origin = vec3::new(0_f32, 0_f32, 0_f32);
    let up = vec3::new(0_f32, 0_f32, 1_f32);

    let mut camera = mat4::new_identity::<f32>();
    let mut camera_position = vec3::new(6_f32, 6_f32, 4_f32);
    let mut light_position = vec3::new(2_f32, 2_f32, 2_f32);

    let mut projection = mat4::new_identity::<f32>();
    let mut model_view = mat4::new_identity::<f32>();

    while playing {
        current_time = time::now();
        dt = (current_time - last_time).num_nanoseconds().unwrap() as f32 * 0.000001f32;
        ms += dt;
        last_time = current_time;

        events_loop.poll_events(|event| {
            match event {
                glutin::Event::WindowEvent { event: glutin::WindowEvent::Closed, .. } => {
                    playing = false;
                },
                glutin::Event::WindowEvent { event: glutin::WindowEvent::Resized(w, h), .. } => {
                    gl_window.resize(w, h);

                    screen_width = w as usize;
                    screen_height = h as usize;

                    fb_texture.resize_null_2d(screen_width / SIZE,screen_height / SIZE);
                    fb_framebuffer.set(&fb_texture, &[Attachment::Color], 0);
                    fb_renderbuffer.set(DataFormat::DepthComponent, Attachment::Depth, screen_width / SIZE, screen_height / SIZE);
                    /*
                    let aspect = w as f32 / h as f32;
                    let r = ortho_size * aspect;
                    let l = -r;
                    let t = ortho_size;
                    let b = -t;
                    mat4::orthographic(&mut projection, t, r, b, l, 0.0001_f32, 1024_f32);
                    */
                    mat4::perspective(&mut projection, fov, screen_width as f32 / screen_height as f32, 0.0001_f32, 1024_f32);
                },
                _ => (),
            }
        });


        light_position[0] = (ms * 0.001f32).sin() * 6_f32;
        light_position[1] = (ms * 0.001f32).cos() * 6_f32;
        light_position[2] = (ms * 0.001f32).sin() * 6_f32;

        camera_position[0] = (ms * 0.001f32).sin() * 6_f32;
        camera_position[1] = (ms * 0.001f32).cos() * 6_f32;
        camera_position[2] = 3.5_f32 + ((ms * 0.001f32).sin() * 3_f32);

        mat4::look_at(&mut camera, &camera_position, &origin, &up);
        mat4::set_position(&mut camera, &camera_position);
        mat4::inverse(&mut model_view, &camera);


        fb_framebuffer.bind();
        fb_renderbuffer.bind();

        gl_set_viewport(0, 0, screen_width / SIZE, screen_height / SIZE);
        gl_set_clear_color(&[0.3, 0.3, 0.3, 1.0]);
        gl_clear(true, true, true);

        cube_program.bind();

        cube_vertex_array.bind();
        cube_vertex_array.enable_attributes();

        cube_program.get_uniform("projection").set_mat4f(&projection);
        cube_program.get_uniform("model_view").set_mat4f(&model_view);
        cube_program.get_uniform("light").set_3f(&light_position);

        gl_draw_elements(DrawMode::Triangles, 36, IndexKind::UnsignedShort, 0);

        fb_framebuffer.unbind();
        fb_renderbuffer.unbind();


        gl_set_viewport(0, 0, screen_width, screen_height);
        gl_set_clear_color(&[0.3, 0.3, 0.3, 1.0]);
        gl_clear(true, true, true);

        fb_program.bind();
        fb_vertex_array.bind();
        fb_vertex_array.enable_attributes();

        fb_program.get_uniform("diffuse").set_sampler_2d(&fb_texture, 0);

        gl_draw_arrays(DrawMode::TriangleStrip, 0, 4);


        gl_window.swap_buffers().unwrap();
    }
}