glium 0.8.1

Elegant and safe OpenGL wrapper. Glium is an intermediate layer between OpenGL and your application. You still need to manually handle the graphics pipeline, but without having to use OpenGL's old and error-prone API. Its objectives: - Be safe to use. Many aspects of OpenGL that can trigger a crash if misused are automatically handled by glium. - Provide an API that enforces good pratices such as RAII or stateless function calls. - Be compatible with all OpenGL versions that support shaders, providing unified API when things diverge. - Avoid all OpenGL errors beforehand. - Produce optimized OpenGL function calls, and allow the user to easily use modern OpenGL techniques. 
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#[macro_use]
extern crate glium;

use glium::Surface;

mod support;

#[test]
fn no_depth_buffer_depth_test() {
    let display = support::build_display();
    let (vertex_buffer, index_buffer, program) = support::build_fullscreen_red_pipeline(&display);

    let texture = glium::texture::Texture2d::empty_with_format(&display,
                            glium::texture::UncompressedFloatFormat::U8U8U8U8, 
                            glium::texture::MipmapsOption::NoMipmap, 128, 128).unwrap();
    let mut framebuffer = glium::framebuffer::SimpleFrameBuffer::new(&display, &texture);

    let parameters = glium::DrawParameters {
        depth_test: glium::DepthTest::IfLess,
        .. Default::default()
    };

    match framebuffer.draw(&vertex_buffer, &index_buffer, &program,
                           &glium::uniforms::EmptyUniforms, &parameters)
    {
        Err(glium::DrawError::NoDepthBuffer) => (),
        a => panic!("{:?}", a)
    };

    display.assert_no_error(None);
}

#[test]
fn no_depth_buffer_depth_write() {
    let display = support::build_display();
    let (vertex_buffer, index_buffer, program) = support::build_fullscreen_red_pipeline(&display);

    let texture = glium::texture::Texture2d::empty_with_format(&display,
                            glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                            glium::texture::MipmapsOption::NoMipmap, 128, 128).unwrap();
    let mut framebuffer = glium::framebuffer::SimpleFrameBuffer::new(&display, &texture);

    let parameters = glium::DrawParameters {
        depth_write: true,
        .. Default::default()
    };

    match framebuffer.draw(&vertex_buffer, &index_buffer, &program,
                           &glium::uniforms::EmptyUniforms, &parameters)
    {
        Err(glium::DrawError::NoDepthBuffer) => (),
        a => panic!("{:?}", a)
    };

    display.assert_no_error(None);
}

#[test]
fn simple_dimensions() {
    let display = support::build_display();

    let texture = glium::Texture2d::empty_with_format(&display,
                                              glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                            glium::texture::MipmapsOption::NoMipmap,
                                              128, 128).unwrap();

    let framebuffer = glium::framebuffer::SimpleFrameBuffer::new(&display, &texture);
    assert_eq!(framebuffer.get_dimensions(), (128, 128));

    display.assert_no_error(None);
}

#[test]
fn simple_render_to_texture() {
    let display = support::build_display();
    let (vb, ib, program) = support::build_fullscreen_red_pipeline(&display);

    let texture = glium::Texture2d::empty_with_format(&display,
                                              glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                            glium::texture::MipmapsOption::NoMipmap,
                                              128, 128).unwrap();

    let mut framebuffer = glium::framebuffer::SimpleFrameBuffer::new(&display, &texture);
    framebuffer.draw(&vb, &ib, &program, &glium::uniforms::EmptyUniforms, &Default::default()).unwrap();

    let read_back: Vec<Vec<(u8, u8, u8, u8)>> = texture.read();

    assert_eq!(read_back[0][0], (255, 0, 0, 255));
    assert_eq!(read_back[64][64], (255, 0, 0, 255));
    assert_eq!(read_back[127][127], (255, 0, 0, 255));

    display.assert_no_error(None);
}

#[test]
fn depth_texture2d() {
    use std::iter;

    let display = support::build_display();
    let (vb, ib) = support::build_rectangle_vb_ib(&display);

    // the program returns a Z coordinate between 0 (left of screen) and 1 (right of screen)
    let program = program!(&display,
        110 => {
            vertex: "
                #version 110

                attribute vec2 position;

                void main() {
                    gl_Position = vec4(position, position.x, 1.0);
                }
            ",
            fragment: "
                #version 110

                void main() {
                    gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
                }
            ",
        },
        100 => {
            vertex: "
                #version 100

                attribute lowp vec2 position;

                void main() {
                    gl_Position = vec4(position, position.x, 1.0);
                }
            ",
            fragment: "
                #version 100

                void main() {
                    gl_FragColor = vec4(1.0, 1.0, 1.0, 1.0);
                }
            ",
        }).unwrap();

    // empty color attachment to put the data
    let color = glium::Texture2d::empty_with_format(&display,
                                            glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                            glium::texture::MipmapsOption::NoMipmap,
                                            128, 128).unwrap();

    // depth texture with a value of 0.5 everywhere
    let depth_data = iter::repeat(iter::repeat(0.5f32).take(128).collect::<Vec<_>>())
                                  .take(128).collect::<Vec<_>>();
    let depth = match glium::texture::DepthTexture2d::new(&display, depth_data) {
        Err(_) => return,
        Ok(t) => t
    };

    // drawing with the `IfLess` depth test
    let mut framebuffer = glium::framebuffer::SimpleFrameBuffer::with_depth_buffer(&display,
                                                                                   &color, &depth);
    let params = glium::DrawParameters {
        depth_test: glium::DepthTest::IfLess,
        .. Default::default()
    };

    framebuffer.clear_color(0.0, 0.0, 0.0, 1.0);
    framebuffer.draw(&vb, &ib, &program, &glium::uniforms::EmptyUniforms, &params).unwrap();

    // reading back the color
    let read_back: Vec<Vec<(u8, u8, u8, u8)>> = color.read();

    assert_eq!(read_back[0][0], (255, 255, 255, 255));
    assert_eq!(read_back[127][127], (0, 0, 0, 255));

    display.assert_no_error(None);
}

#[test]
fn multioutput() {
    let display = support::build_display();
    let (vb, ib) = support::build_rectangle_vb_ib(&display);

    let program = match glium::Program::from_source(&display,
        "
            #version 110

            attribute vec2 position;

            void main() {
                gl_Position = vec4(position, 0.0, 1.0);
            }
        ",
        "
            #version 330

            out vec4 color1;
            out vec4 color2;

            void main() {
                color1 = vec4(1.0, 1.0, 1.0, 1.0);
                color2 = vec4(1.0, 0.0, 0.0, 1.0);
            }
        ",
        None)
    {
        Err(glium::CompilationError(_)) => return,
        Ok(p) => p,
        e => e.unwrap()
    };

    // building two empty color attachments
    let color1 = glium::Texture2d::empty_with_format(&display,
                                               glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                               glium::texture::MipmapsOption::AutoGeneratedMipmaps,
                                               128, 128).unwrap();
    color1.as_surface().clear_color(0.0, 0.0, 0.0, 1.0);

    let color2 = glium::Texture2d::empty_with_format(&display,
                                               glium::texture::UncompressedFloatFormat::U8U8U8U8,
                                               glium::texture::MipmapsOption::AutoGeneratedMipmaps,
                                               128, 128).unwrap();
    color2.as_surface().clear_color(0.0, 0.0, 0.0, 1.0);

    // building the framebuffer
    let mut framebuffer = glium::framebuffer::MultiOutputFrameBuffer::new(&display,
                                             &[("color1", &color1), ("color2", &color2)]);

    framebuffer.draw(&vb, &ib, &program, &glium::uniforms::EmptyUniforms,
                     &Default::default()).unwrap();

    // checking color1
    let read_back1: Vec<Vec<(u8, u8, u8, u8)>> = color1.read();
    for row in read_back1.iter() {
        for pixel in row.iter() {
            assert_eq!(pixel, &(255, 255, 255, 255));
        }
    }

    // checking color2
    let read_back2: Vec<Vec<(u8, u8, u8, u8)>> = color2.read();
    for row in read_back2.iter() {
        for pixel in row.iter() {
            assert_eq!(pixel, &(255, 0, 0, 255));
        }
    }


    display.assert_no_error(None);
}