smithay/examples/helpers/glium.rs

134 lines
3.8 KiB
Rust

use glium;
use glium::Surface;
use glium::index::PrimitiveType;
use std::ops::Deref;
#[derive(Copy, Clone)]
struct Vertex {
position: [f32; 2],
tex_coords: [f32; 2],
}
implement_vertex!(Vertex, position, tex_coords);
pub struct GliumDrawer<F> {
display: F,
vertex_buffer: glium::VertexBuffer<Vertex>,
index_buffer: glium::IndexBuffer<u16>,
program: glium::Program,
}
impl<F> Deref for GliumDrawer<F> {
type Target = F;
fn deref(&self) -> &F {
&self.display
}
}
impl<F: glium::backend::Facade> GliumDrawer<F> {
pub fn new(display: F) -> GliumDrawer<F> {
// building the vertex buffer, which contains all the vertices that we will draw
let vertex_buffer = glium::VertexBuffer::new(
&display,
&[
Vertex {
position: [0.0, 0.0],
tex_coords: [0.0, 0.0],
},
Vertex {
position: [0.0, 1.0],
tex_coords: [0.0, 1.0],
},
Vertex {
position: [1.0, 1.0],
tex_coords: [1.0, 1.0],
},
Vertex {
position: [1.0, 0.0],
tex_coords: [1.0, 0.0],
},
],
).unwrap();
// building the index buffer
let index_buffer =
glium::IndexBuffer::new(&display, PrimitiveType::TriangleStrip, &[1 as u16, 2, 0, 3]).unwrap();
// compiling shaders and linking them together
let program = program!(&display,
100 => {
vertex: "
#version 100
uniform lowp mat4 matrix;
attribute lowp vec2 position;
attribute lowp vec2 tex_coords;
varying lowp vec2 v_tex_coords;
void main() {
gl_Position = matrix * vec4(position, 0.0, 1.0);
v_tex_coords = tex_coords;
}
",
fragment: "
#version 100
uniform lowp sampler2D tex;
varying lowp vec2 v_tex_coords;
void main() {
lowp vec4 color = texture2D(tex, v_tex_coords);
gl_FragColor.r = color.z;
gl_FragColor.g = color.y;
gl_FragColor.b = color.x;
gl_FragColor.a = color.w;
}
",
},
).unwrap();
GliumDrawer {
display,
vertex_buffer,
index_buffer,
program,
}
}
pub fn render(&self, target: &mut glium::Frame, contents: &[u8], surface_dimensions: (u32, u32),
surface_location: (i32, i32), screen_size: (u32, u32)) {
let image = glium::texture::RawImage2d {
data: contents.into(),
width: surface_dimensions.0,
height: surface_dimensions.1,
format: glium::texture::ClientFormat::U8U8U8U8,
};
let opengl_texture = glium::texture::Texture2d::new(&self.display, image).unwrap();
let xscale = 2.0 * (surface_dimensions.0 as f32) / (screen_size.0 as f32);
let yscale = -2.0 * (surface_dimensions.1 as f32) / (screen_size.1 as f32);
let x = 2.0 * (surface_location.0 as f32) / (screen_size.0 as f32) - 1.0;
let y = 1.0 - 2.0 * (surface_location.1 as f32) / (screen_size.1 as f32);
let uniforms = uniform! {
matrix: [
[xscale, 0.0 , 0.0, 0.0],
[ 0.0 , yscale , 0.0, 0.0],
[ 0.0 , 0.0 , 1.0, 0.0],
[ x , y , 0.0, 1.0]
],
tex: &opengl_texture
};
target
.draw(
&self.vertex_buffer,
&self.index_buffer,
&self.program,
&uniforms,
&Default::default(),
)
.unwrap();
}
}