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