Draft first working version of iced_glow 🎉

glow/src/triangle.rs

@@ -0,0 +1,84 @@
+//! Draw meshes of triangles.
+use crate::{settings, Transformation};
+use iced_native::{Rectangle, Vector};
+use std::mem;
+
+const UNIFORM_BUFFER_SIZE: usize = 100;
+const VERTEX_BUFFER_SIZE: usize = 10_000;
+const INDEX_BUFFER_SIZE: usize = 10_000;
+
+#[derive(Debug)]
+pub(crate) struct Pipeline {}
+
+impl Pipeline {
+    pub fn new(
+        gl: &glow::Context,
+        antialiasing: Option<settings::Antialiasing>,
+    ) -> Pipeline {
+        Pipeline {}
+    }
+
+    pub fn draw(
+        &mut self,
+        gl: &glow::Context,
+        target_width: u32,
+        target_height: u32,
+        transformation: Transformation,
+        scale_factor: f32,
+        meshes: &[(Vector, Rectangle<u32>, &Mesh2D)],
+    ) {
+    }
+}
+
+#[repr(C)]
+#[derive(Debug, Clone, Copy)]
+struct Uniforms {
+    transform: [f32; 16],
+    // We need to align this to 256 bytes to please `wgpu`...
+    // TODO: Be smarter and stop wasting memory!
+    _padding_a: [f32; 32],
+    _padding_b: [f32; 16],
+}
+
+impl Default for Uniforms {
+    fn default() -> Self {
+        Self {
+            transform: *Transformation::identity().as_ref(),
+            _padding_a: [0.0; 32],
+            _padding_b: [0.0; 16],
+        }
+    }
+}
+
+impl From<Transformation> for Uniforms {
+    fn from(transformation: Transformation) -> Uniforms {
+        Self {
+            transform: transformation.into(),
+            _padding_a: [0.0; 32],
+            _padding_b: [0.0; 16],
+        }
+    }
+}
+
+/// A two-dimensional vertex with some color in __linear__ RGBA.
+#[repr(C)]
+#[derive(Copy, Clone, Debug)]
+pub struct Vertex2D {
+    /// The vertex position
+    pub position: [f32; 2],
+    /// The vertex color in __linear__ RGBA.
+    pub color: [f32; 4],
+}
+
+/// A set of [`Vertex2D`] and indices representing a list of triangles.
+///
+/// [`Vertex2D`]: struct.Vertex2D.html
+#[derive(Clone, Debug)]
+pub struct Mesh2D {
+    /// The vertices of the mesh
+    pub vertices: Vec<Vertex2D>,
+    /// The list of vertex indices that defines the triangles of the mesh.
+    ///
+    /// Therefore, this list should always have a length that is a multiple of 3.
+    pub indices: Vec<u32>,
+}