rootvg_mesh/primitive/
solid.rs

1//! Draw triangles!
2use bytemuck::{Pod, Zeroable};
3use std::rc::Rc;
4
5use rootvg_core::color::PackedSrgb;
6use rootvg_core::math::{Angle, Point, Transform, Vector};
7
8use super::{Indexed, MeshUniforms};
9
10/// A low-level primitive to render a mesh of triangles with a solid color.
11#[derive(Debug, Clone, PartialEq)]
12pub struct SolidMesh {
13    /// The vertices and indices of the mesh.
14    pub buffers: Indexed<SolidVertex2D>,
15}
16
17impl SolidMesh {
18    pub fn new() -> Self {
19        Self {
20            buffers: Indexed::new(),
21        }
22    }
23}
24
25/// A two-dimensional vertex with a color.
26#[derive(Copy, Clone, Debug, PartialEq, Zeroable, Pod)]
27#[repr(C)]
28pub struct SolidVertex2D {
29    /// The vertex position in 2D space.
30    pub position: [f32; 2],
31
32    /// The color of the vertex in __linear__ RGBA.
33    pub color: PackedSrgb,
34}
35
36impl SolidVertex2D {
37    pub fn new(position: impl Into<[f32; 2]>, color: impl Into<PackedSrgb>) -> Self {
38        Self {
39            position: position.into(),
40            color: color.into(),
41        }
42    }
43}
44
45#[derive(Debug)]
46pub struct SolidMeshPrimitive {
47    pub mesh: Rc<SolidMesh>,
48    pub uniform: MeshUniforms,
49}
50
51impl SolidMeshPrimitive {
52    pub fn new(mesh: &Rc<SolidMesh>) -> Self {
53        Self {
54            mesh: Rc::clone(mesh),
55            uniform: MeshUniforms::default(),
56        }
57    }
58
59    pub fn new_with_offset(mesh: &Rc<SolidMesh>, offset: Point) -> Self {
60        Self {
61            mesh: Rc::clone(mesh),
62            uniform: MeshUniforms {
63                offset: offset.into(),
64                ..Default::default()
65            },
66        }
67    }
68
69    pub fn new_with_rotation(
70        mesh: &Rc<SolidMesh>,
71        angle: Angle,
72        rotation_origin: Point,
73        offset: Point,
74    ) -> Self {
75        let transform = Transform::translation(-rotation_origin.x, -rotation_origin.y)
76            .then_rotate(angle)
77            .then_translate(Vector::new(rotation_origin.x, rotation_origin.y));
78
79        Self::new_with_transform(mesh, offset, transform)
80    }
81
82    pub fn new_with_transform(mesh: &Rc<SolidMesh>, offset: Point, transform: Transform) -> Self {
83        Self {
84            mesh: Rc::clone(mesh),
85            uniform: MeshUniforms::new(offset, Some(transform)),
86        }
87    }
88}
89
90impl Clone for SolidMeshPrimitive {
91    fn clone(&self) -> Self {
92        Self {
93            mesh: Rc::clone(&self.mesh),
94            uniform: self.uniform,
95        }
96    }
97}
98
99impl PartialEq for SolidMeshPrimitive {
100    fn eq(&self, other: &Self) -> bool {
101        Rc::ptr_eq(&self.mesh, &other.mesh) && self.uniform == other.uniform
102    }
103}