vertra 0.3.0

A cross-platform graphics editor built with Rust and WebAssembly.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238

//! Gizmo and selection-box mesh builders.

use crate::geometry::Geometry;
use crate::mesh::{MeshData, Vertex};
use crate::transform::Transform;

/// Target arm length of the gizmo in screen pixels.
/// The gizmo will always appear this size regardless of camera distance.
pub(crate) const GIZMO_SCREEN_PX: f32 = 80.0;

/// Build the three-axis **translate** gizmo: thin box shafts ending in cone tips.
///
/// * X axis (red)   - cone pointing +X
/// * Y axis (green) - cone pointing +Y
/// * Z axis (blue)  - cone pointing +Z
pub fn build_gizmo_mesh_data(center: [f32; 3], scale: f32) -> (Vec<Vertex>, Vec<u32>) {
    let mut mesh    = MeshData::new();
    let shaft_h     = scale * 0.025;
    let cone_r      = scale * 0.09;
    let cone_h      = scale * 0.28;
    let shaft_len   = scale - cone_h;
    let dot_r       = scale * 0.07;
    let t = |pos: [f32; 3]| Transform::from_position(pos[0], pos[1], pos[2]);
    let [cx, cy, cz] = center;

    Geometry::Sphere { radius: dot_r, subdivisions: 8 }
        .generate_mesh_data(&mut mesh, &t(center), [0.9, 0.9, 0.9, 1.0]);

    // X (red)
    Geometry::Box { width: shaft_len, height: shaft_h*2.0, depth: shaft_h*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx+shaft_len*0.5, cy, cz]), [0.95,0.15,0.15,1.0]);
    push_cone(&mut mesh,
        [cx+scale, cy, cz], [cx+scale-cone_h, cy, cz],
        [0.0,1.0,0.0], [0.0,0.0,1.0], cone_r, [0.95,0.15,0.15,1.0]);

    // Y (green)
    Geometry::Box { width: shaft_h*2.0, height: shaft_len, depth: shaft_h*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx, cy+shaft_len*0.5, cz]), [0.15,0.95,0.15,1.0]);
    push_cone(&mut mesh,
        [cx, cy+scale, cz], [cx, cy+scale-cone_h, cz],
        [1.0,0.0,0.0], [0.0,0.0,1.0], cone_r, [0.15,0.95,0.15,1.0]);

    // Z (blue)
    Geometry::Box { width: shaft_h*2.0, height: shaft_h*2.0, depth: shaft_len }
        .generate_mesh_data(&mut mesh, &t([cx, cy, cz+shaft_len*0.5]), [0.15,0.15,0.95,1.0]);
    push_cone(&mut mesh,
        [cx, cy, cz+scale], [cx, cy, cz+scale-cone_h],
        [1.0,0.0,0.0], [0.0,1.0,0.0], cone_r, [0.15,0.15,0.95,1.0]);

    (mesh.vertices, mesh.indices)
}

/// Build the **rotate** gizmo: three coloured ring-tubes, one per axis.
///
/// * X ring (red)   - YZ plane, rotates around +X
/// * Y ring (green) - XZ plane, rotates around +Y
/// * Z ring (blue)  - XY plane, rotates around +Z
pub fn build_rotate_gizmo_mesh_data(center: [f32; 3], scale: f32) -> (Vec<Vertex>, Vec<u32>) {
    let mut mesh = MeshData::new();
    let ring_r   = scale;
    let tube_r   = scale * 0.045;
    let dot_r    = scale * 0.07;
    let t = |pos: [f32; 3]| Transform::from_position(pos[0], pos[1], pos[2]);

    Geometry::Sphere { radius: dot_r, subdivisions: 8 }
        .generate_mesh_data(&mut mesh, &t(center), [0.9, 0.9, 0.9, 1.0]);

    push_ring_tube(&mut mesh, center, ring_r, tube_r,
        [0.0,1.0,0.0], [0.0,0.0,1.0], [0.95,0.15,0.15,1.0]); // X (red)
    push_ring_tube(&mut mesh, center, ring_r, tube_r,
        [0.0,0.0,1.0], [1.0,0.0,0.0], [0.15,0.95,0.15,1.0]); // Y (green)
    push_ring_tube(&mut mesh, center, ring_r, tube_r,
        [1.0,0.0,0.0], [0.0,1.0,0.0], [0.15,0.15,0.95,1.0]); // Z (blue)

    (mesh.vertices, mesh.indices)
}

/// Build the **scale** gizmo: three axis shafts ending in coloured cubes.
///
/// * X axis (red)   - cube tip along +X
/// * Y axis (green) - cube tip along +Y
/// * Z axis (blue)  - cube tip along +Z
pub fn build_scale_gizmo_mesh_data(center: [f32; 3], scale: f32) -> (Vec<Vertex>, Vec<u32>) {
    let mut mesh  = MeshData::new();
    let shaft_h   = scale * 0.025;
    let cube_hs   = scale * 0.09;
    let shaft_len = scale - cube_hs * 2.0;
    let dot_r     = scale * 0.07;
    let t = |pos: [f32; 3]| Transform::from_position(pos[0], pos[1], pos[2]);
    let [cx, cy, cz] = center;

    Geometry::Sphere { radius: dot_r, subdivisions: 8 }
        .generate_mesh_data(&mut mesh, &t(center), [0.9, 0.9, 0.9, 1.0]);

    // X (red)
    Geometry::Box { width: shaft_len, height: shaft_h*2.0, depth: shaft_h*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx+shaft_len*0.5, cy, cz]), [0.95,0.15,0.15,1.0]);
    Geometry::Box { width: cube_hs*2.0, height: cube_hs*2.0, depth: cube_hs*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx+scale, cy, cz]), [0.95,0.15,0.15,1.0]);

    // Y (green)
    Geometry::Box { width: shaft_h*2.0, height: shaft_len, depth: shaft_h*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx, cy+shaft_len*0.5, cz]), [0.15,0.95,0.15,1.0]);
    Geometry::Box { width: cube_hs*2.0, height: cube_hs*2.0, depth: cube_hs*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx, cy+scale, cz]), [0.15,0.95,0.15,1.0]);

    // Z (blue)
    Geometry::Box { width: shaft_h*2.0, height: shaft_h*2.0, depth: shaft_len }
        .generate_mesh_data(&mut mesh, &t([cx, cy, cz+shaft_len*0.5]), [0.15,0.15,0.95,1.0]);
    Geometry::Box { width: cube_hs*2.0, height: cube_hs*2.0, depth: cube_hs*2.0 }
        .generate_mesh_data(&mut mesh, &t([cx, cy, cz+scale]), [0.15,0.15,0.95,1.0]);

    (mesh.vertices, mesh.indices)
}

/// Build a golden wireframe bounding-box cage (12 edges as thin box prisms).
/// Rendered via the overlay pipeline so it is always visible through objects.
pub fn build_selection_box(center: [f32; 3], half: [f32; 3]) -> (Vec<Vertex>, Vec<u32>) {
    let mut mesh = MeshData::new();
    let color    = [1.0_f32, 0.85, 0.1, 1.0];
    let pad      = (half[0]+half[1]+half[2]) / 3.0 * 0.06;
    let [hx, hy, hz] = [half[0]+pad, half[1]+pad, half[2]+pad];
    let [cx, cy, cz] = center;
    let tk = ((hx+hy+hz) / 3.0 * 0.045).max(0.02);
    let tr = |px: f32, py: f32, pz: f32| Transform::from_position(px, py, pz);

    // Bottom 4 edges
    Geometry::Box { width: hx*2.0, height: tk, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx,      cy-hy, cz-hz), color);
    Geometry::Box { width: hx*2.0, height: tk, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx,      cy-hy, cz+hz), color);
    Geometry::Box { width: tk, height: tk, depth: hz*2.0 }
        .generate_mesh_data(&mut mesh, &tr(cx-hx,   cy-hy, cz),    color);
    Geometry::Box { width: tk, height: tk, depth: hz*2.0 }
        .generate_mesh_data(&mut mesh, &tr(cx+hx,   cy-hy, cz),    color);
    // Top 4 edges
    Geometry::Box { width: hx*2.0, height: tk, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx,      cy+hy, cz-hz), color);
    Geometry::Box { width: hx*2.0, height: tk, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx,      cy+hy, cz+hz), color);
    Geometry::Box { width: tk, height: tk, depth: hz*2.0 }
        .generate_mesh_data(&mut mesh, &tr(cx-hx,   cy+hy, cz),    color);
    Geometry::Box { width: tk, height: tk, depth: hz*2.0 }
        .generate_mesh_data(&mut mesh, &tr(cx+hx,   cy+hy, cz),    color);
    // 4 vertical edges
    Geometry::Box { width: tk, height: hy*2.0, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx-hx,   cy, cz-hz), color);
    Geometry::Box { width: tk, height: hy*2.0, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx+hx,   cy, cz-hz), color);
    Geometry::Box { width: tk, height: hy*2.0, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx-hx,   cy, cz+hz), color);
    Geometry::Box { width: tk, height: hy*2.0, depth: tk }
        .generate_mesh_data(&mut mesh, &tr(cx+hx,   cy, cz+hz), color);

    (mesh.vertices, mesh.indices)
}

/// Build the skybox mesh - a large box visible from inside, rendered with
/// the overlay pipeline (`cull_mode: None`).
pub fn build_skybox_mesh() -> (Vec<Vertex>, Vec<u32>) {
    let mut mesh = MeshData::new();
    let s   = 450.0_f32;
    let top = [0.08, 0.12, 0.22, 1.0_f32];
    let mid = [0.10, 0.13, 0.20, 1.0];
    let bot = [0.05, 0.06, 0.09, 1.0];

    mesh.push_quad([[-s,s,-s],[s,s,-s],[s,s,s],[-s,s,s]], top);
    mesh.push_quad([[-s,-s,s],[s,-s,s],[s,-s,-s],[-s,-s,-s]], bot);
    mesh.push_quad([[-s,s,-s],[-s,-s,-s],[s,-s,-s],[s,s,-s]], mid);
    mesh.push_quad([[s,s,s],[s,-s,s],[-s,-s,s],[-s,s,s]], mid);
    mesh.push_quad([[s,s,-s],[s,-s,-s],[s,-s,s],[s,s,s]], mid);
    mesh.push_quad([[-s,s,s],[-s,-s,s],[-s,-s,-s],[-s,s,-s]], mid);

    (mesh.vertices, mesh.indices)
}

/// Append a torus-tube ring segment into `mesh`.
fn push_ring_tube(
    mesh:   &mut MeshData,
    center: [f32; 3],
    ring_r: f32,
    tube_r: f32,
    perp1:  [f32; 3],
    perp2:  [f32; 3],
    color:  [f32; 4],
) {
    const SEGS: usize = 40;
    let ax = [
        perp1[1]*perp2[2] - perp1[2]*perp2[1],
        perp1[2]*perp2[0] - perp1[0]*perp2[2],
        perp1[0]*perp2[1] - perp1[1]*perp2[0],
    ];
    let step = std::f32::consts::PI * 2.0 / SEGS as f32;
    for i in 0..SEGS {
        let (c1,s1) = ((i as f32*step).cos(), (i as f32*step).sin());
        let (c2,s2) = (((i+1) as f32*step).cos(), ((i+1) as f32*step).sin());
        let mp1 = [center[0]+(perp1[0]*c1+perp2[0]*s1)*ring_r,
                   center[1]+(perp1[1]*c1+perp2[1]*s1)*ring_r,
                   center[2]+(perp1[2]*c1+perp2[2]*s1)*ring_r];
        let mp2 = [center[0]+(perp1[0]*c2+perp2[0]*s2)*ring_r,
                   center[1]+(perp1[1]*c2+perp2[1]*s2)*ring_r,
                   center[2]+(perp1[2]*c2+perp2[2]*s2)*ring_r];
        let o1  = [perp1[0]*c1+perp2[0]*s1, perp1[1]*c1+perp2[1]*s1, perp1[2]*c1+perp2[2]*s1];
        let o2  = [perp1[0]*c2+perp2[0]*s2, perp1[1]*c2+perp2[1]*s2, perp1[2]*c2+perp2[2]*s2];
        let a1v = [mp1[0]+ax[0]*tube_r+o1[0]*tube_r, mp1[1]+ax[1]*tube_r+o1[1]*tube_r, mp1[2]+ax[2]*tube_r+o1[2]*tube_r];
        let b1v = [mp1[0]+ax[0]*tube_r-o1[0]*tube_r, mp1[1]+ax[1]*tube_r-o1[1]*tube_r, mp1[2]+ax[2]*tube_r-o1[2]*tube_r];
        let c1v = [mp1[0]-ax[0]*tube_r-o1[0]*tube_r, mp1[1]-ax[1]*tube_r-o1[1]*tube_r, mp1[2]-ax[2]*tube_r-o1[2]*tube_r];
        let d1v = [mp1[0]-ax[0]*tube_r+o1[0]*tube_r, mp1[1]-ax[1]*tube_r+o1[1]*tube_r, mp1[2]-ax[2]*tube_r+o1[2]*tube_r];
        let a2v = [mp2[0]+ax[0]*tube_r+o2[0]*tube_r, mp2[1]+ax[1]*tube_r+o2[1]*tube_r, mp2[2]+ax[2]*tube_r+o2[2]*tube_r];
        let b2v = [mp2[0]+ax[0]*tube_r-o2[0]*tube_r, mp2[1]+ax[1]*tube_r-o2[1]*tube_r, mp2[2]+ax[2]*tube_r-o2[2]*tube_r];
        let c2v = [mp2[0]-ax[0]*tube_r-o2[0]*tube_r, mp2[1]-ax[1]*tube_r-o2[1]*tube_r, mp2[2]-ax[2]*tube_r-o2[2]*tube_r];
        let d2v = [mp2[0]-ax[0]*tube_r+o2[0]*tube_r, mp2[1]-ax[1]*tube_r+o2[1]*tube_r, mp2[2]-ax[2]*tube_r+o2[2]*tube_r];
        mesh.push_quad([a1v, a2v, b2v, b1v], color);
        mesh.push_quad([d1v, c1v, c2v, d2v], color);
        mesh.push_quad([a1v, d1v, d2v, a2v], color);
        mesh.push_quad([b2v, c2v, c1v, b1v], color);
    }
}

/// Append a cone into `mesh`.
fn push_cone(
    mesh: &mut MeshData,
    tip: [f32; 3], base: [f32; 3],
    perp1: [f32; 3], perp2: [f32; 3],
    radius: f32, color: [f32; 4],
) {
    const SEGS: usize = 10;
    let step = std::f32::consts::PI * 2.0 / SEGS as f32;
    for i in 0..SEGS {
        let (c1,s1) = (((i   as f32)*step).cos()*radius, (( i   as f32)*step).sin()*radius);
        let (c2,s2) = ((((i+1) as f32)*step).cos()*radius, (((i+1) as f32)*step).sin()*radius);
        let v1 = [base[0]+perp1[0]*c1+perp2[0]*s1, base[1]+perp1[1]*c1+perp2[1]*s1, base[2]+perp1[2]*c1+perp2[2]*s1];
        let v2 = [base[0]+perp1[0]*c2+perp2[0]*s2, base[1]+perp1[1]*c2+perp2[1]*s2, base[2]+perp1[2]*c2+perp2[2]*s2];
        mesh.push_triangle([v1, tip, v2], color);
        mesh.push_triangle([base, v2, v1], color);
    }
}