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
use crate::graphics::{gpu, Color, Rectangle, Shape, Target};
use lyon_tessellation as lyon;
/// A set of shapes that can be drawn.
///
/// # Tolerance
/// When shapes contain curves or arcs, they will be approximated using line
/// segments. The `tolerance` parameter controls this approximation by
/// establishing the maximum distance between a curve and its line segments.
///
/// The lower the tolerance provided, the better a [`Mesh`] will approximate
/// a [`Shape`]. However, a lower tolerance can have a noticeable performance
/// impact. Use it wisely!
///
/// [`Mesh`]: struct.Mesh.html
/// [`Shape`]: enum.Shape.html
#[derive(Debug, Clone)]
pub struct Mesh {
tolerance: f32,
buffers: lyon::VertexBuffers<gpu::Vertex, u32>,
}
impl Mesh {
/// Creates a new empty [`Mesh`] with a default tolerance of `0.1`.
///
/// [`Mesh`]: struct.Mesh.html
pub fn new() -> Mesh {
Mesh {
tolerance: 0.1,
buffers: lyon::VertexBuffers::new(),
}
}
/// Creates a new empty [`Mesh`] with the given tolerance.
///
/// Providing a lower tolerance here can allow you to zoom in your [`Mesh`]
/// using a [`Transformation`] and still observe smooth curves. See
/// [Tolerance](#tolerance).
///
/// [`Mesh`]: struct.Mesh.html
/// [`Transformation`]: struct.Transformation.html
pub fn new_with_tolerance(tolerance: f32) -> Mesh {
Mesh {
tolerance,
buffers: lyon::VertexBuffers::new(),
}
}
/// Returns true if the [`Mesh`] is empty.
///
/// [`Mesh`]: struct.Mesh.html
pub fn is_empty(&self) -> bool {
self.buffers.vertices.is_empty()
}
/// Adds a filled [`Shape`] to the [`Mesh`].
///
/// [`Shape`]: enum.Shape.html
/// [`Mesh`]: struct.Mesh.html
#[inline]
pub fn fill(&mut self, shape: Shape, color: Color) {
let mut builder = lyon::BuffersBuilder::new(
&mut self.buffers,
WithColor(color.into_linear()),
);
match shape {
Shape::Rectangle(Rectangle {
x,
y,
width,
height,
}) => {
let _ = lyon::basic_shapes::fill_rectangle(
&lyon::math::rect(x, y, width, height),
&Self::fill_options(self.tolerance),
&mut builder,
)
.expect("Fill rectangle");
}
Shape::Circle { center, radius } => {
let _ = lyon::basic_shapes::fill_circle(
lyon::math::point(center.x, center.y),
radius,
&Self::fill_options(self.tolerance),
&mut builder,
)
.expect("Fill circle");
}
Shape::Ellipse {
center,
horizontal_radius,
vertical_radius,
rotation,
} => {
let _ = lyon::basic_shapes::fill_ellipse(
lyon::math::point(center.x, center.y),
lyon::math::vector(horizontal_radius, vertical_radius),
lyon::math::Angle::radians(rotation),
&Self::fill_options(self.tolerance),
&mut builder,
)
.expect("Fill ellipse");
}
Shape::Polyline { points } => {
let _ = lyon::basic_shapes::fill_polyline(
points
.iter()
.map(|point| lyon::math::point(point.x, point.y)),
&mut lyon::FillTessellator::new(),
&Self::fill_options(self.tolerance),
&mut builder,
)
.expect("Fill polyline");
}
}
}
/// Adds the stroke of a [`Shape`] to the [`Mesh`].
///
/// [`Shape`]: enum.Shape.html
/// [`Mesh`]: struct.Mesh.html
#[inline]
pub fn stroke(&mut self, shape: Shape, color: Color, width: f32) {
let mut builder = lyon::BuffersBuilder::new(
&mut self.buffers,
WithColor(color.into_linear()),
);
match shape {
Shape::Rectangle(Rectangle {
x,
y,
width: rect_width,
height,
}) => {
let _ = lyon::basic_shapes::stroke_rectangle(
&lyon::math::rect(x, y, rect_width, height),
&Self::stroke_options(self.tolerance, width),
&mut builder,
)
.expect("Stroke rectangle");
}
Shape::Circle { center, radius } => {
let _ = lyon::basic_shapes::stroke_circle(
lyon::math::point(center.x, center.y),
radius,
&Self::stroke_options(self.tolerance, width),
&mut builder,
)
.expect("Stroke circle");
}
Shape::Ellipse {
center,
horizontal_radius,
vertical_radius,
rotation,
} => {
let _ = lyon::basic_shapes::stroke_ellipse(
lyon::math::point(center.x, center.y),
lyon::math::vector(horizontal_radius, vertical_radius),
lyon::math::Angle::radians(rotation),
&Self::stroke_options(self.tolerance, width),
&mut builder,
)
.expect("Stroke ellipse");
}
Shape::Polyline { points } => {
let _ = lyon::basic_shapes::stroke_polyline(
points
.iter()
.map(|point| lyon::math::point(point.x, point.y)),
false,
&Self::stroke_options(self.tolerance, width),
&mut builder,
)
.expect("Stroke polyline");
}
}
}
/// Draws the [`Mesh`] on the given [`Target`].
///
/// [`Mesh`]: struct.Mesh.html
/// [`Target`]: struct.Target.html
pub fn draw(&self, target: &mut Target<'_>) {
target.draw_triangles(&self.buffers.vertices, &self.buffers.indices);
}
fn fill_options(tolerance: f32) -> lyon::FillOptions {
lyon::FillOptions::DEFAULT
.with_tolerance(tolerance)
.with_normals(false)
}
fn stroke_options(tolerance: f32, width: f32) -> lyon::StrokeOptions {
lyon::StrokeOptions::DEFAULT
.with_tolerance(tolerance)
.with_line_width(width)
}
}
struct WithColor([f32; 4]);
impl lyon::VertexConstructor<lyon::FillVertex, gpu::Vertex> for WithColor {
fn new_vertex(&mut self, vertex: lyon::FillVertex) -> gpu::Vertex {
gpu::Vertex::new([vertex.position.x, vertex.position.y], self.0)
}
}
impl lyon::VertexConstructor<lyon::StrokeVertex, gpu::Vertex> for WithColor {
fn new_vertex(&mut self, vertex: lyon::StrokeVertex) -> gpu::Vertex {
gpu::Vertex::new([vertex.position.x, vertex.position.y], self.0)
}
}